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Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2019	Mar. 10, 2020	Oct. 31, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Entity Registrant Name	PHATHOM PHARMACEUTICALS, INC.
Entity Central Index Key	0001783183
Entity Tax Identification Number	82-4151574
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Non-accelerated Filer
Entity File Number	001-39094
Entity Shell Company	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Small Business	true
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	100 Campus Drive
Entity Address, Address Line Two	Suite 102
Entity Address, City or Town	Florham Park
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07932
City Area Code	877
Local Phone Number	742-8466
Entity Common Stock, Shares Outstanding		28,964,506
Entity Public Float			$ 366.4
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	PHAT
Security Exchange Name	NASDAQ
Documents Incorporated by Reference	Certain sections of the registrant’s definitive proxy statement for the 2020 annual meeting of stockholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Form 10-K are incorporated by reference into Part III of this Form 10-K.

Combined Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 243,765	$ 879
Prepaid expenses and other current assets (including related party amounts of $0 and $19, respectively)	11,836	23
Total current assets	255,601	902
Property, plant and equipment, net	463
Operating lease right-of-use assets	933
Other long-term assets	181
Total assets	257,178	902
Current liabilities:
Accounts payable (including related party amounts of $200 and $45, respectively)	699	55
Accrued expenses (including related party amounts of $308 and $2, respectively)	2,319	170
Accrued interest (including related party amounts of $0 and $13, respectively)	156	13
Convertible promissory notes payable at fair value (including related party amounts of $0 and $1,950, respectively)		1,950
Operating lease liabilities, current	161
Warrant liabilities	413
Total current liabilities	3,748	2,188
Long-term debt, net of discount	22,777
Operating lease liabilities	635
Other long-term liabilities	2,063
Total liabilities	29,223	2,188
Commitments and contingencies (Note 4)
Stockholders’ equity (deficit):
Common stock, $0.0001 par value; authorized shares —400,000,000 at December 31, 2019; issued shares— 28,964,506 at December 31, 2019; outstanding shares— 24,728,258 at December 31, 2019;	2
Additional paid-in capital	484,372	2
Accumulated deficit	(256,419)	(1,288)
Total stockholders’ equity (deficit)	227,955	(1,286)
Total liabilities and stockholders’ equity	$ 257,178	$ 902

Combined Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Prepaid expenses and other current assets, related parties	$ 0	$ 19
Accounts payable, related parties	200	45
Accrued expenses, related parties	308	2
Accrued interest, related parties	0	13
Convertible promissory notes payable at fair value, related parties	$ 0	$ 1,950
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, authorized shares	400,000,000
Common stock, issued shares	28,964,506
Common stock, outstanding shares	24,728,258

Combined Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating expenses:
Research and development (includes related party amounts of $1,243 and $0, respectively)	$ 20,374	$ 20
In-process research and development	78,897
General and administrative (includes related party amounts of $312 and $321, respectively)	6,944	1,205
Total operating expenses	106,215	1,225
Loss from operations	(106,215)	(1,225)
Other income (expense):
Interest income	1,089
Interest expense (includes related party amounts of $(590) and $(13), respectively)	(4,177)	(13)
Change in fair value of warrant liabilities (includes related party amounts of ($96,278) and ($0), respectively)	(96,272)
Change in fair value of convertible promissory notes (includes related party amounts of ($10,941) and ($50), respectively)	(49,546)	(50)
Other income (expense)	(10)
Total other income (expense)	(148,916)	(63)
Net loss	$ (255,131)	$ (1,288)
Net loss per share, basic and diluted	$ (22.45)	$ (0.21)
Weighted-average shares of common stock outstanding, basic and diluted	11,366,916	6,051,675

Combined Statements of Operations and Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Research and development expenses, related party	$ 1,243	$ 0
General and administrative expenses, related party	312	321
Interest expense, related party	(590)	(13)
Change in fair value of warrant liabilities, related party	(96,278)	0
Change in fair value of convertible promissory notes, related party	$ (10,941)	$ (50)

Combined Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Takeda License	IPO	Common Stock	Common Stock Frazier	Common Stock Takeda License	Common Stock IPO	Additional Paid-in Capital	Additional Paid-in Capital Takeda License	Additional Paid-in Capital IPO	Accumulated Deficit
Beginning balance at Dec. 31, 2017	$ 0			$ 0				$ 0			$ 0
Beginning balance, shares at Dec. 31, 2017				0
Issuance of common stock to founders	2							2
Issuance of common stock, shares				1,000
Net loss	(1,288)										(1,288)
Ending balance at Dec. 31, 2018	(1,286)			$ 0				2			(1,288)
Ending balance, shares at Dec. 31, 2018				0
Beginning balance at Dec. 31, 2017	0			$ 0				0			0
Beginning balance, shares at Dec. 31, 2017				0
Issuance of common stock, shares							10,997,630
Ending balance at Dec. 31, 2019	$ 227,955			$ 2				484,372			(256,419)
Ending balance, shares at Dec. 31, 2019	24,728,258			24,728,258
Beginning balance at Dec. 31, 2018	$ (1,286)			$ 0				2			(1,288)
Beginning balance, shares at Dec. 31, 2018				0
Merger of entities under common control into the Company, shares				6,760,334
Vesting restrictions placed on previously issued and outstanding common stock, shares				(3,373,408)
Issuance of common stock		$ 5,885	$ 191,472				$ 1		$ 5,885	$ 191,471
Issuance of common stock, shares					1,491,072	1,084,000	10,997,630
Conversion of Takeda warrant liability into equity	144,172							144,172
Conversion of May 2019 Notes and accrued interest into common shares	142,437			$ 1				142,436
Conversion of May 2019 Notes and accrued interest into common shares, shares				6,107,918
Vesting of restricted shares, shares				1,660,712
Stock-based compensation	406							406
Net loss	(255,131)										(255,131)
Ending balance at Dec. 31, 2019	$ 227,955			$ 2				$ 484,372			$ (256,419)
Ending balance, shares at Dec. 31, 2019	24,728,258			24,728,258

Combined Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
Combined Statements of Cash Flows - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net loss	$ (255,131)	$ (1,288)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	8
Stock-based compensation	406
Amortization of debt discount	409
Acquired in-process research and development	78,897
Non-cash interest expense (includes related party amounts of $590 and 0, respectively)	2,605
Change in fair value of warrant liabilities (includes related party amounts of $96,278 and $0, respectively)	96,272
Change in fair value of convertible promissory notes (includes related party amounts of $10,941 and $50, respectively)	49,546	50
Changes in operating assets and liabilities:
Prepaid expenses and other current assets (includes related party amounts of $19, and $(19), respectively)	(11,813)	(23)
Accounts payable and accrued expenses (includes related party amounts of $460, and $47, respectively)	2,265	225
Accrued interest (includes related party amounts of $0 and $13, respectively)	156	13
Operating right-of-use asset and lease liabilities	51
Other long-term assets	(181)
Net cash used in operating activities	(36,510)	(1,023)
Cash flows from investing activities
Cash paid for purchased in-process research and development	(25,118)
Cash paid for property, plant and equipment	(132)
Net cash used in investing activities	(25,250)
Cash flows from financing activities
Proceeds from initial public offering, net of issuance costs	191,472
Proceeds from issuance of common stock		2
Proceeds from issuance of convertible promissory notes	88,324	1,900
Net proceeds from issuance of long-term debt	24,850
Net cash provided by financing activities	304,646	1,902
Net increase in cash and cash equivalents	242,886	879
Cash and cash equivalents – beginning of period	879
Cash and cash equivalents – end of period	243,765	$ 879
Supplemental disclosure of cash flow information
Interest paid	1,007
Supplemental disclosure of noncash investing and financing activities
Exchange of accrued interest for convertible promissory notes	27
Issuance of common stock warrants in connection with long-term debt	419
Property and equipment purchases included in accounts payable and accrued liabilities	339
Final interest payment fee	2,063
Operating lease liabilities arising from obtaining right-of-use assets	796
Conversion of convertible promissory notes and accrued interest into common shares	142,437
Takeda Warrants
Supplemental disclosure of noncash investing and financing activities
Conversion of Takeda Warrants into Equity	144,172
Takeda License
Supplemental disclosure of noncash investing and financing activities
Issuance of Takeda Warrants in connection with Takeda License	47,894
Issuance of common stock in connection with Takeda License	$ 5,885

Combined Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement Of Cash Flows [Abstract]
Non-cash interest expense, related party	$ 590	$ 0
Change in fair value of warrant liabilities related party	96,278	0
Change in fair value of convertible promissory notes related party	10,941	50
Related parties prepaid expenses and other assets current	19	(19)
Related parties accounts payable and accrued expenses	460	47
Related parties accrued interest	$ 0	$ 13

Organization, Basis of Presentation and Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Organization, Basis of Presentation and Summary of Significant Accounting Policies

1. Organization, Basis of Presentation and Summary of Significant Accounting Policies

Organization

Phathom Pharmaceuticals, Inc. (the “Company” or “Phathom”) was incorporated in the state of Delaware in January 2018 under the name North Bridge IV, Inc. On March 13, 2019, the Company changed its name to Phathom Pharmaceuticals, Inc. and merged with YamadaCo IIA, Inc. (“YamadaCo”), a Delaware corporation formed in September 2017, with Phathom being the surviving entity (the “Merger”). All activities of YamadaCo prior to 2018 related to formation and were insignificant. The Company is a late clinical-stage biopharmaceutical company focused on developing and commercializing novel treatments for gastrointestinal diseases.

On October 29, 2019, the Company completed its initial public offering (the “IPO”) and issued 10,997,630 shares of common stock for net proceeds of approximately $191.5 million.

Stock Split and Conversion

During 2018, without consideration of the forward stock split described immediately below, both the Company and YamadaCo issued 1,000 shares of common stock at a purchase price of $1.00 per share and had no other capital transactions prior to the Merger. Immediately prior to the Merger, the Company effected a 1,559.1183-for-1 forward stock split for each outstanding share of its common stock and, effective upon the closing of the Merger, each issued and outstanding share of YamadaCo was converted into 1,559.1183 shares of the Company’s common stock. Upon completion of the Merger, the Company had 6,760,334 shares of common stock outstanding, with the prior stockholders of each YamadaCo and Phathom holding an equal number of shares. The accompanying combined financial statements and notes to the combined financial statements give retroactive effect to the forward stock split and conversion for all periods presented.

On October 11, 2019, the Company effected a 2.168-for-1 forward stock split of its common stock (the “Forward Stock Split”). The par value of the common stock was not adjusted as a result of the Forward Stock Split and the authorized shares were increased to 50,000,000 shares of common stock in connection with the Forward Stock Split. The accompanying combined financial statements and notes to the combined financial statements give retroactive effect to the Forward Stock Split for all periods presented, unless otherwise indicated.

Basis of Presentation

The Company’s combined financial statements are prepared in accordance with U.S. generally accepted accounting principles. The accompanying combined financial statements include the accounts of the Company (the receiving entity) and YamadaCo, prior to the Merger. The Company and YamadaCo were entities under the common control of Frazier Life Sciences IX, L.P. (“Frazier”) as a result of, among other things, Frazier’s; (i) ownership of a majority of the outstanding capital stock of both companies, (ii) financing of both companies, (iii) control of the board of directors of both companies, and (iv) management of both companies. Both the Company and YamadaCo were formed for the purpose of identifying potential assets around which to form an operating company. As the merged entities were under common control, the combined financial statements report the financial position, results of operations and cash flows of the Company and YamadaCo as though the transfer of net assets and equity interests had occurred at the beginning of 2018. All intercompany accounts and transactions have been eliminated in combination.

