0001564590-22-018867 | 10-Q | XBRL Viewer

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Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2022	May 04, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Entity Registrant Name	MERUS N.V.
Trading Symbol	MRUS
Entity Central Index Key	0001651311
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		43,550,059
Entity File Number	001-37773
Entity Incorporation, State or Country Code	P7
Entity Tax Identification Number	00-0000000
Entity Address, Address Line One	Yalelaan 62
Entity Address, City or Town	Utrecht
Entity Address, Postal Zip Code	3584 CM
Entity Address, Country	NL
City Area Code	+31 85
Local Phone Number	016 2500
Document Quarterly Report	true
Document Transition Report	false
Title of 12(b) Security	Common shares, nominal value €0.09 per share
Security Exchange Name	NASDAQ

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 194,575	$ 241,435
Marketable securities	164,239	168,990
Accounts receivable	2,671	1,697
Accounts receivable (related party)		4,609
Prepaid expenses and other current assets	18,248	7,448
Total current assets	379,733	424,179
Marketable securities	25,466	20,297
Property and equipment, net	3,509	3,549
Operating lease right-of-use assets	3,334	3,733
Intangible assets, net	2,233	2,347
Deferred tax assets	80	417
Other assets	3,145	2,078
Total assets	417,500	456,600
Current liabilities:
Accounts payable	5,388	13,237
Accrued expenses and other liabilities	20,948	22,506
Current portion of lease obligation	1,491	1,494
Current portion of deferred revenue	33,696	16,613
Current portion of deferred revenue (related party)		18,048
Total current liabilities	61,523	71,898
Lease obligation	1,874	2,257
Deferred revenue, net of current portion	56,630	10,962
Deferred revenue, net of current portion (related party)		55,282
Total liabilities	120,027	140,399
Stockholders’ equity:
Common shares, €0.09 par value; 67,500,000 shares authorized as at March 31, 2022 and December 31, 2021; 43,549,325 and 43,467,052 shares issued and outstanding as at March 31, 2022 and December 31, 2021, respectively	4,489	4,481
Additional paid-in capital	794,074	787,869
Accumulated other comprehensive income	(15,269)	(9,221)
Accumulated deficit	(485,821)	(466,928)
Total stockholders’ equity	297,473	316,201
Total liabilities and stockholders’ equity	417,500	456,600
Commitments and contingencies - Note 6

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - € / shares	Mar. 31, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Common shares, par value	€ 0.09	€ 0.09
Common shares, authorized	67,500,000	67,500,000
Common shares, issued	43,549,325	43,467,052
Common shares, outstanding	43,549,325	43,467,052

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Total revenue	$ 11,655	$ 8,350
Operating expenses:
Research and development	26,975	20,806
General and administrative	11,753	9,333
Total operating expenses	38,728	30,139
Operating loss	(27,073)	(21,789)
Other (loss) income, net:
Interest (expense) income, net	106	(82)
Foreign exchange gains	7,730	12,203
Other (losses) gains , net	458	(437)
Total other income, net	8,294	11,684
Net loss before income taxes	(18,779)	(10,105)
Income tax expense	114	49
Net loss	(18,893)	(10,154)
Other comprehensive loss:
Currency translation adjustment	(6,048)	(9,391)
Comprehensive loss	$ (24,941)	$ (19,545)
Net loss per share attributable to common stockholders:
Basic and diluted	$ (0.43)	$ (0.28)
Weighted-average common shares outstanding:
Basic and diluted	43,490	36,210
Collaboration Revenue [Member]
Total revenue from contracts with customers	$ 11,655	$ 1,599
Collaboration Revenue (Related Party) [Member]
Total revenue from contracts with customers		$ 6,751

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (18,893)	$ (10,154)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization of property and equipment	283	324
Amortization of intangible assets	68	74
Foreign exchange gain	(7,790)	(12,056)
Stock-based compensation expense	5,334	3,400
Amortization of discount on investments	297	35
Deferred tax expense	337	369
Changes in operating assets and liabilities:
Accounts receivable	3,549	(340)
Operating lease right-of-use assets and lease obligations	14	(17)
Prepaid expenses and other current assets	(12,152)	(1,574)
Accounts payable	(7,635)	756
Accrued expenses and other liabilities	(1,146)	1,130
Deferred revenue	(8,663)	37,396
Net cash provided by (used in) operating activities	(46,397)	19,343
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities	(55,142)	(20,645)
Proceeds from maturities of marketable securities	54,517	18,128
Purchases of property and equipment	(342)	(157)
Net cash used in investing activities	(967)	(2,674)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net	0	129,568
Proceeds from stock options exercised	879	4,697
Repurchase of restricted stock units	0	(285)
Net cash provided by financing activities	879	150,457
Foreign exchange impact on cash, cash equivalents and restricted cash	(377)	(3,070)
Net increase (decrease) in cash, cash equivalents and restricted cash	(46,862)	164,056
Cash, cash equivalents, and restricted cash, beginning of period	241,749	163,282
Cash, cash equivalents, and restricted cash, end of period	194,887	327,338
SUPPLEMENTAL DISCLOSURES:
Income taxes paid	0	66
Non-cash purchases of property, equipment and intangibles	0	25
Non-cash issuance of stock options	0	572
CASH, CASH EQUIVALENTS AND RESTRICTED CASH
Cash and cash equivalents	194,575	327,137
Restricted cash included in non-current other assets	312	201
Cash, cash equivalents, and restricted cash, end of period	194,887	327,338
Lilly
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net	$ 0	$ 16,477

