Phathom Pharmaceuticals (PHAT) 10-Q 11 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 06, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Entity Registrant Name	PHATHOM PHARMACEUTICALS, INC.
Entity Central Index Key	0001783183
Entity Tax Identification Number	82-4151574
Entity Current Reporting Status	Yes
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		31,329,613
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	PHAT
Security Exchange Name	NASDAQ

Balance Sheets (Unaudited)

Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 237,974	$ 287,496
Prepaid expenses and other current assets (including related party amounts of $0 and $82, respectively)	4,836	3,872
Total current assets	242,810	291,368
Property, plant and equipment, net	907	986
Operating lease right-of-use assets	2,261	2,373
Other long-term assets	385	384
Total assets	246,363	295,111
Current liabilities:
Accounts payable (including related party amounts of $335 and $173, respectively)	10,857	16,782
Accrued clinical trial expenses	10,868	19,997
Accrued expenses (including related party amounts of $1,000 and $734, respectively)	6,566	10,606
Accrued interest	312	312
Current portion of long-term debt	11,765	7,353
Operating lease liabilities, current	477	474
Total current liabilities	40,845	55,524
Long-term debt, net of discount	35,587	39,634
Operating lease liabilities	1,467	1,557
Other long-term liabilities	4,125	4,125
Total liabilities	82,024	100,840
Commitments and contingencies (Note 4)
Stockholders’ equity:
Preferred stock, $0.0001 par value; authorized shares — 40,000,000 at March 31, 2021 and December 31, 2020 ; no shares issued and outstanding at March 31, 2021 and December 31, 2020
Common stock, $0.0001 par value; authorized shares — 400,000,000; issued shares — 31,321,613 and 31,262,769 at March 31, 2021 and December 31, 2020, respectively; outstanding shares — 28,876,510 and 28,516,010 at March 31, 2021 and December 31, 2020, respectively	3	3
Additional paid-in capital	584,666	579,755
Accumulated deficit	(420,330)	(385,487)
Total stockholders’ equity	164,339	194,271
Total liabilities and stockholders’ equity	$ 246,363	$ 295,111

Balance Sheets (Unaudited) (Par

Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Prepaid expenses and other current assets, related parties	$ 0	$ 82
Accounts payable, related parties	335	173
Accrued expenses, related parties	$ 1,000	$ 734
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, authorized shares	40,000,000	40,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, authorized shares	400,000,000	400,000,000
Common stock, issued shares	31,321,613	31,262,769
Common stock, outstanding shares	28,876,510	28,516,010

Statements of Operations and Co

Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating expenses:
Research and development (includes related party amounts of $939 and $404 respectively)	$ 20,580	$ 15,865
General and administrative (includes related party amounts of $16 and $43, respectively)	13,004	4,510
Total operating expenses	33,584	20,375
Loss from operations	(33,584)	(20,375)
Other income (expense):
Interest income	14	878
Interest expense	(1,272)	(738)
Change in fair value of warrant liabilities	0	95
Other income (expense)	(1)	(1)
Total other income (expense)	(1,259)	234
Net loss and comprehensive loss	$ (34,843)	$ (20,141)
Net loss per share, basic and diluted	$ (0.96)	$ (0.62)
Weighted-average shares of common stock outstanding, basic and diluted	36,298,968	32,470,402

Statements of Operations and _2

Statements of Operations and Comprehensive Loss (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Research and development expenses, related party	$ 939	$ 404
General and administrative expenses, related party	$ 16	$ 43

Statements of Stockholders' Equ

Statements of Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2019	$ 227,955	$ 2	$ 484,372	$ (256,419)
Beginning balance, shares at Dec. 31, 2019		24,728,258
Conversion of Lender Warrants into equity	318		318
Vesting of restricted shares, shares		425,295
Stock-based compensation	563		563
Net loss	(20,141)			(20,141)
Ending balance at Mar. 31, 2020	208,695	$ 2	485,253	(276,560)
Ending balance, shares at Mar. 31, 2020		25,153,553
Beginning balance at Dec. 31, 2020	$ 194,271	$ 3	579,755	(385,487)
Beginning balance, shares at Dec. 31, 2020	28,516,010	28,516,010
Issuance of common stock from exercise of stock options	$ 412		412
Issuance of common stock from exercise of stock options, shares		36,998
401(k) matching contribution	323		323
401(k) matching contribution, shares		8,356
Vesting of restricted shares, shares		301,656
Stock-based compensation	3,818		3,818
ESPP shares issued	358		358
ESPP shares issued, shares		13,490
Net loss	(34,843)			(34,843)
Ending balance at Mar. 31, 2021	$ 164,339	$ 3	$ 584,666	$ (420,330)
Ending balance, shares at Mar. 31, 2021	28,876,510	28,876,510

Statements of Cash Flows (Unaud

Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net loss	$ (34,843)	$ (20,141)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	125	52
Stock-based compensation	3,818	563
Amortization of debt discount	364	199
Change in fair value of warrant liabilities	0	(95)
Other	357
Changes in operating assets and liabilities:
Prepaid expenses and other current assets (includes the change in related party amounts of $82, and $0, respectively)	(965)	6,680
Accounts payable and accrued expenses (includes the change in related party amounts of $428, and $289, respectively)	(9,516)	1,492
Accrued clinical trial expenses	(9,129)	0
Accrued interest		81
Operating right-of-use asset and lease liabilities	25	(48)
Other long-term assets	(1)	(200)
Net cash used in operating activities	(49,765)	(11,417)
Cash flows from investing activities
Cash paid for property, plant and equipment	(169)	(676)
Net cash used in investing activities	(169)	(676)
Cash flows from financing activities
Proceeds from issuance of common stock from exercise of stock options	412
Net proceeds from issuance of long-term debt		25,000
Net cash provided by financing activities	412	25,000
Net (decrease) increase in cash and cash equivalents	(49,522)	12,907
Cash and cash equivalents – beginning of period	287,496	243,765
Cash and cash equivalents – end of period	237,974	256,672
Supplemental disclosure of cash flow information
Interest paid	906	458
Supplemental disclosure of noncash investing and financing activities
Property and equipment purchases included in accounts payable and accrued liabilities	21	20
Final interest payment fee		2,063
Settlement of ESPP liability in common stock	358
Settlement of 401(k) liability in common stock	$ 323
Lender Warrants
Supplemental disclosure of noncash investing and financing activities
Conversion of Lender Warrants into equity		$ 318