Liquidity and Capital Resources

From inception to December 31, 2019, the Company has devoted substantially all of its efforts to organizing and staffing the Company, business planning, raising capital, in-licensing its initial product candidate, vonoprazan, meeting with regulatory authorities, and initiating the Phase 3 clinical trials of vonoprazan. The Company has a limited operating history, has never generated any revenue, and the sales and income potential of its business is unproven. The Company has incurred net losses and negative cash flows from operating activities since its inception and expects to continue to incur net losses into the foreseeable future as it continues the development and commercialization of vonoprazan. From inception to December 31, 2019, the Company has funded its operations through the issuance of convertible promissory notes, commercial bank debt and the sale of 10,997,630 shares of common stock for net proceeds of approximately $191.5 million in its IPO.

The accompanying combined financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business, and do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or amounts and classification of liabilities that may result from the outcome of this uncertainty. Management is required to perform a two-step analysis over the Company’s ability to continue as a going concern. Management must first evaluate whether there are conditions and events that raise substantial doubt about the Company’s ability to continue as a going concern (Step 1). If management concludes that substantial doubt is raised, management is also required to consider whether its plans alleviate that doubt (Step 2).

As a result of the IPO that closed on October 29, 2019, management believes that it has sufficient working capital on hand to fund operations through at least the next twelve months from the date these combined financial statements were available to be issued. There can be no assurance that the Company will be successful in acquiring additional funding, that the Company’s projections of its future working capital needs will prove accurate, or that any additional funding would be sufficient to continue operations in future years.

Use of Estimates

The preparation of the Company’s combined financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in the Company’s combined financial statements and accompanying notes. The most significant estimates in the Company’s combined financial statements relate to accruals for research and development expenses, and the valuation of convertible promissory notes, warrant liabilities and various other equity instruments. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results could differ materially from those estimates and assumptions.

Fair Value Option

As permitted under Accounting Standards Codification (“ASC”) 825, Financial Instruments, (“ASC 825”), the Company has elected the fair value option to account for its convertible promissory notes issued since inception. In accordance with ASC 825, the Company records these convertible promissory notes at fair value with changes in fair value recorded in the combined statements of operations. As a result of applying the fair value option, direct costs and fees related to the convertible promissory notes were recognized in earnings as incurred and not deferred.

Fair Value Measurements

The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

Level 1:

Observable inputs such as quoted prices in active markets.

Level 2:

Inputs, other than the quoted prices in active markets that are observable either directly or indirectly.

Level 3:

Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.

The carrying amounts of the Company’s financial instruments, including cash and cash equivalents classified within the Level 1 designation discussed above, prepaid and other current assets, accounts payable, and accrued liabilities, approximate fair value due to their short maturities. Warrant liabilities and convertible promissory notes are recorded at fair value on a recurring basis.

The Company has no financial assets measured at fair value on a recurring basis. None of the Company’s non-financial assets or liabilities are recorded at fair value on a non-recurring basis. No transfers between levels have occurred during the periods presented.

Liabilities measured at fair value on a recurring basis are as follows (in thousands):

			Fair Value Measurements at Reporting Date Using:
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of December 31, 2018:
Convertible promissory notes	$	1,950	$	—	$	—	$	1,950

As of December 31, 2019:
Warrant liabilities	$	413	$	—	$	—	$	413
Total	$	413	$	—	$	—	$	413

The warrant liabilities consist of an issued and outstanding common stock warrant (the “Takeda Warrant”) and a right to receive an additional common stock warrant (the “Takeda Warrant Right”, and together with the Takeda Warrant, the “Takeda Warrants”) issued to Takeda Pharmaceutical Company Limited (“Takeda”) in connection with a May 2019 license agreement (see Note 4) and warrants (the “Lender Warrants”) issued in connection with a loan and security agreement for commercial bank debt (see Note 7). From inception through October 11, 2019, the date at which the Company increased its authorized shares of common stock available for issuance, the Takeda Warrants were accounted for as liabilities as they did not meet all the conditions for equity classification due to (i) insufficient authorized shares for the Takeda Warrant and (ii) the Takeda Warrant Right not being indexed to the Company’s own stock. The fair value of the Takeda Warrants was derived from the model used to estimate the fair value the Company’s common stock (see Note 8) prior to the IPO. The Company continued to record the Takeda warrants at fair value until October 11, 2019 when the Company’s authorized shares of common stock increased to 50,000,000. The Company reclassified the full balance from warrant liabilities to additional paid-in capital. Additionally, upon the closing of the IPO, the Takeda Warrant Right expired without effect since no fair value had been allocated to it.

The Lender Warrants are accounted for as liabilities as they contain a holder put right under which the lenders could require the Company to pay cash in exchange for the Lender Warrants. Prior to the Company’s IPO, the fair value of the Lender Warrants was estimated using a probability-weighted model considering IPO and non-IPO scenarios. The IPO scenarios utilized a binomial lattice model to estimate a distribution of total equity values as of a projected IPO date. The non-IPO scenario utilized the repurchase price associated with the warrant put right discounted to present value based on venture capital rates of return and the term associated with the put right. Following the Company’s IPO, the fair value of the Lender Warrants was estimated on the date of grant using the Black-Scholes option-pricing model with an expected term equal to the remaining contractual term of the warrants. The Company estimates its expected stock volatility based on the historical volatility of a set of peer companies, which are publicly traded, and expects to continue to do so until it has adequate historical data regarding the volatility of its own publicly-traded stock price. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company uses an expected dividend yield of zero based on the fact that the Company has never paid cash dividends and does not expect to pay cash dividends in the foreseeable future. As of December 31, 2019, the fair value of the Lender Warrants was $0.4 million.

As further described in Note 5, the Company issued convertible promissory notes to Frazier (the “Frazier Notes”) from January 2018 to April 2019 and issued convertible promissory notes in May 2019 (the “May 2019 Notes”) to investors including Frazier. The Company has elected the fair value option for each of its convertible promissory note issuances. The fair value of the Frazier Notes was estimated using a scenario-based analysis that estimated the fair value of the convertible promissory notes based on the probability-weighted present value of expected future investment returns, considering possible outcomes available to the noteholders, including conversions in subsequent equity financings, change of control transactions, settlement and dissolution. The fair value of the May 2019 Notes is estimated using a scenario-based analysis that estimates the fair value of the convertible promissory notes based on the probability-weighted present value of expected future investment returns, considering each of the possible outcomes available to the noteholders, including various IPO, settlement, equity financing, corporate transaction and dissolution scenarios. As of December 31, 2018, the fair value of the Frazier Notes was $2.0 million and the Frazier Notes were exchanged for May 2019 Notes in May 2019. The principal and accrued interest of the May 2019 Notes automatically converted into 6,107,918 shares of common stock immediately prior to the completion of the IPO.

The Company adjusts the carrying value of its warrant liabilities and convertible promissory notes to their estimated fair value at each reporting date, with any related increases or decreases in the fair value recorded as change in fair value of warrant liabilities and change in fair value of convertible promissory notes, respectively, in the combined statements of operations.

Liability

At initial

valuation

date

Fair value method at

initial valuation date

(and relative weighting)

KEY unobservable inputs

Range

Fair value at

conversion date

Conversion

Date

Takeda

Warrants

47,894

Financing transactions (40%)

Income approach (60%)

Transaction prices per share

Estimated time to liquidity

Discount rate

$9.33 - $19.00

0.09 - 1.77 years

7.5%

144,172

October 11, 2019

May 2019 Notes

90,250

Financing transactions (40%)

Income approach (60%)

Estimated time to liquidity

Volatility Discount rate

0.09 - 1.77 years

65%

22.6% - 25%

139,847

October 29, 2019

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands):

	Warrant Liabilities			Convertible Promissory Notes
Balance at January 1, 2018	$	—		$	—
Issuance of convertible promissory notes		—			1,900
Change in fair value		—			50
Balance at December 31, 2018		—			1,950
Issuance of convertible promissory notes		—			90,750
Exchange of convertible promissory notes (Note 5)		—			(2,399	)
Issuance of warrants		48,313			—
Change in fair value		96,272			49,546
Reclass Takeda Warrant into equity (Note 4)		(144,172	)		—
Conversion of May 2019 Notes into common shares upon IPO (Note 5)		—			(139,847	)
Balance at December 31, 2019	$	413		$	—

Cash and Cash Equivalents

The Company considers all highly liquid investments with original maturities of three months or less when purchased to be cash equivalents. Cash and cash equivalents include cash in readily available checking accounts and money market funds.

Concentrations of Credit Risk

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.

Property, Plant, and Equipment, Net

Property, plant and equipment are recorded at cost, less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the useful life of the asset. Computer equipment and related software are depreciated over two to three years. Furniture and fixtures are depreciated over three years. Leasehold improvements are amortized over the lesser of the lease term or the estimated useful lives of the related assets. Expenditures for repairs and maintenance of assets are charged to expense as incurred. Upon retirement or sale, the cost and related accumulated depreciation of assets disposed of are removed from the accounts and any resulting gain or loss is included in loss from operations.

Impairment of Long-Lived Assets

The Company reviews long-lived assets, including property, plant and equipment, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition are less than the carrying amount. The impairment loss, if recognized, would be based on the excess of the carrying value of the impaired asset over its respective fair value. No impairment losses have been recorded through December 31, 2019.

Leases

At the inception of a contractual arrangement, the Company determines whether the contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company records the associated lease liability and corresponding right-of-use asset upon commencement of the lease using the implicit rate or a discount rate based on a credit-adjusted secured borrowing rate commensurate with the term of the lease. The Company additionally evaluates leases at their inception to determine if they are to be accounted for as an operating lease or a finance lease. A lease is accounted for as a finance lease if it meets one of the following five criteria: the lease has a purchase option that is reasonably certain of being exercised, the present value of the future cash flows is substantially all of the fair market value of the underlying asset, the lease term is for a significant portion of the remaining economic life of the underlying asset, the title to the underlying asset transfers at the end of the lease term, or if the underlying asset is of such a specialized nature that it is expected to have no alternative uses to the lessor at the end of the term. Leases that do not meet the finance lease criteria are accounted for as an operating lease. Operating lease assets represent a right to use an underlying asset for the lease term and operating lease liabilities represent an obligation to make lease payments arising from the lease. Operating lease liabilities with a term greater than one year and their corresponding right-of-use assets are recognized on the balance sheet at the commencement date of the lease based on the present value of lease payments over the expected lease term. Certain adjustments to the right-of-use asset may be required for items such as initial direct costs paid or incentives received. As the Company’s leases do not typically provide an implicit rate, the Company utilizes the appropriate incremental borrowing rate, determined as the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and in a similar economic environment. Lease cost is recognized on a straight-line basis over the lease term and variable lease payments are recognized as operating expenses in the period in which the obligation for those payments is incurred. Variable lease payments primarily include common area maintenance, utilities, real estate taxes, insurance, and other operating costs that are passed on from the lessor in proportion to the space leased by the Company. The Company has elected the practical expedient to not separate between lease and non-lease components.

Research and Development Expenses and Accruals

All research and development costs are expensed in the period incurred and consist primarily of salaries, payroll taxes, employee benefits, stock-based compensation charges for those individuals involved in research and development efforts, external research and development costs incurred under agreements with contract research organizations and consultants to conduct and support the Company’s ongoing clinical trials of vonoprazan, and costs related to manufacturing vonoprazan for clinical trials.

The Company has entered into various research and development contracts with clinical research organizations, clinical manufacturing organizations and other companies. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and payments made in advance of or after performance are reflected in the accompanying balance sheets as prepaid expenses or accrued liabilities, respectively. The Company records accruals for estimated costs incurred for ongoing research and development activities. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the services, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates may be made in determining the prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates.

In-Process Research and Development

The Company evaluates whether acquired intangible assets are a business under applicable accounting standards. Additionally, the Company evaluates whether the acquired assets have a future alternative use. Intangible assets that do not have future alternative use are considered acquired in-process research and development. When the acquired in-process research and development assets are not part of a business combination, the value of the consideration paid is expensed on the acquisition date. Future costs to develop these assets are recorded to research and development expense as they are incurred.

