0000950170-22-008476 | 10-Q | XBRL Viewer

Print Document View Excel Document

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2022	May 02, 2022
Document and Entity Information [Line Items]
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	IGM Biosciences, Inc.
Entity Central Index Key	0001496323
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	IGMS
Security Exchange Name	NASDAQ
Entity File Number	001-39045
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0349194
Entity Address, Address Line One	325 E. Middlefield Road
Entity Address, City or Town	Mountain View
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94043
City Area Code	650
Local Phone Number	965-7873
Document Quarterly Report	true
Document Transition Report	false
Common Stock
Document and Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		27,399,763
Non-voting Common Stock
Document and Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		15,126,858

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 75,417	$ 133,334
Restricted Cash	698	701
Marketable securities	112,045	96,208
Prepaid expenses and other current assets	9,649	10,504
Total current assets	197,809	240,747
Property, plant and equipment, net	29,984	28,495
Operating lease right-of-use assets	28,941	27,849
Other non-current assets	1,007	1,036
Total assets	257,741	298,127
Current liabilities:
Accounts payable	4,011	5,584
Accrued liabilities	19,303	18,876
Lease liabilities, current	4,054	3,320
Total current liabilities	27,368	27,780
Lease liabilities, non-current	25,854	25,439
Total liabilities	53,222	53,219
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value; 200,000,000 shares authorized; no shares issued and outstanding	0	0
Additional paid-in-capital	610,005	598,373
Accumulated other comprehensive loss	(193)	(66)
Accumulated deficit	(405,618)	(353,724)
Total stockholders’ equity	204,519	244,908
Total liabilities and stockholders’ equity	257,741	298,127
Common Stock Class Undefined
Stockholders' equity:
Common stock, value	261	261
Non-voting Common Stock
Stockholders' equity:
Common stock, value	$ 64	$ 64

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	200,000,000	200,000,000
Preferred Stock, shares Issued	0	0
Preferred Stock, shares outstanding	0	0
Common Stock Class Undefined
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	26,091,963	26,066,818
Common stock, shares outstanding	26,091,963	26,066,818
Non-voting Common Stock
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	6,431,205	6,431,205
Common stock, shares outstanding	6,431,205	6,431,205

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses:
Research and development	$ 38,875	$ 23,572
General and administrative	13,081	8,134
Total operating expenses	51,956	31,706
Operating Income (Loss), Total	(51,956)	(31,706)
Other income, net	62	62
Net loss	$ (51,894)	$ (31,644)
Net loss per share, basic and diluted	$ (1.53)	$ (0.95)
Weighted-average common shares outstanding, basic and diluted	33,838,895	33,328,994

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 17: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 20: 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(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124509347&loc=SL7669619-108580

Reference 25: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8924-108599

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124509347&loc=SL7669625-108580

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

+ Details

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net loss	$ (51,894)	$ (31,644)
Other comprehensive (loss) income:
Unrealized loss on marketable securities	(127)	(12)
Comprehensive loss	$ (52,021)	$ (31,656)

- Definition

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

+ References

+ Details

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Non-voting Common Stock	Common Stock	Common Stock Non-voting Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance at Dec. 31, 2020	$ 381,815		$ 255	$ 64	$ 570,030	$ 26	$ (188,560)
Balance, shares at Dec. 31, 2020		6,431,205	25,542,931
Exercise of stock options, net of shares withheld for taxes and exercise costs	(53)				(53)
Exercise of stock options, net of shares withheld for taxes and exercise costs, shares			37,065
Issuance of fully vested restricted stock units, shares			1,216
Unrealized loss on marketable securities	(12)					(12)
Stock-based compensation expense	5,504				5,504
Net loss	(31,644)						(31,644)
Balance at Mar. 31, 2021	355,610		$ 255	64	575,481	14	(220,204)
Balance, shares at Mar. 31, 2021		6,431,205	25,581,212
Balance at Dec. 31, 2021	244,908		$ 261	64	598,373	(66)	(353,724)
Balance, shares at Dec. 31, 2021		6,431,205	26,066,818
Exercise of stock options, net of shares withheld for taxes and exercise costs	133				133
Exercise of stock options, net of shares withheld for taxes and exercise costs, shares			23,432
Issuance of fully vested restricted stock units, shares			1,713
Unrealized loss on marketable securities	(127)					(127)
Stock-based compensation expense	11,499				11,499
Net loss	(51,894)						(51,894)
Balance at Mar. 31, 2022	$ 204,519		$ 261	$ 64	$ 610,005	$ (193)	$ (405,618)
Balance, shares at Mar. 31, 2022		6,431,205	26,091,963

- Definition

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

+ References

+ Details

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-URI http://asc.fasb.org/extlink&oid=122038336&loc=d3e74512-122707

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(31))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

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	$ (51,894)	$ (31,644)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,224	673
Stock-based compensation expense	11,499	5,504
Net amortization of premiums and accretion of discounts on investments	165	195
Non-cash lease expense	1,001	672
Changes in assets and liabilities:
Prepaid expenses and other current assets	933	(2,500)
Other assets	29	(338)
Accounts payable	(1,244)	1,045
Accrued liabilities	362	(1,158)
Lease liabilities, net	(944)	(711)
Net cash used in operating activities	(38,869)	(28,262)
Cash flows from investing activities:
Purchase of property, plant and equipment	(2,977)	(6,073)
Purchases of marketable securities	(40,146)	(12,989)
Proceeds from maturities of marketable securities	24,000	58,673
Net cash (used in) provided by investing activities	(19,123)	39,611
Cash flows from financing activities:
Payment of employee taxes and exercise costs for shares withheld	(7)	(418)
Proceeds from exercise of stock options	140	365
Payment of deferred offering costs	(61)	0
Net cash provided by (used in) financing activities	72	(53)
Net decrease in cash and cash equivalents	(57,920)	11,296
Beginning of period	134,035	241,080
End of period	76,115	252,376
Supplemental disclosure of non-cash investing and financing activities:
Right-of-use assets recognized in exchange for lease obligations	2,093	1,844
Acquisition of property, plant and equipment in accounts payable and accrued liabilities	231	856
Issuance costs for public offerings in accounts payable	$ 460	$ 269

Organization	3 Months Ended
Organization	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Note 1. Organization Description of the Business IGM Biosciences, Inc. (the Company) was incorporated in the state of Delaware in August 1993 under the name Palingen, Inc. and the name was subsequently changed to IGM Biosciences, Inc. in 2010. The Company’s headquarters are in Mountain View, California. IGM Biosciences, Inc. is a biotechnology company engaged in the development of IgM antibody therapeutics for the treatment of cancer, infectious diseases and autoimmune and inflammatory diseases. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (GAAP) and applicable rules and regulations of the Securities and Exchange Commission (SEC) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2021 has been derived from the audited financial statements at that date but does not include all of the information required by GAAP for complete financial statements. These unaudited interim condensed consolidated financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments which are necessary for a fair statement of the Company’s financial information. The interim results of operations for the three months ended March 31, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 or for any other interim period or for any other future year. The accompanying unaudited condensed consolidated financial statements include the accounts of the Company's wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The accompanying interim unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2021, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 29, 2022. Liquidity The Company has incurred net operating losses and negative cash flows from operations since its inception and had an accumulated deficit of $405.6 million as of March 31, 2022. As of March 31, 2022, the Company had cash, cash equivalents, and marketable securities of $187.5 million. Management believes that the existing financial resources, including the $218.0 million of net proceeds received in April 2022 as part of a public offering (see Note 10), are sufficient to continue operating activities at least one year past the issuance date of these condensed consolidated financial statements. The Company has historically financed its operations primarily through the sale of common stock and pre-funded warrants in its public offerings and the sale of convertible preferred stock and the issuance of unsecured promissory notes in private placements. To date, none of the Company’s product candidates have been approved for sale, and the Company has not generated any revenue since inception. Management expects operating losses to continue and increase for the foreseeable future, as the Company progresses its planned research and development activities for its product candidates. The Company’s prospects are subject to risks, expenses and uncertainties frequently encountered by companies in the biotechnology industry as discussed below. While the Company has been able to raise multiple rounds of financing, there can be no assurance that in the event the Company requires additional financing, such financing will be available on terms which are favorable or at all. Failure to raise sufficient capital when needed or generate sufficient cash flow from operations would impact the ability to pursue business strategies and could require the Company to delay, scale back or discontinue one or more product development programs, or other aspects of the Company's business objectives.