Statements of Cash Flows (Una_2

Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Cash Flows [Abstract]
Related parties prepaid expenses and other assets current	$ 82	$ 0
Related parties accounts payable and accrued expenses	$ 428	$ 289

Organization, Basis of Presenta

Organization, Basis of Presentation and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
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. Basis of Presentation The Company’s financial statements are prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). 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. All intercompany accounts and transactions have been eliminated. Interim results may not be indicative of the results that may be expected for the full year. In the opinion of management, these unaudited financial statements include all normal and recurring adjustments considered necessary for a fair presentation of these interim unaudited financial statements. Liquidity and Capital Resources From inception to March 31, 2021, 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, preparing for and managing the Phase 3 clinical trials of vonoprazan, building a commercial organization in preparation for a potential product launch following successful development and approval, and providing other general and administrative support for these operations. 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 preparation for commercialization of vonoprazan. From inception to March 31, 2021, 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 2019 IPO. Additionally, in December 2020, the Company raised net proceeds of $88.6 million from the sale of 2,250,000 shares of common stock at a public offering price of $39.48 per share after deducting underwriting discounts and commissions, and an additional $0.2 million in offering costs. The accompanying 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). Management believes that it has sufficient working capital on hand to fund operations through at least the next twelve months from the date these financial statements were available to be issued. There can be no assurance that the Company will be successful in acquiring additional funding (if needed), 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 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 financial statements and accompanying notes. The most significant estimates in the Company’s 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 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, are classified within the Level 1 designation discussed above, while prepaid and other current assets, accounts payable, and accrued liabilities, approximate fair value due to their short maturities. Warrant liabilities and convertible promissory notes were 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. The warrant liabilities consisted of warrants (the “Lender Warrants”) issued in connection with the loan and security agreement (the “Loan Agreement”) for commercial bank debt (see Note 6). The Lender Warrants were accounted for as liabilities as they contained a holder put right under which the lenders could have required the Company to pay cash in exchange for the Lender Warrants. 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. When the Company drew down the Term Loan B under the Loan Agreement in March 2020 (see Note 6), the Lenders’ put right expired, and the Company recorded a final fair value adjustment and reclassified the Lender Warrants balance of $0.3 million to additional paid-in-capital. The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands): Warrant Liabilities Balance at December 31, 2019 413 Change in fair value (95 ) Reclassification of Lender Warrants into equity (Note 6) (318 ) Balance at March 31, 2020 $ — 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 March 31, 2021. 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 with forfeitures recognized as they occur. The Company also maintains an employee stock purchase program ("ESPP") under which it issues shares. The Company estimates the fair value of stock options and shares that will be issued under the ESPP using the Black-Scholes valuation model, which requires the use of estimates. The Company recognizes stock-based compensation cost for shares that it will issue under the ESPP on a straight-line basis over the requisite service period of the award. 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 Basic net loss per share is computed by dividing the 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 its warrant (the “Takeda Warrant”) issued to Takeda Pharmaceutical Company Limited (“Takeda”) in connection with a May 2019 license agreement (see Note 4) 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 exercisable for little consideration. For the three months ended March 31, 2021 and 2020, the Company has excluded weighted-average unvested shares of 2,582,666 and 4,082,104, respectively, from the weighted-average number of common shares outstanding. Diluted net loss per share is computed by dividing the 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 and warrants. 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 (warrants, stock options, and common shares subject to repurchase) would be antidilutive. Recently Adopted Accounting Standards In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which simplifies the accounting for income taxes. ASU 2019-12 is effective for annual reporting periods, and interim periods within those annual periods, beginning after December 15, 2020 on a prospective basis, and early adoption is permitted. The Company adopted this guidance effective January 1, 2021, and the adoption did not have a material impact on the Company's financial statements. Recently Issued Accounting Pronouncements The Company assesses the adoption impacts of recently issued accounting standards by the Financial Accounting Standards Board or other standard setting bodies on the Company's financial statements as well as material updates to previous assessments, if any, from the Company’s Annual Report on Form 10-K for the year ended December 31, 2020. There were no new material accounting standards issued in the first quarter of 2021 that impacted the Company.

Balance Sheet Details

Balance Sheet Details	3 Months Ended
	Mar. 31, 2021
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): March 31, December 31, 2021 2020 Computer equipment and software $ 560 $ 516 Furniture and fixtures 749 747 Leasehold improvements 54 54 1,363 1,317 Less: accumulated depreciation (456 ) (331 ) Total property, plant and equipment, net $ 907 $ 986 Depreciation expense for the three months ended March 31, 2021 and 2020 was approximately $125,000 and $52,000, respectively. No property, plant or equipment was disposed of during the three months ended March 31, 2021 or the year ended December 31, 2020. Accrued Expenses Accrued expenses consist of the following (in thousands): March 31, December 31, 2021 2020 Accrued research and development expenses $ 3,202 $ 4,864 Accrued compensation expenses 1,827 4,587 Accrued professional & consulting expenses 1,463 1,123 Accrued other 74 32 Total accrued expenses $ 6,566 $ 10,606