General and Administrative Expenses

General and administrative expenses consist of salaries, stock-based compensation, facilities and third-party expenses. General and administrative expenses are associated with the activities of the executive, finance, accounting, information technology, legal, medical affairs and human resource functions.

Stock-Based Compensation

Stock-based compensation expense represents the cost of the grant date fair value of equity awards recognized over the requisite service period of the awards (generally the vesting period) on a straight-line basis. The Company recognizes forfeitures as they occur.

Income Taxes

The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the statement of operations in the period that includes the enactment date.

The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes.

The Company records uncertain tax positions on the basis of a two-step process whereby (i) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability.

Comprehensive Loss

Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. The Company’s comprehensive loss was the same as its reported net loss for all periods presented.

Segment Reporting

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker in making decisions on how to allocate resources and assess performance. The Company views its operations and manages its business as one operating segment.

Net Loss Per Share

For the years ended December 31, 2019 and 2018, the net loss per share was recast to include in the numerator the net losses of both the Company and YamadaCo and include in the denominator the combined weighted-average outstanding shares of both the Company and YamadaCo. Basic net loss per share is computed by dividing the combined net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. The Company included 7,588,000 shares of common stock under the Takeda Warrant in the calculation of basic weighted-average common shares outstanding from the time it became exercisable at the Company’s IPO because the Takeda Warrant is issuable for little consideration. The Company has excluded weighted-average unvested shares of 3,593,034 from the weighted-average number of common shares outstanding for the year ended December 31, 2019. No shares of common stock were unvested during the year ended December 31, 2018. Diluted net loss per share is computed by dividing the combined net loss by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of unvested common stock, options, warrants and convertible promissory notes. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the potentially dilutive securities would be antidilutive.

The following potentially dilutive securities were excluded from the computation of diluted net loss per share for the periods presented because their inclusion would have been antidilutive:

	Years Ended December 31,
	2019		2018
Warrants		16,446		—
Stock options		1,400,528		—
Shares subject to repurchase		3,593,034		—

Recently Adopted Accounting Pronouncements

In June 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. This guidance expands the scope of Topic 718, Compensation—Stock Compensation, which currently only includes share-based payments to employees, to include share-based payments issued to nonemployees for goods or services. Consequently, the accounting for share-based payments to nonemployees and employees will be substantially aligned. This ASU supersedes Subtopic 505-50, Equity—Equity-Based Payments to Non-Employees and is effective for public companies for annual periods beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted as long as ASU No. 2014-09 has been adopted by the Company. The Company adopted this guidance effective January 1, 2018, and the adoption did not have a material impact on the Company's financial statements.

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which requires a lessee to recognize a lease liability and a right-of-use asset for all leases with lease terms of more than 12 months. Additionally, certain qualitative and quantitative disclosures will be required in the financial statements. This guidance is effective for annual reporting periods beginning after December 15, 2018, including interim periods within those fiscal years, and early adoption is permitted. Companies may adopt this guidance using a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. The Company adopted this guidance effective January 1, 2018, and at the time of adoption, there was no impact on the Company’s financial statements as the Company did not have any leases at the time of adoption. During 2019, adoption of this standard has resulted in the recognition of operating lease right-of-use assets of $0.9 million and lease liabilities of $0.8 million as of December 31, 2019. The standard did not materially impact the Company’s combined statements of operations or combined statements of cash flows.

Recently Issued Accounting Pronouncements

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates, modifies and adds disclosure requirements on fair value measurements. The standard is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU No. 2018-13 will have on the Company’s financial statements.

Balance Sheet Details

12 Months Ended

Dec. 31, 2019

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Details

2. Balance Sheet Details

Property, Plant and Equipment, net

Property, plant and equipment, net, consist of the following (in thousands):

	Years Ended December 31,
	2019			2018
Computer equipment and software	$	152		$	—
Furniture and fixtures		306			—
Leasehold improvements		13			—
		471		$	—
Less: accumulated depreciation		(8	)		—
Total property, plant and equipment, net	$	463		$	—

Depreciation expense for the year ended December 31, 2019 was approximately $8,000. There was no depreciation expense for the year ended December 31, 2018. No property, plant or equipment was disposed of during the year ended December 31, 2019.

Accrued Expenses

Accrued expenses consist of the following (in thousands):

	Years Ended December 31,
	2019		2018
Accrued R&D expenses	$	384	$	—
Accrued compensation expenses		1,052		76
Accrued professional & consulting expenses		478		94
Accrued other		405		—
Total accrued expenses	$	2,319	$	170

Related Party Transactions

12 Months Ended

Dec. 31, 2019

Related Party Transactions

3. Related Party Transactions

Frazier is a principal stockholder of the Company and is represented on the Company’s board of directors. For the years ended December 31, 2019 and 2018, the Company conducted its operations within office space controlled by Frazier and Frazier allocated a portion of the costs associated with this office to the Company. In addition, Frazier paid for various goods and services, such as employee wages, insurance and expense reimbursements and various administrative services associated with the operations of the Company and charged the Company for those expenses. As of December 31, 2019 and 2018, the Company had outstanding accounts payable and accrued expenses due to Frazier in the amount of $0.1 million and $45,000 respectively, related to these shared operating expenses. For the years ended December 31, 2019 and 2018, the Company incurred $0.4 million and $0.3 million, respectively, of shared operating expenses. In addition to the shared operating expenses, the Company issued convertible promissory notes to Frazier during 2018 and 2019 (see Note 5).

Frazier is a principal stockholder in PCI Pharma Services (“PCI”). In the third quarter of 2019, the Company engaged PCI for clinical manufacturing services. As of December 31, 2019, the Company had $0.3 million outstanding accounts payable and accrued expenses related to these manufacturing services. For the year ended December 31, 2019, the Company incurred $1.1 million of expenses related to services performed by PCI.

Mountain Field LLC (“Mountain Field”) is an entity owned by the chairman of the Company’s board of directors. During the years ended December 31, 2019 and 2018, the Company charged Mountain Field for certain rent and payroll related expenses. These shared expenses were allocated based on usage of the related facilities and time incurred by personnel. As of December 31, 2019, and 2018, the Company had an outstanding accounts receivable balance from Mountain Field of $0 and $19,000, respectively, related to shared operating expenses. For the years ended December 31, 2019 and 2018, the Company charged Mountain Field $0.1 million and $4,000, respectively, for shared expenses.

Takeda became a common stockholder of the Company as of May 7, 2019 in connection with the Takeda License (see Note 4). In conjunction with the Takeda License, Takeda will provide proprietary supplies for the Company’s ongoing clinical development of vonoprazan in addition to the exclusive license for the commercialization of vonoprazan in the United States, Canada and Europe. As of December 31, 2019, the Company had $0.1 million in outstanding accounts payable and accrued expenses related to these supply services. For the year ended December 31, 2019, the Company incurred $0.1 million of expenses related to services performed by Takeda.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2019

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

4. Commitments and Contingencies

License Agreement

On May 7, 2019, the Company entered into a license agreement with Takeda pursuant to which it was granted an exclusive license to commercialize vonoprazan in the United States, Canada and Europe (the “Takeda License”). The Company also has the right to sublicense its rights under the agreement, subject to certain conditions. The agreement will remain in effect, on a country-by-country and product-by-product basis, until the later of (i) the expiration of the last to expire valid patent claim covering vonoprazan alone or in combination with at least one other therapeutically active ingredient, (ii) the expiration of the applicable regulatory exclusivity and (iii) 15 years from the date of first commercial sale, unless earlier terminated. The Company may terminate the Takeda License upon six months’ written notice. The Company and Takeda may terminate the Takeda License in the case of the other party’s insolvency or material uncured breach. Takeda may terminate the Takeda License if the Company challenges, or assists in challenging, licensed patents.

In consideration of the Takeda License, the Company (i) paid Takeda $25.0 million in cash, (ii) issued Takeda 1,084,000 shares of its common stock at a fair value of $5.9 million, (iii) issued the Takeda Warrant to purchase 7,588,000 shares of its common stock at an exercise price of $0.00004613 per share at an initial fair value of $47.9 million, and (iv) issued the Takeda Warrant Right to receive an additional common stock warrant should Takeda’s fully-diluted ownership of the Company represent less than a certain specified percentage of the fully-diluted capitalization, including shares issuable upon conversion of then outstanding convertible promissory notes, calculated immediately before the closing of the Company’s IPO, with a nominal initial fair value due to the low probability of issuance. The Takeda Warrant Right expired upon completion of the IPO, and no additional warrant was issued. In addition, the Company is obligated to pay Takeda up to an aggregate of $250.0 million in sales milestones upon the achievement of specified levels of product sales, and a low double-digit royalty rate on aggregate net sales of licensed products, subject to certain adjustments. The Company incurred $0.1 million of transaction costs in connection with the Takeda License. The Takeda Warrant has an exercise price of $0.00004613 per share, expires on May 7, 2029 and becomes exercisable upon (i) certain change of control transactions of the Company or (ii) the consummation of an IPO by the Company. Following the October 11, 2019 increase in the Company’s authorized shares of common stock to 50,000,000, the Company recorded a non-cash charge related to the final fair value adjustment of the Takeda Warrants and reclassified the full balance of $144.2 million from warrant liabilities to additional paid-in capital. Additionally, upon closing of the IPO, the Takeda Warrant Right expired without effect since no fair value had been allocated to it.

The transaction has been accounted for as an asset acquisition as substantially all of the fair value is concentrated in a group of similar assets. The $78.9 million fair value of the consideration paid for these research and development assets, which have no alternative future use, was recorded as in-process research and development in the Company’s combined statement of operations for the year ended December 31, 2019.

Contingencies

In the event the Company becomes subject to claims or suits arising in the ordinary course of business, the Company would accrue a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated.

Convertible Promissory Notes

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Convertible Promissory Notes

5. Convertible Promissory Notes

Frazier Convertible Note Financing

From January 2018 to April 2019, the Company issued the Frazier Notes for an aggregate of $2.4 million and bearing interest at per annum rates ranging from 1.68% to 2.55%. Of the Frazier Notes, $1.9 million were issued in 2018 and $0.5 million were issued in April 2019. Due to certain embedded features within the Frazier Notes, the Company elected to account for these notes and all their embedded features under the fair value option. The Company recorded changes in the fair value of the Frazier Notes in the combined statements of operations until May 2019, when the Frazier Notes and related accrued interest were exchanged, at their then fair value of $2.4 million, for the May 2019 Notes. For the years ended December 31, 2019 and 2018, the Company recognized $50,000 of other income and $50,000 of other expense, respectively, in the combined statements of operations related to changes in the fair value of the Frazier Notes. For the year ended December 31, 2019 and 2018, the Company recognized $15,000 and $13,000, respectively, of interest expense in connection with the Frazier Notes.

May 2019 Convertible Note Financing

On May 7, 2019, the Company entered into a note purchase agreement under which it issued the unsecured May 2019 Notes for an aggregate of $90.3 million, resulting in gross proceeds to the Company of $87.8 million in cash and $2.4 million related to the exchange of the Frazier Notes and related accrued interest for the May 2019 Notes. Including the conversion of the Frazier Notes, Frazier purchased $20.0 million of the May 2019 Notes. The May 2019 Notes bore interest at a rate of 6% per annum and were subordinated to borrowings under the Company’s loan and security agreement (see Note 7).