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Note 2. Summary of Significant Accounting Policies

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates, including, but not limited to, those related to investments, manufacturing accruals, accrued research and development expenses, stock-based compensation, operating lease right-of-use (ROU) assets and liabilities, income tax uncertainties and the valuation of deferred tax assets. The Company bases its estimates on its historical experience and also on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates.

Segments

The Company operates and manages its business as one reportable and operating segment, which is the business of developing engineered IgM antibodies for the treatment of cancer, infectious diseases and autoimmune and inflammatory diseases. The

Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating and evaluating financial performance. All long-lived assets are maintained in, and all losses are attributable to, the United States of America.

Concentration of Credit Risk and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of cash, cash equivalents, and marketable securities. The Company invests in money market funds, U.S. Treasury securities, corporate bonds, commercial paper, and U.S. government agency securities. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash and issuers of investments to the extent recorded on the balance sheets. The Company’s investment policy limits investments to high credit quality securities issued by the U.S. Government and its agencies, highly rated banks, and corporate issuers, subject to certain concentration limits and restrictions on maturities. The Company has not experienced any losses on its deposits of cash, cash equivalents, and marketable securities.

The Company’s future results of operations involve a number of other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, the Company’s early stages of clinical drug development; uncertainties related to the use of engineered IgM antibodies, which is a novel and unproven therapeutic approach; the Company’s ability to advance product candidates into, and successfully complete, clinical trials on the timelines it projects; the Company’s ability to adequately demonstrate sufficient safety and efficacy of its product candidates; the Company’s ability to enroll patients in its ongoing and future clinical trials; the Company’s ability to successfully manufacture and supply its product candidates for clinical trials; the Company’s ability to obtain additional capital to finance its operations; uncertainties related to the projections of the size of patient populations suffering from the diseases the Company is targeting; the Company’s ability to obtain, maintain, and protect its intellectual property rights; developments relating to the Company’s competitors and its industry, including competing product candidates and therapies; general economic and market conditions; and other risks and uncertainties, including those more fully described in the “Risk Factors” section of this Quarterly Report on Form 10-Q.

The Company’s product candidates will require approvals from the U.S. Food and Drug Administration (FDA) and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company was denied approval, approval was delayed or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash and cash equivalents. Cash equivalents consist primarily of amounts invested in money market funds and commercial paper and are stated at fair value. Restricted cash consists of a grant received from a non-profit organization which the Company will utilize as it incurs expenses for services performed under the grant agreement.

Marketable Securities

The Company’s marketable securities have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. Treasury securities, U.S. government agency securities, corporate debt, and commercial paper. The specific identification method is used to determine the cost basis of fixed income securities sold. These securities are recorded on the condensed consolidated balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive income (loss). The cost of investment securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other income, net. Realized gains and losses and declines in fair value judged to be other-than-temporary, if any, are also included in other income, net. The Company evaluates securities for other-than-temporary impairment at the balance sheet date. Declines in fair value determined to be other-than-temporary are also included in other income, net. All available-for-sale securities are considered available to support current operations and are classified as current assets.

Property, Plant and Equipment

Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is determined using the straight-line method over the estimated useful lives of the respective assets, generally three to five years. Leasehold improvements are depreciated using the straight-line method over the shorter of the lease term or the estimated useful economic lives of the related assets. Assets are held in construction in progress until placed in service, upon which date, we begin to depreciate these assets.

Upon retirement or sale of the assets, the cost and related accumulated depreciation and amortization are removed from the balance sheet and the resulting gain or loss are recorded to the statements of operations. Repairs and maintenance are charged to the condensed consolidated statements of operations as incurred.

Leases

The Company determines if an arrangement is a lease at inception. In addition, the Company determines whether leases meet the classification criteria of a finance or operating lease at the lease commencement date considering: (1) whether the lease transfers ownership of the underlying asset to the lessee at the end of the lease term, (2) whether the lease grants the lessee an option to purchase the underlying asset that the lessee is reasonably certain to exercise, (3) whether the lease term is for a major part of the remaining economic life of the underlying asset, (4) whether the present value of the sum of the lease payments and residual value guaranteed by the lessee equals or exceeds substantially all of the fair value of the underlying asset, and (5) whether the underlying asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. As of March 31, 2022, the Company's lease population consisted of real estate. As of March 31, 2022, the Company did not have finance leases.

Operating leases are included in operating lease ROU assets, lease liabilities, current, and lease liabilities, non-current in the Company’s condensed consolidated balance sheet. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the present value of lease payments, the Company uses its incremental borrowing rate based on the information available at the lease commencement date if the rate implicit in the lease is not readily determinable. The Company determines the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to the Company.

The determination of the Company’s incremental borrowing rate requires management judgment including the development of a synthetic credit rating and cost of debt as the Company currently does not carry any debt. The Company believes that the estimates used in determining the incremental borrowing rate are reasonable based upon current facts and circumstances. Applying different judgments to the same facts and circumstances could result in the estimated amounts to vary. The operating lease ROU assets also include adjustments for prepayments and accrued lease payments and exclude lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease cost is recognized on a straight-line basis over the expected lease term. Variable lease costs represent payments that are dependent on usage, a rate or index. Variable lease cost primarily relates to common area maintenance charges. Lease agreements that include lease and non-lease components are accounted for as a single lease component. Lease agreements with a noncancelable term of less than 12 months are not recorded on the Company’s condensed consolidated balance sheet.

Impairment of Long-Lived Assets

The Company evaluates the carrying amount of its long-lived assets, such as property and equipment, whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss would be recognized when estimated future cash flows expected to result from the use of the asset and its eventual disposition are less than the carrying amount of the asset. As of March 31, 2022, there was no impairment of long-lived assets.

Fair Value Measurement

The Company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the condensed consolidated financial statements on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:

Level 1—Observable inputs, such as quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3—Unobservable inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value.

Financial instruments classified within Level 2 of the fair value hierarchy are valued based on other observable inputs, including broker or dealer quotations or alternative pricing sources. When quoted prices in active markets for identical assets or liabilities are not available, the Company relies on non-binding quotes from its investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments, or historical pricing trends of a security relative to its peers. To validate the fair value determination provided by its investment managers, the Company reviews the pricing movement in the context of overall market trends and trading information from its investment managers. In addition, the Company assesses the inputs and methods used in determining the fair value in order to determine the classification of securities in the fair value hierarchy.

Research and Development Expenses

The Company expenses research and development costs as they are incurred. Research and development expenses consist primarily of: (i) personnel-related expenses, including salaries, benefits and stock-based compensation expense, for personnel in the Company’s research and development functions; (ii) fees paid to third parties such as contractors, consultants and contract research organizations (CROs) for conducting clinical trials, animal studies, and other costs related to clinical and preclinical testing; (iii) costs related to acquiring and manufacturing research and clinical trial materials, including under agreements with third parties such as contract manufacturing organizations (CMOs), and other vendors; (iv) costs related to the preparation of regulatory submissions; (v) expenses related to laboratory supplies and services; (vi) fees under license agreements where no alternative future use exists; and (vii) depreciation of equipment and facilities expenses.