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
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. The Company has conducted operations within office space controlled by Frazier and Frazier allocated a portion of the costs associated with this office space 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 March 31, 2021 and December 31, 2020 the Company had outstanding accounts payable and accrued expenses due to Frazier in the amount of $17,000 and $35,000, respectively, related to these shared operating expenses. For the three months ended March 31, 2021 and 2020, the Company incurred $16,000 and $43,000, respectively, of shared operating expenses. In addition to the shared operating expenses, the Company issued convertible promissory notes to Frazier during 2018 and 2019. 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 March 31, 2021 and December 31, 2020, the Company had $0.9 million and $0.4 million, respectively, outstanding accounts payable and accrued expenses related to these manufacturing services. For the three months ended March 31, 2021 and 2020, the Company incurred $0.9 million and $0.4 million, respectively, of expenses related to services performed by PCI. Takeda became a common stockholder of the Company in connection with the May 2019 license agreement (see Note 4). In conjunction with this license, Takeda provides 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 March 31, 2021 and December 31, 2020, the Company had $22,000 and $22,000, respectively, in outstanding accounts payable and accrued expenses related to these supply services. The Company did not have any such expenses incurred for the three months ended March 31, 2021 and 2020 related to services performed by Takeda. On May 5, 2020, the Company entered into a Commercial Supply Agreement (the “Commercial Supply Agreement”) with Takeda, pursuant to which Takeda will supply commercial quantities of vonoprazan bulk drug product. Pursuant to the Commercial Supply Agreement, Takeda has agreed to supply the Company with and the Company has agreed to purchase from Takeda certain quantities of vonoprazan bulk drug product according to approved specifications at a fixed price per batch of bulk drug product in order to commercialize vonoprazan in accordance with the Takeda License. Unless terminated earlier, the term of the Commercial Supply Agreement extends for a period of two years from the date the Company places an order for bulk drug product for the first commercial launch of vonoprazan in any jurisdiction in the licensed territory, provided that this two-year period will expire no later than December 31, 2023. The Commercial Supply Agreement will terminate immediately upon the termination of the Takeda License in accordance with its terms. As of March 31, 2021 and December 31, 2020, the Company had $0.2 million and $0.2 million, respectively, in outstanding accounts payable and accrued expenses related to these bulk drug product costs. For the three months ended March 31, 2021, the Company incurred no expense related to the Commercial Supply Agreement. The Company has a remaining minimum purchase obligation of approximately $2.2 million related to this agreement. In connection with the Takeda License, the Company entered into a temporary services agreement (the “Temporary Services Agreement”) with Takeda on November 24, 2020. Pursuant to the Temporary Services Agreement, Takeda agreed to provide or procure the provision of services related to the ongoing clinical development of vonoprazan. The Temporary Services Agreement will terminate immediately upon termination of the Takeda License in accordance with its terms. As of March 31, 2021 and December 31, 2021, the Company had $0.2 million and $0.2 million, respectively, in outstanding accounts payable and accrued expenses related to these temporary services.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
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 fumarate 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 fumarate 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 a right to receive an additional common stock warrant (the “Takeda Warrant Right”) 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 without effect since no fair value had been allocated to it 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 became exercisable upon the consummation of the IPO. 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. Purchase Commitments In December 2020, the Company entered into a supply agreement with Sandoz pursuant to which Sandoz will supply commercial quantities of amoxicillin capsules and clarithromycin tablets, package these antibiotics with vonoprazan, and provide in finished convenience packs. The supply agreement commits the Company to a minimum purchase obligation of approximately $3.8 million in the first 24-month period following the launch of the final product. The Company has not incurred any expenses under the agreement during the three months ended March 31, 2021. 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.

Lease Commitments

Lease Commitments	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Lease Commitments	5. Lease Commitments As of March 31, 2021, the Company had operating leases for office space in both Buffalo Grove, Illinois and Florham Park, New Jersey, with remaining lease terms of 4.1 years and 4.4 years, respectively. Both operating leases contain an option to extend the term for one additional five year period, which was not considered in the determination of the right-of-use asset or lease liability as the Company did not consider it reasonably certain that it would exercise such options. The total rent expense for the three months ended March 31, 2021 and 2020 was approximately $0.2 million and $0.1 million, respectively. The following table summarizes supplemental balance sheet information related to the operating leases as of March 31, 2021 and December 31, 2020. March 31, December 31, 2021 2020 Assets: Operating lease right-of-use assets 2,261 2,373 Total right-of-use assets $ 2,261 $ 2,373 Liabilities: Operating lease liabilities, current 477 474 Operating lease liabilities, non-current 1,467 1,557 Total operating lease liabilities $ 1,944 $ 2,031 As of March 31, 2021, the future minimum annual lease payments under the operating leases were as follows (in thousands): 2021 $ 368 2022 503 2023 516 2024 529 Thereafter 342 Total minimum lease payments $ 2,258 Less: amount representing interest (314 ) Present value of operating lease liabilities 1,944 Less: operating lease liabilities, current (477 ) Operating lease liabilities $ 1,467 Weighted-average remaining lease term (in years) 4.31 Weighted-average incremental borrowing rate 7.25 % Operating cash flows for the three months ended March 31, 2021 included $0.2 million in cash payments for operating leases. Operating cash flows for the three months ended March 31, 2020 included $0.3 million in cash payments for operating leases, $0.2 million of which were prepaid lease payments.

Debt

Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Debt	6 . Debt Total debt consists of the following (in thousands): March 31, 2021 Long-term debt, current portion $ 11,765 Long-term debt, non-current portion 38,235 Unamortized debt discount (2,648 ) Total debt, net of debt discount $ 47,352 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 an additional $25.0 million (“Term Loan B”) on March 16, 2020. The Term Loans bear interest at a floating rate of the higher of the Wall Street Journal Prime rate plus 1.75% (5% at March 31, 2021) or 7.25%. Under the original Loan Agreement, the monthly payments consisted of interest-only through May 31, 2021. On March 11, 2020, the Company entered into the first amendment and on March 11, 2021, the Company entered into the second amendment (together the “Amendments”) to the Loan Agreement. Pursuant to the Amendments, the interest-only payment period was extended through July 31, 2021, and could be further extended either (i) until December 31, 2021, if the Company receives positive data from its Phase 3 clinical trial in H. pylori provided, in each case, that the Company had drawn down an additional $25.0 million, Term Loan B, pursuant to the Loan Agreement. 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 March 31, 2021, 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, which expire ten years from the date of issuance. Upon completion of the IPO in 2019, the Lender Warrants became exercisable for 16,446 shares of common stock. The Lender Warrants included a put option pursuant to which, in the event that the Company did not draw down Term Loan B on or before March 31, 2020, the warrant holders could have required that the Company repurchase the warrants for a total aggregate repurchase price of $0.5 million. Upon the Term Loan B draw in March 2020, the Lender Warrants became exercisable and the put option related to the Lender Warrants expired. Accordingly, the Company The initial $0.4 million fair value of the Lender Warrants, the $4.1 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. During the three months ended March 31, 2021 and 2020, the Company recognized $1.3 million and $0.7 million, respectively, of interest expense, including amortization of the debt discount, in connection with the Loan Agreement. As of March 31, 2021, the Company had outstanding Term Loans of $50.0 million and accrued interest of $0.3 million. Future minimum principal and interest payments under the Term Loans, including the final payment fee, as of March 31, 2021 are as follows (in thousands): Year ending December 31: 2021 $ 10,032 2022 20,187 2023 18,889 2024 11,614 Total principal and interest payments 60,722 Less interest and final payment fee (10,722 ) Total term loan borrowings $ 50,000