Due to certain embedded features within the May 2019 Notes, the Company elected to account for these notes and all their embedded features under the fair value option. The outstanding principal and accrued interest of the May 2019 Notes automatically converted into 6,107,918 shares of common stock immediately prior to the completion of the IPO on October 29, 2019. In connection with the IPO conversion, the Company recorded a non-cash charge related to the final fair value adjustment of the convertible promissory notes payable in the amount of $44.6 million. For the year ended December 31, 2019, the Company recognized $49.5 million of other expense in the combined statements of operations related to increases in the fair value of the May 2019 Notes. For the year ended December 31, 2019, the Company recognized $2.6 million of interest expense in connection with the May 2019 Notes.

Leases Commitments

12 Months Ended

Dec. 31, 2019

Leases [Abstract]

Leases Commitments

6. Lease Commitments

In August 2019, the Company entered into a 65-month operating lease for 10,043 rentable square feet of office space for offices located in Buffalo Grove, Illinois. The lease contains an option to extend the term for one additional five-year period, which has not been considered in the determination of the right-of-use asset or the lease liability as the Company did not consider it reasonably certain that it would exercise such option. The lease commenced in October 2019, the date on which the underlying asset was made available for use to the Company. The Company's lease provides for fixed monthly payments for the term of the lease, with monthly rent increasing approximately 3% every 12 months following the commencement date. The total rent expense for the year ended December 31, 2019 was approximately $51,000.

The following table summarizes supplemental balance sheet information related to leases as of December 31, 2019. The Company had no leases during the year ended December 31, 2018.

	Year Ended December 31,
	2019
Assets:
Operating lease right-of-use assets	$	933
Total right-of-use assets		933

Liabilities:
Operating lease liabilities, current		161
Operating lease liabilities, non-current		635
Total operating lease liabilities	$	796

As of December 31, 2019, the future minimum annual lease payments under the operating lease were as follows (in thousands):

2020	$	166
2021		171
2022		176
2023		181
2024		186
Thereafter		80
Total minimum lease payments	$	960

Less: amount representing interest		(164	)
Present value of operating lease liabilities		796
Less: operating lease liabilities, current		(161	)
Operating lease liabilities	$	635

Weighted-average remaining lease term (in years)		5.33
Weighted-average incremental borrowing rate		7.25	%

The table below summarizes the Company’s lease costs, cash payments, and operating lease liabilities arising from obtaining right-of-use assets under its operating lease obligations during the year ended December 31, 2019:

	December 31, 2019
Total operating lease expense		51

Supplemental non-cash information:
Operating lease liabilities arising from obtaining right-of-use assets		796

In December 2019, the Company entered into a 62-month operating lease for 9,420 rentable square feet of office space in Florham Park, New Jersey. The lease contains an option to extend the term for one additional five-year period, which will not be considered in the determination of the right-of-use asset or the lease liability as the Company is not reasonably certain that it would exercise such option. The Company has future minimum lease payment obligations of approximately $1.7 million related to the leased office space. The lease liability and the corresponding right-of-use asset associated with this lease obligation will be recorded upon the commencement of the lease, or the date in which the underlying asset is made available for use to the Company, which had not occurred as of December 31, 2019.

Long-Term Debt

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Long-Term Debt

7. Long-Term Debt

Long-term debt consists of the following (in thousands):

	December 31, 2019
Long-term debt	$	25,000
Unamortized debt discount		(2,223	)
Long-term debt, net of debt discount	$	22,777

On May 14, 2019, the Company entered into a loan and security agreement (the “Loan Agreement”, and all amounts borrowed thereunder the “Term Loans”) with Silicon Valley Bank (“SVB”), as administrative and collateral agent, and lenders including SVB and WestRiver Innovation Lending Fund VIII, L.P. (“WestRiver”). The Company borrowed $25.0 million (“Term Loan A”) at the inception of the Loan Agreement and has the right to borrow an additional $25.0 million (“Term Loan B”). Term Loan B is available through March 31, 2020, provided that (i) the Company has received at least $150.0 million of net cash proceeds in connection with the issuance and sale, subsequent to April 1, 2019, of its equity securities and subordinated debt, (ii) the Company has initiated Phase 3 clinical trials for vonoprazan, and (iii) no event of default has occurred.

The Term Loans bear interest at a floating rate of the higher of the Wall Street Journal Prime rate plus 1.75% (6.5% at December 31, 2019) or 7.25%. The monthly payments consist of interest-only through May 31, 2021 or, in the event of positive data with respect to the Company’s Phase 3 clinical trial in both indications for vonoprazan sufficient to file an NDA with the FDA, through May 31, 2022. Subsequent to the interest-only period, the Term Loans will be payable in equal monthly installments of principal, plus accrued and unpaid interest through the maturity date of May 1, 2024. In addition, the Company is obligated to pay a final payment fee of 8.25% of the original principal amount of the Term Loans. As of December 31, 2019, the final payment fee of $2.1 million has been recorded as an other long-term liability.

The Company may elect to prepay all or a portion of the Term Loans prior to maturity, subject to a prepayment fee of up to 2.0% of the then outstanding principal balance and payment of a pro rata portion of the final payment fee. After repayment, no Term Loan amounts may be borrowed again.

The borrowings under the Loan Agreement are collateralized by substantially all of the Company’s assets, excluding intellectual property and certain other assets. The Loan Agreement includes affirmative and negative covenants. The affirmative covenants include, among others, covenants requiring the Company to maintain its legal existence and governmental approvals, deliver certain financial reports, maintain insurance coverage and satisfy certain requirements regarding its operating accounts. The negative covenants include, among others, limitations on the Company’s ability to incur additional indebtedness and liens, merge with other companies or consummate certain changes of control, acquire other companies, engage in new lines of business, make certain investments, pay dividends, transfer or dispose of assets, amend certain material agreements or enter into various specified transactions. The Loan Agreement also contains customary events of default, including bankruptcy, the failure to make payments when due, and a material adverse change. Upon the occurrence of an event of default, subject to any specified cure periods, all amounts owed by the Company would begin to bear interest at a rate that is 4.00% above the rate effective immediately before the event of default and may be declared immediately due and payable by SVB, as collateral agent. As of December 31, 2019, the Company was in compliance with all applicable covenants under the Loan Agreement.

In connection with the Loan Agreement, the Company issued the Lender Warrants to purchase stock of the Company. The Lender Warrants become exercisable only if the Company borrows Term Loan B, and the number, class and per share price of the shares subject to the warrants is dependent on the terms of certain future equity financing transactions of the Company, including an IPO. Upon completion of the IPO, the Lender Warrants became exercisable for 16,446 shares of common stock. The Lender Warrants expire ten years from the date of issuance, subject to earlier termination on December 31, 2020 if the Company does not draw down Term Loan B on or before March 31, 2020. The Lender Warrants include a put option pursuant to which, in the event that the Company does not draw down Term Loan B on or before March 31, 2020, the warrant holders may require that the Company repurchase the warrants for a total aggregate repurchase price of $0.5 million. The put right is exercisable through September 30, 2020.

The initial $0.4 million fair value of the Lender Warrants, the $2.1 million final payment fee and $0.2 million of debt issuance costs have been recorded as debt discount and are being amortized to interest expense using the effective interest method over the term of the Term Loans. For the year ended December 31, 2019, the Company recognized $1.6 million of interest expense, including amortization of the debt discount, in connection with the Loan Agreement. As of December 31, 2019, the Company had outstanding Term Loans of $25.0 million and accrued interest of $0.2 million.

Future minimum principal and interest payments under the Term Loans, including the final payment fee, as of December 31, 2019 are as follows (in thousands):

Year ending December 31:
2020	$	1,843
2021		6,609
2022		9,533
2023		8,920
2024		5,599
Total principal and interest payments		32,504
Less interest and final payment fee		(7,504	)
Long-term debt	$	25,000

Stockholders' Equity

12 Months Ended

Dec. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stockholders’ Equity

8. Stockholders’ Equity

Common Stock

In March 2019, subsequent to the Merger, the Company sold 1,491,072 shares of the Company’s common stock to Frazier.

In March 2019, the founders granted the Company a repurchase right for the 3,373,408 shares of common stock originally purchased in 2018. The Company has the right, but not the obligation, to repurchase unvested shares in the event the founder’s relationship with the Company is terminated, subject to certain limitations, at the original purchase price of the stock. The repurchase right lapsed for 843,352 shares in March 2019 and the repurchase right for the remaining 2,530,056 shares lapses in equal monthly amounts over the following 48-month period ending in March 2023. The fair value of the founder shares at the date the repurchase right was granted is being recognized as stock-based compensation expense on a straight-line basis over the vesting period. As of December 31, 2019, 2,055,684 shares of common stock were subject to repurchase by the Company and the associated repurchase liability was not significant. The amount of recognized and unrecognized stock-based compensation related to the founder stock was immaterial for all periods presented.

In May 2019, the Company issued Takeda 1,084,000 shares of common stock in connection with the Takeda License.

For the period from January 1, 2019 to May 6, 2019, the Company issued 2,524,852 shares of common stock to various employees and consultants of the Company for aggregate proceeds of approximately $1,000. Upon issuance, these shares were subject to a repurchase option by the Company at the original purchase price of the shares. The repurchase rights generally lapse as to 25% of the shares on the first anniversary of the vesting commencement date, and the repurchase right lapses as to 1/48th of the shares each one-month period thereafter, subject to the purchaser remaining continuously an employee, consultant or director of the Company. In November 2019, the Company repurchased 17,560 shares at the original purchase price for an aggregate purchase price of $5.20. As of December 31, 2019, 2,177,861 shares remain available for repurchase by the Company and the associated repurchase liability was not significant.

On October 29, 2019, upon completion of the IPO, the Company sold 10,997,630 shares of common stock, which included the exercise in full by the underwriters of their option to purchase 1,434,473 additional shares at a public offering price of $19.00 per share. The net proceeds were approximately $191.5 million, after deducting underwriting discounts, commissions and offering costs.

Equity Incentive Plan

The Company’s 2019 Equity Incentive Plan (the “Existing Incentive Plan”) provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, and other stock awards to eligible recipients, including employees, directors or consultants of the Company. The Company had 2,231,739 shares of common stock authorized for issuance under the Existing Incentive Plan, of which, 1,400,528 stock options and 16,260 restricted stock awards were granted in 2019. As a result of the adoption of the 2019 Equity Incentive Plan, no further shares are available for issuance under the Existing Incentive Plan.

2019 Incentive Award Plan

In October 2019, the board of directors adopted, and the Company’s stockholders approved the 2019 Equity Incentive Plan (the “2019 Plan”), which became effective in connection with the IPO. Under the 2019 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and other awards to individuals who are then employees, officers, non-employee directors or consultants of the Company or its subsidiaries. As of December 31, 2019, an aggregate of 2,700,000 shares of the Company’s common stock were available for issuance under awards granted pursuant to the 2019 Plan. The number of shares initially available for issuance will be increased by (i) the number of shares subject to stock options or similar awards granted under the Existing Incentive Plan that expire or otherwise terminate without having been exercised in full after the effective date of the 2019 Plan and unvested shares issued pursuant to awards granted under the Existing Incentive Plan that are forfeited to or repurchased by the Company after the effective date of the 2019 Plan, with the maximum number of shares to be added to the 2019 Plan pursuant to clause (i) above equal to 1,416,788 shares, and (ii) an annual increase on January 1 of each calendar year beginning in 2020 and ending in 2029, equal to the lesser of (a) 5% of the shares of common stock outstanding on the final day of the immediately preceding calendar year and (b) such smaller number of shares as determined by the board of directors.

