Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2019	May 20, 2019
Document And Entity Information Abstract
Entity Registrant Name	HOOKIPA Pharma Inc.
Entity Central Index Key	0001760542
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		21,588,756
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 70,508	$ 48,580
Accounts receivable	1,328	4,919
Prepaid expenses and other current assets	13,067	8,812
Total current assets	84,903	62,311
Non-current assets:
Property and equipment, net	4,512	4,337
Operating lease assets	8,920
Other non-current assets	3,645	1,603
Total non-current assets	17,077	5,940
Total assets	101,980	68,251
Current liabilities
Accounts payable	3,298	3,656
Deferred revenues	6,368	6,619
Accrued expenses and other current liabilities	5,428	4,420
Total current liabilities	15,094	14,695
Non-current liabilities
Loans payable, non-current	4,499	4,392
Operating lease liabilities, non-current	6,311
Deferred revenues, non-current	823	1,663
Other non-current liabilities	3,262	3,102
Total non-current liabilities	14,895	9,157
Total liabilities	29,989	23,852
Commitments and contingencies (Note 11)
Redeemable convertible preferred stock (series A, B, C and D), $0.0001 par value; 1,666,961 shares and 1,323,506 shares authorized, issued and outstanding at March 31, 2019 and December 31, 2018, respectively; aggregate liquidation preference of $137.1 million and $99.7 million at March 31, 2019 and December 31, 2018, respectively	142,048	104,774
Stockholders’ equity (deficit):
Common stock value	0	0
Additional paid-in capital	3,710	3,327
Accumulated other comprehensive loss	(4,457)	(3,720)
Accumulated deficit	(69,310)	(59,982)
Total stockholders’ equity (deficit)	(70,057)	(60,375)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	$ 101,980	$ 68,251

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Redeemable convertible preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Redeemable convertible preferred stock, authorized	1,666,961	1,323,506
Redeemable convertible preferred stock, shares issued	1,666,961	1,323,506
Redeemable convertible preferred stock, shares outstanding	1,666,961	1,323,506
Liquidation preference	$ 137.1	$ 99.7
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	25,614,706	18,454,860
Common stock, shares issued	1,006,595	1,006,595
Common stock, shares outstanding	1,006,595	1,006,595
Class A common stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	19,006,880	0
Common stock, shares issued	0	0
Common stock, shares outstanding	0	0

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
Revenue from collaboration and licensing	$ 2,235
Operating expenses:
Research and development	(10,179)	$ (4,969)
General and administrative	(2,711)	(1,480)
Total operating expenses	(12,890)	(6,449)
Loss from operations	(10,655)	(6,449)
Other income (expense):
Grant income	1,192	2,071
Interest income	64
Interest expense	(213)	(193)
Other income and expenses, net	283	22
Total other income (expense), net	1,326	1,900
Net loss before tax	(9,329)	(4,549)
Income tax expense	0	(24)
Net loss	(9,329)	(4,573)
Other comprehensive loss:
Foreign currency translation (loss) gain, net of tax	(736)	1,539
Comprehensive loss	$ (10,065)	$ (3,034)
Net loss per share—basic and diluted	$ (9.27)	$ (5.02)
Weighted average common shares outstanding — basic and diluted	1,006,595	911,777

CONDENSED CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ DEFICIT - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Convertible Preferred Stock	Total
Balance at the beginning of the period at Dec. 31, 2017					$ 104,774
Balance at the beginning of the period (in shares) at Dec. 31, 2017					1,323,506
Balance at the end of the period at Mar. 31, 2018					$ 104,774
Balance at the end of the period (in shares) at Mar. 31, 2018					1,323,506
Balance at the beginning of the period at Dec. 31, 2017	$ 0	$ 2,451	$ (1,362)	$ (43,745)		$ (42,656)
Balance at the beginning of the period (in shares) at Dec. 31, 2017	911,777
Increase (Decrease) in Stockholders' Equity
Foreign currency translation adjustment, net of tax			1,539			1,539
Stock-based compensation expense		206				206
Net loss				(4,573)		(4,573)
Balance at the end of the period at Mar. 31, 2018	$ 0	2,657	177	(48,318)		(45,484)
Balance at the end of the period (in shares) at Mar. 31, 2018	911,777
Balance at the beginning of the period at Dec. 31, 2018					$ 104,774	$ 104,774
Balance at the beginning of the period (in shares) at Dec. 31, 2018					1,323,506	1,323,506
Increase (Decrease) in Temporary Equity
Issuance of Series D preferred stock, net of issuance costs of $158					$ 37,274
Issuance of Series D preferred stock, net of issuance costs of $158 (in shares)					257,000
Balance at the end of the period at Mar. 31, 2019					$ 142,048	$ 142,048
Balance at the end of the period (in shares) at Mar. 31, 2019					1,580,506	1,666,961
Balance at the beginning of the period at Dec. 31, 2018	$ 0	3,327	(3,720)	(59,982)		$ (60,375)
Balance at the beginning of the period (in shares) at Dec. 31, 2018	1,006,595
Increase (Decrease) in Stockholders' Equity
Foreign currency translation adjustment, net of tax			(736)			(736)
Stock-based compensation expense		383				383
Net loss				(9,329)		(9,329)
Balance at the end of the period at Mar. 31, 2019	$ 0	$ 3,710	$ (4,456)	$ (69,311)		$ (70,057)
Balance at the end of the period (in shares) at Mar. 31, 2019	1,006,595

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating activities:
Net loss	$ (9,329)	$ (4,573)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	383	206
Depreciation expense	566	140
Other non-cash items	(54)	(7)
Changes in operating assets and liabilities:
Accounts receivable	3,509	(1)
Prepaid expenses and other current assets	(3,711)	(889)
Other non-current assets	(6,069)	(1)
Accounts payable	958	(622)
Deferred revenues	(935)	0
Accrued expenses and other liabilities	4,434	(483)
Net cash used in operating activities	(12,056)	(4,972)
Investing activities:
Purchases of property and equipment	(400)	(262)
Net cash used in investing activities	(400)	(262)
Financing activities:
Payments related to finance leases	(1,395)
Proceeds from issuance of redeemable convertible preferred stock	37,274	6,439
Payments of deferred offering costs	(722)
Proceeds from borrowings		440
Net cash provided by financing activities	35,157	6,879
Net decrease / increase in cash and cash equivalents	22,701	1,645
Cash and cash equivalents at beginning of period	48,580	61,362
Effect of exchange rate changes on cash and cash equivalents	(773)	1,750
Cash and cash equivalents at end of period	70,508	64,757
Supplemental disclosure of cash flow information:
Cash paid for income taxes	$ 0	$ (1)

Nature of the business and organization	3 Months Ended
Nature of the business and organization	Mar. 31, 2019
Nature of the business and organization
Nature of the business and organization	1. Nature of the business and organization HOOKIPA Pharma Inc. ("HOOKIPA" or the "Company") is a clinical stage biopharmaceutical company developing a new class of immunotherapeutics targeting infectious diseases and cancers based on its proprietary arenavirus platform that is designed to reprogram the body’s immune system. The Company was incorporated under the name of Hookipa Biotech, Inc. under the laws of the State of Delaware in February 2017 as a fully-owned subsidiary of Hookipa Biotech AG. In June 2018, the Company changed its name from Hookipa Biotech, Inc. to HOOKIPA Pharma Inc. and in order to effectuate the change of the jurisdiction of incorporation, the Company acquired all of the shares of Hookipa Biotech AG, now Hookipa Biotech GmbH. HOOKIPA is headquartered in New York, with European research and preclinical development operations headquartered in Vienna, Austria. In April 2019, the Company closed its initial public offering (“IPO”) and its shares started trading on the Nasdaq Global Select Market under the ticker symbol “HOOK”. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations, the ability to establish clinical- and commercial-scale manufacturing processes and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities and may not ultimately lead to a marketing approval and commercialization of a product. Even if the Company’s drug development efforts are successful, it is uncertain if and when the Company will realize significant revenue from product sales.

Summary of significant accounting policies

3 Months Ended

Mar. 31, 2019

Summary of significant accounting policies

Summary of significant accounting policies

2. Summary of significant accounting policies

Basis of presentation

The Company’s condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP"). The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany accounts and transactions have been eliminated in consolidation.

