Kineta (KANT) 10-Q 15 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 03, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity File Number	001-37695
Entity Registrant Name	YUMANITY THERAPEUTICS, INC.
Entity Central Index Key	0001445283
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Title of 12(b) Security	Common Stock
Trading Symbol	YMTX
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-8436652
Document Quarterly Report	true
Document Transition Report	false
Entity Address, Address Line One	40 Guest Street
Entity Address, Address Line Two	Suite 4410
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02135
City Area Code	617
Local Phone Number	409-5300
Entity Common Stock, Shares Outstanding		10,308,350

Condensed Consolidated Balance

Condensed Consolidated Balance sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 43,532	$ 80,819
Marketable securities	2,899	4,498
Prepaid expenses and other current assets	1,725	2,264
Total current assets	48,156	87,581
Property and equipment, net	487	874
Operating lease right-of-use assets	19,864	23,678
Deposits	386	386
Restricted cash	928	2,066
Assets held-for-sale		250
Total assets	69,821	114,835
Current liabilities:
Accounts payable	976	7,384
Accrued expenses and other current liabilities	5,412	7,851
Current portion of long-term debt	5,678	2,891
Operating lease liabilities	4,909	4,468
Current portion of finance lease obligation	65	166
Deferred revenue	823	8,104
Total current liabilities	17,863	30,864
Long-term debt, net of discount and current portion	8,742	13,237
Operating lease liabilities, net of current portion	10,738	14,479
Finance lease obligation, net of current portion	9	48
Total liabilities	37,352	58,628
Commitments and contingencies (Note 10)
Stockholders' equity/(deficit):
Common stock, $0.001 par value; 125,000,000 shares authorized; 10,308,350 and 10,193,831 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively	10	10
Additional paid-in capital	209,361	204,007
Accumulated deficit	(176,902)	(147,810)
Total stockholders' equity	32,469	56,207
Total liabilities and stockholders' equity	$ 69,821	$ 114,835

Condensed Consolidated Balanc_2

Condensed Consolidated Balance sheets (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	10,308,350	10,193,831
Common stock, shares outstanding	10,308,350	10,193,831

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Collaboration revenue	$ 1,635	$ 3,308	$ 7,282	$ 3,308
Operating expenses:
Research and development	6,624	5,489	20,729	14,457
General and administrative	4,513	3,725	15,277	8,356
Total operating expenses	11,137	9,214	36,006	22,813
Loss from operations	(9,502)	(5,906)	(28,724)	(19,505)
Other income (expense):
Change in fair value of preferred unit warrant liability	0	(46)	0	(72)
Interest Expense	(454)	(501)	(1,407)	(1,410)
Interest income and other income (expense), net	0	(24)	(95)	21
Gain on debt extinguishment	0		1,134	0
Total other income (expense), net	(454)	(479)	(368)	(1,317)
Net loss	(9,956)	(6,385)	(29,092)	(20,822)
Gain on extinguishment of Class B preferred units	0		0	6,697
Net loss applicable to common shareholders	$ (9,956)	$ (6,385)	$ (29,092)	$ (14,125)
Net loss per share/unit, basic and diluted	$ (0.97)	$ (2.96)	$ (2.84)	$ (6.55)
Weighted Average Number of Shares Outstanding, Basic and Diluted	10,304,775	2,159,403	10,239,502	2,155,276

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (9,956)	$ (6,385)	$ (29,092)	$ (20,822)
Other comprehensive loss:
Unrealized gains on marketable securities, net of tax of $0	0	0	0	0
Comprehensive loss	$ (9,956)	$ (6,385)	$ (29,092)	$ (20,822)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Unrealized gain on marketable securities, net of tax	$ 0	$ 0	$ 0	$ 0

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Preferred Units and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Preferred Units [Member]	Common Units [Member]	Defaulting Class B Preferred Units [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2019	$ (91,900)	$ 89,699	$ 5,120				$ (97,020)
Beginning balance, shares at Dec. 31, 2019		12,391,101	2,163,099
Stock/equity-based compensation expense	570		$ 570
Net loss	(7,465)						(7,465)
Ending balance at Mar. 31, 2020	(98,795)	$ 89,699	$ 5,690				(104,485)
Ending balance, shares at Mar. 31, 2020		12,391,101	2,163,099
Beginning balance at Dec. 31, 2019	(91,900)	$ 89,699	$ 5,120				(97,020)
Beginning balance, shares at Dec. 31, 2019		12,391,101	2,163,099
Net loss	(20,822)
Ending balance at Sep. 30, 2020	(103,971)	$ 103,949	$ 6,886	$ 288			(111,145)
Ending balance, shares at Sep. 30, 2020		16,959,370	2,162,309	836,319
Beginning balance at Mar. 31, 2020	(98,795)	$ 89,699	$ 5,690				(104,485)
Beginning balance, shares at Mar. 31, 2020		12,391,101	2,163,099
Forfeiture of unvested incentive units, shares			(351)
Stock/equity-based compensation expense	502		$ 502
Gain on extinguishment of Class B preferred units	6,697	$ (6,697)					6,697
Exchange of Class B preferred units for Defaulting Class B preferred units	288	$ (288)		$ 288
Issuance of Class C preferred units, net of issuance costs of $388(Share)		5,404,588
Issuance of Class C preferred units, net of issuance costs of $388		$ 21,235
Net loss	(6,972)						(6,972)
Ending balance at Jun. 30, 2020	(98,280)	$ 103,949	$ 6,192	$ 288			(104,760)
Ending balance, shares at Jun. 30, 2020		16,959,370	2,162,748	836,319
Exchange of Class B preferred units for Defaulting Class B preferred units(Share)		(836,319)		836,319
Forfeiture of unvested incentive units, shares			(439)
Stock/equity-based compensation expense	694		$ 694
Net loss	(6,385)						(6,385)
Ending balance at Sep. 30, 2020	(103,971)	$ 103,949	$ 6,886	$ 288			(111,145)
Ending balance, shares at Sep. 30, 2020		16,959,370	2,162,309	836,319
Beginning balance at Dec. 31, 2020	56,207				$ 10	$ 204,007	(147,810)
Beginning balance, shares at Dec. 31, 2020					10,193,831
Stock/equity-based compensation expense	1,407					1,407
Net loss	(8,682)						(8,682)
Ending balance at Mar. 31, 2021	48,932				$ 10	205,414	(156,492)
Ending balance, shares at Mar. 31, 2021					10,193,831
Beginning balance at Dec. 31, 2020	$ 56,207				$ 10	204,007	(147,810)
Beginning balance, shares at Dec. 31, 2020					10,193,831
Exercises of common stock options (Share)	9,241
Net loss	$ (29,092)
Ending balance at Sep. 30, 2021	32,469				$ 10	209,361	(176,902)
Ending balance, shares at Sep. 30, 2021					10,308,350
Beginning balance at Mar. 31, 2021	48,932				$ 10	205,414	(156,492)
Beginning balance, shares at Mar. 31, 2021					10,193,831
Exercises of common stock options	57					57
Exercises of common stock options (Share)					6,083
Stock/equity-based compensation expense	1,259					1,259
Issuance of common stock from at the market offering, net of issuance costs	1,313					1,313
Issuance of common stock from at the market offering, net of issuance costs(Share)					82,132
Net loss	(10,454)						(10,454)
Ending balance at Jun. 30, 2021	41,107				$ 10	208,043	(166,946)
Ending balance, shares at Jun. 30, 2021					10,282,046
Exercises of common stock options	26					26
Exercises of common stock options (Share)					3,158
Vesting of restricted stock units (in shares)					23,146
Stock/equity-based compensation expense	1,292					1,292
Net loss	(9,956)						(9,956)
Ending balance at Sep. 30, 2021	$ 32,469				$ 10	$ 209,361	$ (176,902)
Ending balance, shares at Sep. 30, 2021					10,308,350