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Lilly	Common Stock [Member]	Common Stock [Member] Lilly	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] Lilly	Accumulated Deficit [Member]	Accumulated Deficit [Member] Lilly	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Lilly
Beginning balance at Dec. 31, 2020	$ 102,263		$ 3,211		$ 490,093		$ (400,112)		$ 9,071
Beginning balance, shares at Dec. 31, 2020			31,602,953
Issuance of common stock	129,403	$ 16,477	$ 610	$ 77	128,793	$ 16,400		$ 0		$ 0
Issuance of common stock, shares			5,575,757	706,834
Exercise of stock options and vesting of restricted stock units	4,824		$ 42		4,782
Exercise of stock options and vesting of restricted stock units, shares			386,097
Repurchase of restricted stock units	(285)				(285)
Stock-based compensation	3,400				3,400
Currency translation adjustment	(9,391)								(9,391)
Net loss	(10,154)						(10,154)
Ending balance at Mar. 31, 2021	236,537		$ 3,940		643,183		(410,266)		(320)
Ending balance, shares at Mar. 31, 2021			38,271,641
Beginning balance at Dec. 31, 2021	316,201		$ 4,481		787,869		(466,928)		(9,221)
Beginning balance, shares at Dec. 31, 2021			43,467,052
Exercise of stock options and vesting of restricted stock units	879		$ 8		871
Exercise of stock options and vesting of restricted stock units, shares			82,273
Stock-based compensation	5,334				5,334
Currency translation adjustment	(6,048)								(6,048)
Net loss	(18,893)						(18,893)
Ending balance at Mar. 31, 2022	$ 297,473		$ 4,489		$ 794,074		$ (485,821)		$ (15,269)
Ending balance, shares at Mar. 31, 2022			43,549,325

Overview

3 Months Ended

Mar. 31, 2022

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Overview

1. Overview

Merus N.V. is a clinical-stage oncology company developing innovative antibody therapeutics, headquartered in Utrecht, the Netherlands. Merus US, Inc. is a wholly-owned subsidiary of Merus N.V. located at 139 Main Street, Cambridge, Massachusetts, United States (collectively, the “Company”).

Since inception, the Company has generated an accumulated deficit of $485.8 million as of March 31, 2022. The Company expects to continue to incur significant expenses and operating losses for the foreseeable future as its antibody candidates advance through discovery, pre-clinical development and clinical trials and as it seeks regulatory approval and pursues commercialization of any approved antibody candidate.

As a result, the Company may need additional financing to support its continuing operations. Until the Company can generate significant revenue from product sales, if ever, the Company expects to finance its operations through public equity offerings, debt financings, or other sources, which may include collaborations, business development and licensing opportunities with third parties. Adequate additional financing may not be available to the Company on acceptable terms, or at all. The Company’s inability to raise capital as and when needed would have a negative impact on its financial condition and ability to pursue its business strategy. The Company will need to generate significant revenues to achieve profitability and may never do so.

Based on the Company’s current operating plan, the Company expects that its existing cash and cash equivalents and marketable securities of $$384.3 million as of March 31, 2022, will fund the Company’s operations beyond 2024.

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

The principal accounting policies applied in the preparation of these unaudited condensed consolidated financial statements are described in the Company’s audited financial statements as of and for the year ended December 31, 2021, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on February 28, 2022 (the “Annual Report on Form 10-K”). There have been no material changes in the Company’s significant accounting policies during the three months ended March 31, 2022.

Basis of Presentation

The Company prepared its unaudited consolidated condensed financial statements in compliance with generally accepted accounting principles in the U.S. ("U.S. GAAP"). Any reference in these notes to applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification ("ASC") and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB").

The unaudited condensed consolidated financial statements include the accounts of Merus N.V. and its wholly owned, controlled subsidiary, Merus US, Inc. All intercompany transactions and balances of subsidiaries have been eliminated in consolidation. In the opinion of management, these financial statements reflect all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the results for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the unaudited condensed consolidated financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The three months ended March 31, 2022 and 2021 are referred to as the first quarter of 2022 and 2021, respectively. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period.

The unaudited condensed consolidated financial statements presented herein do not contain the required disclosures under U.S. GAAP for annual financial statements. Therefore, these unaudited condensed consolidated financial statements should be read in conjunction with the annual audited consolidated financial statements and related notes as of and for the year ended December 31, 2021, included in the Annual Report on Form 10-K.

Going Concern

At each reporting period, the Company evaluates whether there are conditions or events that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued. The Company is required to make certain additional disclosures if it concludes substantial doubt exists and it is not alleviated by the Company’s plans or when its plans alleviate substantial doubt about the Company’s ability to continue as a going concern.

The Company’s evaluation entails analyzing prospective operating budgets and forecasts for expectations of the Company’s cash needs, and comparing those needs to the current cash, cash equivalent and marketable securities balances. After considering the Company’s current research and development plans, the timing expectations related to the progress of its clinical-stage programs and its plans to pursue commercialization of any approved antibody candidate, and after considering its existing cash, cash equivalents and marketable securities as of March 31, 2022, the Company did not identify conditions or events that raise substantial doubt about the Company’s ability to continue as a going concern within one year from the date these financial statements were issued. Additional details of the Company’s cash runway are described in Note 1 Overview.

Investments in Debt Securities

3 Months Ended

Mar. 31, 2022

Debt Securities [Abstract]

Investments in Debt Securities

3. Investments in Debt Securities

The following tables summarize the Company’s investments in debt securities and their presentation in the condensed consolidated balance sheet:

	March 31, 2022		December 31, 2021
	(in thousands)
Money market funds	$	5,232	$	5,684
Corporate paper and notes		135,469		155,039
U.S. government agency securities		6,082		2,093
U.S. treasuries		48,154		32,155
Total	$	194,937	$	194,971

Fair value of debt securities	$	194,165	$	194,773

	March 31, 2022		December 31, 2021
	(in thousands)
Cash equivalents	$	5,232	$	5,684
Current marketable securities		164,239		168,990
Non-current marketable securities		25,466		20,297
Total	$	194,937	$	194,971

The Company does not intend to sell and it is unlikely that the Company will be required to sell the above investments before recovery of their amortized cost bases, which may be at maturity. The Company determined that there was no material change in the credit risk of any of its investments.

The fair value of money market funds is determined based on publicly available market price for these funds (Level 1). The fair value of other debt securities is determined based on the publicly available inputs which includes a market price for the same or similar instruments adjusted for estimates in interest yield (Level 2).