The accompanying condensed consolidated balance sheets as of March 31, 2019, the condensed consolidated statements of operations and comprehensive loss and of cash flows for the three months ended March 31, 2019 and 2018, and the condensed consolidated statement of redeemable convertible preferred stock and stockholders’ deficit for the three months ended March 31, 2019 are unaudited.

The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements, except for the accounting of lease agreements that have been reported in accordance with ASC 842 and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement for interim reporting. Certain information and footnote disclosures typically included in annual financial statements prepared in accordance with GAAP have been condensed or omitted. Accordingly, these unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements as of and for the year ended December 31, 2018, which are included in the Company’s prospectus related to the Company’s IPO, filed April 19, 2019 (File No. 333-230451) with the Securities and Exchange Commission ("SEC”), pursuant to Rule 424 (b) under the Securities Act of 1933, as amended. The results for any interim period are not necessarily indicative of results for any future period.

Stock split

On April 5, 2019, the Company effected a 11.643‑for-one stock split of its issued and outstanding shares of common stock. The par value of the common stock was not adjusted as a result of the split. All issued and outstanding share and per share amounts of common stock and options included in the accompanying condensed consolidated financial statements have been adjusted to reflect this stock split for all periods presented. The conversion ratios for each series of the Company’s redeemable convertible preferred stock (see Note 7) have been adjusted proportionally.

Going concern

Since inception, the Company’s activities have consisted primarily of performing research and development to advance its technologies. The Company is still in the development phase and has not been marketing its technologies to date. Through March 31, 2019, the Company has funded its operations with proceeds from sales of redeemable convertible preferred stock, collaboration and licensing agreements, grants and borrowings under various agreements with foreign public funding agencies. Since inception, the Company has incurred recurring losses, including net losses of $9.3 million and $4.6 million for the three months ended March 31, 2019 and 2018, respectively. As of March 31, 2019, the Company had an accumulated deficit of $69.3 million. The Company expects to continue to generate operating losses in the foreseeable future. As of May 20, 2019, the filing date of this Quarterly Report on Form 10‑Q, the Company expected that its cash and cash equivalents would be sufficient to fund its operating expenses, capital expenditure requirements and debt service payments through at least 12 months from the issuance date of the condensed consolidated financial statements.

The Company will seek additional funding in order to reach its development and commercialization objectives. The Company will seek funds through further equity financings, debt financings, collaborations, strategic alliances and marketing, distribution or licensing arrangements. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into collaborations or other arrangements. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects.

The accompanying condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The condensed consolidated financial statements do not reflect any adjustments relating to the recoverability and classification of assets or the amounts and classification of liabilities that might be necessary if the Company is unable to continue as a going concern.

Use of estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue, income and expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, the recognition of revenue and income, the accrual of research and development expenses, the valuation of common and preferred stock, the valuation of stock-based awards and the valuation of liabilities. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates as there are changes in circumstances, facts and experience. Actual results may differ from those estimates or assumptions.

Concentrations of credit risk and of significant suppliers

Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents and short-term bank deposits. As of December 31, 2018 and March 31, 2019, the Company’s cash and cash equivalents included substantial amounts of cash balances held in euros on accounts with European banks in excess of publicly insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships.

The Company relies, and expects to continue to rely, on a small number of vendors to manufacture supplies and raw materials for its development programs. These programs could be adversely affected by a significant interruption in these manufacturing services or the availability of raw materials.

Deferred offering costs

The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of an equity financing, these costs are recorded in stockholders’ equity as a reduction of the additional paid-in capital generated as a result of the offering. Should the in-process equity financing be abandoned, the deferred offering costs would be expensed immediately as a charge to operating expenses in the condensed consolidated statements of operations and comprehensive loss. As of March 31, 2019 and December 31, 2018, the Company recorded deferred offering costs of $2.3 million and $1.5 million, respectively, in prepaid expenses and other current assets.

Property and equipment

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful life of each asset as follows:


		Estimated useful life
Leasehold improvements (1)		5 years
Laboratory equipment		3 - 10 years
Furniture and fixtures		3 - 10 years
Computer equipment and software		3 - 4 years

(1)

In the course of the application of ASC 842, the economic useful lives of the leasehold improvements were adjusted to the lease terms.

Costs for capital assets not yet placed into service are capitalized as construction-in-progress and depreciated once placed into service. Expenditures for repairs and maintenance are charged to expense as incurred.

Redeemable convertible preferred stock

The Company has applied the guidance in ASC 480‑10‑S99‑3A, SEC Staff Announcement: Classification and Measurement of Redeemable Securities and has therefore classified the Series A, Series B, Series C and Series D redeemable convertible preferred stock as mezzanine equity. The redeemable convertible preferred stock is recorded outside of stockholders’ equity because, in the event of certain deemed liquidation events considered not solely within the Company’s control, such as a merger, acquisition and sale of all or substantially all of the Company’s assets, the convertible preferred stock will become redeemable at the option of the holders. In the event of a change of control of the Company, proceeds received from the sale of such shares will be distributed in accordance with the liquidation preferences set forth in the Company’s Preferred Stock agreements. The Company has determined not to adjust the carrying values of the redeemable convertible preferred stock to the liquidation preferences of such shares because of the uncertainty of whether or when such an event would occur.

Recent accounting pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that the Company adopts as of the specified effective date.

Adopted as of current period

In February 2016, the FASB issued ASU No. 2016‑02, Leases (Topic 842) ("ASU 2016‑02"), which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether cost of the lease is recognized based on an effective interest method or on a straight-line basis over the term of the lease. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification.

The FASB subsequently issued the following amendments to ASU 2016‑02 that have the same effective date and transition date: ASU No. 2018-01, Leases (Topic 842): Land Easement Practical Expedient for Transition to Topic 842, ASU No. 2018‑10, Codification Improvements to Topic 842, Leases, ASU No. 2018‑11, Leases (Topic 842): Targeted Improvements, ASU No. 2018‑20, Narrow-Scope Improvement for Lessors, and ASU No. 2019‑01, Leases (Topic 842): Codification Improvements. The Company adopted these amendments with ASU 2016‑02 (collectively, the new leasing standards) effective January 1, 2019. The new leasing standards were adopted using the modified retrospective transition approach, as of January 1, 2019, with no restatement of prior periods or cumulative adjustment to retained earnings. Upon adoption, the Company elected the package of transition practical expedients, which allowed the Company to carry forward prior conclusions related to whether any expired or existing contracts are or contain leases, the lease classification for any expired or existing leases and initial direct costs for existing leases. The Company also elected the practical expedient to not reassess certain land easements, elected to use hindsight in determining the lease term and made an accounting policy election to not recognize leases with an initial term of 12 months or less within the condensed consolidated balance sheets and to recognize those lease payments on a straight-line basis in the condensed consolidated statements of operations over the lease term. Upon adoption of the new leasing standards an operating lease asset of $3.3 million and a corresponding operating lease liability of $3.3 million were recorded in the condensed consolidated balance sheets. The adoption of the new leasing standards did not have an impact on the Company’s condensed consolidated statements of operations.

The determination whether an arrangement was qualified as a lease was made at contract inception. Operating lease assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease assets and liabilities are recognized at the commencement date of the lease based upon the present value of lease payments over the lease term. When determining the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain that the option will be exercised. The Company uses the implicit rate when readily determinable and uses its incremental borrowing rate when the implicit rate is not readily determinable based upon the information available at the commencement date in determining the present value of the lease payments. The incremental borrowing rate is determined using a secured borrowing rate for the same currency and term as the associated lease. The lease payments used to determine operating lease assets may include lease incentives, stated rent increases and escalation clauses linked to rates of inflation when determinable and are recognized as operating lease assets on the condensed consolidated balance sheets. In addition, certain of the Company’s arrangements contain lease and non-lease components. The Company elected to generally separate lease payments from non-lease payments but applied an accounting choice to not separate lease payments from certain non-lease payments for its office and laboratory space leases and its car leases. Operating leases are reflected in operating lease assets, in accrued expenses and other current liabilities and in non-current operating lease liabilities in the condensed consolidated balance sheets. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.