Accrued Research and Development Expenses

The Company records accruals for estimated costs of research, preclinical studies, clinical trials, and manufacturing, which are significant components of research and development expenses. A substantial portion of the Company’s ongoing research and development activities is conducted by third-party service providers, CROs and CMOs. The Company’s contracts with CROs generally include pass-through fees such as costs related to animal studies and safety tests, regulatory expenses, investigator fees, travel costs and other miscellaneous costs, including shipping and printing fees. The Company’s contracts with the CMOs generally include fees such as initiation fees, reservation fees, verification run costs, materials and reagents expenses, taxes, etc. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company accrues the costs incurred under agreements with these third parties based on estimates of actual work completed in accordance with the respective agreements. The Company determines the estimated costs through discussions with internal personnel and external service providers as to the progress, or stage of completion or actual timeline (start-date and end-date) of the services and the agreed-upon fees to be paid for such services. In the event the Company makes advance payments, the payments are recorded as a prepaid expense and recognized as the services are performed.

As actual costs become known, the Company adjusts its accruals. Although the Company does not expect its estimates to be materially different from amounts actually incurred, such estimates for the status and timing of services performed relative to the actual status and timing of services performed may vary and could result in the Company reporting amounts that are too high or too low in any particular period. The Company’s accrual is dependent, in part, upon the receipt of timely and accurate reporting from CROs and other third-party vendors. Variations in the assumptions used to estimate accruals including, but not limited to, the number of patients enrolled, the rate of patient enrollment and the actual services performed, may vary from the Company’s estimates, resulting in adjustments to clinical trial expenses in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect its financial condition and results of operations. Through March 31, 2022, there have been no material differences from the Company’s estimated accrued research and development expenses to actual expenses.

Acquired In-Process Research and Development Expenses

The Company has entered into agreements (See Note 5 – License Agreements) with third parties to acquire the rights to develop and potentially commercialize certain products. Such agreements generally require an initial payment by the Company when the contract is executed. The purchase of license rights for use in research and development activities, including product development, are expensed as incurred and are classified as research and development expense. Additionally, the Company may be obligated to make future royalty payments in the event the Company commercializes the technology and achieves a certain sales volume. In accordance with ASC 730, Research and Development, expenditures for research and development, including upfront licensing fees and milestone payments associated with products not yet been approved by the FDA, are charged to research and development expense as incurred. Future contract milestone and /or royalty payments will be recognized as expense after the achievement of the milestone and the corresponding milestone payment is legally due.

Contingent Consideration

Certain agreements the Company enters into involve the potential payment of future consideration that is contingent upon certain performance and revenue milestones being achieved (See Note 5 – License Agreements). Contingent consideration obligations incurred in connection with the purchase of license rights for use in research and development activities are recorded when legally due.

Stock-Based Compensation

The Company accounts for stock-based compensation by measuring and recognizing compensation expense for all share-based awards made to employees, non-employees and directors based on estimated grant-date fair values. The Company uses the straight-line method to allocate compensation cost to reporting periods over the requisite service period, which is generally the vesting period. The grant date fair value of restricted stock units is estimated based on the closing stock price of the Company’s common stock on the date of grant. The grant date fair value of stock options granted to employees and directors is estimated using the Black-Scholes option-pricing model. If the service inception date precedes the grant date, the Company accrues for the stock-based compensation based on the fair value at the reporting date. The Company accounts for forfeitures as they occur. The fair value of each purchase under the employee stock purchase plan (ESPP) is estimated at the beginning of the offering period using the Black-Scholes option pricing model and recorded as expense over the service period using the straight-line method.

Comprehensive Loss

Comprehensive loss represents the net loss for the period and other comprehensive loss. Other comprehensive loss reflects certain gains and losses that are recorded as a component of stockholders’ deficit and are not reflected in the consolidated statements of operations. The Company’s other comprehensive income (loss) consists of changes in unrealized gains and losses on available-for-sale investments.

Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock (including non-voting common stock and pre-funded warrants) outstanding during the period, without consideration for all other common stock equivalents. Shares of common stock into which the pre-funded warrants may be exercised are considered outstanding for the purposes of computing net loss per share because the shares may be issued for little or no consideration, are fully vested, and are exercisable after the original issuance date. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive given the net loss for each period presented.

Recently Issued Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. The measurement of expected credit losses is based on historical experience, current conditions, and reasonable and supportable forecasts that affect collectability. This ASU also eliminates the concept of “other-than-temporary” impairment when evaluating available-for-sale debt securities and instead focuses on determining whether any impairment is a result of a credit loss or other factors. An entity will recognize an allowance for credit losses on available-for-sale debt securities rather than an other-than-temporary impairment that reduces the cost basis of the investment. This ASU is effective for fiscal years beginning after December 15, 2022 and interim periods within those fiscal years. Early adoption is permitted. The Company is currently assessing the impact of this standard on its condensed consolidated financial statements and related disclosures.

Fair Value Measurement

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

Fair Value Measurement

Note 3. Fair Value Measurement

The Company measures and reports certain financial instruments as assets and liabilities at fair value on a recurring basis. The following tables set forth the fair value of the Company’s financial assets, which consist of investments measured and recognized at fair value (in thousands):


		March 31, 2022
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Included within cash and cash equivalents:
Money market funds	Level 1	$	17,499	$	—	$	—		$	17,499
U.S. treasury securities	Level 1		5,998		—		—			5,998
Commercial paper	Level 2		31,584		—		—			31,584
U.S. government agency securities	Level 2		11,995		—		(3	)		11,992
Included within short-term investments:
U.S. treasury securities	Level 1		48,704		—		(95	)		48,609
Corporate bonds	Level 2		19,417		—		(83	)		19,334
Commercial paper	Level 2		44,114		—		(12	)		44,102
Total		$	179,311	$	—	$	(193	)	$	179,118


		December 31, 2021
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Included within cash and cash equivalents:
Money market funds	Level 1	$	99,326	$	—	$	—		$	99,326
Commercial paper	Level 2		25,996		—		(1	)		25,995
Corporate bonds	Level 2		1,802		—		(1	)		1,801
Included within short-term investments:
U.S. treasury securities	Level 1		2,499		—		—			2,499
U.S. government agency securities	Level 2		24,260		—		(24	)		24,236
Commercial paper	Level 2		51,376		—		(11	)		51,365
Corporate bonds	Level 2		18,137		—		(29	)		18,108
Total		$	223,396	$	—	$	(66	)	$	223,330

The Company evaluates transfers between levels at the end of each reporting period. There were no transfers between Levels 1, 2 and 3 during the three months ended March 31, 2022. As of March 31, 2022 and December 31, 2021, there were no financial instruments classified as Level 3.

As of March 31, 2022 and December 31, 2021, all debt securities with an unrealized loss position have been in a loss position for less than one year. The aggregate fair value of debt securities in an unrealized loss position as of March 31, 2022 and December 31, 2021 were $122.1 million and $113.0 million, respectively, with no individual securities in a significant unrealized loss position. The Company evaluated its securities for other-than-temporary impairment and considered the decline in market value to be primarily attributable to current economic and market conditions and would not be required to sell the securities before recovery of the amortized cost basis. Based on this analysis, these marketable securities were not considered to be other-than-temporarily impaired as of March 31, 2022 and December 31, 2021.