Employee Stock Purchase Plan

In October 2019, the board of directors adopted, and the Company’s stockholders approved, the Employee Stock Purchase Plan (the “ESPP”), which became effective in connection with the IPO. The ESPP permits participants to purchase common stock through payroll deductions of up to 20% of their eligible compensation, which includes a participant’s gross base compensation for services to the Company, including overtime payments and excluding sales commissions, incentive compensation, bonuses, expense reimbursements, fringe benefits and other special payments. A total of 270,000 shares of common stock is initially reserved for issuance under the ESPP. In addition, the number of shares available for issuance under the ESPP will be annually increased on January 1 of each calendar year beginning in 2020 and ending in 2029, by an amount equal to the lesser of: (i) 1% of the shares outstanding on the final day of the immediately preceding calendar year and (ii) such smaller number of shares as is determined by the board of directors.

A summary of the Company’s unvested shares is as follows:

Balance at January 1, 2019	—
Vesting restrictions placed on previously issued shares	3,373,408
Sale of unvested common stock	2,524,852
Issuance of unvested restricted stock awards	16,260
Unvested common stock repurchased	(17,560	)
Share vesting	(1,660,712	)
Balance at December 31, 2019	4,236,248

For accounting purposes, unvested shares of common stock are considered issued, but not outstanding until they vest.

Common stock reserved for future issuance consists of the following:

	December 31, 2019
Common stock warrants		7,604,446
Stock options outstanding		1,400,528
Shares available for issuance under the 2019 Incentive Plan		2,700,000
Shares available for issuance under the ESPP Plan		270,000
Balance at December 31, 2019		11,974,974

Stock Options

The fair value of each employee and non-employee stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company, prior to the IPO on October 29, 2019, was a private company and lacked company-specific historical and implied volatility information. Therefore, it estimated its expected volatility based on the historical volatility of a publicly traded set of peer companies. Due to the lack of historical exercise history, the expected term of the Company’s stock options for employees was determined utilizing the “simplified” method for awards. The expected term of stock options granted to non-employees was equal to the contractual term of the option award. The risk-free interest rate was determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield was zero based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future.

A summary of the Company’s stock option activity and related information is as follows:

	Options Outstanding		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term		Aggregate Intrinsic Value (in thousands)
Balance at December 31, 2018
Options granted		1,400,528	$	9.10		—		—
Options exercised and shares vested		—		—		—		—
Options cancelled		—		—		—		—
Balance at December 31, 2019		1,400,528	$	9.10		9.69	$	30,874
Options exercisable as of December 31, 2019		—		—		—		—

The estimated weighted-average fair value of employee and nonemployee director stock options granted during 2019 was $5.12. As of December 31, 2019, the Company had $6.8 million of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted-average period of 3.75 years.

Valuation Assumptions

The weighted-average assumptions used to estimate the fair value of stock options using the Black-Scholes option valuation model and the resulting weighted average fair value of stock options granted were as follows:

	Years Ended December 31,
	2019			2018
Assumptions:
Expected term (in years)		6.07			—
Expected volatility		60.17	%		—
Risk free interest rate		1.58	%		—
Dividend yield		—			—

Stock-Based Compensation Expense

Stock-based compensation expense recognized for all equity awards, including founder stock, has been reported in the combined statements of operations as follows (in thousands):

	Years Ended December 31,
	2019		2018
Research and development expense	$	106	$	—
General and administrative expense		300		—
Total	$	406	$	—

Income Taxes

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Income Taxes

9. Income Taxes

A reconciliation between the provision for income taxes and income taxes computed using the U.S. federal statutory corporate tax rate is as follows (in thousands):

	Years Ended December 31,
	2019			2018
Income taxes computed at the statutory rate	$	(53,578	)	$	(271	)
State income taxes, net of federal benefit		—			—
Permanent items		552			2
Change in fair value of warrants and convertible debt		30,622			12
Research and development credit		(697	)		—
Change in valuation allowance		23,046			257
Other		55			—
Provision (benefit) for income taxes	$	—		$	—

Significant components of the Company’s net deferred tax assets are as follows (in thousands):

	Years Ended December 31,
	2019			2018
Deferred tax assets:
Net operating loss carryforwards	$	6,322		$	5
Accruals and reserves		204			16
Intangible assets		16,050			236
Other		921			—
Gross deferred tax assets		23,497			257
Less valuation allowance		(23,301	)		(257	)
Deferred tax assets, net of valuation allowance		196			—
Deferred tax liabilities:
Other		(196	)		—
Net deferred tax assets	$	—		$	—

Based upon the Company’s history of operating losses, the Company is unable to conclude that it is more likely than not that the benefit of its deferred tax assets will be realized. Accordingly, the Company has provided a full valuation allowance for its deferred tax assets as of December 31, 2019 and 2018.

As of December 31, 2019 and 2018, the Company had federal net operating loss carryforwards of approximately $30.1 million and $23,000, respectively, which are carried over indefinitely.

As of December 31, 2019, the Company has available federal research and development credits of $0.9 million which begin to expire in 2038.

The Company has not completed a formal analysis of the potential impact of Section 382 on its deferred tax assets as of December 31, 2019. Until this analysis has been completed, the Company has not adjusted any of its deferred tax assets, including net operating losses or research and development credits. The Company will reassess the amount of net operating losses and credits subject to limitation under Section 382 when a study is complete. Due to the existence of the valuation allowance, future changes in the deferred tax assets related to these tax attributes will not impact the Company’s effective tax rate.

The Company recognizes liabilities for uncertain tax positions based on a two-step process. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon settlement. While the Company believes that it has appropriate support for the positions taken on its tax returns, the Company regularly assesses the potential outcome of examinations by tax authorities in determining the adequacy of its provision for income taxes.

The following table summarizes the activity related to the Company's gross unrecognized tax benefits:

	Year Ended December 31,
	2019
Beginning balance	$	—
Increases related to current year tax positions		176
Ending balance	$	176

As of December 31, 2019, the Company has gross unrecognized tax benefits of $0.2 million, none of which would affect the effective tax rate due to a full valuation allowance. The Company does not anticipate any significant changes in its unrecognized tax benefits over the next 12 months. The Company's policy is to recognize the interest expense and/or penalties related to income tax matters as a component of income tax expense. The Company has no accrual for interest or penalties on its balance sheet at December 31, 2019 and has not recognized interest or penalties in its statement of operations for the year ended December 31, 2019.

The Company is subject to taxation in the United States and California. The Company is not currently under examination by any taxing authorities. Due to the carryover of tax attributes, the statute of limitations is currently open for tax years since inception.

Quarterly Financial Information (unaudited)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information (unaudited)

10. Quarterly Financial Information (unaudited)

The following table summarizes the unaudited combined financial results of operations for the quarters indicated:

	2019 Quarter Ended
	March 31,			June 30,			September 30,			December 31,
	(unaudited)
Operating expenses:
Research and development	$	429		$	2,772		$	4,469		$	12,704
In-process research and development		—			78,897			—			—
General and administrative		797			1,345			1,813			2,989
Total operating expenses		1,226			83,014			6,282			15,693
Loss from operations		(1,226	)		(83,014	)		(6,282	)		(15,693	)
Total other income (expense)		(25	)		(4,748	)		(61,830	)		(82,313	)
Net loss	$	(1,251	)	$	(87,762	)	$	(68,112	)	$	(98,006	)
Net loss per share, basic and diluted	$	(0.19	)	$	(13.11	)	$	(9.30	)	$	(3.97	)
Weighted-average shares of common stock outstanding, basic and diluted		6,585,503			6,694,682			7,326,090			24,706,661

	2018 Quarter Ended
	March 31,			June 30,			September 30,			December 31,
	(unaudited)
Operating expenses:
Research and development	$	—		$	—		$	6		$	14
General and administrative		251			255			262			437
Total operating expenses		251			255			268			451
Loss from operations		(251	)		(255	)		(268	)		(451	)
Total other income (expense)		(3	)		(5	)		(22	)		(33	)
Net loss	$	(254	)	$	(260	)	$	(290	)	$	(484	)
Net loss per share, basic and diluted	$	(0.07	)	$	(0.04	)	$	(0.04	)	$	(0.07	)
Weighted-average shares of common stock outstanding, basic and diluted		3,886,328			6,760,334			6,760,334			6,760,334

Subsequent Events

12 Months Ended

Dec. 31, 2019

Subsequent Events [Abstract]

Subsequent Events

11. Subsequent Events

In March 2020, the Company entered into the First Amendment (the “Amendment”) to the Loan Agreement which amended certain terms of the Loan Agreement, dated as of May 14, 2019.

The Amendment redefined the events that extend the interest-only period of the Loan Agreement. Pursuant to the Amendment, the interest-only payment period, which ends on May 31, 2021, will be extended either (i) until December 31, 2021, if the Company receives positive data from its Phase 3 clinical trial in H. pylori infection sufficient to file an NDA with the FDA; or (ii) until November 30, 2022, if the Company receives positive data from its Phase 3 clinical trials in both indications for vonoprazan sufficient to file an NDA with the FDA; provided, in each case, that the Company has drawn down Term Loan B.

Subsequent to the interest-only period, the Term Loans will be payable in equal monthly installments of principal, plus accrued and unpaid interest through the maturity date of May 1, 2024.

The Company elected to draw the Term Loan B in March 2020 and received the additional $25.0 million of principal. Upon the Term Loan B draw, the Lender Warrants became exercisable and the put option related to the Lender Warrants expired.

Organization, Basis of Presentation and Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Stock Split and Conversion

Basis of Presentation

Liquidity and Capital Resources

Use of Estimates

Fair Value Option

Fair Value Measurements

Level 1:

Observable inputs such as quoted prices in active markets.

Level 2:

Inputs, other than the quoted prices in active markets that are observable either directly or indirectly.

Level 3:

Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.

Liabilities measured at fair value on a recurring basis are as follows (in thousands):

			Fair Value Measurements at Reporting Date Using:
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of December 31, 2018:
Convertible promissory notes	$	1,950	$	—	$	—	$	1,950

As of December 31, 2019:
Warrant liabilities	$	413	$	—	$	—	$	413
Total	$	413	$	—	$	—	$	413

Liability

At initial

valuation

date

Fair value method at

initial valuation date

(and relative weighting)

KEY unobservable inputs

Range

Fair value at

conversion date

Conversion

Date

Takeda

Warrants

47,894

Financing transactions (40%)

Income approach (60%)

Transaction prices per share

Estimated time to liquidity

Discount rate

$9.33 - $19.00

0.09 - 1.77 years

7.5%

144,172

October 11, 2019

May 2019 Notes

90,250

Financing transactions (40%)

Income approach (60%)

Estimated time to liquidity

Volatility Discount rate

0.09 - 1.77 years

65%

22.6% - 25%

139,847

October 29, 2019

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands):

	Warrant Liabilities			Convertible Promissory Notes
Balance at January 1, 2018	$	—		$	—
Issuance of convertible promissory notes		—			1,900
Change in fair value		—			50
Balance at December 31, 2018		—			1,950
Issuance of convertible promissory notes		—			90,750
Exchange of convertible promissory notes (Note 5)		—			(2,399	)
Issuance of warrants		48,313			—
Change in fair value		96,272			49,546
Reclass Takeda Warrant into equity (Note 4)		(144,172	)		—
Conversion of May 2019 Notes into common shares upon IPO (Note 5)		—			(139,847	)
Balance at December 31, 2019	$	413		$	—

Cash and Cash Equivalents

Concentrations of Credit Risk

Property, Plant, and Equipment, Net

Impairment of Long-Lived Assets

Leases

Research and Development Expenses and Accruals

In-Process Research and Development

General and Administrative Expenses

Stock-Based Compensation

The following potentially dilutive securities were excluded from the computation of diluted net loss per share for the periods presented because their inclusion would have been antidilutive:

	Years Ended December 31,
	2019		2018
Warrants		16,446		—
Stock options		1,400,528		—
Shares subject to repurchase		3,593,034		—

Recently Adopted and Issued Accounting Pronouncements

Recently Adopted Accounting Pronouncements

Recently Issued Accounting Pronouncements

Organization, Basis of Presentation and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Schedule of Liabilities Measured at Fair Value on Recurring Basis