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stockholders' Equity	7. 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 March 31, 2021, 1,265,028 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 March 31, 2021, 1,180,075 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 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 On December 16, 2020, the Company completed an underwritten public offering, in which it sold 2,250,000 shares of its common stock at a price of $42.00 per share for total gross proceeds of $94.5 million. The net purchase price after deducting underwriting discounts and commissions was $39.48 per share, which generated net proceeds of $88.8 million. The Company incurred an additional $0.2 million of offering expenses in connection with this public offering. In November 2020 the Company entered into an Open Market Sale Agreement (the “Sales Agreement”) with Jefferies LLC (the “Sales Agent”), under which it may, from time to time, sell shares of its common stock having an aggregate offering price of up to $125.0 million through the Sales Agent (the “ATM Offering”). Pursuant to the Sales Agreement, the Company will pay the Sales Agent a commission for its services in acting as an agent in the sale of common stock in an amount equal to 3% of the gross sales price per share sold. No shares were sold under the ATM Offering as of March 31, 2021. A summary of the Company’s unvested shares is as follows: Balance at December 31, 2020 2,746,759 Share vesting (301,656 ) Balance at March 31, 2021 2,445,103 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: March 31, 2021 Common stock warrants 7,604,446 Stock options and performance-based units outstanding 4,360,544 Shares available for issuance under the 2019 Incentive Plan 2,063,814 Shares available for issuance under the ESPP Plan 858,783 Balance at March 31, 2021 14,887,587 Preferred Stock The Company is authorized to issue up to 40 million shares of preferred stock. As of March 31, 2021, and December 31, 2020, there were no shares of preferred stock issued or outstanding. 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 Incentive Award Plan (the “2019 Plan”) in October 2019, 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 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. 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. The Company initially had 2,700,000 shares of common stock available for issuance under the 2019 Plan, which was increased by 1,250,511 and Performance-based Units During 2020, the Company granted 220,000 performance-based stock units (“PSU”) whereby vesting depends upon the approval by the U.S. Food and Drug Administration ("FDA") of vonoprazan for H. pylori Number of Stock Units Weighted- Average Grant Date Fair Value Per Share Unvested balance at December 31, 2020 220,000 $ 32.48 Granted 90,050 38.54 Vested — — Forfeited — — Unvested balance at March 31, 2021 310,050 $ 34.24 As of March 31, 2021, there was approximately $11.6 million of related unrecognized compensation cost, which will begin to be recognized when vesting is probable. 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 was 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. As of March 31, 2021, 858,783 shares of common stock remain available for issuance, which includes the 13,490 shares sold to employees during the three months ended March 31, 2021 as well as the annual increases of 312,628 and 289,645 shares that were authorized on January 1, 2021and 2020 respectively. The ESPP is considered a compensatory plan, and the Company recorded related stock-based compensation of $0.1 million for the three months ended March 31, 2021. The weighted-average assumptions used to estimate the fair value of ESPP awards using the Black-Scholes option valuation model were as follows: Three Months Ended March 31, 2021 2020 Assumptions: Expected term (in years) 0.75 — Expected volatility 81.83 % 0.00 % Risk free interest rate 0.10 % — Dividend yield — — The estimated weighted-average fair value of ESPP awards during 2021 was $15.85. As of March 31, 2021, the total unrecognized compensation expense related to the ESPP was $0.3 million, which is expected to be recognized over a weighted-average period of approximately 0.6 years. 401(k) Plan The Company established a 401(k) savings plan during the year ended December 31, 2020. The Company’s contributions to the plan are discretionary. During the year ended December 31, 2020, the Company incurred $0.3 million of expense related to employer contributions, which was based on a 75% match of employees’ annual contributions. In January 2021, the Board of Directors approved the discretionary match, which was settled by contributing 8,356 shares. During the three months ended March 31, 2021, the Company incurred $0.4 million of expense related to estimated 2021 employer contribution liabilities, which was based on a 75% match of employees’ contributions during the period. 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, 2020 2,728,742 $ 21.36 9.10 $ 34,432 Options granted 1,358,750 39.06 Options exercised and shares vested (36,998 ) 11.14 Options cancelled — — Balance at March 31, 2021 4,050,494 $ 27.39 9.18 $ 43,966 Options exercisable as of March 31, 2021 457,531 $ 11.83 8.50 $ 11,774 The estimated weighted-average fair value of employee and nonemployee director stock options granted during 2021 was $23.5. As of March 31, 2021, the Company had $56.5 million of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted-average period of 3.3 years. The weighted-average assumptions used to estimate the fair value of stock options using the Black-Scholes option valuation model were as follows: Three Months Ended March 31, 2021 2020 Assumptions: Expected term (in years) 6.07 6.08 Expected volatility 67.49 % 62.63 % Risk free interest rate 0.60 % 1.19 % Dividend yield — — Stock-Based Compensation Expense Stock-based compensation expense recognized for all equity awards, including founder stock, has been reported in the statements of operations as follows (in thousands): Three Months Ended March 31, 2021 2020 Research and development expense $ 859 $ 114 General and administrative expense 2,959 449 Total $ 3,818 $ 563