The following table presents the contractual maturities of the Company’s investments as of March 31, 2022 and December 31, 2021 (in thousands):


	March 31,		December 31,
	2022		2021
Due in less than one year	$	179,118	$	223,330
Due in more than one year		—		—
Total	$	179,118	$	223,330

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Balance Sheet Components

3 Months Ended

Mar. 31, 2022

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Components

Note 4. Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):


	March 31,		December 31,
	2022		2021
Accrued research and development materials and services	$	11,527	$	10,829
Accrued professional services		2,420		1,019
Accrued compensation		4,943		6,748
Other		413		280
Total accrued liabilities	$	19,303	$	18,876

License Agreements

3 Months Ended

Mar. 31, 2022

License Agreement [Abstract]

License Agreements

Note 5. License Agreements

The Company enters into arrangements to in-license research and development technology rights with third parties relating to its clinical and pre-clinical programs and product candidates. These arrangements may include non-refundable, upfront payments, payments for options to acquire additional rights relating to its product candidates, as well as contingent obligations for potential development, regulatory and commercial performance milestone payments, and royalty payments. The Company’s obligation to make payments for contingent obligations is contingent upon the respective milestones being achieved as well as its continued involvement in the programs and/or the lack of any adverse events which could cause the discontinuance of the programs. The activities under these license agreements are performed with no guarantee of either technological or commercial success.

For the three months ended March 31, 2022, the Company recorded $0.1 million as research and development expense in our condensed consolidated statements of operations related to license agreements, and $1.6 million, for the three months ended March 31, 2021.

As of March 31, 2022, the Company’s license agreements for technologies optioned by the Company, including the Medivir agreement described below, included potential future payments for development, regulatory, and sales milestones totaling approximately $365.9 million plus royalties on net sales that range from single digits to mid-teens.

Medivir Agreement

In January 2021, the Company entered into an exclusive license agreement with Medivir AB (Medivir) through which the Company received global, exclusive development and commercialization rights for birinapant, a clinical-stage Second Mitochondrial-derived Activator of Caspases (SMAC) mimetic. Under the terms of the agreement, the Company made an upfront payment of $1.0 million upon signing the agreement, and made an additional $1.5 million payment in November 2021 due to the Company's initiation of a Phase 1 clinical study of IGM-8444 in combination with birinapant. Under the terms of the agreement, should birinapant be successfully developed and approved, the Company is obligated to make additional milestone payments up to a total of approximately $348.5 million, plus tiered royalties from the mid-single digits up to mid-teens on net sales.

Common Stock and Non-Voting Common Stock

3 Months Ended

Mar. 31, 2022

Stockholders' Equity Note [Abstract]

Common Stock and Non-Voting Common Stock

Note 6. Common Stock and Non-Voting Common Stock

As of March 31, 2022 and December 31, 2021, the Company’s certificate of incorporation authorized the Company to issue 1,200,000,000 shares of common stock (including 200,000,000 shares of non-voting common stock) and 200,000,000 shares of preferred stock, at a par value of $0.01 per share. Each share of common stock (excluding non-voting common stock) is entitled to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the Company’s Board of Directors, subject to prior rights of the preferred stockholders. As of March 31, 2022 and December 31, 2021, no dividends have been declared.

The Company had reserved common stock, on an as-converted basis, for future issuance as follows:


	March 31,		December 31,
	2022		2021
Stock options, issued and outstanding		5,538,692		3,764,001
Restricted stock units		715,397		358,535
Stock options and restricted stock units, future issuance		1,740,384		2,618,117
Employee stock purchase plan, available for future grants		855,206		855,206
Pre-funded warrants (Note 7)		1,334,332		1,334,332
Total		10,184,011		8,930,191

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-URI http://asc.fasb.org/topic&trid=2208762

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496180-112644

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 15: 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(e)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Pre-Funded Warrants

3 Months Ended

Mar. 31, 2022

Stockholders' Equity Note [Abstract]

Pre-Funded Warrants

Note 7. Pre-Funded Warrants

In December 2020, the Company issued pre-funded warrants to purchase 1,334,332 shares of common stock in an underwritten public offering at the offering price of the common stock, less the $0.01 per share exercise price of each warrant, and were issued to two separate related party affiliates. The pre-funded warrants were recorded as a component of stockholders’ equity within additional paid-in-capital and will expire on the date any such warrant is exercised in full.

Subject to applicable law, upon exercise of a pre-funded warrant, a holder may elect to receive the same number of shares of non-voting common stock as the shares of common stock for which the pre-funded warrant is exercisable, provided that (i) at the time of such election there is a sufficient number of authorized but unissued and otherwise unreserved shares of non-voting common stock and (ii) the Company consents to such election.

The outstanding pre-funded warrants to purchase shares of common stock are exercisable at any time after their original issuance. However, the Company may not effect the exercise of any pre-funded warrants, and a holder will not be entitled to exercise any portion of any pre-funded warrants that, upon giving effect to such exercise, would cause: (i) the aggregate number of shares of the Company’s common stock beneficially owned by such holder (together with its affiliates) to exceed 9.99% of the number of shares of the Company’s common stock outstanding immediately after giving effect to the exercise; or (ii) the combined voting power of the Company’s securities beneficially owned by such holder (together with its affiliates) to exceed 9.99% of the combined voting power of all of the Company’s securities outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the pre-funded warrants. However, any holder of a pre-funded warrant may increase or decrease such percentage to any other percentage not in excess of 19.99% upon at least 61 days’ prior notice from the holder to the Company. As of March 31, 2022, no shares underlying the pre-funded warrants had been exercised. All of the outstanding pre-funded warrants are included in the weighted-average number of shares of common stock used to calculate basic net loss per share attributable to common stockholders (see “Note 9 Net Loss Per Share Attributable to Common Stockholders”).

Stock-Based Compensation

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Stock-Based Compensation

Note 8. Stock-Based Compensation

The 2018 Omnibus Incentive Plan (the 2018 Plan) provides for an increase in the number of shares reserved for issuance on the first day of each fiscal year equal to the least of (i) 8,768,800 shares, (ii) 4% of the Company’s common stock and non-voting common stock outstanding at December 31 of the immediately preceding year, or (iii) such number of shares as determined by the Company’s Board of Directors. As a result of this provision, on January 1, 2022 and 2021, an additional 1,299,921 and 1,278,965 shares, respectively, became available for issuance under the 2018 Plan. As of March 31, 2022, the 2018 Plan had 1,740,384 shares of common stock available for future issuance.

Total stock-based compensation expense related to the Company’s equity incentive plans and employee stock purchase plan was recorded in the statements of operations as follows (in thousands):


	Three Months Ended
	March 31,
	2022		2021
Research and development	$	6,607	$	1,865
General and administrative		4,892		3,639
Total stock-based compensation expense	$	11,499	$	5,504

The following table summarizes the Company's stock awards granted for each of the periods indicated:


	For the Three Months Ended March 31,
	2022				2021
	Grants		Weighted- Average Grant Date Fair Value		Grants		Weighted- Average Grant Date Fair Value
Stock options		1,859,642	$	12.85		724,052	$	65.20
Restricted stock units		374,755	$	16.06		1,966	$	63.23

Net Loss Per Share Attributable to Common Stockholders

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Net Loss Per Share Attributable to Common Stockholders

Note 9. Net Loss Per Share Attributable to Common Stockholders

Basic and diluted net loss per share is computed by dividing net loss by the weighted-average number of common stock and pre-funded warrants outstanding for the period. Shares of common stock into which the pre-funded warrants may be exercised are considered outstanding for the purposes of computing net loss per share because the shares may be issued for little or no consideration, are fully vested, and are exercisable after the original issuance date. For periods in which the Company generated a net loss, the Company does not include the potential impact of dilutive securities in diluted net loss per share, as the impact of these items is anti-dilutive.