Liabilities measured at fair value on a recurring basis are as follows (in thousands):

			Fair Value Measurements at Reporting Date Using:
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of December 31, 2018:
Convertible promissory notes	$	1,950	$	—	$	—	$	1,950

As of December 31, 2019:
Warrant liabilities	$	413	$	—	$	—	$	413
Total	$	413	$	—	$	—	$	413

Schedule of Adjustment of Carrying Value to Their Estimated Fair Value

Liability

At initial

valuation

date

Fair value method at

initial valuation date

(and relative weighting)

KEY unobservable inputs

Range

Fair value at

conversion date

Conversion

Date

Takeda

Warrants

47,894

Financing transactions (40%)

Income approach (60%)

Transaction prices per share

Estimated time to liquidity

Discount rate

$9.33 - $19.00

0.09 - 1.77 years

7.5%

144,172

October 11, 2019

May 2019 Notes

90,250

Financing transactions (40%)

Income approach (60%)

Estimated time to liquidity

Volatility Discount rate

0.09 - 1.77 years

65%

22.6% - 25%

139,847

October 29, 2019

Schedule of Reconciliation of Liabilities Measured at Fair Value

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands):

	Warrant Liabilities			Convertible Promissory Notes
Balance at January 1, 2018	$	—		$	—
Issuance of convertible promissory notes		—			1,900
Change in fair value		—			50
Balance at December 31, 2018		—			1,950
Issuance of convertible promissory notes		—			90,750
Exchange of convertible promissory notes (Note 5)		—			(2,399	)
Issuance of warrants		48,313			—
Change in fair value		96,272			49,546
Reclass Takeda Warrant into equity (Note 4)		(144,172	)		—
Conversion of May 2019 Notes into common shares upon IPO (Note 5)		—			(139,847	)
Balance at December 31, 2019	$	413		$	—

Schedule of Potentially Dilutive Securities from Computation of Diluted Net Loss Per Share

The following potentially dilutive securities were excluded from the computation of diluted net loss per share for the periods presented because their inclusion would have been antidilutive:

	Years Ended December 31,
	2019		2018
Warrants		16,446		—
Stock options		1,400,528		—
Shares subject to repurchase		3,593,034		—

Balance Sheet Details (Tables)

12 Months Ended

Dec. 31, 2019

Balance Sheet Related Disclosures [Abstract]

Schedule of Property, Plant and Equipment, Net

Property, plant and equipment, net, consist of the following (in thousands):

	Years Ended December 31,
	2019			2018
Computer equipment and software	$	152		$	—
Furniture and fixtures		306			—
Leasehold improvements		13			—
		471		$	—
Less: accumulated depreciation		(8	)		—
Total property, plant and equipment, net	$	463		$	—

Schedule of Accrued Expenses

Accrued expenses consist of the following (in thousands):

	Years Ended December 31,
	2019		2018
Accrued R&D expenses	$	384	$	—
Accrued compensation expenses		1,052		76
Accrued professional & consulting expenses		478		94
Accrued other		405		—
Total accrued expenses	$	2,319	$	170

Leases Commitments (Tables)

12 Months Ended

Dec. 31, 2019

Leases [Abstract]

Summary of Supplemental Balance Sheet Information Related to Leases

The following table summarizes supplemental balance sheet information related to leases as of December 31, 2019. The Company had no leases during the year ended December 31, 2018.

	Year Ended December 31,
	2019
Assets:
Operating lease right-of-use assets	$	933
Total right-of-use assets		933

Liabilities:
Operating lease liabilities, current		161
Operating lease liabilities, non-current		635
Total operating lease liabilities	$	796

Summary of Future Minimum Lease Payments Under Operating Lease

As of December 31, 2019, the future minimum annual lease payments under the operating lease were as follows (in thousands):

2020	$	166
2021		171
2022		176
2023		181
2024		186
Thereafter		80
Total minimum lease payments	$	960

Less: amount representing interest		(164	)
Present value of operating lease liabilities		796
Less: operating lease liabilities, current		(161	)
Operating lease liabilities	$	635

Weighted-average remaining lease term (in years)		5.33
Weighted-average incremental borrowing rate		7.25	%

Summary of Lease Costs, Cash Payments, and Operating Lease Liabilities Arising from Obtaining Right-of-use Assets

	December 31, 2019
Total operating lease expense		51

Supplemental non-cash information:
Operating lease liabilities arising from obtaining right-of-use assets		796

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Schedule of Long-Term Debt

Long-term debt consists of the following (in thousands):

	December 31, 2019
Long-term debt	$	25,000
Unamortized debt discount		(2,223	)
Long-term debt, net of debt discount	$	22,777

Schedule of Future Minimum Principal and Interest Payments Under Term Loans

Future minimum principal and interest payments under the Term Loans, including the final payment fee, as of December 31, 2019 are as follows (in thousands):

Year ending December 31:
2020	$	1,843
2021		6,609
2022		9,533
2023		8,920
2024		5,599
Total principal and interest payments		32,504
Less interest and final payment fee		(7,504	)
Long-term debt	$	25,000

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 235
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-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
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Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 942
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Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
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-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Unvested Shares

A summary of the Company’s unvested shares is as follows:

Balance at January 1, 2019	—
Vesting restrictions placed on previously issued shares	3,373,408
Sale of unvested common stock	2,524,852
Issuance of unvested restricted stock awards	16,260
Unvested common stock repurchased	(17,560	)
Share vesting	(1,660,712	)
Balance at December 31, 2019	4,236,248

Summary of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consists of the following:

	December 31, 2019
Common stock warrants		7,604,446
Stock options outstanding		1,400,528
Shares available for issuance under the 2019 Incentive Plan		2,700,000
Shares available for issuance under the ESPP Plan		270,000
Balance at December 31, 2019		11,974,974

Summary of Stock Option Activity

A summary of the Company’s stock option activity and related information is as follows:

	Options Outstanding		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term		Aggregate Intrinsic Value (in thousands)
Balance at December 31, 2018
Options granted		1,400,528	$	9.10		—		—
Options exercised and shares vested		—		—		—		—
Options cancelled		—		—		—		—
Balance at December 31, 2019		1,400,528	$	9.10		9.69	$	30,874
Options exercisable as of December 31, 2019		—		—		—		—

Summary of Weighted-Average Assumptions Used to Estimate Fair Value of Stock Options Granted

	Years Ended December 31,
	2019			2018
Assumptions:
Expected term (in years)		6.07			—
Expected volatility		60.17	%		—
Risk free interest rate		1.58	%		—
Dividend yield		—			—

Summary of Stock-Based Compensation Expense

Stock-based compensation expense recognized for all equity awards, including founder stock, has been reported in the combined statements of operations as follows (in thousands):

	Years Ended December 31,
	2019		2018
Research and development expense	$	106	$	—
General and administrative expense		300		—
Total	$	406	$	—

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Reconciliation Between Provision for Income Taxes and Income Taxes Computed Using U.S. Federal Statutory Corporate Tax Rate

A reconciliation between the provision for income taxes and income taxes computed using the U.S. federal statutory corporate tax rate is as follows (in thousands):

	Years Ended December 31,
	2019			2018
Income taxes computed at the statutory rate	$	(53,578	)	$	(271	)
State income taxes, net of federal benefit		—			—
Permanent items		552			2
Change in fair value of warrants and convertible debt		30,622			12
Research and development credit		(697	)		—
Change in valuation allowance		23,046			257
Other		55			—
Provision (benefit) for income taxes	$	—		$	—

Components of Deferred Tax Assets

Significant components of the Company’s net deferred tax assets are as follows (in thousands):

	Years Ended December 31,
	2019			2018
Deferred tax assets:
Net operating loss carryforwards	$	6,322		$	5
Accruals and reserves		204			16
Intangible assets		16,050			236
Other		921			—
Gross deferred tax assets		23,497			257
Less valuation allowance		(23,301	)		(257	)
Deferred tax assets, net of valuation allowance		196			—
Deferred tax liabilities:
Other		(196	)		—
Net deferred tax assets	$	—		$	—

Summary of Activity Related to Gross Unrecognized Benefits

The following table summarizes the activity related to the Company's gross unrecognized tax benefits:

	Year Ended December 31,
	2019
Beginning balance	$	—
Increases related to current year tax positions		176
Ending balance	$	176

Quarterly Financial Information (unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information (unaudited)

The following table summarizes the unaudited combined financial results of operations for the quarters indicated:

	2019 Quarter Ended
	March 31,			June 30,			September 30,			December 31,
	(unaudited)
Operating expenses:
Research and development	$	429		$	2,772		$	4,469		$	12,704
In-process research and development		—			78,897			—			—
General and administrative		797			1,345			1,813			2,989
Total operating expenses		1,226			83,014			6,282			15,693
Loss from operations		(1,226	)		(83,014	)		(6,282	)		(15,693	)
Total other income (expense)		(25	)		(4,748	)		(61,830	)		(82,313	)
Net loss	$	(1,251	)	$	(87,762	)	$	(68,112	)	$	(98,006	)
Net loss per share, basic and diluted	$	(0.19	)	$	(13.11	)	$	(9.30	)	$	(3.97	)
Weighted-average shares of common stock outstanding, basic and diluted		6,585,503			6,694,682			7,326,090			24,706,661

	2018 Quarter Ended
	March 31,			June 30,			September 30,			December 31,
	(unaudited)
Operating expenses:
Research and development	$	—		$	—		$	6		$	14
General and administrative		251			255			262			437
Total operating expenses		251			255			268			451
Loss from operations		(251	)		(255	)		(268	)		(451	)
Total other income (expense)		(3	)		(5	)		(22	)		(33	)
Net loss	$	(254	)	$	(260	)	$	(290	)	$	(484	)
Net loss per share, basic and diluted	$	(0.07	)	$	(0.04	)	$	(0.04	)	$	(0.07	)
Weighted-average shares of common stock outstanding, basic and diluted		3,886,328			6,760,334			6,760,334			6,760,334

Organization, Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)			4 Months Ended	12 Months Ended		24 Months Ended
	Oct. 29, 2019 USD ($) shares	Oct. 11, 2019 shares	May 06, 2019 shares	Dec. 31, 2019 USD ($) Segment shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) shares	May 07, 2019 USD ($)
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Proceeds from Initial Public Offering (IPO)				$ 191,472,000
Description of forward stock split		2.168-for-1			1,559.1183-for-1
Forward stock split conversion ratio		2.168			1,559.1183
Common stock, authorized shares \| shares		50,000,000		400,000,000		400,000,000
Fair value liabilities, level 1 to level 2 transfers, amount				$ 0	$ 0	$ 0
Fair value liabilities, level 2 to level 1 transfers, amount				0	0	0
Fair value liability, transfers into level 3				0	0
Fair value liability, transfers out of level 3				$ 0	$ 0
Expected dividend yield				0.00%
Impairment losses				$ 0
Number of operating segment \| Segment				1
Operating lease right-of-use assets				$ 933,000		933,000
Lease liabilities				$ 796,000		796,000
Unvested Shares
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Weighted-average unvested shares \| shares				3,593,034	0
Furniture and Fixtures
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Property and equipment, useful life				3 years
Minimum \| Computer Equipment and Related Software
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Property and equipment, useful life				2 years
Maximum \| Computer Equipment and Related Software
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Property and equipment, useful life				3 years
Frazier Notes
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Fair value of convertible notes					$ 2,000,000
May 2019 Notes
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Fair value of convertible notes							$ 2,400,000
Lender Warrants
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Fair value of warrants				$ 400,000		400,000
Takeda Warrant
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Common stock, authorized shares \| shares		50,000,000
Shares of common stock included in calculation of basic weighted-average common shares \| shares				7,588,000
Fair Value, Recurring
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Financial assets fair value disclosure				$ 0		0
Fair Value, Nonrecurring
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Non-financial assets fair value disclosure				0		0
Non-financial liabilities fair value disclosure				$ 0		$ 0
YamadaCo
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Merger of entities under common control into the Company, shares \| shares					6,760,334
Common Stock
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Common stock shares issued \| shares			2,524,852		1,000
Purchase price \| $ / shares					$ 1.00
Convertible securities converted into shares of common stock \| shares				6,107,918
Merger of entities under common control into the Company, shares \| shares				6,760,334
Common Stock \| May 2019 Notes
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Convertible securities converted into shares of common stock \| shares				6,107,918
Common Stock \| YamadaCo
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Convertible securities converted into shares of common stock \| shares					1,559.1183
IPO \| Common Stock
Organization Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Common stock shares issued \| shares	10,997,630			10,997,630		10,997,630
Proceeds from Initial Public Offering (IPO)	$ 191,500,000					$ 191,500,000