Supplemental Balance Sheet Information

3 Months Ended

Mar. 31, 2022

Balance Sheet Related Disclosures [Abstract]

Supplemental Balance Sheet Information

4. Supplemental Balance Sheet Information

Prepaid expenses and other current assets consisted of the following:

	March 31, 2022		December 31, 2021
	(In thousands)
Prepaid research and development expenses	$	10,049	$	2,146
Prepaid general and administrative expenses		5,269		2,760
Interest receivable		496		367
Other		2,434		2,175
Total	$	18,248	$	7,448

Accrued expenses and other liabilities consisted of the following:

	March 31, 2022		December 31, 2021
	(In thousands)
Accrued research and development expenses	$	15,593	$	15,174
Accrued general and administrative expenses		1,994		4,861
Accrued personnel costs		2,695		1,362
Other		666		1,109
Total	$	20,948	$	22,506

Income Taxes

3 Months Ended

Mar. 31, 2022

Income Tax Disclosure [Abstract]

Income Taxes

5. Income Taxes

The Company files income tax returns in the U.S. federal and Massachusetts jurisdictions as well as in the Netherlands. The components of the income tax expense (benefit) from continuing operations are as follows:

	Three Months Ended March 31,
	2022			2021
	(In thousands)
U.S. federal	$	(171	)	$	(226	)
U.S. state		(52	)		(94	)
Total current income tax benefit	$	(223	)	$	(320	)

U.S. federal	$	238		$	261
U.S. state		99			108
Total deferred income tax expense	$	337		$	369

Total income tax expense	$	114		$	49

After consideration of all positive and negative evidence, we believe that it is more-likely-than-not that the Netherlands deferred tax assets, that are not supported by reversing temporary differences, will not be realized. As a result, we established a full valuation allowance against deferred tax assets of the Netherlands.

Under Dutch tax law, net operating loss carryforwards may be used to offset future taxable income in full up to €1.0 million and 50% of taxable income that exceeds €1.0 million. Effective as of January 1, 2022, these losses can be carried forward indefinitely.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 17
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 270
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6424409&loc=d3e44925-109338

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-URI http://asc.fasb.org/topic&trid=2144680

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Commitments and Contingencies

3 Months Ended

Mar. 31, 2022

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

6. Commitments and Contingencies

Litigation

On April 5, 2018, an unnamed third party filed a notice of opposition against the Company’s EP 2604625 patent, entitled “Generation of Binding Molecules,” in the European Opposition Division of the European Patent Office (the “EPO”). The notice asserted, as applicable, added subject matter, lack of novelty, lack of inventive step, and insufficiency. On August 20, 2018, the Company timely responded to these submissions. An opposition hearing was held in June 2019, wherein the EPO revoked the EP 2604625 patent in its entirety under Art. 123(2) EPC. The Company timely appealed that decision in December 2019 before the Technical Board of Appeals for the EPO (the “TBA”) seeking reinstatement of the patent and proposing auxiliary requests for certain amended claims. The TBA issued a communication on April 20, 2022, issuing preliminary appreciation of matters concerning the appeal, but which are not binding on the board and are subject to an oral proceeding scheduled for May 10, 2022. As this opposition proceeding continues, the Company cannot be certain that it will ultimately prevail.

From time to time, the Company may be involved in various other claims and legal proceedings relating to claims arising out of the Company’s operations. The Company is not currently a party to any material legal proceedings.

Leases

3 Months Ended

Mar. 31, 2022

Leases [Abstract]

Leases

7. Leases

The Company has noncancelable operating leases for offices and lab spaces expiring at various dates through 2026. There have been no changes in the Company’s lease arrangements for the three months ended March 31, 2022.

The components of lease expense for the three months ended March 31, 2022 and 2021 are as follows:

	Three Months Ended March 31,
	2022		2021
	(In thousands)
Lease cost
Operating lease cost	$	385	$	418
Variable lease cost		76		91
Total lease cost included in operating expenses	$	461	$	509
Other information
Cash paid for amounts included in the measurement of lease liabilities included in operating cash flows	$	399	$	435

Collaborations

3 Months Ended

Mar. 31, 2022

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Collaborations

8. Collaborations

Lilly

On January 18, 2021, Eli Lilly and Company, (“Lilly”) agreed to pay the Company a $40.0 million, non-refundable upfront payment, and purchased 706,834 common shares at a stated price per share of $28.295, for an aggregate purchase price of $20.0 million. The Company and Lilly agreed to collaborate with respect to the discovery and research of bispecific antibodies utilizing the Company’s proprietary Biclonics® bispecific technology platform. The collaboration encompasses up to three (3) independent programs directed to the generation of T-cell re-directing bispecific antibodies that bind CD3 and a tumor associated antigen target selected by Lilly to be the subject of each program.

The objective of each program would be to develop a lead compound that Lilly would be able to continue to develop through clinical trials. Lilly agreed to fund the research activities the Company conducts for each program under an agreed research plan and budget. Lilly receives an exclusive, worldwide, royalty-bearing, sublicensable license, under certain patent rights and know-how to exploit certain compounds and products directed to designated targets in combination with CD3, or directed to such designated target(s) alone as a monospecific antibody or monospecific antibody drug conjugate, subject to rights granted by Merus to third parties under one or more existing third party agreements. Merus retains all rights not granted to Lilly. Lilly has certain rights to replace selected targets, including the right to substitute a target selection after initial selection for a period of time. The Company may be entitled to further milestones and royalties in the future dependent on development and commercialization of any resulting product.

The initial term of the arrangement includes a three-year research term for the Company to perform research and development activities, subject to two extension terms of six months at Lilly’s discretion. While the arrangement may be terminated in its entirety or on a program-by-program basis at will by Lilly, there are no direct costs or penalties to Lilly to terminate the arrangement prior to the end of the initial term.

At inception of the arrangement, the Company identified a single performance obligation comprised of a combined delivery of a license and related activities, including research activities associated with the first target and the activities of the joint steering committee. The Company also identified two other combined performance obligations relating to options exercisable by Lilly to select a second and third target to advance selected targets through discovery and research.

The transaction price at inception was comprised of fixed consideration of $43.5 million that was derived from the $40.0 million upfront payment and $20.0 million share purchase proceeds, net of the fair value of shares of the shares delivered to Lilly of $16.5 million, and variable consideration associated with the funding of research services for the first target at inception. All other consideration under the arrangement was determined to be variable consideration and fully constrained at inception.