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (29,092)	$ (20,822)
Adjustments to reconcile net loss to net cash used in operating activities:
Net amortization of premiums (accretion of discounts) on marketable securities	(9)	(3)
Depreciation and amortization expense	513	577
Non-cash lease expense	3,814	1,692
Stock/equity-based compensation expense	3,958	1,766
Other non-cash expense	55	0
Non-cash interest expense	412	387
Gain on debt extinguishment	(1,134)	0
Change in fair value of preferred unit warrant liability	0	(72)
Loss (gain) on sale of property and equipment	63	(2)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	668	(1,365)
Deposits	0	(339)
Operating lease liabilities	(3,300)	(858)
Accounts payable	(6,417)	286
Accrued expenses and other current liabilities	(2,428)	683
Deferred revenue	(7,281)	11,693
Net cash used in operating activities	(40,178)	(6,377)
Cash flows from investing activities:
Purchases of marketable securities	(11,267)	(3,597)
Proceeds from sales and maturities of marketable securities	12,875	1,350
Purchases of property and equipment	(114)	(173)
Proceeds from sale of property and equipment	0	13
Net cash provided by (used in) investing activities	1,494	(2,407)
Cash flows from financing activities:
Proceeds from issuance of Class C preferred units, net of offering costs paid	0	21,235
Proceeds from Paycheck Protection Program loan	0	1,123
Proceeds from at the market offering, net of issuance costs	1,313	0
Proceeds from exercise of stock options	83	0
Payments of principal portion of long-term debt	(894)	0
Payments of debt issuance costs related to long-term debt	(103)	(72)
Payments of finance lease obligations	(140)	(264)
Net cash provided by financing activities	259	22,022
Net (decrease) increase in cash, cash equivalents and restricted cash	(38,425)	13,238
Cash, cash equivalents and restricted cash at beginning of period	82,885	14,246
Cash, cash equivalents and restricted cash at end of period	44,460	27,484
Supplemental cash flow information:
Cash paid for interest	326	952
Supplemental disclosure of noncash investing and financing activities:
Additions to property and equipment included in accounts payable and accrued expenses	9	0
Additions to property and equipment under finance lease	0	7
Deferred financing costs included in accounts payable	0	1,412
Operating lease liabilities arising from obtaining right-of-use assets	$ 0	$ 10,219

Nature of Business and Basis of

Nature of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	1. Nature of Business and Basis of Presentation Yumanity Therapeutics, Inc. (together with its wholly owned subsidiaries, the “Company” or “Yumanity”) is a clinical stage biopharmaceutical company engaged in the research and development of treatments for neurodegenerative diseases caused by protein misfolding. The Company is subject to risks similar to those of other early clinical stage companies in the biopharmaceutical industry, including dependence on key individuals, the need to develop commercially viable products, competition from other companies, many of whom are larger and better capitalized, the impact of the ongoing COVID-19 pandemic and the need to obtain adequate additional financing to fund the development of its product candidates. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be maintained, that any product candidates developed will obtain required regulatory approval or that any approved products will be commercially viable. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from the sale of its products. Merger with Proteostasis Therapeutics, Inc. On December 22, 2020, Proteostasis Therapeutics, Inc. (“Proteostasis” or “PTI”) completed its previously announced merger transaction with Yumanity, Inc. (formerly Yumanity Therapeutics, Inc.) in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated as of August 22, 2020, as amended on November 6, 2020 (the “Merger Agreement”), by and among Pangolin Merger Sub, Inc., a wholly-owned subsidiary of Proteostasis (“Merger Sub”), Yumanity Holdings, LLC (“Holdings”) and Yumanity, Inc., pursuant to which Merger Sub merged with and into Yumanity, Inc., with Yumanity, Inc. surviving as a wholly owned subsidiary of Proteostasis (the “Merger”). Immediately prior to the effective time of the Merger, Holdings merged with and into Yumanity, Inc. and Yumanity, Inc. continued to exist as the surviving corporation. On December 22, 2020, in connection with, and prior to the completion of, the Merger, Proteostasis effected a 1-for-20 reverse stock split of its common stock (the “Reverse Stock Split”) . Immediately following the Merger, Proteostasis changed its name to “Yumanity Therapeutics, Inc.” At the effective time of the Merger (the “Effective Time”), each share of Yumanity Inc.’s common stock, par value $ 0.01 (the “Yumanity Common Stock”), outstanding immediately prior to the Effective Time was converted into the right to receive shares of PTI based on an exchange ratio set forth in the Merger Agreement. At the Effective Time following the Reverse Stock Split, the exchange ratio was determined to be 0.2108 shares of PTI Common Stock for each share of Yumanity Common Stock (the “Exchange Ratio”). At the closing of the Merger on December 22, 2020, PTI issued an aggregate of 6,024,433 shares of its common stock to Yumanity, based on the Exchange Ratio. In addition, all options and warrants exercisable for shares of common stock of Yumanity, Inc. became options and warrants exercisable for shares of common stock of PTI equal to the Exchange Ratio multiplied by the number of shares of Yumanity Inc.’s common stock previously represented by such stock options and warrants, as applicable, with a proportionate adjustment in exercise price. No fractional shares were issued in connection with the Exchange Ratio. The transaction was accounted for as a reverse merger and as an asset acquisition in accordance with GAAP. Under this method of accounting, Yumanity was deemed to be the accounting acquirer for financial reporting purposes. This determination was primarily based on the fact that, immediately following the Merger: (i) Yumanity’s equity holders owned a majority of the voting rights in the combined organization, (ii) Yumanity designated a majority of the members (7 of 9) of the initial board of directors of the combined organization and (iii) Yumanity’s senior management hold all key positions in the senior management of the combined organization. Accordingly, for accounting purposes, (i) the Merger was treated as the equivalent of the Yumanity issuing stock to acquire the net assets of PTI, (ii) the net assets of PTI were allocated a portion of the transaction price and recorded based upon their relative fair values in the financial statements at the time of closing, (iii) the reported historical operating results of the combined organization prior to the Merger will be those of Yumanity and (iv) for periods prior to the transaction, shareholders’ equity of the combined organization is presented based on the historical equity structure of Yumanity. As a result, as of the closing date of the Merger, the net assets of PTI were recorded at their acquisition-date fair values in the financial statements of Yumanity and the reported operating results prior to the Merger will be those of Yumanity. As used herein, the words “the Company” refer to, for periods following the Merger, Yumanity Therapeutics, Inc., together with its wholly owned subsidiaries, and for periods prior to the Merger, Holdings, and its wholly owned subsidiary, as applicable. The Yumanity Reorganization On December 22, 2020, immediately prior to the closing of the Merger, pursuant to the terms of the Merger Agreement, the Company completed the Yumanity Reorganization whereby Holdings, the sole stockholder and holding company parent of Yumanity, Inc., merged with and into Yumanity, Inc., with Yumanity, Inc. as the surviving corporation. In connection with the Yumanity Reorganization, each outstanding common unit of Holdings was exchanged for shares of common stock of Yumanity, Inc. based upon a ratio associated with the terms of each common unit, each outstanding preferred unit of Holdings was converted into shares of common stock of Yumanity, Inc. based upon the ratio associated with each individual series of preferred units, each outstanding option to purchase shares of common units of Holdings was converted into an outstanding option to purchase shares of common stock of Yumanity, Inc. on a 1-for-1 basis, with a corresponding adjustment to the exercise price, and each outstanding warrant to purchase preferred units or common units of Holdings was converted into a warrant to purchase shares of common stock of Yumanity, Inc. based upon the ratio associated with each individual series of preferred units or on a 1-for-1 basis, respectively, with a corresponding adjustment to the exercise price, as applicable. Basis of presentation The Company’s condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Unless otherwise noted, all references to common stock/unit share and per share amounts have also been adjusted to reflect the Exchange Ratio. Going concern The Company has evaluated whether there are certain conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the original issuance date of the condensed consolidated financial statements. Since its inception, the Company has funded its operations primarily with equity and debt including proceeds from the Merger. The Company has incurred recurring losses and negative cash flows from operations since inception, including net losses of $ 10.0 million and $ 29.1 million for the three and nine months ended September 30, 2021. In addition, as of September 30, 2021, the Company had an accumulated deficit of $ 176.9 million. The Company expects to continue to generate operating losses for the foreseeable future. As of November 15, 2021, the date of issuance of these unaudited condensed consolidated financial statements, the Company expects that its cash, cash equivalents and marketable securities as of September 30, 2021, will be sufficient to fund its operating expenses, capital expenditure requirements and debt service payments into the third quarter of 2022 . The Company plans to address this condition by raising additional capital to finance its operations. The future viability of the Company is dependent on its ability to raise additional capital to finance its operations. Although the Company has been successful in raising capital in the past, there is no assurance that it will be successful in obtaining such additional financing on terms acceptable to the Company, if at all. Based on its recurring losses from operations incurred since inception, expectation of continuing losses for the foreseeable future and need to raise additional capital to finance its future operations, the Company has concluded that there is substantial doubt about its ability to continue as a going concern for a period of one year from the date that these financial statements are issued. If the Company is unable to obtain additional funding, the Company will be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations. The accompanying financial statements do not include any adjustments that might result from this uncertainty. Impact of the COVID-19 pandemic The COVID-19 pandemic, which began in December 2019 and has spread worldwide, has caused many governments to implement measures to slow the spread of the outbreak. The outbreak and government measures taken in response have had a significant impact, both direct and indirect, on businesses and commerce, as worker shortages have occurred, supply chains have been disrupted, and facilities and production have been suspended. The future progression of the pandemic and its effects on the Company’s business and operations are uncertain. The COVID-19 pandemic is ongoing and may affect the Company’s ability to initiate and complete preclinical studies, delay its clinical trial or future clinical trials, disrupt regulatory activities, or have other adverse effects on its business and operations. The pandemic has already caused significant disruptions in the financial markets, and may continue to cause such disruptions, which could impact the Company’s ability to raise additional funds to support its operations. Moreover, the pandemic has significantly impacted economies worldwide and could result in adverse effects on the Company’s business and operations. Clinical trial sites in many countries, including those in which the Company operates, have incurred delays due to COVID-19. Certain of the sites in the YTX-7739 Phase 1b clinical trial incurred delays due to COVID-19 that resulted in a delay in the results from that study. There continues to be a risk of additional delays to the Company’s clinical programs. To date, the Company has not incurred impairment losses in the carrying values of its assets as a result of the pandemic and it is not aware of any specific related event or circumstance that would require it to revise its estimates reflected in these condensed consolidated financial statements. The extent to which the COVID-19 pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including current and future clinical trials and research and development costs, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19, the actions taken to contain or treat it, and the duration and intensity of the related effects. At-the-Market Offering Program In April 2021, we entered into a sales agreement with Jefferies LLC (“Jefferies”) with respect to an at-the-market (“ATM”) offering program under which we may issue and sell, from time-to-time at our sole discretion, shares of our common stock, in an aggregate offering amount of up to $ 60.0 million. Jefferies acts as our sales agent and will use commercially reasonable efforts to sell shares of common stock from time-to-time, based upon instruction us. We will pay Jefferies up to 3 % of the gross proceeds from any common stock sold through the sales agreement. We sold 82,132 shares of its common stock under the ATM program during the nine months ended September 30, 2021 for gross proceeds of $ 1.3 million. As of September 30, 2021, approximately $ 58.7 million of common stock remained available for future issuance under the ATM program. Private Placement On December 14, 2020, we entered into a subscription agreement with certain accredited investors for the sale by us in a private placement of 1,460,861 shares of our common stock for a price of $ 23.00 per share. We refer to this sale herein as the Private Placement. The Private Placement closed on December 22, 2020 . The aggregate gross proceeds for the issuance and sale of the common stock were $ 33.6 million and, after deducting certain of our expenses, the net proceeds we received in the Private Placement were $ 31.6 million.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Unaudited Interim Financial Information The condensed balance sheet as of December 31, 2020 was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the United States of America (“GAAP”). The accompanying condensed financial statements, as of September 30, 2021 and for the three and nine months ended September 30, 2021, are unaudited and have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited condensed financial statements should be read in conjunction with the Company’s audited financial statements and the notes thereto for the year ended December 31, 2020 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 31, 2021. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s condensed consolidated financial position as of September 30, 2021 and condensed consolidated results of operations and cash flows for the three and nine months ended September 30, 2021 and 2020 have been made. The results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2021. Summary of Significant Accounting Policies The Company’s significant accounting policies, which are disclosed in the audited financial statements for the year ended December 31, 2020 and the notes thereto, are included in the Company’s Annual Report on Form 10-K that was filed with the SEC on March 31, 2021. There were no changes to significant accounting policies during the three and nine months ended September 30, 2021 . Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, revenue recognition, the accrual of research and development expenses, the valuation of common units prior to the Merger and the valuation of stock/unit-based awards. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates as there are changes in circumstances, facts, and experience. Actual results may differ from those estimates or assumptions. Restricted cash Amounts included in restricted cash represent amounts pledged as collateral for Company credit cards as part of the terms of the “New Loan” and for its office and laboratory space lease. These amounts are classified as restricted cash (non-current) in the Company’s condensed consolidated balance sheet. In December 2020, in connection with the Merger, the Company acquired Proteostasis’ restricted cash pledged as collateral for its office and laboratory space lease and amended its loan and security agreement to establish an escrow account in the amount of its Paycheck Protection Program loan. These amounts are classified as restricted cash (non-current) in the Company’s condensed consolidated balance sheet as of September 30, 2021. As of September 30, 2021 and 2020, the cash and restricted cash of $ 44.5 million and $ 27.5 million, respectively, presented in the condensed consolidated statements of cash flows included cash and cash equivalents of $ 43.5 million and $ 27.4 million, respectively, and restricted cash of $ 1.0 million and $ 0.1 million, respectively. Fair value measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:  Level 1 — Quoted prices in active markets for identical assets or liabilities.  Level 2 — Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.  Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). The carrying values of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities. The carrying value of the Company’s long-term debt under its loan and security agreement approximates its fair value due to its variable interest rate. Recently issued accounting pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes—Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. ASU 2019-12 is effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The Company adopted this standard as of January 1, 2021, and depending on the amendment, adoption was applied on a retrospective, modified retrospective, or prospective basis. The adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements and related disclosures.