Organization, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities measured at fair value	$ 413
Warrant Liabilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities measured at fair value	413
Convertible Promissory Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities measured at fair value		$ 1,950
Significant Unobservable Inputs (Level 3)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities measured at fair value	413
Significant Unobservable Inputs (Level 3) \| Warrant Liabilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities measured at fair value	$ 413
Significant Unobservable Inputs (Level 3) \| Convertible Promissory Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities measured at fair value		$ 1,950

Organization, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Adjustment of Carrying Value to Their Estimated Fair Value (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Oct. 29, 2019 USD ($)	Oct. 11, 2019 USD ($)	May 07, 2019 USD ($)
Takeda and Lender Warrants
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of warrant liabilities			$ 144,172	$ 47,894
Conversion date	Oct. 11, 2019
Takeda Warrants \| Income Approach \| Discount Rate
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities, measurement input	7.5
Takeda Warrants \| Minimum \| Financing Transactions
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities, measurement input	9.33
Warrant liabilities, measurement input [Extensible List]	us-gaap:MeasurementInputExercisePriceMember
Takeda Warrants \| Minimum \| Income Approach \| Expected Term
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities, term	1 month 2 days
Takeda Warrants \| Maximum \| Financing Transactions
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities, measurement input	19.00
Warrant liabilities, measurement input [Extensible List]	us-gaap:MeasurementInputExercisePriceMember
Takeda Warrants \| Maximum \| Income Approach \| Expected Term
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities, term	1 year 9 months 7 days
May 2019 Notes
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of convertible promissory notes		$ 139,847		$ 90,250
Conversion date	Oct. 29, 2019
May 2019 Notes \| Income Approach \| Volatility
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible promissory notes, measurement input	65
May 2019 Notes \| Minimum \| Financing Transactions
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible promissory notes, term	1 month 2 days
Convertible promissory notes, measurement input [Extensible List]	us-gaap:MeasurementInputExpectedTermMember
May 2019 Notes \| Minimum \| Income Approach \| Discount Rate
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible promissory notes, measurement input	22.6
May 2019 Notes \| Maximum \| Financing Transactions
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible promissory notes, term	1 year 9 months 7 days
Convertible promissory notes, measurement input [Extensible List]	us-gaap:MeasurementInputExpectedTermMember
May 2019 Notes \| Maximum \| Income Approach \| Discount Rate
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible promissory notes, measurement input	25

Organization, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Adjustment of Carrying Value to Their Estimated Fair Value (Parenthetical) (Details)	May 07, 2019
Takeda Warrants \| Financing Transactions
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value method, valuation processes percentage	40.00%
Takeda Warrants \| Income Approach
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value method, valuation processes percentage	60.00%
May 2019 Notes \| Financing Transactions
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value method, valuation processes percentage	40.00%
May 2019 Notes \| Income Approach
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value method, valuation processes percentage	60.00%

Organization, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Reconciliation of Liabilities Measured at Fair Value (Details) - Significant Unobservable Inputs (Level 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Warrant Liabilities
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Issuance of warrants	$ 48,313
Change in fair value	96,272
Reclass Takeda Warrant into equity (Note 4)	(144,172)
Ending Balance	413
Convertible Promissory Notes
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning Balance	1,950
Issuance of convertible promissory notes	90,750	$ 1,900
Exchange of convertible promissory notes (Note 5)	(2,399)
Change in fair value	49,546	50
Conversion of May 2019 Notes into commonshares upon IPO (Note 5)	$ (139,847)
Ending Balance		$ 1,950

Organization, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details)	12 Months Ended
	Dec. 31, 2019 shares
Warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share	16,446
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share	1,400,528
Shares Subject to Repurchase
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share	3,593,034

Balance Sheet Details - Schedule of Property, Plant and Equipment, net (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 471
Less: accumulated depreciation	(8)
Total property, plant and equipment, net	463
Computer Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	152
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	306
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 13

Balance Sheet Details - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 8,000	$ 0
Disposal of property, plant or equipment	$ 0

Balance Sheet Details - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued Liabilities Current [Abstract]
Accrued R&D expenses	$ 384
Accrued compensation expenses	1,052	$ 76
Accrued professional & consulting expenses	478	94
Accrued other	405
Total accrued expenses	$ 2,319	$ 170

Related Party Transactions - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Frazier
Related Party Transaction [Line Items]
Outstanding accounts payable and accrued expenses	$ 100,000	$ 45,000
Shared operating expenses	400,000	300,000
PCI Pharma Services \| Clinical Manufacturing Services
Related Party Transaction [Line Items]
Outstanding accounts payable and accrued expenses	300,000
Expense related to services	1,100,000
Mountain Field LLC
Related Party Transaction [Line Items]
Outstanding accounts receivable	0	19,000
Shared operating expenses	100,000	$ 4,000
Takeda \| Takeda License
Related Party Transaction [Line Items]
Outstanding accounts payable and accrued expenses	100,000
Expense related to services	$ 100,000

Commitments and Contingencies - Additional Information (Details) - USD ($)			12 Months Ended
	Oct. 11, 2019	May 07, 2019	Dec. 31, 2019
Commitments And Contingencies [Line Items]
Common stock fair value			$ 2,000
Common stock, shares issued			28,964,506
Common stock, authorized shares	50,000,000		400,000,000
Full balance of Takeda warrant liabilities at fair value			$ 96,272,000
Acquired in-process research and development			$ 78,897,000
Takeda License \| Takeda
Commitments And Contingencies [Line Items]
License agreement description			The agreement will remain in effect, on a country-by-country and product-by-product basis, until the later of (i) the expiration of the last to expire valid patent claim covering vonoprazan alone or in combination with at least one other therapeutically active ingredient, (ii) the expiration of the applicable regulatory exclusivity and (iii) 15 years from the date of first commercial sale, unless earlier terminated. The Company may terminate the Takeda License upon six months’ written notice. The Company and Takeda may terminate the Takeda License in the case of the other party’s insolvency or material uncured breach. Takeda may terminate the Takeda License if the Company challenges, or assists in challenging, licensed patents.
Agreement expiration term from date of first commercial sale		15 years
Cash consideration paid for license		$ 25,000,000
Common stock fair value		$ 5,900,000
Common stock, shares issued		1,084,000
Warrants exercise price		$ 0.00004613
Initial fair value of warrants		$ 47,900,000
Additional warrant issued		0
Maximum amount payable in sales milestones upon achievement of specified levels of product sales		$ 250,000,000
Transaction costs		$ 100,000
Warrants expiration date		May 07, 2029
Full balance of Takeda warrant liabilities at fair value	$ 144,200,000
Acquired in-process research and development		$ 78,900,000
Takeda License \| Takeda \| Common Stock
Commitments And Contingencies [Line Items]
Warrants issued to purchase shares		7,588,000

Convertible Promissory Notes - Additional Information (Details) - USD ($)			1 Months Ended	12 Months Ended
	Oct. 29, 2019	May 07, 2019	Apr. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Frazier Convertible Note Financing
Debt Instrument [Line Items]
Aggregate amount of debt instrument			$ 2,400,000
Debt instrument issued, amount			$ 500,000		$ 1,900,000
Interest expense				$ 15,000	13,000
Frazier Convertible Note Financing \| Other Income (Expense)
Debt Instrument [Line Items]
Increases (decreases) in fair value of debt instrument				(50,000)	$ 50,000
Frazier Convertible Note Financing \| Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate percentage			1.68%
Frazier Convertible Note Financing \| Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate percentage			2.55%
May 2019 Convertible Note Financing
Debt Instrument [Line Items]
Aggregate amount of debt instrument		$ 90,300,000
Debt instrument, interest rate percentage		6.00%
Fair value of convertible promissory notes		$ 2,400,000
Interest expense				2,600,000
Proceeds from issuance of unsecured debt		87,800,000
Non-cash charge related to final fair value adjustment of convertible promissory notes payable	$ 44,600,000
May 2019 Convertible Note Financing \| Common Stock
Debt Instrument [Line Items]
Debt instrument conversion, shares issued	6,107,918
May 2019 Convertible Note Financing \| Frazier
Debt Instrument [Line Items]
Debt instrument purchased amount		$ 20,000,000
May 2019 Convertible Note Financing \| Other Income (Expense)
Debt Instrument [Line Items]
Increases (decreases) in fair value of debt instrument				$ 49,500,000

Leases Commitments - Additional Information (Details)	1 Months Ended			12 Months Ended
Leases Commitments - Additional Information (Details)	Dec. 31, 2019 USD ($) ft² Option	Oct. 31, 2019	Aug. 31, 2019 ft² Option	Dec. 31, 2019 USD ($) ft²
Lessee Lease Description [Line Items]
Future minimum lease payment obligations	$ 960,000			$ 960,000
Buffalo Grove, Illinois
Lessee Lease Description [Line Items]
Operating lease, term of contract			65 months
Operating lease rentable square feet \| ft²			10,043
Operating lease number of option to extend \| Option			1
Operating lease, option to extend description				The lease contains an option to extend the term for one additional five-year period
Lessee, operating lease, existence of option to terminate				true
Operating lease, renewal term			5 years
Operating lease, commencement date		2019-10
Operating lease, monthly rent increasing in every 12 month, percentage		3.00%
Operating leases, rent expense				$ 51,000
Florham Park, New Jersey
Lessee Lease Description [Line Items]
Operating lease, term of contract	62 months			62 months
Operating lease rentable square feet \| ft²	9,420			9,420
Operating lease number of option to extend \| Option	1
Operating lease, option to extend description				The lease contains an option to extend the term for one additional five-year period
Lessee, operating lease, existence of option to terminate				true
Operating lease, renewal term	5 years			5 years
Future minimum lease payment obligations	$ 1,700,000			$ 1,700,000

Leases Commitments - Summary of Supplemental Balance Sheet Information Related to Leases (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Assets:
Operating lease right-of-use assets	$ 933
Liabilities:
Operating lease liabilities, current	161
Operating lease liabilities, non-current	635
Total operating lease liabilities	$ 796

Leases Commitments - Summary of Future Annual Minimum Lease Payments Under Operating Lease (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Leases [Abstract]
2020	$ 166
2021	171
2022	176
2023	181
2024	186
Thereafter	80
Total minimum lease payments	960
Less: amount representing interest	(164)
Total operating lease liabilities	796
Less: operating lease liabilities, current	(161)
Operating lease liabilities	$ 635
Weighted-average remaining lease term (in years)	5 years 3 months 29 days
Weighted-average incremental borrowing rate	7.25%

Leases Commitments - Summary of Lease Costs, Cash Payments, and Operating Lease Liabilities Arising from Obtaining Right-of-use Assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Lease Cost [Abstract]
Total operating lease expense	$ 51
Supplemental non-cash information:
Operating lease liabilities arising from obtaining right-of-use assets	$ 796