The following equity instruments were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented:


	March 31,
	2022		2021
Stock options		5,538,692		3,603,469
Estimated shares issuable under the employee stock purchase plan		16,138		7,848
Unvested restricted stock units		715,397		417
Total		6,270,227		3,611,734

Subsequent Events

3 Months Ended

Mar. 31, 2022

Subsequent Events [Abstract]

Subsequent Events

Note 10. Subsequent Events

Follow-on Offering

On April 1, 2022, pursuant to a registration on Form S-3, the Company completed a public offering of 10,000,000 shares of common stock, including 8,695,653 shares of its non-voting common stock and 1,304,347 shares of its voting common stock, upon the full exercise by the underwriters of their option to purchase additional shares, each at a price to the public of $23.00 per share. After deducting underwriting discounts and commissions and offering costs paid or payable by the Company of approximately $12.0 million, the net proceeds from the offering were approximately $218.0 million.

Sanofi Agreement

On May 6, 2022, a global collaboration and license agreement with Genzyme Corporation (the Sanofi Agreement), a wholly owned subsidiary of Sanofi (Sanofi), became effective after expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (HSR) and customary closing conditions were met. The Company entered into the Sanofi Agreement on March 28, 2022; however, as of March 31, 2022, the Company determined that the effective date had not yet occurred since the HSR waiting period and related closing conditions had not yet been met as of that date.

Under the terms of the Sanofi Agreement, the Company will generate, develop, manufacture and commercialize IgM antibodies directed to six primary targets, three of which are intended as oncology targets and three of which are intended as immunology targets. The Company will receive a $150.0 million upfront payment from Sanofi and will be eligible to receive potentially over $6.0 billion in aggregate development, regulatory and commercial milestone payments. Following regulatory approval, for licensed products directed to oncology collaboration targets, the companies will equally share profits and losses from commercialization of those licensed products in certain major markets, and IGM will be eligible to receive tiered royalties on net sales of such licensed products in the rest of world that are in the low double-digit to mid-teen percentages. Following regulatory approval, for licensed products directed to immunology targets, IGM will be eligible to receive tiered royalties on global net sales of such licensed products in the high single-digit to low-teen percentages.