The fixed consideration was allocated equally amongst the three performance obligations and the variable consideration associated with each target was allocated to the performance obligation of each respective target. The equal allocation of the fixed consideration was based on the estimated standalone selling price of each performance obligation as each was materially the same.

On February 12, 2021, the Company and Lilly completed the initial exchange of fixed consideration and transfer of common shares. The Company initially deferred $43.5 million allocated to the performance obligations to be recognized as revenue over time using a cost-to-cost measure of progress toward the development of a lead compound for each respective target, anticipated to be recognized

as revenue within the initial research term, along with research funding. Development milestones, commercialization milestones and royalties are variable consideration, fully constrained, to be included in the transaction price for each performance obligation and recognized in future periods in accordance with the Company’s revenue recognition policy. The revenue recognized relating to each combined performance obligation is presented in the notes according to the source of consideration received (upfront, reimbursement revenue, milestone), reflective of their differing timing of receipt.

As of March 31, 2022, research activities are on-going. No milestones have been achieved to date.

Incyte

On January 23, 2017, the Company completed the sale of shares and exchange of a license with Incyte Corporation (“Incyte”). The Company initially deferred $152.6 million of the transaction price allocated to the license and related performance obligation as deferred revenue, to be recognized as revenue over time as the primary benefit of the license to Incyte is access to the Company’s intellectual property covering its Biclonics® technology platform for the generation of potential product candidates. Development milestones, commercialization milestones and royalties are variable consideration, fully constrained, to be recognized in future periods in accordance with the Company’s revenue recognition policy. Cost reimbursements for research services are recognized as they are performed over time as these are considered a separate performance obligation.

In January 2022, the Company announced that Incyte elected to opt-out of its ex-U.S. development of MCLA-145, from the parties joint collaboration agreement executed in 2017. At inception of the collaboration, for the designated product candidate (MCLA-145), the Company retained the exclusive right to develop and commercialize products and product candidates in the United States, while Incyte obtained the exclusive right to develop and commercialize products and product candidates arising from such program outside the United States. For MCLA-145, the parties conducted and shared equally the costs of mutually agreed global development activities. Incyte’s opt-out of ex-U.S. rights to MCLA-145 provides the Company the exclusive right to develop and commercialize potential MCLA-145 products globally. Under the collaboration, Incyte will continue to support the program for a limited time while ex-U.S. activities are transitioned to the Company, and Incyte will retain a right to a residual royalty of up to 4% on sales of future commercialization of MCLA-145, if approved.

There were no development or commercialization milestones achieved during the three months ended March 31, 2022.

ONO

On March 14, 2018, the Company granted ONO Pharmaceuticals Co. Ltd. (“ONO”) an exclusive, worldwide, royalty-bearing license, with the right to sublicense, research, test, make, use and market a limited number of bispecific antibody candidates based on the Company’s Biclonics^® technology platform against two undisclosed targets directed to a particular undisclosed target combination. ONO agreed to pay the Company an upfront, non-refundable payment of €0.7 million. In addition, the Company was entitled to €0.3 million intended to compensate the Company for research services already completed upon entering into the agreement, and €0.2 million to be paid to the Company over time for full-time equivalent funding. The Company is entitled to research and development milestones in addition to royalties on future sales. The Company identified performance obligations for: (1) provision of a license for the target combination, and (2) research and development services. The Company concluded that ONO would be able to develop and benefit from the license, independent of the research and development services. Certain of the research and development services are capable of being performed by third parties with an appropriate sub-license, and are recognized over time as these services are delivered. Milestone payments are fully constrained as variable consideration to be recognized in future periods in accordance with the Company’s revenue recognition policy.

Amounts related to the provision of a license are amortized over the intended period of use.

Simcere

In January 2018, the Company granted Simcere Pharmaceuticals Group (“Simcere”) an exclusive license to develop and commercialize up to three bispecific antibodies in China to be produced by Merus utilizing the Company’s Biclonics^® technology platform (the “Simcere Agreement”). The Company received an upfront, non-refundable payment of $2.75 million, relating to three separate research programs.

At inception of the arrangement, the Company identified three performance obligations comprised of the combined delivery of a license and performance of research and development activities with respect to each program. The Company performed research and development activities to achieve candidate nomination. The Company concluded that these activities were not distinct from the underlying license for each program as Simcere would not be able to benefit from the license apart from research and development activities at this phase of development.

The transaction price under the arrangement comprised fixed consideration of $2.75 million. The transaction price was allocated to each separate performance obligation on a relative standalone fair value basis. The Company deferred the portion of the upfront payment allocated to the three performance obligations as deferred revenue, to be recognized over time. Compensation for research

and development services prior to candidate nomination are allocated to each program performance obligation and also recognized over time. Development milestone payments allocated to each of the program performance obligations are constrained as variable consideration to be recognized in future periods in accordance with the Company’s revenue recognition policy.

The Company has achieved three milestones under this agreement and has received an aggregate of $1.8 million in milestone payments. In January 2022, the Company and Simcere terminated the Simcere Agreement, effective March 30, 2022.

Contract Assets and Liabilities

The following tables provide amounts by year indicated and by line item included in the Company's accompanying condensed consolidated financial statements attributable to transactions arising from its collaboration arrangements. The dollar amounts in the tables below are in thousands.

	Incyte			Lilly			Other			Total
CONTRACT ASSETS
Accounts receivable
Balance at January 1, 2022	$	1,634		$	—		$	41		$	1,675
Billings		2,888			1,186			489			4,563
Cash receipts		(4,522	)		(1,186	)		(482	)		(6,190	)
Adjustments		—			—			—			—
Foreign exchange		—			—			2			2
Balance at March 31, 2022		—			—			50			50

Unbilled receivables
Balance at January 1, 2022	$	2,975		$	1,203		$	453		$	4,631
Accrued receivables		1,551			958			49			2,558
Billings		(2,888	)		(1,186	)		(489	)		(4,563	)
Adjustments		—			—			—			—
Foreign exchange		—			—			(5	)		(5	)
Balance at March 31, 2022		1,638			975			8			2,621

CONTRACT LIABILITIES
Deferred revenue
Balance at January 1, 2022	$	73,330		$	27,353		$	222		$	100,905
Allocation of contract consideration		—			—			—			—
Revenue recognized in the period		(4,402	)		(4,038	)		(222	)		(8,662	)
Foreign exchange		(1,416	)		(501	)		—			(1,917	)
Balance at March 31, 2022		67,512			22,814			—			90,326
Less: current portion		(17,689	)		(16,007	)		—			(33,696	)
Non-current balance at March 31, 2022		49,823			6,807			—			56,630

The balance of unbilled receivables predominantly represents reimbursement revenue under the Company’s collaboration arrangements earned in the period to be billed and collected in the next period, generally quarterly. Incyte was a related party as more fully described in Note 10.