Long-Term Debt - Schedule of Long-Term Debt (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Debt Disclosure [Abstract]
Long-term debt	$ 25,000
Unamortized debt discount	(2,223)
Long-term debt, net of debt discount	$ 22,777

Long-Term Debt - Additional Information (Details) - USD ($)		9 Months Ended	12 Months Ended
	May 14, 2019	Dec. 31, 2019	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt		$ 25,000,000	$ 25,000,000
Loan Agreement
Debt Instrument [Line Items]
Interest bearing rate upon customary events	4.00%
Warrants exercisable shares of common stock	16,446
Warrants expire term	10 years
Warrants earlier termination date	Dec. 31, 2020
Aggregate repurchase price of warrants	$ 500,000
Fair value of warrant liabilities	400,000
Interest expense			$ 1,600,000
Term Loans
Debt Instrument [Line Items]
Aggregate amount of debt instrument	25,000,000
Debt instrument, additional borrowing capacity amount	$ 25,000,000
Debt instrument, covenant description			Term Loan B is available through March 31, 2020, provided that (i) the Company has received at least $150.0 million of net cash proceeds in connection with the issuance and sale, subsequent to April 1, 2019, of its equity securities and subordinated debt, (ii) the Company has initiated Phase 3 clinical trials for vonoprazan, and (iii) no event of default has occurred.
Debt instrument, interest rate percentage	7.25%	6.50%	6.50%
Debt instrument, description			The monthly payments consist of interest-only through May 31, 2021 or, in the event of positive data with respect to the Company’s Phase 3 clinical trial in both indications for vonoprazan sufficient to file an NDA with the FDA, through May 31, 2022.
Debt instrument maturity date	May 01, 2024
Debt instrument, final payment fee percentage	8.25%
Debt instrument, final payment fee	$ 2,100,000	$ 2,100,000	$ 2,100,000
Debt issuance costs	$ 200,000
Long-term debt		25,000,000	25,000,000
Accrued interest		200,000	$ 200,000
Term Loans \| Prime Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.75%
Term Loans \| Minimum
Debt Instrument [Line Items]
Threshold proceeds from issuance of equity securities and subordinated debt to borrow additional debt		$ 150,000,000
Term Loans \| Maximum
Debt Instrument [Line Items]
Debt instrument, prepayment fee percentage of outstanding principal amount	2.00%

Long-Term Debt - Schedule of Future Minimum Principal and Interest Payments Under Term Loans (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Debt Disclosure [Abstract]
2020	$ 1,843
2021	6,609
2022	9,533
2023	8,920
2024	5,599
Total principal and interest payments	32,504
Less interest and final payment fee	(7,504)
Long-term debt	$ 25,000

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended				4 Months Ended	12 Months Ended		24 Months Ended
	Oct. 29, 2019	Nov. 30, 2019	Oct. 31, 2019	May 31, 2019	Mar. 31, 2019	May 06, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from issuance of common stock								$ 2
Repurchases of shares							17,560
Proceeds from Initial Public Offering (IPO)							$ 191,472
Stock options, granted							1,400,528
Common stock initially reserved for issuance							11,974,974		11,974,974
Expected dividend yield							0.00%
Unrecognized stock-based compensation expense							$ 6,800		$ 6,800
Unrecognized stock-based compensation expense, weighted-average period for recognition							3 years 9 months
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock initially reserved for issuance							1,400,528		1,400,528
Expected dividend yield							0.00%
Existing Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares authorized for issuance							2,231,739		2,231,739
Number of shares available for issuance							0		0
Stock options, granted							1,400,528
Annual increase to shares available for issuance percentage of outstanding common stock			5.00%
Equity plan, description			The number of shares initially available for issuance will be increased by (i) the number of shares subject to stock options or similar awards granted under the Existing Incentive Plan that expire or otherwise terminate without having been exercised in full after the effective date of the 2019 Plan and unvested shares issued pursuant to awards granted under the Existing Incentive Plan that are forfeited to or repurchased by the Company after the effective date of the 2019 Plan, with the maximum number of shares to be added to the 2019 Plan pursuant to clause (i) above equal to 1,416,788 shares, and (ii) an annual increase on January 1 of each calendar year beginning in 2020 and ending in 2029, equal to the lesser of (a) 5% of the shares of common stock outstanding on the final day of the immediately preceding calendar year and (b) such smaller number of shares as determined by the board of directors.
Common stock initially reserved for issuance							2,700,000		2,700,000
Existing Incentive Plan \| Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock awards, granted							16,260
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual increase to shares available for issuance percentage of outstanding common stock			1.00%
Equity plan, description			In addition, the number of shares available for issuance under the ESPP will be annually increased on January 1 of each calendar year beginning in 2020 and ending in 2029, by an amount equal to the lesser of: (i) 1% of the shares outstanding on the final day of the immediately preceding calendar year and (ii) such smaller number of shares as is determined by the board of directors.
Common stock initially reserved for issuance			270,000				270,000		270,000
Employee and Nonemployee Director
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Estimated weighted-average fair value							$ 5.12
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued						2,524,852		1,000
Number of shares authorized to repurchase					3,373,408
Stock repurchase program, number of shares right lapse					843,352
Remaining number of shares to be repurchased					2,530,056
Stock repurchase program, period in force					48 months
Stock repurchase program expiration date					Mar. 31, 2023
Proceeds from issuance of common stock						$ 1,000
Repurchase right lapse each month after first anniversary, shares						0.000208
Repurchases of shares		17,560
Shares aggregate repurchase price		$ 5.20
Common Stock \| Existing Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares authorized for issuance							2,700,000		2,700,000
Additional number of shares available for issuance			1,416,788
Common Stock \| Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum percentage of eligible compensation contributed by participants			20.00%
Common Stock \| IPO
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued	10,997,630						10,997,630		10,997,630
Common stock, price per share	$ 19.00
Proceeds from Initial Public Offering (IPO)	$ 191,500								$ 191,500
Common Stock \| Underwriters
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued	1,434,473
Common Stock \| Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining number of shares to be repurchased							2,177,861		2,177,861
Common Stock \| First Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Repurchase right lapse rate						25.00%
Common Stock \| Takeda License
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued				1,084,000			1,084,000
Common Stock \| Founders
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining number of shares to be repurchased							2,055,684		2,055,684
Common Stock \| Frazier
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued					1,491,072

Stockholders' Equity - Summary of Unvested Shares (Details)	12 Months Ended
	Dec. 31, 2019 shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Vesting restrictions placed on previously issued shares	3,373,408
Sale of unvested common stock	2,524,852
Issuance of unvested restricted stock awards	16,260
Unvested common stock repurchased	(17,560)
Share vesting	(1,660,712)
Balance at December 31, 2019	4,236,248

Stockholders' Equity - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2019	Oct. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock reserved for future issuance (in shares)	11,974,974
Common stock warrants
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock reserved for future issuance (in shares)	7,604,446
Stock Options Outstanding
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock reserved for future issuance (in shares)	1,400,528
2019 Equity Incentive Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock reserved for future issuance (in shares)	2,700,000
ESPP Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock reserved for future issuance (in shares)	270,000	270,000

Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options Outstanding, Options granted	1,400,528
Options Outstanding, Ending Balance	1,400,528
Weighted-Average Exercise Price, Options granted	$ 9.10
Weighted-Average Exercise Price, Ending Balance	$ 9.10
Weighted-Average Remaining Contractual Term	9 years 8 months 8 days	0 years
Weighted-Average Remaining Contractual Term, Options exercisable	0 years
Aggregate Intrinsic Value, Balance	$ 30,874

Stockholders' Equity - Summary of Weighted-Average Assumptions Used to Estimate Fair Value of Stock Options Granted (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Assumptions:
Expected term (in years)	6 years 25 days	0 years
Expected volatility	60.17%
Risk free interest rate	1.58%
Expected dividend yield	0.00%

Stockholders' Equity - Summary of Stock-Based Compensation Expense (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 406
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	106
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 300

Income Taxes - Reconciliation Between Provision for Income Taxes and Income Taxes Computed Using U.S. Federal Statutory Corporate Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income taxes computed at the statutory rate	$ (53,578)	$ (271)
Permanent items	552	2
Change in fair value of warrants and convertible debt	30,622	12
Research and development credit	(697)
Change in valuation allowance	23,046	257
Other	55
Provision (benefit) for income taxes	$ 0	$ 0

Income Taxes - Components of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 6,322	$ 5
Accruals and reserves	204	16
Intangible assets	16,050	236
Other	921
Gross deferred tax assets	23,497	257
Less valuation allowance	(23,301)	$ (257)
Deferred tax assets, net of valuation allowance	196
Deferred tax liabilities:
Other	(196)
Net deferred tax assets	$ 0

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Gross unrecognized tax benefits	$ 176,000
Unrecognized tax benefits that would affect effective tax rate	0
Interest or penalties related income tax	0
Accrual for interest or penalties related to income tax	0
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards which are carried over indefinitely	30,100,000	$ 23,000
Research and development credits	$ 900,000
Research and development credits expiration period	2038

Income Taxes - Summary of Activity Related to Gross Unrecognized Tax Benefits (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Income Tax Disclosure [Abstract]
Increases related to current year tax positions	$ 176
Ending balance	$ 176

Schedule of Quarterly Financial Information (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Operating expenses:
Research and development	$ 12,704	$ 4,469	$ 2,772	$ 429	$ 14	$ 6			$ 20,374	$ 20
In-process research and development			78,897						78,897
General and administrative	2,989	1,813	1,345	797	437	262	$ 255	$ 251	6,944	1,205
Total operating expenses	15,693	6,282	83,014	1,226	451	268	255	251	106,215	1,225
Loss from operations	(15,693)	(6,282)	(83,014)	(1,226)	(451)	(268)	(255)	(251)	(106,215)	(1,225)
Total other income (expense)	(82,313)	(61,830)	(4,748)	(25)	(33)	(22)	(5)	(3)	(148,916)	(63)
Net loss	$ (98,006)	$ (68,112)	$ (87,762)	$ (1,251)	$ (484)	$ (290)	$ (260)	$ (254)	$ (255,131)	$ (1,288)
Net loss per share, basic and diluted	$ (3.97)	$ (9.30)	$ (13.11)	$ (0.19)	$ (0.07)	$ (0.04)	$ (0.04)	$ (0.07)	$ (22.45)	$ (0.21)
Weighted-average shares of common stock outstanding, basic and diluted	24,706,661	7,326,090	6,694,682	6,585,503	6,760,334	6,760,334	6,760,334	3,886,328	11,366,916	6,051,675

Subsequent Events - Additional Information (Details) - USD ($) $ in Millions		12 Months Ended
	May 14, 2019	Dec. 31, 2019	Mar. 17, 2020
Term Loans
Subsequent Event [Line Items]
Debt instrument, description		The monthly payments consist of interest-only through May 31, 2021 or, in the event of positive data with respect to the Company’s Phase 3 clinical trial in both indications for vonoprazan sufficient to file an NDA with the FDA, through May 31, 2022.
Debt instrument maturity date	May 01, 2024
Aggregate amount of debt instrument	$ 25.0
Term Loans \| Amendment
Subsequent Event [Line Items]
Debt instrument, description		Pursuant to the Amendment, the interest-only payment period, which ends on May 31, 2021, will be extended either (i) until December 31, 2021, if the Company receives positive data from its Phase 3 clinical trial in H. pylori infection sufficient to file an NDA with the FDA; or (ii) until November 30, 2022, if the Company receives positive data from its Phase 3 clinical trials in both indications for vonoprazan sufficient to file an NDA with the FDA; provided, in each case, that the Company has drawn down Term Loan B.
Term Loan B \| Subsequent Event
Subsequent Event [Line Items]
Aggregate amount of debt instrument			$ 25.0