Organization, Basis of Presen_2

Organization, Basis of Presentation and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The Company’s financial statements are prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). 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. All intercompany accounts and transactions have been eliminated. Interim results may not be indicative of the results that may be expected for the full year. In the opinion of management, these unaudited financial statements include all normal and recurring adjustments considered necessary for a fair presentation of these interim unaudited financial statements.
Liquidity and Capital Resources	Liquidity and Capital Resources From inception to March 31, 2021, 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, preparing for and managing the Phase 3 clinical trials of vonoprazan, building a commercial organization in preparation for a potential product launch following successful development and approval, and providing other general and administrative support for these operations. 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 preparation for commercialization of vonoprazan. From inception to March 31, 2021, 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 2019 IPO. Additionally, in December 2020, the Company raised net proceeds of $88.6 million from the sale of 2,250,000 shares of common stock at a public offering price of $39.48 per share after deducting underwriting discounts and commissions, and an additional $0.2 million in offering costs. The accompanying 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). Management believes that it has sufficient working capital on hand to fund operations through at least the next twelve months from the date these financial statements were available to be issued. There can be no assurance that the Company will be successful in acquiring additional funding (if needed), 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	Use of Estimates The preparation of the Company’s 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 financial statements and accompanying notes. The most significant estimates in the Company’s 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 Measurements	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, are classified within the Level 1 designation discussed above, while prepaid and other current assets, accounts payable, and accrued liabilities, approximate fair value due to their short maturities. Warrant liabilities and convertible promissory notes were 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. The warrant liabilities consisted of warrants (the “Lender Warrants”) issued in connection with the loan and security agreement (the “Loan Agreement”) for commercial bank debt (see Note 6). The Lender Warrants were accounted for as liabilities as they contained a holder put right under which the lenders could have required the Company to pay cash in exchange for the Lender Warrants. 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. When the Company drew down the Term Loan B under the Loan Agreement in March 2020 (see Note 6), the Lenders’ put right expired, and the Company recorded a final fair value adjustment and reclassified the Lender Warrants balance of $0.3 million to additional paid-in-capital. The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands): Warrant Liabilities Balance at December 31, 2019 413 Change in fair value (95 ) Reclassification of Lender Warrants into equity (Note 6) (318 ) Balance at March 31, 2020 $ —
Cash and Cash Equivalents	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	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, 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	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 March 31, 2021.
Leases	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	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	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 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 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 with forfeitures recognized as they occur. The Company also maintains an employee stock purchase program ("ESPP") under which it issues shares. The Company estimates the fair value of stock options and shares that will be issued under the ESPP using the Black-Scholes valuation model, which requires the use of estimates. The Company recognizes stock-based compensation cost for shares that it will issue under the ESPP on a straight-line basis over the requisite service period of the award.
Income Taxes	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 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	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	Net Loss Per Share Basic net loss per share is computed by dividing the 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 its warrant (the “Takeda Warrant”) issued to Takeda Pharmaceutical Company Limited (“Takeda”) in connection with a May 2019 license agreement (see Note 4) 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 exercisable for little consideration. For the three months ended March 31, 2021 and 2020, the Company has excluded weighted-average unvested shares of 2,582,666 and 4,082,104, respectively, from the weighted-average number of common shares outstanding. Diluted net loss per share is computed by dividing the 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 and warrants. 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 (warrants, stock options, and common shares subject to repurchase) would be antidilutive.
Recently Adopted and Issued Accounting Standards	Recently Adopted Accounting Standards In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which simplifies the accounting for income taxes. ASU 2019-12 is effective for annual reporting periods, and interim periods within those annual periods, beginning after December 15, 2020 on a prospective basis, and early adoption is permitted. The Company adopted this guidance effective January 1, 2021, and the adoption did not have a material impact on the Company's financial statements. Recently Issued Accounting Pronouncements The Company assesses the adoption impacts of recently issued accounting standards by the Financial Accounting Standards Board or other standard setting bodies on the Company's financial statements as well as material updates to previous assessments, if any, from the Company’s Annual Report on Form 10-K for the year ended December 31, 2020. There were no new material accounting standards issued in the first quarter of 2021 that impacted the Company.

Organization, Basis of Presen_3

Organization, Basis of Presentation and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
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 Balance at December 31, 2019 413 Change in fair value (95 ) Reclassification of Lender Warrants into equity (Note 6) (318 ) Balance at March 31, 2020 $ —

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	3 Months Ended
	Mar. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Schedule of Property, Plant and Equipment, Net	Property, plant and equipment, net, consist of the following (in thousands): March 31, December 31, 2021 2020 Computer equipment and software $ 560 $ 516 Furniture and fixtures 749 747 Leasehold improvements 54 54 1,363 1,317 Less: accumulated depreciation (456 ) (331 ) Total property, plant and equipment, net $ 907 $ 986
Schedule of Accrued Expenses	Accrued expenses consist of the following (in thousands): March 31, December 31, 2021 2020 Accrued research and development expenses $ 3,202 $ 4,864 Accrued compensation expenses 1,827 4,587 Accrued professional & consulting expenses 1,463 1,123 Accrued other 74 32 Total accrued expenses $ 6,566 $ 10,606

Lease Commitments (Tables)

Lease Commitments (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Summary of Supplemental Balance Sheet Information Related to the Operating Leases	The following table summarizes supplemental balance sheet information related to the operating leases as of March 31, 2021 and December 31, 2020. March 31, December 31, 2021 2020 Assets: Operating lease right-of-use assets 2,261 2,373 Total right-of-use assets $ 2,261 $ 2,373 Liabilities: Operating lease liabilities, current 477 474 Operating lease liabilities, non-current 1,467 1,557 Total operating lease liabilities $ 1,944 $ 2,031
Summary of Future Minimum Lease Payments Under Operating Leases	As of March 31, 2021, the future minimum annual lease payments under the operating leases were as follows (in thousands): 2021 $ 368 2022 503 2023 516 2024 529 Thereafter 342 Total minimum lease payments $ 2,258 Less: amount representing interest (314 ) Present value of operating lease liabilities 1,944 Less: operating lease liabilities, current (477 ) Operating lease liabilities $ 1,467 Weighted-average remaining lease term (in years) 4.31 Weighted-average incremental borrowing rate 7.25 %

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of Total Debt	Total debt consists of the following (in thousands): March 31, 2021 Long-term debt, current portion $ 11,765 Long-term debt, non-current portion 38,235 Unamortized debt discount (2,648 ) Total debt, net of debt discount $ 47,352
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 March 31, 2021 are as follows (in thousands): Year ending December 31: 2021 $ 10,032 2022 20,187 2023 18,889 2024 11,614 Total principal and interest payments 60,722 Less interest and final payment fee (10,722 ) Total term loan borrowings $ 50,000