Contract Revenues and Expenses

	Three Months Ended March 31, 2022
	(In thousands)
	Incyte		Lilly		Other		Total
Upfront payments	$	4,402	$	4,038	$	222	$	8,662
Reimbursement revenue		1,964		979		—		2,943
Milestones		—		—		—		—
Other		—		—		50		50
Total collaboration revenue	$	6,366	$	5,017	$	272	$	11,655
Operating expenses:
Research and development expense	$	360	$	—	$	—	$	360
General and administrative expense		—		—		—		—
Total operating expenses from collaborations	$	360	$	—	$	—	$	360
Revenue recognized that was included in deferred revenue at the beginning of the period	$	4,402	$	4,038	$	222	$	8,662

	Three Months Ended March 31, 2021
	(In thousands)
	Incyte		Lilly		Other		Total
Upfront payments	$	4,734	$	1,146	$	190	$	6,070
Reimbursement revenue		2,017		263		—		2,280
Milestones		—		—		—		—
Total collaboration revenue	$	6,751	$	1,409	$	190	$	8,350
Operating expenses:
Research and development expense	$	359	$	—	$	—	$	359
General and administrative expense		—		—		—		—
Total operating expenses from collaborations	$	359	$	—	$	—	$	359
Revenue recognized that was included in deferred revenue at the beginning of the period	$	4,734	$	—	$	190	$	4,924

Employee Benefits

3 Months Ended

Mar. 31, 2022

Compensation And Retirement Disclosure [Abstract]

Employee Benefits

9. Employee Benefits

Stock-Based Compensation

Stock-based compensation expense is classified in the condensed consolidated statements of operations and comprehensive loss as follows:

	Three Months Ended March 31,
	2022		2021
	(In thousands)
Research and development	$	2,450	$	1,637
General and administrative		2,884		1,763
Total	$	5,334	$	3,400

The weighted-average grant date fair value of options, estimated as of the grant date using the Black Scholes option pricing model was $24.92 per option for the 1,522,250 options granted during the three months ended March 31, 2022. The following assumptions were used to estimate the fair value of the options granted during the three months ended March 31, 2022.

Volatility	76.2	%
Risk-free interest rate	1.6	%
Expected holding period (in years)	6.1
Dividend yield	-

In addition, the Company granted 20,000 RSUs during the three months ended March 31, 2022 with a weighted average grant date fair value of $24.61 per unit.

Executive Settlement

In April 2020, Mark Throsby, Ph.D. resigned as the Executive Vice President and Chief Scientific Officer of the Company effective July 31, 2020. In connection with his departure, Mr. Throsby entered into a Settlement Agreement with the Company, pursuant to which Mr. Throsby received a severance payment equal to 8 months of his annual salary and amortized bonus aggregating approximately $0.3 million. Further, subject to Mr. Throsby’s continued compliance with the terms and conditions of the Settlement Agreement, Mr. Throsby’s unvested equity awards continued to vest until October 31, 2020 as if Mr. Throsby had continued in full time service with the Company through such date. The post-termination exercise period of Mr. Throsby's options was extended to March 31, 2021. The Company incrementally recognized $0.1 million in respect of the severance payment and a net reversal of $0.4 million of stock-based compensation expense in respect of share-based payments in research and development expense in the consolidated statement of operations in the prior year.

In March 2021, the Company and Mr. Throsby amended the Settlement Agreement, extending the post-termination expiration period of his outstanding options to extend to October 31, 2021, three months following his performance of certain consulting services through July 31, 2021. As a result, additional compensation cost of $0.2 million was recognized for the quarter ended March 31, 2021. In July 2021, the Company and Mr. Throsby entered into the 2^nd Amendment to the Settlement Agreement, extending Mr. Throsby’s consulting services period to February 28, 2022, extending the post-termination period of his outstanding options to May 2022. As the modification occurred in Mr. Throsby’s post-employment period, the options cease to be within the scope of ASC 718 and are recharacterized as an issuance of a standalone derivative instrument. The Company recognized a $0.4 million net gain associated with the derivative instrument included as other income in the statement of operations for the three months ended March 31, 2022

Related Party Transactions

3 Months Ended

Mar. 31, 2022

Related Party Transactions

10. Related Party Transactions

•

In 2006, the Company has entered into the Incyte collaboration and license agreement and the Incyte share subscription agreement in which the terms and transactional amounts incurred between Incyte and the Company are more fully described in Note 8. Incyte’s holdings of the Company’s total outstanding shares fell below 10.0% due to the Company issuing additional shares of common stocks through various financing events of 2021. Effective January 1, 2022, these unaudited condensed consolidated financial statements no longer present the Company’s transactions with Incyte separately as related party. Incyte holds approximately 8.2% of the outstanding shares of the Company as of March 31, 2022. See Note 8 for additional details of transactional activities between Incyte and the Company for the three months ended March 31, 2022.

Subsequent Events

3 Months Ended

Mar. 31, 2022

Subsequent Events [Abstract]

Subsequent Events

11. Subsequent Events

In April 2022, the lease agreement between the Company and Kadans Science Partner XII B.V. (“Kadans”) commenced. The Company has begun certain fit-out construction on approximately 5,030 square meters of office and laboratory space in the premises, which is expected to complete on or around December 2022. The lease provides for a base rent of approximately €1.3 million per annum. The rent amount is subject to adjustment based on the consumer price index (the “CPI”) annually, subject to certain limitations if the CPI is greater than 3.0%. The initial term of the lease is ten years with two 5-year renewal options following the initial term, unless earlier terminated by the Company or Kadans, except that the earliest Kadans may terminate the lease is 20 years from the completion date of the premise construction. The Company is currently assessing the impact of the lease agreement.