Fair Value Measurements and Mar

Fair Value Measurements and Marketable Securities	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements and Marketable Securities	3. Fair Value Measurements and Marketable Securities The following tables present the Company’s fair value hierarchy for its assets and liabilities, which are measured at fair value on a recurring basis (in thousands): Fair Value Measurements at September 30, 2021 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 41,886 $ — $ 41,886 Marketable securities: Commercial paper 2,899 — 2,899 $ 41,886 $ 2,899 $ — $ 44,785 Fair Value Measurements at December 31, 2020 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 77,129 $ — $ — $ 77,129 Commercial paper — 1,800 — 1,800 Marketable securities: Commercial paper — 4,498 — 4,498 $ 77,129 $ 6,298 $ — $ 83,427 Marketable securities were valued by the Company using quoted prices in active markets for similar securities, which represent a Level 2 measurement within the fair value hierarchy. Marketable securities by security type consisted of the following (in thousands): September 30, 2021 Amortized Gross Gross Fair Commercial paper $ 2,899 $ — $ — $ 2,899 $ 2,899 $ — $ — $ 2,899 December 31, 2020 Amortized Gross Gross Fair Commercial paper $ 4,498 $ — $ — $ 4,498 $ 4,498 $ — $ — $ 4,498 The Company’s marketable securities are due within one year .