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2021
Summary of Unvested Shares	A summary of the Company’s unvested shares is as follows: Balance at December 31, 2020 2,746,759 Share vesting (301,656 ) Balance at March 31, 2021 2,445,103
Summary of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance consists of the following: March 31, 2021 Common stock warrants 7,604,446 Stock options and performance-based units outstanding 4,360,544 Shares available for issuance under the 2019 Incentive Plan 2,063,814 Shares available for issuance under the ESPP Plan 858,783 Balance at March 31, 2021 14,887,587
Summary of PSU Activity Under the 2019 Incentive Award Plan	The following table summarizes PSU activity under the 2019 Incentive Award Plan during the three months ended March 31, 2021. Number of Stock Units Weighted- Average Grant Date Fair Value Per Share Unvested balance at December 31, 2020 220,000 $ 32.48 Granted 90,050 38.54 Vested — — Forfeited — — Unvested balance at March 31, 2021 310,050 $ 34.24
Summary of Weighted-Average Assumptions Used to Estimate Fair Value of Stock Options Granted and ESPP Awards	The weighted-average assumptions used to estimate the fair value of stock options using the Black-Scholes option valuation model were as follows: Three Months Ended March 31, 2021 2020 Assumptions: Expected term (in years) 6.07 6.08 Expected volatility 67.49 % 62.63 % Risk free interest rate 0.60 % 1.19 % Dividend yield — —
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, 2020 2,728,742 $ 21.36 9.10 $ 34,432 Options granted 1,358,750 39.06 Options exercised and shares vested (36,998 ) 11.14 Options cancelled — — Balance at March 31, 2021 4,050,494 $ 27.39 9.18 $ 43,966 Options exercisable as of March 31, 2021 457,531 $ 11.83 8.50 $ 11,774
Summary of Stock-Based Compensation Expense	Stock-based compensation expense recognized for all equity awards, including founder stock, has been reported in the statements of operations as follows (in thousands): Three Months Ended March 31, 2021 2020 Research and development expense $ 859 $ 114 General and administrative expense 2,959 449 Total $ 3,818 $ 563
Employee Stock Purchase Plan
Summary of Weighted-Average Assumptions Used to Estimate Fair Value of Stock Options Granted and ESPP Awards	The weighted-average assumptions used to estimate the fair value of ESPP awards using the Black-Scholes option valuation model were as follows: Three Months Ended March 31, 2021 2020 Assumptions: Expected term (in years) 0.75 — Expected volatility 81.83 % 0.00 % Risk free interest rate 0.10 % — Dividend yield — —

Organization, Basis of Presen_4

Organization, Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)	Dec. 16, 2020shares	Oct. 29, 2019USD ($)shares	Dec. 31, 2020USD ($)$ / sharesshares	May 31, 2019shares	Mar. 31, 2021USD ($)Segmentshares	Mar. 31, 2020USD ($)shares	May 06, 2019shares	Dec. 31, 2020USD ($)$ / shares
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
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
Conversion of Lender Warrants into equity						$ 318,000
Impairment losses					$ 0
Number of operating segment | Segment					1
Accounting Standards Update 2019-12
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, Accounting Standards Update, adopted [true false]					true
Change in accounting principle, Accounting Standards Update, Adoption date					Jan. 1, 2021
Change in accounting principle, Accounting Standards Update, Immaterial effect [true false]					true
Unvested Shares
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Weighted-average unvested shares | shares					2,582,666	4,082,104
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
Lender Warrants
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Expected cash dividend yield					0.00%
Takeda Warrant | Takeda License | Takeda
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Shares of common stock included in calculation of basic weighted-average common shares | shares					7,588,000	7,588,000
Fair Value, Recurring
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Financial assets fair value disclosure					$ 0
Fair Value, Nonrecurring
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Non-financial assets fair value disclosure					0
Non-financial liabilities fair value disclosure					$ 0
Common Stock
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Common stock shares issued | shares							2,524,852
Common Stock | Takeda License
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Common stock shares issued | shares				1,084,000
Additional Paid-in Capital
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Conversion of Lender Warrants into equity						$ 318,000
Additional Paid-in Capital | Lender Warrants
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Conversion of Lender Warrants into equity						$ 300,000
IPO | Common Stock
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Common stock shares issued | shares		10,997,630	2,250,000
Proceeds from Initial Public Offering (IPO)		$ 191,500,000
Public offering price per share | $ / shares			$ 39.48					$ 39.48
Offering costs			$ 200,000					$ 200,000
Underwritten Public Offering
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Common stock shares issued | shares	2,250,000
Proceeds from Initial Public Offering (IPO)			$ 88,600,000
Underwritten Public Offering | Common Stock
Organization Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Common stock shares issued | shares		1,434,473

Organization, Basis of Presen_5

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) - Warrant Liabilities $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning Balance	$ 413
Change in fair value	(95)
Reclassification of Lender Warrants into equity (Note 6)	$ (318)

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Property, Plant and Equipment, net (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 1,363	$ 1,317
Less: accumulated depreciation	(456)	(331)
Total property, plant and equipment, net	907	986
Computer Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	560	516
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	749	747
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 54	$ 54

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 125,000	$ 52,000
Disposal of property, plant or equipment	$ 0		$ 0

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accrued Liabilities Current [Abstract]
Accrued research and development expenses	$ 3,202	$ 4,864
Accrued compensation expenses	1,827	4,587
Accrued professional & consulting expenses	1,463	1,123
Accrued other	74	32
Total accrued expenses	$ 6,566	$ 10,606

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)	May 05, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Commercial Supply Agreement
Related Party Transaction [Line Items]
Agreement extends period for termination	2 years
Minimum purchase obligation	$ 2,200,000
Drug Product | Commercial Supply Agreement
Related Party Transaction [Line Items]
Outstanding accounts payable and accrued expenses		$ 200,000		$ 200,000
Expense related to services		0
Takeda | Temporary Services Agreement
Related Party Transaction [Line Items]
Outstanding accounts payable and accrued expenses		200,000		200,000
Frazier
Related Party Transaction [Line Items]
Outstanding accounts payable and accrued expenses		17,000		35,000
Shared operating expenses		16,000	$ 43,000
PCI Pharma Services | Clinical Manufacturing Services
Related Party Transaction [Line Items]
Outstanding accounts payable and accrued expenses		900,000		400,000
Expense related to services		900,000	400,000
Takeda | Takeda License
Related Party Transaction [Line Items]
Outstanding accounts payable and accrued expenses		22,000		$ 22,000
Expense related to services		$ 0	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	Oct. 11, 2019	May 07, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Commitments And Contingencies [Line Items]
Common stock fair value			$ 3,000		$ 3,000
Common stock, shares issued			31,321,613		31,262,769
Common stock, authorized shares	50,000,000		400,000,000		400,000,000
Fair value adjustment of warrants			$ 0	$ (95,000)
Expenses incurred related to purchase commitments			0
Minimum
Commitments And Contingencies [Line Items]
Purchase obligation in the first 24-month period			$ 3,800,000
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 fumarate 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 7, 2029
Fair value adjustment of warrants	$ 144,200,000
Takeda License | Takeda | Common Stock
Commitments And Contingencies [Line Items]
Warrants issued to purchase shares		7,588,000