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Preparation	Basis of Presentation The Company prepared its unaudited consolidated condensed financial statements in compliance with generally accepted accounting principles in the U.S. ("U.S. GAAP"). Any reference in these notes to applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification ("ASC") and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB"). The unaudited condensed consolidated financial statements include the accounts of Merus N.V. and its wholly owned, controlled subsidiary, Merus US, Inc. All intercompany transactions and balances of subsidiaries have been eliminated in consolidation. In the opinion of management, these financial statements reflect all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the results for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the unaudited condensed consolidated financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The three months ended March 31, 2022 and 2021 are referred to as the first quarter of 2022 and 2021, respectively. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period. The unaudited condensed consolidated financial statements presented herein do not contain the required disclosures under U.S. GAAP for annual financial statements. Therefore, these unaudited condensed consolidated financial statements should be read in conjunction with the annual audited consolidated financial statements and related notes as of and for the year ended December 31, 2021, included in the Annual Report on Form 10-K.
Going Concern	Going Concern At each reporting period, the Company evaluates whether there are conditions or events that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued. The Company is required to make certain additional disclosures if it concludes substantial doubt exists and it is not alleviated by the Company’s plans or when its plans alleviate substantial doubt about the Company’s ability to continue as a going concern.

Investments in Debt Securities (Tables)

3 Months Ended

Mar. 31, 2022

Debt Securities [Abstract]

Summary of Investments in Debt Securities in Condensed Consolidated Balance Sheet

The following tables summarize the Company’s investments in debt securities and their presentation in the condensed consolidated balance sheet:

	March 31, 2022		December 31, 2021
	(in thousands)
Money market funds	$	5,232	$	5,684
Corporate paper and notes		135,469		155,039
U.S. government agency securities		6,082		2,093
U.S. treasuries		48,154		32,155
Total	$	194,937	$	194,971

Fair value of debt securities	$	194,165	$	194,773

	March 31, 2022		December 31, 2021
	(in thousands)
Cash equivalents	$	5,232	$	5,684
Current marketable securities		164,239		168,990
Non-current marketable securities		25,466		20,297
Total	$	194,937	$	194,971

Supplemental Balance Sheet Information (Tables)

3 Months Ended

Mar. 31, 2022

Balance Sheet Related Disclosures [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following:

	March 31, 2022		December 31, 2021
	(In thousands)
Prepaid research and development expenses	$	10,049	$	2,146
Prepaid general and administrative expenses		5,269		2,760
Interest receivable		496		367
Other		2,434		2,175
Total	$	18,248	$	7,448

Summary of Accrued Expenses and Other Liabilities

Accrued expenses and other liabilities consisted of the following:

	March 31, 2022		December 31, 2021
	(In thousands)
Accrued research and development expenses	$	15,593	$	15,174
Accrued general and administrative expenses		1,994		4,861
Accrued personnel costs		2,695		1,362
Other		666		1,109
Total	$	20,948	$	22,506

Income Taxes (Tables)

3 Months Ended

Mar. 31, 2022

Income Tax Disclosure [Abstract]

Summary of Components of Expense for (Benefit) from Income Taxes

The components of the income tax expense (benefit) from continuing operations are as follows:

	Three Months Ended March 31,
	2022			2021
	(In thousands)
U.S. federal	$	(171	)	$	(226	)
U.S. state		(52	)		(94	)
Total current income tax benefit	$	(223	)	$	(320	)

U.S. federal	$	238		$	261
U.S. state		99			108
Total deferred income tax expense	$	337		$	369

Total income tax expense	$	114		$	49

Leases (Tables)

3 Months Ended

Mar. 31, 2022

Leases [Abstract]

Summary of Components of Lease Cost

The components of lease expense for the three months ended March 31, 2022 and 2021 are as follows:

	Three Months Ended March 31,
	2022		2021
	(In thousands)
Lease cost
Operating lease cost	$	385	$	418
Variable lease cost		76		91
Total lease cost included in operating expenses	$	461	$	509
Other information
Cash paid for amounts included in the measurement of lease liabilities included in operating cash flows	$	399	$	435

Collaborations (Tables)

3 Months Ended

Mar. 31, 2022

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Summary of Company's Accompanying Condensed Consolidated Financial Statements Attributable to Transactions Arising From Collaboration Arrangements

	Incyte			Lilly			Other			Total
CONTRACT ASSETS
Accounts receivable
Balance at January 1, 2022	$	1,634		$	—		$	41		$	1,675
Billings		2,888			1,186			489			4,563
Cash receipts		(4,522	)		(1,186	)		(482	)		(6,190	)
Adjustments		—			—			—			—
Foreign exchange		—			—			2			2
Balance at March 31, 2022		—			—			50			50

Unbilled receivables
Balance at January 1, 2022	$	2,975		$	1,203		$	453		$	4,631
Accrued receivables		1,551			958			49			2,558
Billings		(2,888	)		(1,186	)		(489	)		(4,563	)
Adjustments		—			—			—			—
Foreign exchange		—			—			(5	)		(5	)
Balance at March 31, 2022		1,638			975			8			2,621

CONTRACT LIABILITIES
Deferred revenue
Balance at January 1, 2022	$	73,330		$	27,353		$	222		$	100,905
Allocation of contract consideration		—			—			—			—
Revenue recognized in the period		(4,402	)		(4,038	)		(222	)		(8,662	)
Foreign exchange		(1,416	)		(501	)		—			(1,917	)
Balance at March 31, 2022		67,512			22,814			—			90,326
Less: current portion		(17,689	)		(16,007	)		—			(33,696	)
Non-current balance at March 31, 2022		49,823			6,807			—			56,630

Summary of Company's Collaboration Arrangements Earned in Period to Be Billed and Collected in Next Period