Collaboration Agreement

Collaboration Agreement	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration Agreement	4. Collaboration Agreement In June 2020, the Company entered into an exclusive license and research collaboration agreement (the “Collaboration Agreement”) with Merck Sharp & Dohme Corp. (“Merck”) to support the research, development and commercialization of products for the treatment of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD). Pursuant to the Collaboration Agreement, the Company granted Merck an exclusive, worldwide license with the right to grant and authorize sublicenses, under certain intellectual property rights related to two certain undisclosed targets in connection with the Company’s ALS and FTLD programs to make, have made, use, import, offer to sell and sell compounds and products covered by such intellectual property rights. In the event that the exploitation of such compound or product would infringe during the term of the Merck Collaboration Agreement a claim of an issued patent controlled by Yumanity, Yumanity also granted Merck a non-exclusive, sublicensable, royalty-free license under such issued patent to exploit such compound and product. Under the terms of the Collaboration Agreement, the Company and Merck are each responsible to perform certain research activities in accordance with a mutually agreed upon research plan. Upon the completion of certain stages of the research plan, Merck will elect to either advance and make certain contractual option payments or terminate the applicable research program. If Merck elects not to advance a research program, such program terminates and the rights granted to Merck in the program revert to the Company. Following completion of the research program, Merck is responsible for the development and commercialization of the compounds developed pursuant to the research program and any product containing such compounds. Under the terms of the Collaboration Agreement, the Company received an upfront payment totaling $ 15.0 million in July 2020 and is eligible to receive up to $ 280.0 million upon achievement of specified research and development milestones, and up to $ 250.0 million upon achievement of specified sales-based milestones as well as a tiered, mid-single digit royalty on net sales of licensed products, subject to customary reductions. Unless terminated earlier, the Collaboration Agreement will continue in full force and effect until one or more products has received marketing authorization and, thereafter, until expiration of all royalty obligations under the Collaboration Agreement. The Company or Merck may terminate the Collaboration Agreement upon an uncured material breach by the other party or insolvency of the other party. Merck may also terminate the Merck Collaboration Agreement for any reason upon certain notice to the Company. Merck also participated in the Company’s Class C preferred units financing in June 2020 with terms consistent with those of other investors that purchased Class C preferred units in June 2020. The Class C preferred units were issued at a price of $ 4.0008 per unit, which was determined to be fair value based on the same price paid by other investors that purchased Class C preferred units in the financing. The equity investment was considered to be distinct from the Collaboration Agreement. The Company assessed the promised goods and services to determine if they are distinct. Based on this assessment, the Company determined that Merck cannot benefit from the promised goods and services separately from the others as they are highly interrelated and therefore not distinct. Accordingly, the promised goods and services represent one combined performance obligation and the entire transaction price was allocated to that single combined performance obligation. The performance obligation is being satisfied over the research term as the Company performs the research and development activities through the first substantive option period, and participates in a Joint Steering Committee to oversee research and development activities. Accordingly, the upfront payment of $ 15.0 million was recorded as deferred revenue and will be recognized as revenue as the performance obligation is satisfied. The Company recognizes revenue using the cost-to-cost method, which it believes best depicts the transfer of control to the customer. Under the cost-to-cost method, the extent of progress towards completion is measured based on the ratio of actual costs incurred to the total estimated costs expected upon satisfying the identified performance obligation. Under this method, revenue is recorded as a percentage of the estimated transaction price based on the extent of progress towards completion. As of September 30, 2021, the aggregate amount of the transaction price related to the unsatisfied portion of the performance obligation is $ 0.8 million , which is expected to be recognized as revenue within the next year. For the three and nine months ended September 30, 2021, the Company recorded $ 1.6 million and $ 7.3 million of collaboration revenue, respectively, related to the Collaboration Agreement. At contract inception, the potential milestone payments that the Company is eligible to receive were excluded from the transaction price as they were fully constrained. At the end of each reporting period, the Company reevaluates the transaction price and as uncertain events are resolved or other changes in circumstances occur, and if necessary, the Company will adjust its estimate of the transaction price. Any additions to the transaction price would be reflected in the period as a cumulative revenue catch-up. At the inception of the arrangement, the Company evaluated the options held by Merck to either advance or terminate the applicable research program to determine if they provided Merck with any material rights. The Company concluded that the options were not issued at a significant and incremental discount, and therefore do not provide Merck with a material right. As such, these options were excluded as performance obligations and will be accounted for if and when they occur. The Company assessed the Collaboration Agreement to determine whether a significant financing component exists and concluded that a significant financing component does not exist.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consisted of the following (in thousands): September 30, December 31, 2021 2020 Accrued employee compensation and benefits $ 1,417 $ 4,295 Accrued external research and development expenses 2,568 1,780 Accrued professional fees 767 987 Other 660 789 $ 5,412 $ 7,851

Debt

Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt	6. Debt Long-term debt consisted of the following (in thousands): September 30, December 31, 2021 2020 Principal amount of long-term debt $ 14,106 $ 16,123 Less: Current portion of long-term debt ( 5,678 ) ( 2,891 ) Long-term debt, net of current portion 8,428 13,232 Debt discount, net of accretion ( 272 ) ( 348 ) Accrued end-of-term payment 586 353 Long-term debt, net of discount and current portion $ 8,742 $ 13,237 We have outstanding principal borrowings of $ 14.1 million under a loan and security agreement entered into in December 2019 (the “Term Loan”) with Hercules Capital, Inc. (the “Lender”). Another $ 5.0 million became available upon the occurrence of a developmental milestone and an equity event defined in the agreement, but we elected not to draw it. An additional $ 10.0 million may become available to be drawn upon lender approval. Borrowings under the Term Loan were repayable in monthly interest-only payments until August 1, 2021. The interest-only period is followed by monthly payments of equal principal plus interest until the loan maturity date of January 1, 2024 . Outstanding borrowings bear interest at the greater of (i) 8.75 % and (ii) the prime rate as reported in the Wall Street Journal plus 4.00 %. A final payment fee of 5.25 % of the amounts drawn under the Term Loan is due upon the earlier of the maturity date or the repayment date if paid early, whether voluntary or upon acceleration due to default. We may repay the Term Loan at any time by paying the outstanding principal balance in full, along with any unpaid accrued interest, the final payment fees of 5.25 % of the amounts drawn and a prepayment fee calculated on amounts being prepaid. The prepayment fee is 3.0 % if the Term Loan is repaid within the one-year anniversary of the draw date, 2.0 % if paid between the first and second-year anniversary of the draw date and 1.0 % if paid after the second anniversary of the draw date but before the maturity date. In April 2020, the Term Loan was amended to permit indebtedness consisting of a loan under the Paycheck Protection Program (“PPP”) of the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) provided that such loan shall be unsecured, shall not contain any terms or conditions that are adverse to the Lender’s rights under the loan and that the Company will not prepay such loan. In June 2020, the Term Loan was amended and an additional final payment fee of $ 0.3 million became due upon repayment of the loan. On December 22, 2020, the Company entered into an Unconditional Secured Guaranty and Pledge Agreement (the “Guaranty”) with the Lender as a condition to the Lender’s consent to the Merger under the Term Loan between Yumanity, Inc. as borrower and the Lender. Immediately prior to the Merger, Yumanity, Inc. entered into a Fourth Amendment and Consent to Loan and Security Agreement dated as of December 22, 2020 with the Lender (the “Loan Amendment”). The Guaranty provides for the Company’s guaranty of Yumanity Inc.’s obligations under the Loan Agreement and provides the Lender a security interest in all of Company’s assets other than intellectual property as collateral. The Loan Amendment provides for the Lender’s consent to the Merger and to the creation and funding of a Silicon Valley Bank Paycheck Protection Program escrow account to hold funds in connection with Yumanity’s outstanding Paycheck Protection Program loan amounts for which Yumanity has submitted a forgiveness application. The Loan Amendment also amends the definition of “Change in Control” to include the situations in which the Company no longer controls Yumanity, Inc. The remaining terms and conditions of the Loan Agreement generally continue in the form existing prior to the Loan Amendment. As of September 30, 2021 and December 31, 2020, the interest rate applicable to borrowings under the Term Loan was 8.75 %. For the nine months ended September 30, 2021 , the weighted average effective interest rate on outstanding borrowings under the Term Loan was approximately 9.41 %. On March 29, 2021, the Term Loan was amended again to allow for the creation of a new foreign subsidiary, as well as changing certain covenants related to the financial operations of said subsidiary. The subsidiary was formed on April 23, 2021. On April 13, 2021, the Term Loan was amended to reduce the additional final payment fee of $ 0.3 million to $ 0.1 million upon repayment of the loan. Borrowings under the Term Loan are collateralized by substantially all of the Company’s personal property, other than its intellectual property. There were no financial covenants associated with the Term Loan; however, the Company is subject to certain affirmative and negative covenants restricting the Company’s activities, including limitations on dispositions, mergers or acquisitions; encumbering its intellectual property; incurring indebtedness or liens; paying dividends; making certain investments; and engaging in certain other business transactions. The obligations under the Term Loan are subject to acceleration upon the occurrence of specified events of default, including a material adverse change in the Company’s business, operations or financial or other condition. Upon the occurrence of an event of default and until such event of default is no longer continuing, the annual interest rate will be 5.0 % above the otherwise applicable rate. In April 2020, prior to entering into the Merger Agreement with PTI in August 2020, the Company issued a Promissory Note to Silicon Valley Bank, pursuant to which it received loan proceeds of $ 1.1 million (the “Loan”) provided under the PPP established under the CARES Act and guaranteed by the U.S. Small Business Administration. On April 3, 2021, the Company was notified by Silicon Valley Bank that the Loan forgiveness application was accepted by the Small Business Association as of March 30, 2021. Accordingly, the Company has recognized $ 1.1 million in income for debt extinguishment. As of September 30, 2021, future principal payments due are as follows (in thousands): Year Aggregate 2021 $ 1,374 2022 5,805 2023 6,341 2024 586 2025 — $ 14,106