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2022
Accounting Policies [Abstract]
Description of the Business	Description of the Business IGM Biosciences, Inc. (the Company) was incorporated in the state of Delaware in August 1993 under the name Palingen, Inc. and the name was subsequently changed to IGM Biosciences, Inc. in 2010. The Company’s headquarters are in Mountain View, California. IGM Biosciences, Inc. is a biotechnology company engaged in the development of IgM antibody therapeutics for the treatment of cancer, infectious diseases and autoimmune and inflammatory diseases.
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (GAAP) and applicable rules and regulations of the Securities and Exchange Commission (SEC) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2021 has been derived from the audited financial statements at that date but does not include all of the information required by GAAP for complete financial statements. These unaudited interim condensed consolidated financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments which are necessary for a fair statement of the Company’s financial information. The interim results of operations for the three months ended March 31, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 or for any other interim period or for any other future year. The accompanying unaudited condensed consolidated financial statements include the accounts of the Company's wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The accompanying interim unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2021, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 29, 2022.
Liquidity	Liquidity The Company has incurred net operating losses and negative cash flows from operations since its inception and had an accumulated deficit of $405.6 million as of March 31, 2022. As of March 31, 2022, the Company had cash, cash equivalents, and marketable securities of $187.5 million. Management believes that the existing financial resources, including the $218.0 million of net proceeds received in April 2022 as part of a public offering (see Note 10), are sufficient to continue operating activities at least one year past the issuance date of these condensed consolidated financial statements. The Company has historically financed its operations primarily through the sale of common stock and pre-funded warrants in its public offerings and the sale of convertible preferred stock and the issuance of unsecured promissory notes in private placements. To date, none of the Company’s product candidates have been approved for sale, and the Company has not generated any revenue since inception. Management expects operating losses to continue and increase for the foreseeable future, as the Company progresses its planned research and development activities for its product candidates. The Company’s prospects are subject to risks, expenses and uncertainties frequently encountered by companies in the biotechnology industry as discussed below. While the Company has been able to raise multiple rounds of financing, there can be no assurance that in the event the Company requires additional financing, such financing will be available on terms which are favorable or at all. Failure to raise sufficient capital when needed or generate sufficient cash flow from operations would impact the ability to pursue business strategies and could require the Company to delay, scale back or discontinue one or more product development programs, or other aspects of the Company's business objectives.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates, including, but not limited to, those related to investments, manufacturing accruals, accrued research and development expenses, stock-based compensation, operating lease right-of-use (ROU) assets and liabilities, income tax uncertainties and the valuation of deferred tax assets. The Company bases its estimates on its historical experience and also on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates.
Segments	Segments The Company operates and manages its business as one reportable and operating segment, which is the business of developing engineered IgM antibodies for the treatment of cancer, infectious diseases and autoimmune and inflammatory diseases. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating and evaluating financial performance. All long-lived assets are maintained in, and all losses are attributable to, the United States of America.
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of cash, cash equivalents, and marketable securities. The Company invests in money market funds, U.S. Treasury securities, corporate bonds, commercial paper, and U.S. government agency securities. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash and issuers of investments to the extent recorded on the balance sheets. The Company’s investment policy limits investments to high credit quality securities issued by the U.S. Government and its agencies, highly rated banks, and corporate issuers, subject to certain concentration limits and restrictions on maturities. The Company has not experienced any losses on its deposits of cash, cash equivalents, and marketable securities. The Company’s future results of operations involve a number of other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, the Company’s early stages of clinical drug development; uncertainties related to the use of engineered IgM antibodies, which is a novel and unproven therapeutic approach; the Company’s ability to advance product candidates into, and successfully complete, clinical trials on the timelines it projects; the Company’s ability to adequately demonstrate sufficient safety and efficacy of its product candidates; the Company’s ability to enroll patients in its ongoing and future clinical trials; the Company’s ability to successfully manufacture and supply its product candidates for clinical trials; the Company’s ability to obtain additional capital to finance its operations; uncertainties related to the projections of the size of patient populations suffering from the diseases the Company is targeting; the Company’s ability to obtain, maintain, and protect its intellectual property rights; developments relating to the Company’s competitors and its industry, including competing product candidates and therapies; general economic and market conditions; and other risks and uncertainties, including those more fully described in the “Risk Factors” section of this Quarterly Report on Form 10-Q. The Company’s product candidates will require approvals from the U.S. Food and Drug Administration (FDA) and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company was denied approval, approval was delayed or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash and cash equivalents. Cash equivalents consist primarily of amounts invested in money market funds and commercial paper and are stated at fair value. Restricted cash consists of a grant received from a non-profit organization which the Company will utilize as it incurs expenses for services performed under the grant agreement.
Investments	The Company’s marketable securities have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. Treasury securities, U.S. government agency securities, corporate debt, and commercial paper. The specific identification method is used to determine the cost basis of fixed income securities sold. These securities are recorded on the condensed consolidated balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive income (loss). The cost of investment securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other income, net. Realized gains and losses and declines in fair value judged to be other-than-temporary, if any, are also included in other income, net. The Company evaluates securities for other-than-temporary impairment at the balance sheet date. Declines in fair value determined to be other-than-temporary are also included in other income, net. All available-for-sale securities are considered available to support current operations and are classified as current assets.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is determined using the straight-line method over the estimated useful lives of the respective assets, generally three to five years. Leasehold improvements are depreciated using the straight-line method over the shorter of the lease term or the estimated useful economic lives of the related assets. Assets are held in construction in progress until placed in service, upon which date, we begin to depreciate these assets. Upon retirement or sale of the assets, the cost and related accumulated depreciation and amortization are removed from the balance sheet and the resulting gain or loss are recorded to the statements of operations. Repairs and maintenance are charged to the condensed consolidated statements of operations as incurred.
Leases	Leases The Company determines if an arrangement is a lease at inception. In addition, the Company determines whether leases meet the classification criteria of a finance or operating lease at the lease commencement date considering: (1) whether the lease transfers ownership of the underlying asset to the lessee at the end of the lease term, (2) whether the lease grants the lessee an option to purchase the underlying asset that the lessee is reasonably certain to exercise, (3) whether the lease term is for a major part of the remaining economic life of the underlying asset, (4) whether the present value of the sum of the lease payments and residual value guaranteed by the lessee equals or exceeds substantially all of the fair value of the underlying asset, and (5) whether the underlying asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. As of March 31, 2022, the Company's lease population consisted of real estate. As of March 31, 2022, the Company did not have finance leases. Operating leases are included in operating lease ROU assets, lease liabilities, current, and lease liabilities, non-current in the Company’s condensed consolidated balance sheet. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the present value of lease payments, the Company uses its incremental borrowing rate based on the information available at the lease commencement date if the rate implicit in the lease is not readily determinable. The Company determines the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to the Company. The determination of the Company’s incremental borrowing rate requires management judgment including the development of a synthetic credit rating and cost of debt as the Company currently does not carry any debt. The Company believes that the estimates used in determining the incremental borrowing rate are reasonable based upon current facts and circumstances. Applying different judgments to the same facts and circumstances could result in the estimated amounts to vary. The operating lease ROU assets also include adjustments for prepayments and accrued lease payments and exclude lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease cost is recognized on a straight-line basis over the expected lease term. Variable lease costs represent payments that are dependent on usage, a rate or index. Variable lease cost primarily relates to common area maintenance charges. Lease agreements that include lease and non-lease components are accounted for as a single lease component. Lease agreements with a noncancelable term of less than 12 months are not recorded on the Company’s condensed consolidated balance sheet.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates the carrying amount of its long-lived assets, such as property and equipment, whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss would be recognized when estimated future cash flows expected to result from the use of the asset and its eventual disposition are less than the carrying amount of the asset. As of March 31, 2022, there was no impairment of long-lived assets.
Fair Value Measurement	Fair Value Measurement The Company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the condensed consolidated financial statements on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows: Level 1—Observable inputs, such as quoted prices in active markets for identical assets or liabilities at the measurement date. Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3—Unobservable inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. Financial instruments classified within Level 2 of the fair value hierarchy are valued based on other observable inputs, including broker or dealer quotations or alternative pricing sources. When quoted prices in active markets for identical assets or liabilities are not available, the Company relies on non-binding quotes from its investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments, or historical pricing trends of a security relative to its peers. To validate the fair value determination provided by its investment managers, the Company reviews the pricing movement in the context of overall market trends and trading information from its investment managers. In addition, the Company assesses the inputs and methods used in determining the fair value in order to determine the classification of securities in the fair value hierarchy.
Research and Development Expenses	Research and Development Expenses The Company expenses research and development costs as they are incurred. Research and development expenses consist primarily of: (i) personnel-related expenses, including salaries, benefits and stock-based compensation expense, for personnel in the Company’s research and development functions; (ii) fees paid to third parties such as contractors, consultants and contract research organizations (CROs) for conducting clinical trials, animal studies, and other costs related to clinical and preclinical testing; (iii) costs related to acquiring and manufacturing research and clinical trial materials, including under agreements with third parties such as contract manufacturing organizations (CMOs), and other vendors; (iv) costs related to the preparation of regulatory submissions; (v) expenses related to laboratory supplies and services; (vi) fees under license agreements where no alternative future use exists; and (vii) depreciation of equipment and facilities expenses.
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company records accruals for estimated costs of research, preclinical studies, clinical trials, and manufacturing, which are significant components of research and development expenses. A substantial portion of the Company’s ongoing research and development activities is conducted by third-party service providers, CROs and CMOs. The Company’s contracts with CROs generally include pass-through fees such as costs related to animal studies and safety tests, regulatory expenses, investigator fees, travel costs and other miscellaneous costs, including shipping and printing fees. The Company’s contracts with the CMOs generally include fees such as initiation fees, reservation fees, verification run costs, materials and reagents expenses, taxes, etc. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company accrues the costs incurred under agreements with these third parties based on estimates of actual work completed in accordance with the respective agreements. The Company determines the estimated costs through discussions with internal personnel and external service providers as to the progress, or stage of completion or actual timeline (start-date and end-date) of the services and the agreed-upon fees to be paid for such services. In the event the Company makes advance payments, the payments are recorded as a prepaid expense and recognized as the services are performed. As actual costs become known, the Company adjusts its accruals. Although the Company does not expect its estimates to be materially different from amounts actually incurred, such estimates for the status and timing of services performed relative to the actual status and timing of services performed may vary and could result in the Company reporting amounts that are too high or too low in any particular period. The Company’s accrual is dependent, in part, upon the receipt of timely and accurate reporting from CROs and other third-party vendors. Variations in the assumptions used to estimate accruals including, but not limited to, the number of patients enrolled, the rate of patient enrollment and the actual services performed, may vary from the Company’s estimates, resulting in adjustments to clinical trial expenses in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect its financial condition and results of operations. Through March 31, 2022, there have been no material differences from the Company’s estimated accrued research and development expenses to actual expenses.
Acquired In-Process Research and Development Expenses	Acquired In-Process Research and Development Expenses The Company has entered into agreements (See Note 5 – License Agreements) with third parties to acquire the rights to develop and potentially commercialize certain products. Such agreements generally require an initial payment by the Company when the contract is executed. The purchase of license rights for use in research and development activities, including product development, are expensed as incurred and are classified as research and development expense. Additionally, the Company may be obligated to make future royalty payments in the event the Company commercializes the technology and achieves a certain sales volume. In accordance with ASC 730, Research and Development, expenditures for research and development, including upfront licensing fees and milestone payments associated with products not yet been approved by the FDA, are charged to research and development expense as incurred. Future contract milestone and /or royalty payments will be recognized as expense after the achievement of the milestone and the corresponding milestone payment is legally due.
Contingent Considerations	Contingent Consideration Certain agreements the Company enters into involve the potential payment of future consideration that is contingent upon certain performance and revenue milestones being achieved (See Note 5 – License Agreements). Contingent consideration obligations incurred in connection with the purchase of license rights for use in research and development activities are recorded when legally due.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation by measuring and recognizing compensation expense for all share-based awards made to employees, non-employees and directors based on estimated grant-date fair values. The Company uses the straight-line method to allocate compensation cost to reporting periods over the requisite service period, which is generally the vesting period. The grant date fair value of restricted stock units is estimated based on the closing stock price of the Company’s common stock on the date of grant. The grant date fair value of stock options granted to employees and directors is estimated using the Black-Scholes option-pricing model. If the service inception date precedes the grant date, the Company accrues for the stock-based compensation based on the fair value at the reporting date. The Company accounts for forfeitures as they occur. The fair value of each purchase under the employee stock purchase plan (ESPP) is estimated at the beginning of the offering period using the Black-Scholes option pricing model and recorded as expense over the service period using the straight-line method.
Comprehensive Loss	Comprehensive Loss Comprehensive loss represents the net loss for the period and other comprehensive loss. Other comprehensive loss reflects certain gains and losses that are recorded as a component of stockholders’ deficit and are not reflected in the consolidated statements of operations. The Company’s other comprehensive income (loss) consists of changes in unrealized gains and losses on available-for-sale investments.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock (including non-voting common stock and pre-funded warrants) outstanding during the period, without consideration for all other common stock equivalents. Shares of common stock into which the pre-funded warrants may be exercised are considered outstanding for the purposes of computing net loss per share because the shares may be issued for little or no consideration, are fully vested, and are exercisable after the original issuance date. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive given the net loss for each period presented.
Recently Adopted Accounting Standards and Accounting Pronouncements	Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. The measurement of expected credit losses is based on historical experience, current conditions, and reasonable and supportable forecasts that affect collectability. This ASU also eliminates the concept of “other-than-temporary” impairment when evaluating available-for-sale debt securities and instead focuses on determining whether any impairment is a result of a credit loss or other factors. An entity will recognize an allowance for credit losses on available-for-sale debt securities rather than an other-than-temporary impairment that reduces the cost basis of the investment. This ASU is effective for fiscal years beginning after December 15, 2022 and interim periods within those fiscal years. Early adoption is permitted. The Company is currently assessing the impact of this standard on its condensed consolidated financial statements and related disclosures.

Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

Summary of Investments Measured and Recognized at Fair Value

The following tables set forth the fair value of the Company’s financial assets, which consist of investments measured and recognized at fair value (in thousands):


		March 31, 2022
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Included within cash and cash equivalents:
Money market funds	Level 1	$	17,499	$	—	$	—		$	17,499
U.S. treasury securities	Level 1		5,998		—		—			5,998
Commercial paper	Level 2		31,584		—		—			31,584
U.S. government agency securities	Level 2		11,995		—		(3	)		11,992
Included within short-term investments:
U.S. treasury securities	Level 1		48,704		—		(95	)		48,609
Corporate bonds	Level 2		19,417		—		(83	)		19,334
Commercial paper	Level 2		44,114		—		(12	)		44,102
Total		$	179,311	$	—	$	(193	)	$	179,118


		December 31, 2021
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Included within cash and cash equivalents:
Money market funds	Level 1	$	99,326	$	—	$	—		$	99,326
Commercial paper	Level 2		25,996		—		(1	)		25,995
Corporate bonds	Level 2		1,802		—		(1	)		1,801
Included within short-term investments:
U.S. treasury securities	Level 1		2,499		—		—			2,499
U.S. government agency securities	Level 2		24,260		—		(24	)		24,236
Commercial paper	Level 2		51,376		—		(11	)		51,365
Corporate bonds	Level 2		18,137		—		(29	)		18,108
Total		$	223,396	$	—	$	(66	)	$	223,330

Summary of Contractual Maturities of Investments

The following table presents the contractual maturities of the Company’s investments as of March 31, 2022 and December 31, 2021 (in thousands):


	March 31,		December 31,
	2022		2021
Due in less than one year	$	179,118	$	223,330
Due in more than one year		—		—
Total	$	179,118	$	223,330

Balance Sheet Components (Tables)

3 Months Ended

Mar. 31, 2022

Balance Sheet Related Disclosures [Abstract]

Schedule of Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):


	March 31,		December 31,
	2022		2021
Accrued research and development materials and services	$	11,527	$	10,829
Accrued professional services		2,420		1,019
Accrued compensation		4,943		6,748
Other		413		280
Total accrued liabilities	$	19,303	$	18,876

Common Stock and Non-Voting Common Stock (Tables)

3 Months Ended

Mar. 31, 2022

Stockholders' Equity Note [Abstract]

Schedule of Number of Common Stock Reserved for Future Issuance

The Company had reserved common stock, on an as-converted basis, for future issuance as follows:


	March 31,		December 31,
	2022		2021
Stock options, issued and outstanding		5,538,692		3,764,001
Restricted stock units		715,397		358,535
Stock options and restricted stock units, future issuance		1,740,384		2,618,117
Employee stock purchase plan, available for future grants		855,206		855,206
Pre-funded warrants (Note 7)		1,334,332		1,334,332
Total		10,184,011		8,930,191

Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Summary of Stock-Based Compensation Expense

Total stock-based compensation expense related to the Company’s equity incentive plans and employee stock purchase plan was recorded in the statements of operations as follows (in thousands):


	Three Months Ended
	March 31,
	2022		2021
Research and development	$	6,607	$	1,865
General and administrative		4,892		3,639
Total stock-based compensation expense	$	11,499	$	5,504

Summary of Company's stock awards granted

The following table summarizes the Company's stock awards granted for each of the periods indicated:


	For the Three Months Ended March 31,
	2022				2021
	Grants		Weighted- Average Grant Date Fair Value		Grants		Weighted- Average Grant Date Fair Value
Stock options		1,859,642	$	12.85		724,052	$	65.20
Restricted stock units		374,755	$	16.06		1,966	$	63.23

Net Loss Per Share Attributable to Common Stockholders (Tables)

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Summary of Potentially Dilutive Securities Not Included in the Diluted Per Share Calculations


	March 31,
	2022		2021
Stock options		5,538,692		3,603,469
Estimated shares issuable under the employee stock purchase plan		16,138		7,848
Unvested restricted stock units		715,397		417
Total		6,270,227		3,611,734

Organization - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 01, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Subsidiary Sale Of Stock [Line Items]
Proceeds from common stock issuance	$ 218,000
Accumulated deficit		$ (405,618)	$ (353,724)
Cash, and investments		$ 187,500
Underwritten Public Offering \| Pre-funded Warrant
Subsidiary Sale Of Stock [Line Items]
Pre-funded warrants to purchase an additional shares of common stock				1,334,332
Underwritten Public Offering \| Common Stock
Subsidiary Sale Of Stock [Line Items]
Common stock, price per share				$ 0.01

- Definition

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

+ References + Details

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) Segment
Summary Of Significant Accounting Policies [Line Items]
Number of operating segment \| Segment	1
Impairment of long-lived assets \| $	$ 0
ASU 2019-12
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, immaterial effect	true
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life	5 years

- Definition

Indicates (true false) whether accounting standards update was adopted.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 20
-Section 65
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=121483254&loc=SL120254523-199619

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S65
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124359872&loc=SL124427846-239511

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124402435&loc=SL124402458-218513

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123459177&loc=SL121830611-158277

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 926
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 926
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 7
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123597120&loc=SL122642865-165497

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123597120&loc=SL122642865-165497

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123597120&loc=SL120254526-165497

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123597120&loc=SL120254526-165497

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=122640432&loc=SL120254519-210437

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123341672&loc=SL120154346-209984

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=122150657&loc=SL122150809-237846

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124402435&loc=SL124402458-218513

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Publisher FASB
-Subparagraph (a)

Reference 32: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 45
-Paragraph 24
-URI http://asc.fasb.org/extlink&oid=124436220&loc=d3e21930-107793

Reference 33: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 45
-Paragraph 23
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124436220&loc=d3e21914-107793

+ Details

Fair Value Measurement - Additional Information (Details) $ in Millions	Mar. 31, 2022 USD ($) Instrument	Dec. 31, 2021 USD ($) Instrument
Fair Value Disclosures [Abstract]
Number of financial instruments classified as level 3 \| Instrument	0	0
Unrealized loss position \| $	$ 122.1	$ 113.0

Fair Value Measurement - Summary of Investments Measured and Recognized at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	$ 179,311	$ 223,396
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(193)	(66)
Fair Value	179,118	223,330
Fair Value, Recurring \| Financial Assets Included Within Cash and Cash Equivalents \| Money Market Funds \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	17,499	99,326
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0
Fair Value	17,499	99,326
Fair Value, Recurring \| Financial Assets Included Within Cash and Cash Equivalents \| U.S. Treasury Securities \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	5,998
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	5,998
Fair Value, Recurring \| Financial Assets Included Within Cash and Cash Equivalents \| Commercial Paper \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	31,584	25,996
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(1)
Fair Value	31,584	25,995
Fair Value, Recurring \| Financial Assets Included Within Cash and Cash Equivalents \| U.S. Government Agency Securities \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	11,995
Gross Unrealized Gains	0
Gross Unrealized Losses	(3)
Fair Value	11,992
Fair Value, Recurring \| Financial Assets Included Within Cash and Cash Equivalents \| Corporate Bonds \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		1,802
Gross Unrealized Gains		0
Gross Unrealized Losses		(1)
Fair Value		1,801
Fair Value, Recurring \| Financial Assets Included Within Short-Term Investments \| U.S. Treasury Securities \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	48,704	2,499
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(95)	0
Fair Value	48,609	2,499
Fair Value, Recurring \| Financial Assets Included Within Short-Term Investments \| Commercial Paper \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	44,114	51,376
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(12)	(11)
Fair Value	44,102	51,365
Fair Value, Recurring \| Financial Assets Included Within Short-Term Investments \| U.S. Government Agency Securities \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		24,260
Gross Unrealized Gains		0
Gross Unrealized Losses		(24)
Fair Value		24,236
Fair Value, Recurring \| Financial Assets Included Within Short-Term Investments \| Corporate Bonds \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	19,417	18,137
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(83)	(29)
Fair Value	$ 19,334	$ 18,108