Lease Commitments - Additional

Lease Commitments - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)Option	Mar. 31, 2020USD ($)
Lessee Lease Description [Line Items]
Operating leases, rent expense	$ 0.2	$ 0.1
Cash payments for operating lease costs	$ 0.2	0.3
Prepaid Lease Payments
Lessee Lease Description [Line Items]
Cash payments for operating lease costs		$ 0.2
Buffalo Grove, Illinois
Lessee Lease Description [Line Items]
Operating leases, remaining lease terms	4 years 1 month 6 days
Operating lease number of option to extend | Option	1
Operating lease, option to extend description	Both operating leases contain 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
Florham Park, New Jersey
Lessee Lease Description [Line Items]
Operating leases, remaining lease terms	4 years 4 months 24 days
Operating lease number of option to extend | Option	1
Operating lease, option to extend description	Both operating leases contain 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

Lease Commitments - Summary of

Lease Commitments - Summary of Supplemental Balance Sheet Information Related to the Operating Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets:
Operating lease right-of-use assets	$ 2,261	$ 2,373
Liabilities:
Operating lease liabilities, current	477	474
Operating lease liabilities	1,467	1,557
Total operating lease liabilities	$ 1,944	$ 2,031

Lease Commitments - Summary o_2

Lease Commitments - Summary of Future Annual Minimum Lease Payments Under Operating Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Leases [Abstract]
2021	$ 368
2022	503
2023	516
2024	529
Thereafter	342
Total minimum lease payments	2,258
Less: amount representing interest	(314)
Present value of operating lease liabilities	1,944	$ 2,031
Less: operating lease liabilities, current	(477)	(474)
Operating lease liabilities	$ 1,467	$ 1,557
Weighted-average remaining lease term (in years)	4 years 3 months 21 days
Weighted-average incremental borrowing rate	7.25%

Debt - Schedule of Total Debt (

Debt - Schedule of Total Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Long-term debt, current portion	$ 11,765	$ 7,353
Long-term debt, non-current portion	38,235
Unamortized debt discount	(2,648)
Total debt, net of debt discount	$ 47,352

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($) $ in Thousands	May 14, 2019	Mar. 31, 2021	Mar. 31, 2020	Mar. 16, 2020	Mar. 11, 2020
Debt Instrument [Line Items]
Long-term debt outstanding		$ 50,000
Loan Agreement
Debt Instrument [Line Items]
Interest bearing rate upon customary events	4.00%
Warrants expire term	10 years
Warrants exercisable shares of common stock	16,446
Aggregate repurchase price of warrants	$ 500
Adjustments to additional paid-in-capital, warrants issued		300
Fair value of warrant liabilities	$ 400
Interest expense		$ 1,300	$ 700
Term Loans
Debt Instrument [Line Items]
Debt instrument, additional borrowing capacity amount				$ 25,000	$ 25,000
Debt instrument, interest rate percentage	7.25%	5.00%
Debt instrument, description		Under the original Loan Agreement, the monthly payments consisted of interest-only through May 31, 2021. On March 11, 2020, the Company entered into the first amendment and on March 11, 2021, the Company entered into the second amendment (together the “Amendments”) to the Loan Agreement. Pursuant to the Amendments, the interest-only payment period was extended through July 31, 2021, and could be further 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 a New Drug Application (“NDA”) with the U.S. Food and Drug Administration (“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;
Aggregate amount of debt instrument	$ 25,000
Debt instrument, maturity date	May 1, 2024
Debt instrument, final payment fee percentage	8.25%
Debt instrument, final payment fee		$ 4,100
Debt issuance costs	$ 200
Long-term debt outstanding		50,000
Accrued interest		$ 300
Term Loans | Maximum
Debt Instrument [Line Items]
Debt instrument, prepayment fee percentage of outstanding principal amount	2.00%
Term Loans | Prime Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.75%

Debt - Schedule of Future Minim

Debt - Schedule of Future Minimum Principal and Interest Payments Under Term Loans (Details) $ in Thousands	Mar. 31, 2021USD ($)
Debt Disclosure [Abstract]
2021	$ 10,032
2022	20,187
2023	18,889
2024	11,614
Total principal and interest payments	60,722
Less interest and final payment fee	(10,722)
Total term loan borrowings	$ 50,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)

Dec. 16, 2020

Oct. 29, 2019

Jan. 31, 2021

Dec. 31, 2020

Nov. 30, 2020

Nov. 30, 2019

Oct. 31, 2019

May 31, 2019

Mar. 31, 2019

Mar. 31, 2021

Mar. 31, 2020

May 06, 2019

Dec. 31, 2020

Dec. 31, 2019

Jan. 01, 2021

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Preferred stock, shares authorized

40,000,000

40,000,000

40,000,000

Preferred stock, shares issued

0

0

0

Preferred stock, shares outstanding

0

0

0

Stock options, granted

1,358,750

Stock-based compensation cost

$ 3,818,000

$ 563,000

Common stock initially reserved for issuance

14,887,587

Unrecognized stock-based compensation expense

$ 56,500,000

Unrecognized stock-based compensation expense, weighted-average period for recognition

3 years 3 months 18 days

Defined contribution plan employer contribution expense

$ 300,000

Defined contribution plan liability

$ 400,000

Defined contribution plan, employer matching contribution, percentage

75.00%

75.00%

Employer discretionary match number of shares settled

8,356

Dividend yield

0.00%

Stock Options

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Dividend yield

0.00%

2019 Equity Incentive Plan

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Common stock, shares authorized for issuance

2,231,739

Stock options, granted

1,400,528

Number of shares available for issuance

0

2019 Equity Incentive Plan | Restricted Stock

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Stock awards, granted

16,260

2019 Incentive Award Plan

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Common stock, shares authorized for issuance

1,158,580

1,158,580

Stock options, granted

1,358,750

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. The Company initially had 2,700,000 shares of common stock available for issuance under the 2019 Plan, which was increased by 1,250,511 and 1,158,580 shares that were authorized on January 1, 2021 and 2020 respectively. During the three months ended March 31, 2021, 1,358,750 stock options and 90,050 performance-based units were granted.