Stock_Equity-Based Compensation

Stock/Equity-Based Compensation	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock/Equity-Based Compensation	7. Stock/Equity-Based Compensation Restricted Stock Units (RSUs) On January 14, 2021, the Company’s compensation committee of the board approved payment to be made to Company employees through a grant of RSUs based on the February 1, 2021 closing share price of the Company’s common stock with a fair value of $ 2.2 million. The requisite service period for the awards ranges from one to four years (the vesting period). The Company recognized employee stock-based compensation expense for the RSU grant on a straight-line basis over the vesting period of the awards. As of September 30, 2021 , 122,469 RSUs were granted and 87,052 were outstanding, and the Company recognized $ 0.2 million and $ 0.7 million of stock-based compensation expense during the three and nine months ended September 30, 2021, respectively. The following table summarizes the Company’s RSU activity for the nine months ended September 30, 2021: Units Weighted Unvested balance at December 31, 2020 — $ — Issued 122,469 $ 17.89 Vested ( 23,146 ) $ 17.89 Forfeited ( 12,271 ) $ 17.89 Unvested balance at September 30, 2021 87,052 $ 17.89 Summary of plans Upon completion of the Merger, the Company assumed PTI’s 2016 Stock Option and Incentive Plan (the “2016 Plan”) and PTI’s 2016 Employee Stock Purchase Plan (the “2016 ESPP”). 2016 Stock Option and Incentive Plan On February 3, 2016, PTI’s stockholders approved the 2016 Plan, which became effective on February 9, 2016. The 2016 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock units, restricted stock awards and other stock-based awards. The number of shares initially reserved for issuance under the 2016 Plan was 79,092 shares. The number of shares of common stock that may be issued under the 2016 Plan will automatically increase each January 1, beginning January 1, 2017, by the lesser of 3 % of the shares of the Company’s common stock outstanding on the immediately preceding December 31, or an amount determined by the Company’s board of directors or the compensation committee of the board of directors. The shares of common stock underlying any awards that are forfeited, canceled, repurchased, or are otherwise terminated by the Company under the 2016 Plan and the 2008 Equity Incentive Plan, as amended (the “2008 Plan”) will be added back to the shares of common stock available for issuance under the 2016 Plan. On January 1, 2021, an additional 303,495 shares were reserved for issuance under the 2016 Plan in accordance with the provisions of the 2016 Plan described above. Options granted under the 2016 Plan with service-based vesting conditions generally vest over four years and expire after ten years . As of September 30, 2021 the total number of shares of the Company’s common stock reserved for issuance under the 2016 Plan was 626,100 , of which 136,329 shares are available for future issuance under the 2016 Plan. 2016 Employee Stock Purchase Plan On February 3, 2016, PTI’s stockholders approved the 2016 ESPP, which became effective in connection with the completion of the PTI’s initial public offering. A total of 6,938 shares of common stock were initially reserved for issuance under the 2016 ESPP. In addition, the number of shares of common stock that may be issued under the 2016 ESPP will automatically increase each January 1, beginning January 1, 2017, by the lesser of (i) 6,938 shares of common stock, (ii) 1 % of the Company’s shares of common stock outstanding on the immediately preceding December 31, or (iii) an amount determined by the Company’s board of directors or the compensation committee of the board of directors. As of September 30, 2021, the total number of shares reserved under the 2016 ESPP was 41,626 shares. The number of shares reserved for issuance under the 2016 ESPP was increased by 6,937 shares effective as of January 1, 2021 in accordance with the provisions of the 2016 ESPP described above. Yumanity Therapeutics, Inc. Amended and Restated 2018 Stock Option and Grant Plan On December 4, 2018, the Company’s board of directors adopted the 2018 Unit Option and Grant Plan (the “2018 Plan”), which was approved by the Company’s members on December 5, 2018. The 2018 Plan provided for the Company to grant unit options, restricted unit awards and unrestricted unit awards to employees, directors and consultants of the Company. As part of the Yumanity Reorganization and the Merger, the 2018 Plan was amended and restated as the “Yumanity Therapeutics, Inc. Amended and Restated 2018 Stock Option and Grant Plan”. Each stock option outstanding under the 2018 Plan at the Effective Time of the Merger was automatically converted into a stock option exercisable for the same number of shares of Yumanity common stock, and then assumed by the Company, based on the Exchange Ratio and the exercise price per share of such outstanding stock option, as adjusted for the Exchange Ratio. The 2018 Plan is administered by the board of directors or, at the discretion of the board of directors, by a committee of the board of directors. The exercise prices, vesting and other restrictions are determined at the discretion of the board of directors, or its committee if so delegated. Options granted under the 2018 Plan with service-based vesting conditions generally vest over four years and expire after ten years . The total number of common shares that may be issued under the 2018 Plan is 1,527,210 as of September 30, 2021. Shares that are forfeited, canceled, reacquired by the Company prior to vesting, satisfied without the issuance of shares or otherwise terminated (other than by exercise) and units that are withheld upon the exercise of an option or settlement of an award to cover exercise price or tax withholding shall be added back to units available under the 2018 Plan. As of September 30, 2021 , 330,609 sh ares remain available for issuance under the 2018 Plan. Under each plan, the exercise price per option granted is not less than the fair market value of common stock as of the date of grant. 2021 Inducement Plan On April 13, 2021 the Board of Directors approved the adoption of the Company’s 2021 Inducement Plan (the “2021 Plan”), which is used exclusively for the grant of equity awards to individuals who were not previously employees of the Company (or following a bona fide period of non-employment), as an inducement material to such individual’s entering into employment with the Company, pursuant to Rule 416 under the Securities Act of 1933. As of September 30, 2021 , the total number of shares of the Company’s common stock that may be issued under the 2021 Plan is 504,000 shares of which 233,600 shares are available for future issuance under the 2021 Plan. Shares that are expired, forfeited, canceled or otherwise terminated without having been fully exercised will be available for future grant under the 2021 Plan. Option valuation The fair value of option grants is estimated using the Black-Scholes option-pricing model. Prior to the Merger, the Company was a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock/unit volatility based on the historical volatility of a publicly traded set of peer companies. The expected term of the Company’s options has been determined utilizing a midpoint convention estimate. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. Option activity The following table summarizes the Company’s option activity during nine months ended September 30, 2021: Number Weighted Weighted Aggregate (in years) (in thousands) Outstanding as of December 31, 2020 944,961 $ 20.70 8.29 6,522 Granted 986,014 $ 15.33 9.91 — Exercised ( 9,241 ) 8.97 7.37 9 Forfeited ( 139,290 ) $ 13.70 — Outstanding as of September 30, 2021 1,782,444 $ 19.01 7.92 1,521 Vested and expected to vest as of September 30, 2021 1,767,444 $ 19.03 7.90 — The aggregate intrinsic value of options is calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock/units for those stock/unit options that had exercise prices lower than the fair value of the Company’s common stock/units. The grant date fair value of options granted during the period was $ 13.7 million, or $ 13.89 per sh are on a weighted-average basis and will be recognized as compensation expense over the requisite service period ranging from one to four years . Stock/equity-based compensation The Company recorded stock/equity-based compensation expense related to common stock/unit options and restricted units in the following expense categories in its condensed consolidated statements of operations (in thousands): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research and development expenses $ 320 $ 154 $ 1,066 $ 529 General and administrative expenses 972 540 2,892 1,237 $ 1,292 $ 694 $ 3,958 $ 1,766 As of September 30, 2021 , total unrecognized compensation cost related to unvested options and restricted common stock was $ 12.5 million, which is expected to be recognized over a weighted average period o f 2.65 years .