In July 2018, the FASB issued ASU No. 2018‑11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception ("ASU 2018‑11"). Part I applies to entities that issue financial instruments such as warrants, convertible debt or convertible preferred stock that contain down-round features. Part II replaces the indefinite deferral for certain mandatorily redeemable noncontrolling interests and mandatorily redeemable financial instruments of nonpublic entities contained within ASC Topic 480 with a scope exception and does not impact the accounting for these mandatorily redeemable instruments. For public entities, this guidance is required to be adopted for annual periods beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted ASU 2018‑11 as of January 1, 2019. The adoption of this ASU did not have a material impact on its consolidated loss from operations or cash flows.

Recently Issued Accounting Pronouncements

In November 2018, the FASB issued ASU 2018-18, Clarifying the Interaction Between Topic 808 and Topic 606, which clarifies when transactions between participants in a collaborative arrangement are within the scope of the FASB’s revenue standard, Topic 606. This ASU becomes effective for the Company in the year ending December 31, 2020 and early adoption is permitted. The Company is currently assessing the impact that this ASU will have on its consolidated financial statements

In August 2018, the FASB issued ASU 2018‑13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, (“ASU 2018‑13”). The new standard removes certain disclosures, modifies certain disclosures and adds additional disclosures related to fair value measurement. The new standard will be effective beginning January 1, 2020 and early adoption is permitted. The Company is currently evaluating the impact that the adoption of ASU 2018‑13 will have on its consolidated financial statements.

In August 2018, the FASB issued ASU 2018‑15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350‑40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, (“ASU 2018‑15”). The amendments in this update align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by the amendments in this update. The new standard will be effective beginning January 1, 2020 and early adoption is permitted. The amendments in this update should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Company is currently evaluating the impact that the adoption of ASU 2018‑15 will have on its consolidated financial statements.

In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments-Credit Losses.” The standard modifies the impairment model for most financial assets, including trade accounts receivables and loans, and will require the use of an “expected loss” model for instruments measured at amortized cost. Under this model, entities will be required to estimate the lifetime expected credit loss on such instruments and record an allowance to offset the amortized cost basis of the financial asset, resulting in a net presentation of the amount expected to be collected on the financial asset. The effective date of the standard is for fiscal years beginning after December 15, 2019 with early adoption permitted. We are currently evaluating the potential impact of the adoption of this update on our consolidated financial statements.

Collaboration and Licensing Agreements	3 Months Ended
Collaboration and Licensing Agreements	Mar. 31, 2019
Collaboration and Licensing Agreements
Collaboration and Licensing Agreements	3. Collaboration and Licensing Agreements Gilead Collaboration and License Agreement In June 2018, the Company has entered into a collaboration and license agreement (the “Gilead Agreement”) with Gilead Sciences, Inc. (“Gilead”) whereby the parties agreed to collaborate with respect to two preclinical research programs to evaluate potential vaccine products for the treatment, cure, diagnosis or prevention of the hepatitis B virus (HBV) and the human immunodeficiency virus (HIV). Under the Gilead Agreement, the Company granted Gilead an exclusive, royalty-bearing license to the Company’s technology platforms. In June 2018, the Company has received a non-refundable $10.0 million upfront payment from Gilead of which $0.9 million was recorded as revenue from collaboration and licensing in the three months ended March 31, 2019 and $6.1 million was included as a liability in deferred revenues, current and non-current, as of March 31, 2019. Approximately 91% of the upfront payment included in deferred revenue as of March 31, 2019 is expected to be recognized in the remainder of 2019, and the remaining 9% in 2020. Gilead is also obligated to make additional payments to the Company upon the achievement of pre-clinical, development and commercial milestones. The development milestones amount to a total of $280 million. The commercial milestones amount to a total of $100 million. Additionally, Gilead is obligated to pay royalties on net sales for each program. All payments from Gilead have a 60 days payment term. In addition to the $0.9 million recognition of the upfront payment, the Company recognized $1.3 million revenue from cost reimbursements for research and development services in the three months ended March 31, 2019. Sublicense fees payable to certain licensors of technologies upon the receipt of the non-refundable upfront payment, were capitalized as a contract asset and will be amortized over the period in which the revenue from the triggering payment is recognized. As of March 31, 2019 and December 31, 2018, the contract asset relating to the sublicense payment was $0.6 million and $0.4 million, respectively.

Leases

3 Months Ended

Mar. 31, 2019

Leases

Leases

4. Leases

The Company leases real estate, including office and laboratory space and has entered into various other agreements with respect to assets used in conducting its business. The Company’s leases have remaining lease terms ranging from 2 years to 5 years. Some of the lease agreements contain rent holidays and rent escalation clauses that were included in the calculation of the right of use assets and lease liabilities.

Certain of the Company’s leases qualify as operating leases, and certain of its leases qualify as finance leases. The following table summarizes the presentation in the condensed consolidated balance sheets:


		March 31,
	Balance sheet location	2019
Assets
Operating lease assets	Operating lease assets	$	8,920
Finance lease assets	Other non-current assets		1,879
Total lease assets			10,799
Liabilities
Current operating lease liability	Accrued expenses and other current liabilities		1,643
Current finance lease liability	Accrued expenses and other current liabilities		145
Total current lease liabilities			1,788
Non-current operating lease liability	Operating lease liabilities, non-current		6,311
Non-current finance lease liability	Other non-current liabilities		460
Total non-current lease liabilities			6,771
Total lease liabilities		$	8,559

In the three months ended March 31, 2019 the Company terminated a lease of office space and derecognized the relating right of use asset and the lease liability of $0.2 million.

The following table summarizes the effect of lease costs in the Company’s condensed consolidated statements of operations and comprehensive loss:


		Three months ended
	Income statement location	March 31, 2019
Operating lease expenses	Research and development expenses	$	202
	General and administrative expenses		111
Finance lease amortization expenses	Research and development expenses		62
	General and administrative expenses		3
Interest on finance lease liabilities	Interest expenses		3
Sublease income	Other income (expense)		(11)
Net lease expense		$	370

The minimum lease payments, net of income from subleases, for the next five years and thereafter are expected to be as follows:


	March 31, 2019
	Operating lease		Finance lease		Total
2019 (remaining nine months)	$	1,244	$	107	$	1,351
2020		1,757		142		1,899
2021		1,762		129		1,891
2022		1,762		122		1,884
2023		1,749		120		1,869
2024		128		10		138
Thereafter		—		—		—
Total lease payments		8,402		630		9,032
Less: interest		(448)		(25)		(473)
Present value of lease liabilities	$	7,954	$	605	$	8,559

Under the prior lease guidance minimum rental commitments under non-cancelable leases for each of the next five years and total thereafter as of December 31, 2018, were as follows (in thousands):


Year ending December 31	Amount
2019	$	520
2020		278
2021		43
2022		43
2023		11
Thereafter		—
Total	$	895

These annual minimum lease payments did not include the embedded lease obligations under an agreement with a contract manufacturing organization, which commenced in February 2019.

The weighted average remaining lease term and weighted average discount rate of operating leases are as follows:


	March 31,
	2019

Weighted average remaining lease term in years	4.8
Weighted average discount rate (1)	2.3	%

(1)

The majority of the contracts are concluded in euros. The discount rate was determined on a currency-equivalent basis.

The weighted average remaining lease term and weighted average discount rate of finance leases are as follows:


	March 31,
	2019

Weighted average remaining lease term in years	4.7
Weighted average discount rate (1)	1.7	%

(1)

The contracts are concluded in euros. The discount rate was determined on a currency-equivalent basis.

The Company subleases certain of its leased real estate that it does not currently utilize to a third party. The sublease has a remaining lease terms of 2 years without an option to renew and has been qualified as an operating lease. The Company recognizes sublease income as incurred in its condensed consolidated statements of operations and comprehensive loss. The Company continued to account for the head lease as it did before sublease commencement.

Supplemental disclosure of cash flow information related to our operating and finance leases included in cash flows provided by operating activities in our condensed consolidated statements of cash flows is as follows:


	Three months ended
	March 31, 2019

Cash paid for amounts included in the measurement of operating lease liabilities (1)	$	1,260
Cash paid for amounts included in the measurement of finance lease liabilities (1)		1,355
Operating lease assets obtained in exchange for lease obligations (2)		5,233
Finance lease assets obtained in exchange for lease obligations (2)		634

(1)

The cash paid for amounts included in the measurement of lease liabilities includes upfront payments

(2)

The lease assets reported in the cash flow information exclude upfront payments.