Contract Revenues and Expenses

	Three Months Ended March 31, 2022
	(In thousands)
	Incyte		Lilly		Other		Total
Upfront payments	$	4,402	$	4,038	$	222	$	8,662
Reimbursement revenue		1,964		979		—		2,943
Milestones		—		—		—		—
Other		—		—		50		50
Total collaboration revenue	$	6,366	$	5,017	$	272	$	11,655
Operating expenses:
Research and development expense	$	360	$	—	$	—	$	360
General and administrative expense		—		—		—		—
Total operating expenses from collaborations	$	360	$	—	$	—	$	360
Revenue recognized that was included in deferred revenue at the beginning of the period	$	4,402	$	4,038	$	222	$	8,662

	Three Months Ended March 31, 2021
	(In thousands)
	Incyte		Lilly		Other		Total
Upfront payments	$	4,734	$	1,146	$	190	$	6,070
Reimbursement revenue		2,017		263		—		2,280
Milestones		—		—		—		—
Total collaboration revenue	$	6,751	$	1,409	$	190	$	8,350
Operating expenses:
Research and development expense	$	359	$	—	$	—	$	359
General and administrative expense		—		—		—		—
Total operating expenses from collaborations	$	359	$	—	$	—	$	359
Revenue recognized that was included in deferred revenue at the beginning of the period	$	4,734	$	—	$	190	$	4,924

Employee Benefits (Tables)

3 Months Ended

Mar. 31, 2022

Compensation And Retirement Disclosure [Abstract]

Summary of Stock-based Compensation Expense Classified in Condensed Consolidated Statements of Operations and Comprehensive Loss

Stock-based compensation expense is classified in the condensed consolidated statements of operations and comprehensive loss as follows:

	Three Months Ended March 31,
	2022		2021
	(In thousands)
Research and development	$	2,450	$	1,637
General and administrative		2,884		1,763
Total	$	5,334	$	3,400

Summary of Assumptions Used to Estimate Fair Value of Options Granted

The following assumptions were used to estimate the fair value of the options granted during the three months ended March 31, 2022.

Volatility	76.2	%
Risk-free interest rate	1.6	%
Expected holding period (in years)	6.1
Dividend yield	-

Overview - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ (485,821)	$ (466,928)
Cash and cash equivalents and marketable securities	$ 384,300

- Definition

The cumulative amount of the reporting entity's undistributed earnings or deficit.

+ References + Details

Investments in Debt Securities - Summary of Investments in Debt Securities in Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule Of Held To Maturity Securities [Line Items]
Total	$ 194,937	$ 194,971
Fair value of debt securities	194,165	194,773
Cash equivalents [member]
Schedule Of Held To Maturity Securities [Line Items]
Total	5,232	5,684
Current marketable securities [member]
Schedule Of Held To Maturity Securities [Line Items]
Total	164,239	168,990
Non-current marketable securities [member]
Schedule Of Held To Maturity Securities [Line Items]
Total	25,466	20,297
Money market funds [member]
Schedule Of Held To Maturity Securities [Line Items]
Total	5,232	5,684
Corporate paper and notes [member]
Schedule Of Held To Maturity Securities [Line Items]
Total	135,469	155,039
U.S. government agency securities [member]
Schedule Of Held To Maturity Securities [Line Items]
Total	6,082	2,093
U.S. treasuries [member]
Schedule Of Held To Maturity Securities [Line Items]
Total	$ 48,154	$ 32,155

Supplemental Balance Sheet Information - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Prepaid Expense And Other Assets Current [Abstract]
Prepaid research and development expenses	$ 10,049	$ 2,146
Prepaid general and administrative expenses	5,269	2,760
Interest receivable	496	367
Other	2,434	2,175
Total	$ 18,248	$ 7,448

Supplemental Balance Sheet Information - Summary of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables And Accruals [Abstract]
Accrued research and development expenses	$ 15,593	$ 15,174
Accrued general and administrative expenses	1,994	4,861
Accrued personnel costs	2,695	1,362
Other	666	1,109
Total	$ 20,948	$ 22,506

Income Taxes - Summary of Components of Expense for (Benefit) from Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
U.S. federal	$ (171)	$ (226)
U.S. state	(52)	(94)
Total current income tax benefit	(223)	(320)
U.S. federal	238	261
U.S. state	99	108
Total deferred income tax expense	337	369
Total income tax expense	$ 114	$ 49

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Income Taxes - Additional Information (Details) - Dutch Tax Law € in Millions	3 Months Ended
	Mar. 31, 2022 EUR (€)
Income Tax Disclosure [Line Items]
Taxable income that exceeds €1.0 million, percentage	50.00%
Maximum
Income Tax Disclosure [Line Items]
Future taxable income offset limit	€ 1.0
Minimum
Income Tax Disclosure [Line Items]
Future taxable income exceeding limit	€ 1.0

Leases - Summary of Components of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Lease cost
Operating lease cost	$ 385	$ 418
Variable lease cost	76	91
Total lease cost included in operating expenses	461	509
Other information
Cash paid for amounts included in the measurement of lease liabilities included in operating cash flows	$ 399	$ 435

Collaborations - Additional Information (Details) $ / shares in Units, $ in Thousands, € in Millions					1 Months Ended		3 Months Ended
	Jan. 18, 2021 USD ($) $ / shares shares	Aug. 31, 2018 USD ($)	Mar. 14, 2018 EUR (€)	Jan. 23, 2017 USD ($)	Jan. 31, 2022	Jan. 31, 2018 USD ($) Antibody PerformanceObligation Milestone	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Feb. 12, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Proceeds from issuance of common stock, net							$ 0	$ 129,568
Net fair value of shares								$ 285
Lilly Collaborations Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Non-refundable upfront payment receivable	$ 40,000
Issuance of common stock, shares \| shares	706,834
Common stock stated purchase price per share \| $ / shares	$ 28.295
Proceeds from issuance of common stock, net	$ 20,000
Fixed consideration	43,500								$ 43,500
Upfront payment	40,000
Net fair value of shares	$ 16,500
Incyte Collaboration and License Agreement \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Residual royalty percentage					4.00%
Incyte Collaboration and License Agreement \| License and Related Activities
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborations, transaction price as deferred revenue				$ 152,600
Second ONO Research and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Non-refundable upfront payment receivable \| €			€ 0.7
Payment to compensate research services \| €			0.3
Over time payment for full time equivalent funding \| €			€ 0.2
Simcere Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of bispecific antibodies under collaboration and license agreement \| Antibody						3
Non-refundable upfront payment received						$ 2,750
Collaborations, transaction price as revenue						$ 2,750
Milestone payments received		$ 1,800
Number of milestones achieved \| Milestone						3
Simcere Collaboration and License Agreement \| License and Performance \| Research and Development
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of performance obligation \| PerformanceObligation						3