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss per Share	8. Net Loss Per Share Basic and diluted net loss per share was calculated as follows (in thousands, except share and per share amounts): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Numerator: Net loss $ ( 9,956 ) $ ( 6,385 ) ( 29,092 ) ( 20,822 ) Gain on extinguishment of Class B preferred units — — — 6,697 Net loss applicable to common shareholders $ ( 9,956 ) $ ( 6,385 ) $ ( 29,092 ) $ ( 14,125 ) Denominator: Weighted average common shares/units 10,304,775 2,159,403 10,239,502 2,155,276 Net loss per share/unit, basic and diluted $ ( 0.97 ) $ ( 2.96 ) $ ( 2.84 ) $ ( 6.55 ) The following common stock equivalents presented based on amounts outstanding at each period end, have been excluded from the calculation of diluted net loss per share because including them would have had an anti-dilutive impact: As of September 30, 2021 2020 Options to purchase common stock 1,782,444 964,002 Warrants to purchase common stock or shares 99,986 99,986 1,882,430 1,063,988

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases	9. Leases The Company leased office and laboratory facilities in Cambridge, Massachusetts (the “Old Premises”) from an investor in the Company under a noncancelable operating lease that began in April 2015 and expired in March 2020. In February 2020, the Company amended the lease for the Old Premises to extend the lease expiration to April 30, 2020. The amendment was accounted for as a lease reassessment and the right-of-use asset and lease liability were remeasured at the reassessment date of February 2020 resulting in an increase of $ 0.1 million to the right-of-use asset for prepaid rent and a reduction of $ 0.1 million to the lease liability. In May 2020, the Company amended the lease for the Old Premises to extend the lease expiration to May 23, 2020 and recognized the final rent payment of less than $ 0.1 million in expense. In February 2020, the Company entered into a license agreement with a third party for the use of office and laboratory space in Boston, Massachusetts, commencing in May 2020 (the “New Premises”). The Company determined that this license agreement qualified as a lease under ASC 842, Leases (“ASC 842”). The initial term of the license agreement is three years with the option to extend for a total of three one-year periods at fair-market rent at the time of each extension. In addition to use of office and laboratory space, the license fee includes various laboratory, office, and operational support services to be provided by the licensor. The initial monthly license fee escalates 3 % annually and totals approximately $ 12.0 million for the three-year term. Additionally, the licensee agreement for the New Premises requires the Company to pay for a non-exclusive, irrevocable license to use forty-two unreserved parking spaces adjacent to the New Premises at the prevailing monthly parking rate. On May 1, 2020 , the lease commencement date was met and the Company recorded an operating lease asset of $ 10.6 million and a corresponding lease liability of $ 10.2 million. On December 22, 2020, as part of the Merger, the Company acquired a lease for approximately 30,000 square feet of office and laboratory space (the “Merger Premises”) in Boston, Massachusetts. The lease commenced in January 2018 with rent payments commencing in April 2018. The initial term of the lease was ten years with the option to extend for an additional seven years at fair-market rent at the time of the extension. In addition to use of office and laboratory space, the Company is responsible for paying its allocable portion of building and laboratory operating expenses separately from rent, based on actual costs incurred. Remaining fixed lease payments at the time of the Merger were approximately $ 14.2 million. On December 22, 2020, the Company recorded an operating lease asset and corresponding lease liability of $ 10.2 million associated with this lease. The operating lease asset was increased by the value attributable to the below-market lease of $ 3.1 million and an allocated portion of the excess purchase price for the Merger of $ 1.9 million. On January 7, 2021 the Company entered into a sublease agreement (the “Sublease”) with Moma Therapeutics, Inc. (the “Subtenant”), whereby the Company subleased the entire Merger Premises to the Subtenant. The initial term of the Sublease commences on the date the Company receives consent to the Sublease from the landlord and shall continue until 18 months from the commencement date. The Sublease provides for the first monthly installment of rent to be paid by the Subtenant on the date of the Sublease. The Sublease provides for an initial annual base rent of $ 1,939,340 , which increases annually up to a maximum annual base rent of $ 1,997,520 . The Subtenant also is responsible for paying to the Company operating costs, annual tax costs and all utility costs attributable to the Premises during the term of the Sublease. Expense arising from the Merger Premises of $ 0.5 million and $ 1.5 million for the three and nine months ended September 30, 2021 , respectively, and lease income from the Sublease of $ 0.5 million and $ 1.3 million for the three and nine months ended September 30, 2021, respectively, are classified in operating expense on a net basis. The Company also leases property and equipment under agreements that are accounted for as finance leases. The components of lease cost were as follows (in thousands): Nine Months Ended 2021 2020 Operating lease cost $ 4,721 $ 2,085 Short-term lease cost — — Variable lease cost 458 244 Finance lease cost: Amortization of lease assets 133 280 Interest on lease liabilities 6 16 Total finance lease cost $ 139 $ 296 Supplemental disclosure of cash flow information related to leases was as follows (in thousands): Nine Months Ended 2021 2020 Cash paid for amounts included in the measurement $ 4,484 $ 1,428 Cash paid for amounts included in the measurement $ 6 $ 16 Cash paid for amounts included in the measurement $ 140 $ 264 Operating lease liabilities arising from obtaining $ — $ 10,219 Finance lease liabilities arising from obtaining right- $ — $ — The weighted-average remaining lease term and discount rate were as follows: As of September 30, 2021 2020 Weighted-average remaining lease term (in years) used for: Operating leases 5.47 2.58 Finance leases 0.99 0.83 Weighted-average discount rate used for: Operating leases 9.10 % 8.80 % Finance leases 5.59 % 6.90 % Because the interest rates implicit in the license agreement and lease agreement assumed from PTI were not readily determinable, the Company’s incremental borrowing rate was used to calculate the present value of each. The present value of the Company’s finance leases was calculated using the rate implicit in the lease. As of September 30, 2021, future annual lease payments under the Company’s real estate operating leases and equipment finance leases were as follows (in thousands): Year Operating Finance 2021 $ 1,514 $ 26 2022 6,173 50 2023 2,977 — 2024 1,931 — 2025 1,985 — Thereafter 4,840 — Total future lease payments 19,420 76 Less: Imputed interest ( 3,773 ) ( 2 ) Total lease liabilities $ 15,647 $ 74 The following table presents lease assets and liabilities and their classification on the condensed consolidated balance sheet (in thousands): Leases Condensed Consolidated Balance Sheet Classification Amount Assets: Operating lease assets Operating lease right-of- use assets $ 19,864 Finance lease assets Property and equipment, net 66 Total leased assets $ 19,930 Liabilities: Current: Operating lease liabilities Operating lease liabilities $ 4,909 Finance lease liabilities Current portion of finance lease obligation 65 Non-current: Operating lease liabilities Operating lease liabilities, net of current portion 10,738 Finance lease liabilities Finance lease obligation, net of current portion 9 Total lease liabilities $ 15,721

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. Commitments and Contingencies License agreement The Company has a tangible property and patent license agreement with Whitehead Institute for Biomedical Research (“Whitehead”) entered into in 2016 and subsequently amended in 2016 and 2018, under which the Company obtained a certain exclusive and non-exclusive, royalty-bearing, sublicensable, worldwide license to make, sell and distribute products under certain patents owned by Whitehead for certain know-how related to specific neurodegenerative diseases. In consideration for the rights granted by the agreement, the Company paid a one-time license fee of less than $ 0.1 million and issued 300,000 common units valued at $ 0.8 million. The Company is required to pay annual maintenance fees of up to $ 0.1 million through the termination of the agreement. The Company is also required to pay up to an aggregate of approximately $ 1.9 million upon the achievement of certain developmental and regulatory milestones for the first two licensed products under its first indication. The Company is also required to pay additional milestone amounts for subsequent licensed products under its first or subsequent indications, but at a lower rate. The Company did not meet any milestones for the nine months ended September 30, 2021 and the year ended December 31, 2020. The Company must also pay a royalty in the low single digits on future sales by the Company and a mid single to low double digit percentage of certain income received from sublicensees and certain partners. The license agreement remains in effect until the expiration of the last-to-expire patent licensed under the agreement. Whitehead may terminate the agreement upon the Company’s uncured material breach of the agreement, including failure to make required payments under the agreement or to achieve certain milestones, or if the Company becomes insolvent or bankrupt. The Company may terminate the license agreement at any time upon providing certain written notice to Whitehead. Contingent Value Rights Agreement In connection with the Merger, the Company entered into a Contingent Value Rights Agreement (the “CVR Agreement”) with Shareholder Representative Services LLC as representative of the PTI stockholders. The CVR Agreement entitled each holder of Company Common Stock as of immediately prior to the effective time of the Merger (the “Effective Time”) to receive certain net proceeds, if any, derived from the grant, sale or transfer of rights of the CF Assets ( the “CF Assets”) to any one of three specified counterparties completed during the 9 -month period after the Effective Time (with any potential payment obligations continuing until the 10-year anniversary of the closing of the Merger Agreement). The CVR agreement became effective at Closing of the Merger. Due to the fact that no CF Asset sale was completed by the nine-month anniversary of the Effective Time, the CVRs expired. No liability has been recorded at September 30, 2021 or previous periods associated with the CVRs. Indemnification agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, contract research organizations, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and its executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. The Company has not incurred any material costs as a result of such indemnifications and is not currently aware of any indemnification claims.