Accrued expenses and other current liabilities

3 Months Ended

Mar. 31, 2019

Accrued expenses and other current liabilities

Accrued expenses and other current liabilities

5. Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	March 31,		December 31,
	2019		2018

Consulting fees	$	1,267	$	1,764
Salaries and bonuses		1,009		1,404
Social security contributions		121		121
Unearned grant income (current)		856		833
Operating lease liabilities		1,643		—
Finance lease liabilities		145		—
Other accruals and liabilities		387		298
Total	$	5,428	$	4,420

Loans payable

3 Months Ended

Mar. 31, 2019

Loans payable

Loans payable

6. Loans payable

As of March 31, 2019 and December 31, 2018, loans payable consisted of the following (in thousands):


	March 31,		December 31,
	2019		2018

Loans from FFG	$	8,151	$	8,316
Unamortized debt discount		(3,652)		(3,924)
Total Loans payable, net	$	4,499	$	4,392

In connection with the funding agreements with the Austrian Research Promotion Agency, (Österreichische Forschungs- förderungsgesellschaft, or “FFG”), the Company has received various loans (“FFG Loans”). The FFG Loans were made on a project-by-project basis. Amounts due under the FFG Loans bear interest at rates ranging from 0.75% to 1.0% per annum and mature at various dates between March 2021 and March 2024. Interest on amounts due under the loans is payable semi-annually in arrears, with all principal and remaining accrued interest due upon maturity.

The FFG Loans bear interest at rates that are below market rates of interest. The Company accounts for the imputed benefit arising from the difference between an estimated market rate of interest and the rate of interest charged by FFG as grant income from FFG. On the date that FFG loan proceeds are received, the Company recognizes the portion of the loan proceeds allocated to grant funding as a discount to the carrying value of the loan and as unearned income, which is recognized as grant income over the term of the funding agreement.

Redeemable convertible preferred stock

3 Months Ended

Mar. 31, 2019

Redeemable convertible preferred stock

Redeemable convertible preferred stock

7. Redeemable convertible preferred stock

Redeemable convertible preferred stock

The Company has issued Series A redeemable convertible preferred stock (the "Series A Preferred Stock"), Series B redeemable convertible preferred stock (the "Series B Preferred Stock"), Series C redeemable convertible preferred stock (the "Series C Preferred Stock") and Series D redeemable convertible preferred stock (the "Series D Preferred Stock"). Series D Preferred Stock was issued in February 2019. The Preferred Stock has certain contingent redemption features based upon the occurrence of events that are not solely within the control of the Company and is therefore classified as mezzanine equity.

In December 2017 the Company issued and sold 693,500 shares of Series C Preferred Stock at an average price of $85.60 per share for gross proceeds of $59.4 million. An amount of $6.5 million of the gross proceeds from the issuance of Series C Preferred Stock was received on January 4, 2018. The Company incurred issuance costs in connection with the Series C Preferred Stock of $0.1 million.

In February 2019 the Company issued and sold 257,000 shares of Series D Preferred Stock at an average price of $145.65 per share for gross proceeds of $37.4 million. The Company incurred issuance costs in connection with the Series D Preferred Stock of $0.2 million.

Upon issuance of each class of Preferred Stock, the Company assessed the embedded conversion and liquidation features of the shares and determined that such features did not require the Company to separately account for these features. The Company also concluded that no beneficial conversion feature existed on the issuance date of each class of Preferred Stock.

As of March 31, 2019, the Preferred Stock consisted of the following (in thousands, except share amounts):


		Preferred
	Preferred	shares			Common stock
	shares	issued and	Carrying		issuable upon
	authorized	outstanding	value		conversion
Series A Preferred Stock	137,814	137,814	$	0.014	1,604,574
Series B Preferred Stock	492,192	492,192		0.049	5,730,612
Series C Preferred Stock	693,500	693,500		0.069	8,074,447
Series D Preferred Stock	257,000	257,000		0.026	2,992,260
	1,580,506	1,580,506	$	0.158	18,401,893

As of December 31, 2018, the Preferred Stock consisted of the following (in thousands, except share amounts):


		Preferred
	Preferred	shares			Common stock
	shares	issued and	Carrying		issuable upon
	authorized	outstanding	value		conversion
Series A Preferred Stock	137,814	137,814	$	0.014	1,604,574
Series B Preferred Stock	492,192	492,192		0.049	5,730,612
Series C Preferred Stock	693,500	693,500		0.069	8,074,447
	1,323,506	1,323,506	$	0.132	15,409,633

Conversion

Each share of Preferred Stock was convertible, at the option of the holder, at any time, and without the payment of additional consideration, into 11.643 fully paid and non-assessable shares of common stock or non-voting Class A common stock as is determined by dividing the original issue price paid for such Preferred Shares by the applicable conversion price in effect at the time of conversion. Upon the closing of the Company’s the IPO, on April 23, 2019, all outstanding redeemable convertible preferred stock converted into shares of common stock or Class A common stock, as per election of the respective holders of preferred stock.

Liquidation

In the event of any voluntary of involuntary liquidation, dissolution or winding up of the Company or certain deemed liquidation events, the holders of Preferred Shares had a right to receive, certain amounts in preference to any distribution to the holders of common stock. The liquidation preferences of the Preferred Stock were as follows (in thousands):


	March 31,		December 31,
	2019		2018

Series A Preferred Stock	$	8,021	$	8,020
Series B Preferred Stock		34,365		34,367
Series C Preferred Stock		57,283		57,282
Series D Preferred Stock		37,432		—
	$	137,101	$	99,669

Common stock	3 Months Ended
Common stock	Mar. 31, 2019
Common stock
Common stock	8. Common stock In June 2018 the Company became the reporting entity in a transaction between entities under common control. In the accompanying condensed consolidated financial statements and notes, the common stock is retrospectively presented as if the Company had been the reporting entity for all periods during which the previous reporting entity was under common control. As of December 31, 2018, the Company had 1,006,595 shares of common stock outstanding and issued and was authorized to issue 2,038,619 additional shares of common stock upon exercise of stock options and 15,409,633 additional shares of common stock upon conversion of Preferred Stock. As of March 31, 2019, the Company had 1,006,595 shares of common stock outstanding and issued and was authorized to issue additional 24,608,111 shares of common stock. Holders of common stock are entitled to one vote for each share held on all matters submitted to a vote of the stockholders. The holders of common stock do not have any cumulative voting rights. Subject to any preferential dividend rights of any outstanding preferred stock, holders of common stock are entitled to receive ratably any dividends declared by the board of directors out of funds legally available for that purpose. Common stock has no preemptive rights, conversion rights, or other subscription rights or redemption or sinking fund provisions. In the event of a liquidation, dissolution, or winding up of the Company, holders of common stock will be entitled to share ratably in all assets remaining after payment of all debts and other liabilities and any liquidation preference of any outstanding preferred stock. As of March 31, 2019 the Company was, in addition, authorized to issue 19,006,880 shares of a new class of non-voting Class A common Stock, convertible into one share of common stock for each share of Class A common stock at the election of its holder. As of March 31, 2019, the Company has not issued any shares of Class A common stock.

Stock-based compensation

3 Months Ended

Mar. 31, 2019

Stock-based compensation

Stock-based compensation

9. Stock-based compensation

2018 Stock Option and Grant Plan

In connection with a transaction between entities under common control by which the Company became the reporting entity in June 2018, the Board of Directors approved the 2018 Stock Option and Grant Plan, by which options granted by the previous reporting entity under the 2016 Stock Option Plan and outstanding at the time of the effectiveness of the transaction were replaced at similar commercial terms. In the accompanying condensed consolidated financial statements and notes, options issued under previous stock option plans and respective compensation expenses are retrospectively presented as if such options had been issued and outstanding under the 2018 Stock Option and Grant Plan for all periods during which the previous reporting entity was under common control.

Under the 2018 Stock Option and Grant Plan, 2,133,437 shares of common stock have been authorized and reserved for the issuance of incentive stock options or non-qualified stock options to employees, officers, directors, and consultants of the Company, of which 94,818 shares of common stock were issued upon exercise of stock options and 2,038,619 shares were still available as of March 31, 2019.

The exercise price for options granted as a replacement of the 2016 Stock Option Plan is the U.S. dollar equivalent of €0.09, except for 23,286 options granted to an US employee, for which the exercise price is $2.93 following a repricing of these options in December 2018. For any new options, the exercise price shall not be less than 100% of the fair market value of the common stock on the grant date.