Collaborations - Summary of Company's Accompanying Consolidated Financial Statements Attributable to Transactions Arising From Collaboration Arrangements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Incyte
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized in the period	$ 4,402	$ 4,734
Incyte \| Accounts Receivable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022			$ 1,634
Billings	2,888
Cash receipts	(4,522)
Balance at March 31, 2022			1,634
Incyte \| Unbilled Receivables
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022	1,638		2,975
Accrued receivables	1,551
Billings	(2,888)
Balance at March 31, 2022	1,638		2,975
Incyte \| Deferred Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022	67,512		73,330
Foreign exchange	(1,416)
Revenue recognized in the period	(4,402)
Balance at March 31, 2022	67,512		73,330
Less: current portion	(17,689)
Non-current balance at March 31, 2022	49,823
Lilly
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized in the period	4,038	0
Lilly \| Accounts Receivable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Billings	1,186
Cash receipts	(1,186)
Lilly \| Unbilled Receivables
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022	975		1,203
Accrued receivables	958
Billings	(1,186)
Balance at March 31, 2022	975		1,203
Lilly \| Deferred Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022	22,814		27,353
Foreign exchange	(501)
Revenue recognized in the period	(4,038)
Balance at March 31, 2022	22,814		27,353
Less: current portion	(16,007)
Non-current balance at March 31, 2022	6,807
Other
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized in the period	222	190
Other \| Accounts Receivable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022	50		41
Billings	489
Cash receipts	(482)
Foreign exchange	2
Balance at March 31, 2022	50		41
Other \| Unbilled Receivables
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022	8		453
Accrued receivables	49
Billings	(489)
Foreign exchange	(5)
Balance at March 31, 2022	8		453
Other \| Deferred Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022			222
Revenue recognized in the period	(222)
Balance at March 31, 2022			222
Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized in the period	8,662	$ 4,924
Collaboration Agreement \| Accounts Receivable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022	50		1,675
Billings	4,563
Cash receipts	(6,190)
Foreign exchange	2
Balance at March 31, 2022	50		1,675
Collaboration Agreement \| Unbilled Receivables
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022	2,621		4,631
Accrued receivables	2,558
Billings	(4,563)
Foreign exchange	(5)
Balance at March 31, 2022	2,621		4,631
Collaboration Agreement \| Deferred Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at January 1, 2022	90,326		100,905
Foreign exchange	(1,917)
Revenue recognized in the period	(8,662)
Balance at March 31, 2022	90,326		$ 100,905
Less: current portion	(33,696)
Non-current balance at March 31, 2022	$ 56,630

Collaborations - Summary of Company's Collaboration Arrangements Earned in Period to Be Billed and Collected in Next Period (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses:
Research and development	$ 26,975	$ 20,806
General and administrative	11,753	9,333
Total operating expenses	38,728	30,139
Incyte
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payments	4,402	4,734
Reimbursement revenue	1,964	2,017
Milestones	0	0
Other	0
Total collaboration revenue	6,366	6,751
Operating expenses:
Research and development	360	359
General and administrative	0	0
Total operating expenses	360	359
Revenue recognized in the period	4,402	4,734
Lilly
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payments	4,038	1,146
Reimbursement revenue	979	263
Milestones	0	0
Other	0
Total collaboration revenue	5,017	1,409
Operating expenses:
Research and development	0	0
General and administrative	0	0
Total operating expenses	0	0
Revenue recognized in the period	4,038	0
Other
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payments	222	190
Reimbursement revenue	0	0
Milestones	0	0
Other	50
Total collaboration revenue	272	190
Operating expenses:
Research and development	0	0
General and administrative	0	0
Total operating expenses	0	0
Revenue recognized in the period	222	190
Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payments	8,662	6,070
Reimbursement revenue	2,943	2,280
Milestones	0	0
Other	50
Total collaboration revenue	11,655	8,350
Operating expenses:
Research and development	360	359
General and administrative	0	0
Total operating expenses	360	359
Revenue recognized in the period	$ 8,662	$ 4,924

Employee Benefits - Summary of Stock-based Compensation Expense Classified in Condensed Consolidated Statements of Operations and Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 5,334	$ 3,400
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	2,450	1,637
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 2,884	$ 1,763

Employee Benefits - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Apr. 30, 2020	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average fair value of options granted		$ 24.92
Share-based payment award, fair value assumptions, method used		Black Scholes option pricing model
Number of options granted		1,522,250
Severance payment				$ 0.1
Additional compensation cost			$ 0.2
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Net reversal of stock-based compensation expense				$ 0.4
Other Income
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Net gain associated with the derivative instrument		$ 0.4
Postemployment Retirement Benefits
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Executive settlements, cash compensation paid	$ 0.3
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation, RSUs granted		20,000
Weighted average grant date fair value		$ 24.61

Employee Benefits - Summary of Assumptions Used to Estimate Fair Value of Options Granted (Details)	3 Months Ended
	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Volatility	76.20%
Risk-free interest rate	1.60%
Expected holding period (in years)	6 years 1 month 6 days

Related Party Transactions - Additional Information (Details) - Incyte - Merus N V [Member]	Mar. 31, 2022
Related Party Transaction [Line Items]
Ownership percentage	8.20%
Maximum
Related Party Transaction [Line Items]
Ownership percentage	10.00%

Subsequent Events - Additional Information (Details) - Kadans Science Partner XII BV - Office And Laboratory - Subsequent Event € in Millions	1 Months Ended
	Apr. 30, 2022 EUR (€) m²
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Area of property available for operating lease \| m²	5,030
Operating lease, base expense \| €	€ 1.3
Operating lease, rent adjustment description	The rent amount is subject to adjustment based on the consumer price index (the “CPI”) annually, subject to certain limitations if the CPI is greater than 3.0%.
Extended lease term	10 years
Operating lease, renewal term	5 years
Operating lease, termination term	20 years
Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Consumer price Index	3.00%