Related Parties

Related Parties	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Parties	11. Related Parties There were no related party transactions for the three and nine months ended September 30, 2021. The Company leased certain office and laboratory space from an investor in the Company until May 2020. Lease expense and amounts paid to the investor associated with this lease agreement for the nine months ended September 30, 2020 was $ 0.4 million and $ 0.6 million, respectively.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Unaudited Interim Financial Information	Unaudited Interim Financial Information The condensed balance sheet as of December 31, 2020 was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the United States of America (“GAAP”). The accompanying condensed financial statements, as of September 30, 2021 and for the three and nine months ended September 30, 2021, are unaudited and have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited condensed financial statements should be read in conjunction with the Company’s audited financial statements and the notes thereto for the year ended December 31, 2020 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 31, 2021. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s condensed consolidated financial position as of September 30, 2021 and condensed consolidated results of operations and cash flows for the three and nine months ended September 30, 2021 and 2020 have been made. The results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2021.
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The Company’s significant accounting policies, which are disclosed in the audited financial statements for the year ended December 31, 2020 and the notes thereto, are included in the Company’s Annual Report on Form 10-K that was filed with the SEC on March 31, 2021. There were no changes to significant accounting policies during the three and nine months ended September 30, 2021 .
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 reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, revenue recognition, the accrual of research and development expenses, the valuation of common units prior to the Merger and the valuation of stock/unit-based awards. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates as there are changes in circumstances, facts, and experience. Actual results may differ from those estimates or assumptions.
Restricted Cash	Restricted cash Amounts included in restricted cash represent amounts pledged as collateral for Company credit cards as part of the terms of the “New Loan” and for its office and laboratory space lease. These amounts are classified as restricted cash (non-current) in the Company’s condensed consolidated balance sheet. In December 2020, in connection with the Merger, the Company acquired Proteostasis’ restricted cash pledged as collateral for its office and laboratory space lease and amended its loan and security agreement to establish an escrow account in the amount of its Paycheck Protection Program loan. These amounts are classified as restricted cash (non-current) in the Company’s condensed consolidated balance sheet as of September 30, 2021. As of September 30, 2021 and 2020, the cash and restricted cash of $ 44.5 million and $ 27.5 million, respectively, presented in the condensed consolidated statements of cash flows included cash and cash equivalents of $ 43.5 million and $ 27.4 million, respectively, and restricted cash of $ 1.0 million and $ 0.1 million, respectively.
Fair value measurements	Fair value measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:  Level 1 — Quoted prices in active markets for identical assets or liabilities.  Level 2 — Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.  Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). The carrying values of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities. The carrying value of the Company’s long-term debt under its loan and security agreement approximates its fair value due to its variable interest rate.
Recently issued accounting pronouncements	Recently issued accounting pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes—Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. ASU 2019-12 is effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The Company adopted this standard as of January 1, 2021, and depending on the amendment, adoption was applied on a retrospective, modified retrospective, or prospective basis. The adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements and related disclosures.

Fair Value Measurements and M_2

Fair Value Measurements and Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables present the Company’s fair value hierarchy for its assets and liabilities, which are measured at fair value on a recurring basis (in thousands): Fair Value Measurements at September 30, 2021 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 41,886 $ — $ 41,886 Marketable securities: Commercial paper 2,899 — 2,899 $ 41,886 $ 2,899 $ — $ 44,785 Fair Value Measurements at December 31, 2020 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 77,129 $ — $ — $ 77,129 Commercial paper — 1,800 — 1,800 Marketable securities: Commercial paper — 4,498 — 4,498 $ 77,129 $ 6,298 $ — $ 83,427
Summary of Marketable Securities	Marketable securities by security type consisted of the following (in thousands): September 30, 2021 Amortized Gross Gross Fair Commercial paper $ 2,899 $ — $ — $ 2,899 $ 2,899 $ — $ — $ 2,899 December 31, 2020 Amortized Gross Gross Fair Commercial paper $ 4,498 $ — $ — $ 4,498 $ 4,498 $ — $ — $ 4,498

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following (in thousands): September 30, December 31, 2021 2020 Accrued employee compensation and benefits $ 1,417 $ 4,295 Accrued external research and development expenses 2,568 1,780 Accrued professional fees 767 987 Other 660 789 $ 5,412 $ 7,851

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Summary of Long-term Debt	Long-term debt consisted of the following (in thousands): September 30, December 31, 2021 2020 Principal amount of long-term debt $ 14,106 $ 16,123 Less: Current portion of long-term debt ( 5,678 ) ( 2,891 ) Long-term debt, net of current portion 8,428 13,232 Debt discount, net of accretion ( 272 ) ( 348 ) Accrued end-of-term payment 586 353 Long-term debt, net of discount and current portion $ 8,742 $ 13,237
Summary of Future Principal Payments Due	As of September 30, 2021, future principal payments due are as follows (in thousands): Year Aggregate 2021 $ 1,374 2022 5,805 2023 6,341 2024 586 2025 — $ 14,106

Stock_Equity-Based Compensati_2

Stock/Equity-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Summary of Restricted Stock Unit Activity and Related Information	The following table summarizes the Company’s RSU activity for the nine months ended September 30, 2021: Units Weighted Unvested balance at December 31, 2020 — $ — Issued 122,469 $ 17.89 Vested ( 23,146 ) $ 17.89 Forfeited ( 12,271 ) $ 17.89 Unvested balance at September 30, 2021 87,052 $ 17.89
Summary of Stock Option Activity	The following table summarizes the Company’s option activity during nine months ended September 30, 2021: Number Weighted Weighted Aggregate (in years) (in thousands) Outstanding as of December 31, 2020 944,961 $ 20.70 8.29 6,522 Granted 986,014 $ 15.33 9.91 — Exercised ( 9,241 ) 8.97 7.37 9 Forfeited ( 139,290 ) $ 13.70 — Outstanding as of September 30, 2021 1,782,444 $ 19.01 7.92 1,521 Vested and expected to vest as of September 30, 2021 1,767,444 $ 19.03 7.90 —
Summary of Stock-based Compensation Expense, Including Shares Issued to Consultants for Services	The Company recorded stock/equity-based compensation expense related to common stock/unit options and restricted units in the following expense categories in its condensed consolidated statements of operations (in thousands): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research and development expenses $ 320 $ 154 $ 1,066 $ 529 General and administrative expenses 972 540 2,892 1,237 $ 1,292 $ 694 $ 3,958 $ 1,766

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss per Share	Basic and diluted net loss per share was calculated as follows (in thousands, except share and per share amounts): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Numerator: Net loss $ ( 9,956 ) $ ( 6,385 ) ( 29,092 ) ( 20,822 ) Gain on extinguishment of Class B preferred units — — — 6,697 Net loss applicable to common shareholders $ ( 9,956 ) $ ( 6,385 ) $ ( 29,092 ) $ ( 14,125 ) Denominator: Weighted average common shares/units 10,304,775 2,159,403 10,239,502 2,155,276 Net loss per share/unit, basic and diluted $ ( 0.97 ) $ ( 2.96 ) $ ( 2.84 ) $ ( 6.55 )
Schedule of Antidilutive Securities Excluded from Computation of Diluted Weighted-average Shares Outstanding	The following common stock equivalents presented based on amounts outstanding at each period end, have been excluded from the calculation of diluted net loss per share because including them would have had an anti-dilutive impact: As of September 30, 2021 2020 Options to purchase common stock 1,782,444 964,002 Warrants to purchase common stock or shares 99,986 99,986 1,882,430 1,063,988