Options granted under the 2018 Stock Option and Grant Plan generally vest over four years, with 25% of the options vesting upon the first anniversary of the grant date and the remaining 75 % of the options vesting in 12 equal quarterly installments following the first anniversary of the grant date, provided the option holder continues to have an employment or service relationship with the Company on each vesting date.

2019 Stock Option and Incentive Plan

On April 1, 2019, the Company’s stockholders approved the 2019 Stock Option and Incentive Plan, which became effective as of the effectiveness of the registration statement in connection with the Company’s IPO. The maximum number of shares of the Company’s common stock that may be issued under the Company’s 2019 Stock Option and Incentive Plan is 2,608,042, which shall be cumulatively increased each year by up to 4.0% of the then outstanding number of shares.

Stock option activity

The following table summarizes the Company’s stock option activity since January 1, 2019 (in thousands, except share and per share amounts):


				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
	Number of	Exercise		Contractual	Intrinsic
	Shares	Price		Term	Value
				(in years)
Outstanding as of December 31, 2018	1,606,325	$	1.95	8.0	$	13,466
Granted	—		—
Exercised	—		—
Forfeited	(8,687)		3.61
Outstanding as of March 31, 2019	1,597,638	$	1.94	7.8	$	13,410

Options exercisable as of March 31, 2019	720,190	$	0.13	7.8	$	7,345
Options unvested as of March 31, 2019	877,448	$	3.42	7.8	$	6,065

The aggregate intrinsic value of stock options was calculated as the difference between the exercise price of the stock options and the estimated fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The estimated fair value per common stock used for calculating the intrinsic values as of March 31, 2019 and December 31, 2018, was $10.33

No cash from option exercise was received in the three months ended March 31, 2019 and 2018, respectively.

Stock-based compensation

Stock-based compensation expense was classified in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands):


	Three months ended March 31,
	2019		2018

Research and development expenses	$	261	$	93
General and administrative expenses		122		113
	$	383	$	206

Income taxes	3 Months Ended
Income taxes	Mar. 31, 2019
Income taxes
Income taxes	10. Income taxes During the three months ended March 31, 2018 and 2019, the Company recorded no income tax benefits for the net operating losses incurred, due to its uncertainty of realizing a benefit from those items. The Company’s losses before income taxes were generated in the United States and Austria. The Company has evaluated the positive and negative evidence bearing upon its ability to realize the deferred tax assets resulting from its net operating loss carryforwards. Management has considered the Company’s history of cumulative net losses incurred since inception and its lack of commercialization of any products or generation of any revenue from product sales since inception and has concluded that it is more likely than not that the Company will not realize the benefits of its deferred tax assets. Accordingly, a full valuation allowance has been established against the deferred tax assets as of March 31, 2019 and December 31, 2018. Management reevaluates the positive and negative evidence at each reporting period.

Commitments and contingencies	3 Months Ended
Commitments and contingencies	Mar. 31, 2019
Commitments and contingencies
Commitments and contingencies	11. Commitments and contingencies Contract manufacturing arrangements The Company has entered into arrangements with contract manufacturing organizations (“CMOs”) for manufacturing of materials for research and development purposes, including manufacturing of clinical trial materials. These contracts generally provide for non-cancellable obligations or cancellation penalties depending on the time of cancellation. As of March 31, 2019, the Company’s total non-cancellable obligations under contracts with CMOs, excluding embedded lease liabilities, were $14.6 million, of which $5.9 million relate to 2019 (remaining nine months) deliverables $6.7 million relate to 2020 deliverables and $2.0 million relate to 2021 deliverables. Intellectual property licenses The Company has entered into certain license agreements under which it is obligated to make milestone payments upon the achievement of certain development and regulatory milestones, to pay royalties on net sales of licensed products, and to pay a percentage of the sublicense fees which the Company receives from its sublicensees. In the three months ended March 31, 2019, the Company recorded $0.4 million in licensing fees from intellectual property licenses as research and development expenses. These amounts mainly related to the upfront payment and a milestone payment received by the Company under the Gilead Agreement. The amounts recognized as expenses have been agreed to by the licensors but calculation of sublicensing fees on future payments may be subject to interpretation and may change until agreed to by the receiving party. Indemnification agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and senior management that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any claims under indemnification arrangements, and it has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of March 31, 2019 and December 31, 2019. Legal proceedings At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. While it is not feasible to predict the outcome of these matters with certainty, and some lawsuits, claims or proceedings may be disposed or decided unfavorably, the Company does not expect that any asserted or un-asserted legal claims or proceedings, individually or in the aggregate, will have a material adverse effect on the Company. The Company expenses the costs related to such legal proceedings as incurred.

Net loss per share

3 Months Ended

Mar. 31, 2019

Net loss per share

Net loss per share

12. Net loss per share

The following table sets forth the computation of the basic and diluted net loss per share attributable to common stockholders (in thousands, except for per share amounts):


	Three months ended March 31,
	2019		2018

Numerator:
Net loss	$	(9,329)	$	(4,573)

Denominator:
Weighted-average common shares outstanding, basic and diluted		1,006,595		911,777

Net loss per share, basic and diluted	$	(9.27)	$	(5.02)

Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all potential common shares outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows:


	Three months ended March 31,
	2019	2018

Series A Preferred Stock	1,604,574	1,604,574
Series B Preferred Stock	5,730,612	5,730,612
Series C Preferred Stock	8,074,447	8,074,447
Series D Preferred Stock	2,992,260	—
Options issued and outstanding	1,597,638	1,431,181
Total	19,999,531	16,840,814

Related parties	3 Months Ended
Related parties	Mar. 31, 2019
Related parties
Related parties	13. Related parties The Company is party to research and service arrangements with the University of Basel. The Company’s Chief Scientific Officer and his spouse are employees of the University of Basel and both involved in providing the services under these arrangements. In the three months ended March 31, 2019 and 2018, the Company recorded $0.3 million and $0.3 million, respectively, in research and development expenses for service fees paid to the University of Basel. The University of Basel is also entitled to receive de minimis royalties on the net sales of any product that is based on a patent created by the Company’s Chief Scientific Officer in the course of his consulting services to the Company. In the three months ended March 31, 2019 and 2018, no royalties were paid pursuant to the terms of this arrangement. During the three months ended March 31, 2019, the Company issued 50,670 shares of Series D Preferred Stock for total proceeds of $7.4 million to certain stockholders that were related parties.

Subsequent events	3 Months Ended
Subsequent events	Mar. 31, 2019
Subsequent events
Subsequent events	14. Subsequent events Initial public offering On April 23, 2019, the Company closed its IPO of 6,000,000 shares of common stock, at an offering price to the public of $14.00 per share. The Company received net proceeds of approximately $74.8 million, after deducting underwriting discounts and commissions. Upon the closing of the IPO, the Company’s outstanding redeemable convertible preferred stock automatically converted into shares of common stock or Class A common stock, per election of the respective holders of preferred stock. As of May 20, 2019, the Company had 21,588,756 shares of common stock and 3,819,732 shares of Class A common stock outstanding, each $0.0001 par value per share. The related carrying value of $142.0 million was reclassified to common stock and additional paid-in capital. Amended and restated certificate of incorporation In March 2019 and April 2019, the Company’s board of directors and stockholders, respectively, approved an amended and restated certificate of incorporation that, effective simultaneous with closing of the IPO, increased the total number of shares of capital stock which the Company shall have authority to issue to 113,900,000 shares, par value $0.0001 per share, of which 100,000,000 shares shall be shares of Common stock, 3,900,000 shares shall be Class A common stock and 10,000,000 shares shall be undesignated preferred stock.

Summary of significant accounting policies (Policies)

3 Months Ended

Mar. 31, 2019

Summary of significant accounting policies

Basis of presentation

Stock split

Going concern

Use of estimates

Concentrations of credit risk and of significant suppliers

Deferred offering costs

Property and equipment


		Estimated useful life
Leasehold improvements (1)		5 years
Laboratory equipment		3 - 10 years
Furniture and fixtures		3 - 10 years
Computer equipment and software		3 - 4 years

(1)

In the course of the application of ASC 842, the economic useful lives of the leasehold improvements were adjusted to the lease terms.