Number of shares remain available for issuance, annual increase

1,250,511

Common stock initially reserved for issuance

2,063,814

2019 Incentive Award Plan | Performance-Based Stock Units (PSU)

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Stock awards, granted

90,050

90,050

220,000

Stock-based compensation cost

$ 0

Unrecognized stock-based compensation expense

$ 11,600,000

Employee Stock Purchase Plan

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Common stock, shares authorized for issuance

289,645

289,645

Number of shares available for issuance

858,783

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. As of March 31, 2021, 858,783 shares of common stock remain available for issuance, which includes the 13,490 shares sold to employees during the three months ended March 31, 2021 as well as the annual increases of 312,628 and 289,645 shares that were authorized on January 1, 2021and 2020 respectively.

Number of shares remain available for issuance, annual increase

312,628

Stock-based compensation cost

$ 100,000

Common stock initially reserved for issuance

270,000

858,783

Number of shares issued

13,490

Estimated weighted-average fair value

$ 15.85

Unrecognized stock-based compensation expense

$ 300,000

Unrecognized stock-based compensation expense, weighted-average period for recognition

7 months 6 days

Dividend yield

0.00%

Underwritten Public Offering

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Shares issued

2,250,000

Common stock, price per share

$ 42

Proceeds from Initial Public Offering (IPO)

$ 88,600,000

Proceeds from issuance initial public offering gross

$ 94,500,000

Purchase price per share after deducting underwriting discounts and commissions

$ 39.48

Net proceeds after deducting underwriters commission

$ 88,800,000

Purchase of additional offering expenses

$ 200,000

At-the-Market Offering Program

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Shares issued

0

Employee and Nonemployee Director

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Estimated weighted-average fair value

$ 23.5

Open Market Sale Agreement with Jefferies LLC | At-the-Market Offering Program

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Proceeds from issuance of shares

$ 125,000,000

Percentage of gross sales price per share sold

3.00%

Common Stock

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Shares issued

2,524,852

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 shares

$ 1,000

Repurchase right lapse each month after first anniversary, shares

0.000208

Repurchases of shares

17,560

Shares aggregate repurchase price

$ 5.20

Employer discretionary match number of shares settled

8,356

Common Stock | 2019 Incentive Award Plan

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Common stock, shares authorized for issuance

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

2,250,000

Common stock, price per share

$ 19

Proceeds from Initial Public Offering (IPO)

$ 191,500,000

Common Stock | Underwritten Public Offering

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

1,180,075

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

Common Stock | Founders

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Remaining number of shares to be repurchased

1,265,028

Common Stock | Frazier

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Shares issued

1,491,072

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Unvested Shares (Details)	3 Months Ended
	Mar. 31, 2021shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Balance at December 31, 2020	2,746,759
Share vesting	(301,656)
Balance at March 31, 2021	2,445,103

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Mar. 31, 2021	Oct. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock reserved for future issuance (in shares)	14,887,587
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 and Performance-Based Units Outstanding
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock reserved for future issuance (in shares)	4,360,544
2019 Incentive Award Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock reserved for future issuance (in shares)	2,063,814
ESPP Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock reserved for future issuance (in shares)	858,783	270,000

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of PSU Activity Under the 2019 Incentive Award Plan (Details) - $ / shares	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance at December 31, 2020	2,746,759	2,746,759
Balance at March 31, 2021		2,445,103	2,746,759
2019 Incentive Award Plan | Performance-Based Stock Units (PSU)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Balance at December 31, 2020	220,000	220,000
Stock awards, granted	90,050	90,050	220,000
Balance at March 31, 2021		310,050	220,000
Weighted Average Grant Date Fair Value Per Share, Unvested Beginning Balance	$ 32.48	$ 32.48
Weighted Average Grant Date Fair Value Per Share, Granted		38.54
Weighted Average Grant Date Fair Value Per Share, Unvested Ending Balance		$ 34.24	$ 32.48

Stockholders' Equity - Summar_4

Stockholders' Equity - Summary of Weighted-Average Assumptions Used to Estimate Fair Value of Stock Options Granted and ESPP Awards (Details)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Assumptions:
Expected term (in years)	6 years 25 days	6 years 29 days
Expected volatility	67.49%	62.63%
Risk free interest rate	0.60%	1.19%
Dividend yield	0.00%
Employee Stock Purchase Plan
Assumptions:
Expected term (in years)	9 months	0 years
Expected volatility	81.83%	0.00%
Risk free interest rate	0.10%
Dividend yield	0.00%

Stockholders' Equity - Summar_5

Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2021	Sep. 30, 2020	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options Outstanding, Beginning Balance	2,728,742
Options Outstanding, Options granted	1,358,750
Options Outstanding, Options exercised and shares vested	(36,998)
Options Outstanding, Ending Balance	4,050,494		2,728,742
Options Outstanding, Options exercisable as of March 31, 2021	457,531
Weighted-Average Exercise Price, Beginning Balance	$ 21.36
Weighted-Average Exercise Price, Options granted	39.06
Weighted-Average Exercise Price, Options exercised and shares vested	11.14
Weighted-Average Exercise Price, Ending Balance	27.39		$ 21.36
Weighted-Average Exercise Price, Options exercisable as of March 31,2021	$ 11.83
Weighted-Average Remaining Contractual Term		9 years 2 months 4 days	9 years 1 month 6 days
Weighted-Average Remaining Contractual Term, Options exercisable		8 years 6 months
Aggregate Intrinsic Value, Balance	$ 43,966		$ 34,432
Aggregate Intrinsic Value, Options exercisable	$ 11,774

Stockholders' Equity - Summar_6

Stockholders' Equity - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 3,818	$ 563
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	859	114
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,959	$ 449