Fair Value Measurement - Summary of Contractual Maturities of Investments (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Due in less than one year	$ 179,118	$ 223,330
Due in more than one year	0	0
Total	$ 179,118	$ 223,330

Balance Sheet Components - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total property, plant and equipment, net	$ 29,984	$ 28,495

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 1,224	$ 673

Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Accrued research and development materials and services	$ 11,527	$ 10,829
Accrued professional services	2,420	1,019
Accrued compensation	4,943	6,748
Other	413	280
Total accrued liabilities	$ 19,303	$ 18,876

License Agreements - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Jan. 31, 2021
Research And Development Expense
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License expenses recognized	$ 0.1	$ 1.6
License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment based on achievement of specified development	$ 365.9
License Agreement \| Medivir AB
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional milestone payment			$ 1.5
Upfront payment			1.0
License Agreement \| Medivir AB \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment based on achievement of specified development			$ 348.5

Common Stock and Non-Voting Common Stock - Additional Information (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2022 USD ($) Vote $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares
Class Of Stock [Line Items]
Preferred stock, shares authorized	200,000,000	200,000,000
Preferred stock, par value \| $ / shares	$ 0.01	$ 0.01
Common stock, voting rights	Each share of common stock (excluding non-voting common stock) is entitled to one vote.
Number of common stock voting rights held \| Vote	1
Common stock, dividends declared \| $	$ 0	$ 0
Common Stock Including Nonvoting Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized	1,200,000,000	1,200,000,000
Non-voting Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized	200,000,000	200,000,000
Common stock, par value \| $ / shares	$ 0.01	$ 0.01

Common Stock and Non-Voting Common Stock - Schedule of Number of Common Stock Reserved for Future Issuance (Details) - shares	Mar. 31, 2022	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Stock options, issued and outstanding	5,538,692	3,764,001
Restricted stock units	715,397	358,535
Stock options and restricted stock units, future issuance	1,740,384	2,618,117
Employee stock purchase plan, available for future grants	855,206	855,206
Pre-funded warrants (Note 7)	1,334,332	1,334,332
Total	10,184,011	8,930,191

Pre-Funded Warrants - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended
	Apr. 01, 2022	Dec. 31, 2020	Mar. 31, 2022
Class Of Warrant Or Right [Line Items]
Proceeds from common stock issuance	$ 218.0
Maximum allowed holding percentage of shares after exercise of warrants		9.99%
Maximum allowed combined voting percentage of shares after exercise of warrants		9.99%
Maximum allowed percentage of pre-funded warrants to exercise		19.99%
Minimum notice term to increase or decrease the holding percentage of pre-funded warrants		61 days
Number of warrants exercised			0
Underwritten Public Offering \| Common Stock
Class Of Warrant Or Right [Line Items]
Common stock, price per share		$ 0.01
Underwritten Public Offering \| Pre-funded Warrant
Class Of Warrant Or Right [Line Items]
Warrants to purchase an additional shares of common stock		1,334,332

Stock-Based Compensation - Additional Information (Details) - 2018 Plan - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Jan. 01, 2022	Jan. 01, 2021
Share Based Compensation Arrangement By Share Based Payment Award Line Items
Outstanding stock including non-voting common stock, percent	4.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1,740,384
Total stock-based compensation expense	$ 11,499	$ 5,504
Maximum
Share Based Compensation Arrangement By Share Based Payment Award Line Items
Increase in number of shares	8,768,800			1,278,965
Minimum
Share Based Compensation Arrangement By Share Based Payment Award Line Items
Increase in number of shares			1,299,921

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - 2018 Plan - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs Line Items
Total stock-based compensation expense	$ 11,499	$ 5,504
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs Line Items
Total stock-based compensation expense	6,607	1,865
General And Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs Line Items
Total stock-based compensation expense	$ 4,892	$ 3,639

Stock-Based Compensation - Summary of Company's stock awards granted (Details) - $ / shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award Line Items
Number of Shares, Granted	374,755	1,966
Weighted-Average Grant Date Fair Value	$ 16.06	$ 63.23
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award Line Items
Number of Shares, Granted	1,859,642	724,052
Weighted-Average Grant Date Fair Value	$ 12.85	$ 65.20

Stock-Based Compensation - Summary of Fair Value of Employee Stock Options Estimated Weighted-average Assumptions (Details) - $ / shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award Line Items
Weighted-Average Grant Date Fair Value	$ 12.85	$ 65.20

Net Loss Per Share Attributable to Common Stockholders - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss	$ (51,894)	$ (31,644)
Denominator:
Weighted average common shares outstanding used to compute net loss per share, basic and diluted	33,838,895	33,328,994
Net loss per share attributable to common stockholders	$ (1.53)	$ (0.95)

- 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 Attributable to Common Stockholders - Summary of Potentially Dilutive Securities Not Included in the Diluted Per Share Calculations (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in diluted per share calculations	6,270,227	3,611,734
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in diluted per share calculations	5,538,692	3,603,469
Estimated Shares Issuable Under Employee Stock Purchase Plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in diluted per share calculations	16,138	7,848
Unvested restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in diluted per share calculations	715,397	417

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Lessee Lease Description [Line Items]
Increase in right-of-use asset obtained in exchange for operating lease liability	$ 2,093	$ 1,844

Commitments and Contingencies - Schedule of ROU Assets and Related Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets and Liabilities, Lessee [Abstract]
Current operating lease liabilities	$ 4,054	$ 3,320
Non-current operating lease liabilities	$ 25,854	$ 25,439

Subsequent Events - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Apr. 01, 2022	Mar. 31, 2022	Dec. 31, 2020
Subsequent Event [Line Items]
Proceeds from common stock issuance	$ 218.0
License agreement description		Following regulatory approval, for licensed products directed to oncology collaboration targets, the companies will equally share profits and losses from commercialization of those licensed products in certain major markets, and IGM will be eligible to receive tiered royalties on net sales of such licensed products in the rest of world that are in the low double-digit to mid-teen percentages
Underwritten Public Offering \| Subsequent Event
Subsequent Event [Line Items]
Common stock, exercised by underwriters	8,695,653
Offering costs	$ 12.0
Proceeds from common stock issuance	$ 218.0
Underwritten Public Offering \| Pre-funded Warrant
Subsequent Event [Line Items]
Pre-funded warrants to purchase an additional shares of common stock			1,334,332
Underwritten Public Offering \| Pre-funded Warrant \| Subsequent Event
Subsequent Event [Line Items]
Pre-funded warrants to purchase an additional shares of common stock	1,304,347
Common Stock \| Underwritten Public Offering
Subsequent Event [Line Items]
Common stock, price per share			$ 0.01
Common Stock \| Underwritten Public Offering \| Subsequent Event
Subsequent Event [Line Items]
Issuance of common stock, shares	10,000,000
Common stock, price per share	$ 23.00
Sanofi
Subsequent Event [Line Items]
Upfront payment receivable		$ 150.0
Milestone payments receivable		$ 6,000.0