Redeemable convertible preferred stock

Recent accounting pronouncements and Recently Issued Accounting Pronouncements

Recent accounting pronouncements

Adopted as of current period

Recently Issued Accounting Pronouncements

Summary of significant accounting policies (Tables)

3 Months Ended

Mar. 31, 2019

Summary of significant accounting policies

Schedule of estimated useful life of each asset


		Estimated useful life
Leasehold improvements (1)		5 years
Laboratory equipment		3 - 10 years
Furniture and fixtures		3 - 10 years
Computer equipment and software		3 - 4 years

(1)

In the course of the application of ASC 842, the economic useful lives of the leasehold improvements were adjusted to the lease terms.

Leases (Tables)

3 Months Ended

Mar. 31, 2019

Leases

Schedule of operating and finance leases


		March 31,
	Balance sheet location	2019
Assets
Operating lease assets	Operating lease assets	$	8,920
Finance lease assets	Other non-current assets		1,879
Total lease assets			10,799
Liabilities
Current operating lease liability	Accrued expenses and other current liabilities		1,643
Current finance lease liability	Accrued expenses and other current liabilities		145
Total current lease liabilities			1,788
Non-current operating lease liability	Operating lease liabilities, non-current		6,311
Non-current finance lease liability	Other non-current liabilities		460
Total non-current lease liabilities			6,771
Total lease liabilities		$	8,559

Summary of the effect of lease costs


		Three months ended
	Income statement location	March 31, 2019
Operating lease expenses	Research and development expenses	$	202
	General and administrative expenses		111
Finance lease amortization expenses	Research and development expenses		62
	General and administrative expenses		3
Interest on finance lease liabilities	Interest expenses		3
Sublease income	Other income (expense)		(11)
Net lease expense		$	370

Summary of maturities of operating lease liabilities


	March 31, 2019
	Operating lease		Finance lease		Total
2019 (remaining nine months)	$	1,244	$	107	$	1,351
2020		1,757		142		1,899
2021		1,762		129		1,891
2022		1,762		122		1,884
2023		1,749		120		1,869
2024		128		10		138
Thereafter		—		—		—
Total lease payments		8,402		630		9,032
Less: interest		(448)		(25)		(473)
Present value of lease liabilities	$	7,954	$	605	$	8,559

Summary of maturities of finance lease liabilities

The minimum lease payments, net of income from subleases, for the next five years and thereafter are expected to be as follows:


	March 31, 2019
	Operating lease		Finance lease		Total
2019 (remaining nine months)	$	1,244	$	107	$	1,351
2020		1,757		142		1,899
2021		1,762		129		1,891
2022		1,762		122		1,884
2023		1,749		120		1,869
2024		128		10		138
Thereafter		—		—		—
Total lease payments		8,402		630		9,032
Less: interest		(448)		(25)		(473)
Present value of lease liabilities	$	7,954	$	605	$	8,559

Schedule of minimum rental commitments under non-cancelable leases

Under the prior lease guidance minimum rental commitments under non-cancelable leases for each of the next five years and total thereafter as of December 31, 2018, were as follows (in thousands):


Year ending December 31	Amount
2019	$	520
2020		278
2021		43
2022		43
2023		11
Thereafter		—
Total	$	895

Schedule of weighted average remaining lease term and weighted average discount rate of operating leases


	March 31,
	2019

Weighted average remaining lease term in years	4.8
Weighted average discount rate (1)	2.3	%

(1)

The majority of the contracts are concluded in euros. The discount rate was determined on a currency-equivalent basis.

Schedule of weighted average remaining lease term and weighted average discount rate of finance leases


	March 31,
	2019

Weighted average remaining lease term in years	4.7
Weighted average discount rate (1)	1.7	%

(1)

The contracts are concluded in euros. The discount rate was determined on a currency-equivalent basis.

Schedule of supplemental cash flow information related to operating and finance leases


	Three months ended
	March 31, 2019

Cash paid for amounts included in the measurement of operating lease liabilities (1)	$	1,260
Cash paid for amounts included in the measurement of finance lease liabilities (1)		1,355
Operating lease assets obtained in exchange for lease obligations (2)		5,233
Finance lease assets obtained in exchange for lease obligations (2)		634

(1)

The cash paid for amounts included in the measurement of lease liabilities includes upfront payments

(2)

The lease assets reported in the cash flow information exclude upfront payments.

Accrued expenses and other current liabilities (Tables)

3 Months Ended

Mar. 31, 2019

Accrued expenses and other current liabilities

Schedule of accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	March 31,		December 31,
	2019		2018

Consulting fees	$	1,267	$	1,764
Salaries and bonuses		1,009		1,404
Social security contributions		121		121
Unearned grant income (current)		856		833
Operating lease liabilities		1,643		—
Finance lease liabilities		145		—
Other accruals and liabilities		387		298
Total	$	5,428	$	4,420

Loans payable (Tables)

3 Months Ended

Mar. 31, 2019

Loans payable

Schedule of loans payable


	March 31,		December 31,
	2019		2018

Loans from FFG	$	8,151	$	8,316
Unamortized debt discount		(3,652)		(3,924)
Total Loans payable, net	$	4,499	$	4,392

Redeemable convertible preferred stock (Tables)

3 Months Ended

Mar. 31, 2019

Redeemable convertible preferred stock

Schedule of preferred stock


		Preferred
	Preferred	shares			Common stock
	shares	issued and	Carrying		issuable upon
	authorized	outstanding	value		conversion
Series A Preferred Stock	137,814	137,814	$	0.014	1,604,574
Series B Preferred Stock	492,192	492,192		0.049	5,730,612
Series C Preferred Stock	693,500	693,500		0.069	8,074,447
Series D Preferred Stock	257,000	257,000		0.026	2,992,260
	1,580,506	1,580,506	$	0.158	18,401,893

As of December 31, 2018, the Preferred Stock consisted of the following (in thousands, except share amounts):


		Preferred
	Preferred	shares			Common stock
	shares	issued and	Carrying		issuable upon
	authorized	outstanding	value		conversion
Series A Preferred Stock	137,814	137,814	$	0.014	1,604,574
Series B Preferred Stock	492,192	492,192		0.049	5,730,612
Series C Preferred Stock	693,500	693,500		0.069	8,074,447
	1,323,506	1,323,506	$	0.132	15,409,633

Schedule of preferred stock liquidation preference

The liquidation preferences of the Preferred Stock were as follows (in thousands):


	March 31,		December 31,
	2019		2018

Series A Preferred Stock	$	8,021	$	8,020
Series B Preferred Stock		34,365		34,367
Series C Preferred Stock		57,283		57,282
Series D Preferred Stock		37,432		—
	$	137,101	$	99,669

Stock-based compensation (Tables)

3 Months Ended

Mar. 31, 2019

Stock-based compensation

Schedule of summary of stock option activity

The following table summarizes the Company’s stock option activity since January 1, 2019 (in thousands, except share and per share amounts):


				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
	Number of	Exercise		Contractual	Intrinsic
	Shares	Price		Term	Value
				(in years)
Outstanding as of December 31, 2018	1,606,325	$	1.95	8.0	$	13,466
Granted	—		—
Exercised	—		—
Forfeited	(8,687)		3.61
Outstanding as of March 31, 2019	1,597,638	$	1.94	7.8	$	13,410

Options exercisable as of March 31, 2019	720,190	$	0.13	7.8	$	7,345
Options unvested as of March 31, 2019	877,448	$	3.42	7.8	$	6,065

Schedule of stock-based compensation expense

Stock-based compensation expense was classified in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands):


	Three months ended March 31,
	2019		2018

Research and development expenses	$	261	$	93
General and administrative expenses		122		113
	$	383	$	206

Net loss per share (Tables)

3 Months Ended

Mar. 31, 2019

Net loss per share

Schedule of basic and diluted net loss per share


	Three months ended March 31,
	2019		2018

Numerator:
Net loss	$	(9,329)	$	(4,573)

Denominator:
Weighted-average common shares outstanding, basic and diluted		1,006,595		911,777

Net loss per share, basic and diluted	$	(9.27)	$	(5.02)

Schedule of potentially dilutive securities that were not included in the diluted per share calculations


	Three months ended March 31,
	2019	2018

Series A Preferred Stock	1,604,574	1,604,574
Series B Preferred Stock	5,730,612	5,730,612
Series C Preferred Stock	8,074,447	8,074,447
Series D Preferred Stock	2,992,260	—
Options issued and outstanding	1,597,638	1,431,181
Total	19,999,531	16,840,814

Summary of significant accounting policies - Going concern, Deferred offering costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Summary of significant accounting policies
Net loss	$ (9,329)	$ (4,573)
Accumulated deficit	(69,310)		$ (59,982)
Deferred offering costs	$ 2,300		$ 1,500

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Summary of significant accounting policies - Property and equipment (Details)	3 Months Ended
	Mar. 31, 2019
Leasehold improvements
Property and equipment
Estimated useful life	5 years
Laboratory equipment \| Minimum
Property and equipment
Estimated useful life	3 years
Laboratory equipment \| Maximum
Property and equipment
Estimated useful life	10 years
Furniture and fixtures \| Minimum
Property and equipment
Estimated useful life	3 years
Furniture and fixtures \| Maximum
Property and equipment
Estimated useful life	10 years
Computer equipment and software \| Minimum
Property and equipment
Estimated useful life	3 years
Computer equipment and software \| Maximum
Property and equipment
Estimated useful life	4 years

Summary of significant accounting policies - Property and equipment - Revenue recognition from contracts with customers, Comprehensive loss and Recent accounting pronouncements (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Summary of significant accounting policies
Lease, Practical Expedients, Package [true false]	true
Lease, Practical Expedient Land Easement [true false]	false
Operating lease assets	$ 8,920
Operating lease liability	$ 7,954
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Lessee, Finance Lease, Existence of Option to Extend [true false]	true
Lessee, Operating Lease, Existence of Option to Terminate [true false]	true
Lessee, Finance Lease, Existence of Option to Terminate [true false]	true
Restatement Adjustment \| ASU 2016-02
Summary of significant accounting policies
Operating lease assets	$ 3,300
Operating lease liability	$ 3,300

Collaboration and Licensing Agreements (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Jun. 30, 2018 USD ($) item	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Collaboration and Licensing Agreements
Revenue from milestones amount		$ 2,235
Gilead Collaboration and License Agreement
Collaboration and Licensing Agreements
Number of preclinical research programs \| item	2
Non-refundable, upfront payment	$ 10,000
Revenue from collaboration and licensing		900
Liability in deferred revenues		$ 6,100
Percentage of deferred revenue is expected to be recognized		91.00%
Percentage of deferred revenue is expected to be recognized in 2020		9.00%
Payment term (in days)		60 days
Revenue from cost reimbursements		$ 1,300
Contract asset relating to the sublicense payment		600	$ 400
Development Milestones \| Gilead Collaboration and License Agreement
Collaboration and Licensing Agreements
Revenue from milestones amount		280,000
Commercial Milestones \| Gilead Collaboration and License Agreement
Collaboration and Licensing Agreements
Revenue from milestones amount		$ 100,000

Leases (Details) $ in Thousands	3 Months Ended
Leases (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Leases
Right-of-use asset derecognized	$ 200
Lease liability derecognized	200
Presentation of leases in condensed consolidated balance sheets:
Operating lease assets	$ 8,920
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Operating lease assets
Finance lease assets	$ 1,879
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other Assets, Noncurrent
Total lease assets	$ 10,799
Current operating lease liability	$ 1,643
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedExpensesAndOtherCurrentLiabilities
Current finance lease liability	$ 145
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedExpensesAndOtherCurrentLiabilities
Total current lease liabilities	$ 1,788
Non-current operating lease liability	$ 6,311
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Non-current operating lease liability
Non-current finance lease liability	$ 460
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent
Total non-current lease liabilities	$ 6,771
Total lease liabilities	$ 8,559
Minimum
Leases
Remaining lease term (in years)	2 years
Maximum
Leases
Remaining lease term (in years)	5 years

Leases - Lease costs (Details) $ in Thousands	3 Months Ended
Leases - Lease costs (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Leases
Sublease income	$ (11)
Net lease expenses	370
Research and Development Expense
Leases
Operating lease expenses	202
Finance lease amortization expenses	62
General and Administrative Expense
Leases
Operating lease expenses	111
Finance lease amortization expenses	3
Interest expenses
Leases
Interest on finance lease liabilities	$ 3

Leases - Minimum lease payments (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Operating leases
2019 (remaining nine months)	$ 1,244
2020	1,757
2021	1,762
2022	1,762
2023	1,749
2024	128
Total lease payments	8,402
Less: interest	(448)
Present value of lease liabilities	7,954
Finance leases
2019 (remaining nine months)	107
2020	142
2021	129
2022	122
2023	120
2024	10
Total lease payments	630
Less: interest	(25)
Present value of lease liabilities	605
Total
2019 (remaining nine months)	1,351
2020	1,899
2021	1,891
2022	1,884
2023	1,869
2024	138
Total lease payments	9,032
Less: interest	(473)
Present value of lease liabilities	$ 8,559

Leases - Minimum rental commitments under non-cancelable leases (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Minimum rental commitments under non-cancelable leases
2019	$ 520
2020	278
2021	43
2022	43
2023	11
Total	$ 895

Leases - Lease guidance minimum rental commitments - weighted average remaining lease term and weighted average discount rate (Details)	3 Months Ended
	Mar. 31, 2019
Leases
Operating lease, Weighted average remaining lease term (in years)	4 years 9 months 18 days
Operating lease, Weighted average discount rate	2.30%
Finance lease, Weighted average remaining lease term (in years)	4 years 8 months 12 days
Finance lease, Weighted average discount rate	1.70%
Sublease, remaining lease term	2 years

Leases - Supplemental disclosure of cash flow information related to operating and finance leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases
Cash paid for amounts included in the measurement of operating lease liabilities	$ 1,260
Cash paid for amounts included in the measurement of finance lease liabilities	1,355
Operating lease assets obtained in exchange for lease obligations	5,233
Finance lease assets obtained in exchange for lease obligations	$ 634

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accrued expenses and other current liabilities
Consulting fees	$ 1,267	$ 1,764
Salaries and bonuses	1,009	1,404
Social security contributions	121	121
Unearned grant income (current)	856	833
Operating lease liabilities	1,643
Finance lease liabilities	145
Other accruals and liabilities	387	298
Total	$ 5,428	$ 4,420

Loans payable (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans payable
Loans from FFG	$ 8,151	$ 8,316
Unamortized debt discount	(3,652)	(3,924)
Total Loans payable, net	$ 4,499	$ 4,392
Minimum
Loans payable
Interest rate (as a percent)	0.75%
Maximum
Loans payable
Interest rate (as a percent)	1.00%

Redeemable convertible preferred stock (Details) - USD ($)		1 Months Ended		3 Months Ended	12 Months Ended
	Jan. 04, 2018	Feb. 28, 2019	Dec. 31, 2017	Mar. 31, 2019	Dec. 31, 2018
Redeemable convertible preferred stock
Preferred shares issued				1,666,961	1,323,506
Stock issuance cost				$ 722,000
Preferred shares authorized				1,580,506	1,323,506
Preferred shares outstanding				1,580,506	1,323,506
Carrying value				$ 0.158	$ 132.000
Common stock issuable upon conversion				18,401,893	15,409,633
Preferred stock, liquidation preference				$ 137,101,000	$ 99,669,000
Series A Preferred Stock
Redeemable convertible preferred stock
Preferred shares authorized				137,814	137,814
Preferred shares outstanding				137,814	137,814
Carrying value				$ 0.014	$ 14.000
Common stock issuable upon conversion				1,604,574	1,604,574
Preferred stock, liquidation preference				$ 8,021,000	$ 8,020,000
Series B Preferred Stock
Redeemable convertible preferred stock
Preferred shares authorized				492,192	492,192
Preferred shares outstanding				492,192	492,192
Carrying value				$ 0.049	$ 49.000
Common stock issuable upon conversion				5,730,612	5,730,612
Preferred stock, liquidation preference				$ 34,365,000	$ 34,367,000
Series C Preferred Stock
Redeemable convertible preferred stock
Preferred shares issued			693,500
Average price (in dollars per sale)			$ 85.60
Gross Proceeds from issuance of stock	$ 6,500,000		$ 59,400,000
Stock issuance cost	$ 100,000
Preferred shares authorized				693,500	693,500
Preferred shares outstanding				693,500	693,500
Carrying value				$ 0.069	$ 69.000
Common stock issuable upon conversion				8,074,447	8,074,447
Preferred stock, liquidation preference				$ 57,283,000	$ 57,282,000
Series D Preferred Stock
Redeemable convertible preferred stock
Preferred shares issued		257,000
Average price (in dollars per sale)		$ 145.65
Gross Proceeds from issuance of stock		$ 37,400,000
Stock issuance cost		$ 200,000
Preferred shares authorized				257,000
Preferred shares outstanding				257,000
Carrying value				$ 0.026
Common stock issuable upon conversion				2,992,260
Preferred stock, liquidation preference				$ 37,432,000
Class A common stock
Redeemable convertible preferred stock
Number of common stock issued upon conversion				11.643

Common stock (Details)		3 Months Ended	12 Months Ended
Common stock (Details)	Apr. 05, 2019	Mar. 31, 2019 Vote shares	Dec. 31, 2018 shares
Common stock, issued (in shares)		1,006,595	1,006,595
Common stock, outstanding (in shares)		1,006,595	1,006,595
Additional shares of common stock authorized to issue (in shares)		24,608,111	2,038,619
Additional shares of common stock issued upon conversion of preferred stock ( in shares)			15,409,633
Number of votes \| Vote		1
Common stock, Authorized (in shares)		25,614,706	18,454,860
Number of common stock issued upon conversion of each share of Class A Common Stock	11.643
Class A common stock
Common stock, issued (in shares)		0	0
Common stock, outstanding (in shares)		0	0
Common stock, Authorized (in shares)		19,006,880	0
Number of common stock issued upon conversion of each share of Class A Common Stock		1

Stock-based compensation - 2018 Stock Option and Grant Plan (Details)		3 Months Ended	12 Months Ended
	Apr. 01, 2019 shares	Mar. 31, 2019 installment shares	Dec. 31, 2018 € / shares shares
2018 Stock Option and Grant Plan
Stock-based compensation
Number stock option authorized		2,133,437
Issuance of common stock upon exercise of stock options (in shares)		94,818
Number of stock option available for grant		2,038,619
Vesting period		4 years
Percentage of options vesting		75.00%
Number of quarterly installments for vesting \| installment		12
2018 Stock Option and Grant Plan \| First anniversary
Stock-based compensation
Percentage of options vesting		25.00%
2016 Stock Option Plan
Stock-based compensation
Percentage of share price with fair market value		100.00%
2016 Stock Option Plan \| Exercise price 0.09 euros
Stock-based compensation
Exercise price for options granted as a replacement \| € / shares			€ 0.09
Number of shares granted to US employee			23,286
2016 Stock Option Plan \| Exercise price $2.93
Stock-based compensation
Number of shares granted to US employee			2.93
2019 Stock Option and Incentive Plan
Stock-based compensation
Issuance of common stock upon exercise of stock options (in shares)	2,608,042
Number of shares outstanding were cumulatively increased		4.00%

Stock-based compensation - 2019 Stock Option and Incentive Plan (Details) - USD ($)		3 Months Ended		12 Months Ended
	Apr. 01, 2019	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Number of Shares
Beginning balance	1,597,638	1,606,325
Forfeited		(8,687)
Ending balance		1,597,638		1,606,325
Option exercisable		720,190
Option unvested		877,448
Weighted Averaged Exercise Price
Beginning balance	$ 1.94	$ 1.95
Forfeited		3.61
Ending balance		1.94		$ 1.95
Option exercisable		0.13
Option unvested		$ 3.42
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term (in years)		7 years 9 months 18 days		8 years
Weighted Average Remaining Contractual Term, option exercisable		7 years 9 months 18 days
Weighted Average Remaining Contractual Term, option unvested		7 years 9 months 18 days
Aggregate Intrinsic Value, option unvested		$ 6,065,000
Aggregate Intrinsic Value, option exercisable		7,345,000
Aggregate Intrinsic Value, ending balance		13,410,000		$ 13,466,000
Aggregate Intrinsic Value, beginning balance	$ 13,410,000	13,466,000
Estimated fair value per common stock used for calculating the intrinsic values		10.33		$ 10.33
Proceeds from option exercise		0	$ 0
Stock-based compensation
Stock-based compensation expense		383,000	206,000
Research and Development Expense
Stock-based compensation
Stock-based compensation expense		261,000	93,000
General and Administrative Expense
Stock-based compensation
Stock-based compensation expense		$ 122,000	$ 113,000
2019 Stock Option and Incentive Plan
Number of Shares
Exercised	2,608,042

Commitments and contingencies (Details) $ in Millions	3 Months Ended
Commitments and contingencies (Details) $ in Millions	Mar. 31, 2019 USD ($)
Commitments and contingencies
Non-cancellable obligations	$ 14.6
2019 (remaining nine months)	5.9
2020	6.7
2021	2.0
Licensing fees from intellectual property licenses	$ 0.4

Net loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net loss	$ (9,329)	$ (4,573)
Denominator:
Weighted-average common shares outstanding, basic and diluted	1,006,595	911,777
Net loss per share, basic and diluted	$ (9.27)	$ (5.02)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Net loss per share - Antidilutive securities (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Anti-dilutive securities
Anti-dilutive shares	19,999,531	16,840,814
Series A Preferred Stock
Anti-dilutive securities
Anti-dilutive shares	1,604,574	1,604,574
Series B Preferred Stock
Anti-dilutive securities
Anti-dilutive shares	5,730,612	5,730,612
Series C Preferred Stock
Anti-dilutive securities
Anti-dilutive shares	8,074,447	8,074,447
Series D Preferred Stock
Anti-dilutive securities
Anti-dilutive shares	2,992,260
Options issued and outstanding
Anti-dilutive securities
Anti-dilutive shares	1,597,638	1,431,181

Related parties (Details) - USD ($) $ in Millions	3 Months Ended
Related parties (Details) - USD ($) $ in Millions	Mar. 31, 2019	Mar. 31, 2018
Series D Preferred Stock
Related parties
Shares issued	50,670
Proceeds from shares issued	$ 7.4
University of Basel
Related parties
Research and development expenses	0.3	$ 0.3
Royalties paid	$ 0.0	$ 0.0

Subsequent events (Details) $ / shares in Units, $ in Millions	Apr. 23, 2019 USD ($) $ / shares shares	May 20, 2019 USD ($) $ / shares shares	Apr. 30, 2019 $ / shares shares	Mar. 31, 2019 $ / shares shares	Dec. 31, 2018 $ / shares shares
Subsequent events
Common stock, shares issued				1,006,595	1,006,595
Common stock, outstanding (in shares)				1,006,595	1,006,595
Par value per share (in dollar per share) \| $ / shares				$ 0.0001	$ 0.0001
Class A common stock
Subsequent events
Common stock, shares issued				0	0
Common stock, outstanding (in shares)				0	0
Par value per share (in dollar per share) \| $ / shares				$ 0.0001	$ 0.0001
Subsequent events
Subsequent events
Carrying value \| $		$ 142.0
Subsequent events \| Common Stock
Subsequent events
Common stock, outstanding (in shares)		21,588,756
Subsequent events \| Class A common stock
Subsequent events
Common stock, outstanding (in shares)		3,819,732
Par value per share (in dollar per share) \| $ / shares		$ 0.0001
Subsequent events \| IPO
Subsequent events
Authority to issue shares			113,900,000
Par value per share (in dollar per share) \| $ / shares			0.0001
Subsequent events \| IPO \| Common Stock
Subsequent events
Common stock, shares issued	6,000,000
Offering price per share \| $ / shares	$ 14.00
Net proceeds from issuance \| $	$ 74.8
Authority to issue shares			100,000,000
Subsequent events \| IPO \| Class A common stock
Subsequent events
Authority to issue shares			3,900,000
Subsequent events \| IPO \| Undesignated preferred stock
Subsequent events
Authority to issue shares			10,000,000

CONDENSED CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ DEFICIT (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Issuance of series D convertible preferred stock, issuance costs	$ 722
Series D convertible preferred stock
Issuance of series D convertible preferred stock, issuance costs	$ 158

Summary of significant accounting policies - Transaction between entities under common control and Stock split (Details)	Apr. 05, 2019
Summary of significant accounting policies
Stock split ratio	11.643