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Lessee Disclosure [Abstract]
Elements of Lease Expense	The components of lease cost were as follows (in thousands): Nine Months Ended 2021 2020 Operating lease cost $ 4,721 $ 2,085 Short-term lease cost — — Variable lease cost 458 244 Finance lease cost: Amortization of lease assets 133 280 Interest on lease liabilities 6 16 Total finance lease cost $ 139 $ 296
Summary of supplemental disclosure of cash flow information related to leases	Supplemental disclosure of cash flow information related to leases was as follows (in thousands): Nine Months Ended 2021 2020 Cash paid for amounts included in the measurement $ 4,484 $ 1,428 Cash paid for amounts included in the measurement $ 6 $ 16 Cash paid for amounts included in the measurement $ 140 $ 264 Operating lease liabilities arising from obtaining $ — $ 10,219 Finance lease liabilities arising from obtaining right- $ — $ —
Schedule of weighted-average remaining lease term and discount rate	The weighted-average remaining lease term and discount rate were as follows: As of September 30, 2021 2020 Weighted-average remaining lease term (in years) used for: Operating leases 5.47 2.58 Finance leases 0.99 0.83 Weighted-average discount rate used for: Operating leases 9.10 % 8.80 % Finance leases 5.59 % 6.90 %
Summary of future annual operating lease payments	As of September 30, 2021, future annual lease payments under the Company’s real estate operating leases and equipment finance leases were as follows (in thousands): Year Operating Finance 2021 $ 1,514 $ 26 2022 6,173 50 2023 2,977 — 2024 1,931 — 2025 1,985 — Thereafter 4,840 — Total future lease payments 19,420 76 Less: Imputed interest ( 3,773 ) ( 2 ) Total lease liabilities $ 15,647 $ 74
Summary of table presents lease assets and liabilities and their classification on the condensed consolidated balance sheet	The following table presents lease assets and liabilities and their classification on the condensed consolidated balance sheet (in thousands): Leases Condensed Consolidated Balance Sheet Classification Amount Assets: Operating lease assets Operating lease right-of- use assets $ 19,864 Finance lease assets Property and equipment, net 66 Total leased assets $ 19,930 Liabilities: Current: Operating lease liabilities Operating lease liabilities $ 4,909 Finance lease liabilities Current portion of finance lease obligation 65 Non-current: Operating lease liabilities Operating lease liabilities, net of current portion 10,738 Finance lease liabilities Finance lease obligation, net of current portion 9 Total lease liabilities $ 15,721

Nature of Business and Basis _2

Nature of Business and Basis of Presentation - Additional Information (Detail) $ / shares in Units, $ in Thousands	Dec. 22, 2020$ / sharesshares	Dec. 14, 2020USD ($)$ / sharesshares	Apr. 30, 2021USD ($)	Sep. 30, 2021USD ($)$ / shares	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)$ / shares
Nature of Business [Line Items]
Merger Agreement Exchange Ratio	0.2108
Accumulated deficit				$ (176,902)						$ (176,902)		$ (147,810)
Net loss				$ (9,956)	$ (10,454)	$ (8,682)	$ (6,385)	$ (6,972)	$ (7,465)	$ (29,092)	$ (20,822)
Common stock price per share | $ / shares				$ 0.001						$ 0.001		$ 0.001
Proceeds from sale of common stock										$ 1,313	$ 0
At The Market Offering [Member] | Sales Agreement With Jefferies LLC [Member]
Nature of Business [Line Items]
Common Stock, Value, Subscriptions			$ 60,000	$ 58,700						$ 58,700
Sale of Stock, Number of Shares Issued | shares										82,132
Sale of Stock, Consideration Received										$ 1,300
Percentage of commission on gross proceeds of common stock sold			3.00%
Private Placement [Member]
Nature of Business [Line Items]
Stock issued during period, shares, issued | shares		1,460,861
Net proceeds in private placement		$ 31,600
Common stock price per share | $ / shares		$ 23
Transaction Closed Date										Dec. 22, 2020
Common Stock [Member]
Nature of Business [Line Items]
Proceeds from sale of common stock		$ 33,600
PTI Common Stock [Member]
Nature of Business [Line Items]
Stockholders equity reverse stock split conversion ratio	1-for-20 reverse stock split of its common stock (the “Reverse Stock Split”)
Stock Issued During Period, Shares, Conversion of Units | shares	6,024,433
Yumanity Common Stock [Member]
Nature of Business [Line Items]
Common stock price per share | $ / shares	$ 0.01

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	$ 44,500		$ 27,500
Cash and cash equivalents	43,532	$ 80,819	27,400
Restricted Cash	$ 1,000		$ 100

Fair Value Measurements and M_3

Fair Value Measurements and Marketable Securities - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets:
Total assets	$ 44,785	$ 83,427
Commercial Paper [Member]
Assets:
Cash equivalents		1,800
Marketable securities	2,899	4,498
Money Market Funds [Member]
Assets:
Cash equivalents	41,886	77,129
Level 1 [Member]
Assets:
Total assets	41,886	77,129
Level 1 [Member] | Commercial Paper [Member]
Assets:
Cash equivalents		0
Marketable securities		0
Level 1 [Member] | Money Market Funds [Member]
Assets:
Cash equivalents	41,886	77,129
Level 2 [Member]
Assets:
Total assets	2,899	6,298
Level 2 [Member] | Commercial Paper [Member]
Assets:
Cash equivalents		1,800
Marketable securities	2,899	4,498
Level 2 [Member] | Money Market Funds [Member]
Assets:
Cash equivalents		0
Level 3 [Member]
Assets:
Total assets	0	0
Level 3 [Member] | Commercial Paper [Member]
Assets:
Cash equivalents		0
Marketable securities	0	0
Level 3 [Member] | Money Market Funds [Member]
Assets:
Cash equivalents	$ 0	$ 0

Fair Value Measurements and M_4

Fair Value Measurements and Marketable Securities - Summary of Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,899	$ 4,498
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	2,899	4,498
Commercial Paper [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,899	4,498
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 2,899	$ 4,498

Fair Value Measurements and M_5

Fair Value Measurements and Marketable Securities - Additional Information (Detail)	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Marketable securities maturity year	1 year

Collaboration Agreement - Addit

Collaboration Agreement - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Jul. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from collaborative arrangement		$ 1,635	$ 3,308	$ 7,282	$ 3,308
License And Research Collaboration Agreement | Merck
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payments received	$ 15,000
Deferred revenue additions	$ 15,000
Revenue remaining performance obligation		800		800
Revenue from collaborative arrangement		$ 1,600		$ 7,300
License And Research Collaboration Agreement | Merck | Class C Preferred Units
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock price per share	$ 4.0008
License And Research Collaboration Agreement | Merck | Research and Development | Maximum [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, milestone payments receivable	$ 280,000
License And Research Collaboration Agreement | Merck | Sales Based | Maximum [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, milestone payments receivable	$ 250,000

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued employee compensation and benefits	$ 1,417	$ 4,295
Accrued external research and development expenses	2,568	1,780
Accrued professional fees	767	987
Other	660	789
Total accrued expenses	$ 5,412	$ 7,851

Debt - Summary of Long-term Deb

Debt - Summary of Long-term Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Long-term Debt, Unclassified [Abstract]
Principal amount of long-term debt	$ 14,106	$ 16,123
Less: Current portion of long-term debt	(5,678)	(2,891)
Long-term debt, net of current portion	8,428	13,232
Debt discount, net of accretion	(272)	(348)
Accrued end-of-term payment	586	353
Long-term debt, net of discount and current portion	$ 8,742	$ 13,237

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($) $ in Thousands	Apr. 13, 2021	Apr. 03, 2021	Apr. 30, 2020	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term non current				$ 14,106	$ 14,106		$ 16,123
Gain (Loss) on extinguishment of debt				$ 0	$ 1,134	$ 0
Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Gain (Loss) on extinguishment of debt		$ 1,100
Minimum [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 100
Maximum [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 300
Upon Lender Approval
Debt Instrument [Line Items]
Debt instrument additional loan amount								$ 10,000
New Loan
Debt Instrument [Line Items]
Long-term non current								14,100
Debt instrument additional loan amount								$ 5,000
Frequency of periodic payment					monthly
Repayment terms					Borrowings under the Term Loan were repayable in monthly interest-only payments until August 1, 2021. The interest-only period is followed by monthly payments of equal principal plus interest until the loan maturity date of January 1, 2024.
Debt maturity date					Jan. 1, 2024
Outstanding borrowing bear interest rate				8.75%	8.75%
Debt instrument final fee percentage				5.25%	5.25%
Accrued end-of-term payment				$ 300	$ 300
Debt weighted average interest rate				9.41%	9.41%
New Loan | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument fixed interest rate				8.75%	8.75%		8.75%
Debt instrument variable spread					4.00%
Debt instrument description of variable spread					the prime rate as reported in the Wall Street Journal
New Loan | Before One Year Anniversary
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage				3.00%	3.00%
New Loan | After One Year But Before Second Anniversary
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage				2.00%	2.00%
New Loan | After Second Year But Before Maturity
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage				1.00%	1.00%
New Loan | Additional Rate in Event Of Default
Debt Instrument [Line Items]
Debt instrument fixed interest rate				5.00%	5.00%
Paycheck Protection Program Loan
Debt Instrument [Line Items]
Proceeds from Paycheck Protection Program loan			$ 1,100

Debt - Summary of Future Princi

Debt - Summary of Future Principal Payments Due (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Long-term Debt, Unclassified [Abstract]
2021	$ 1,374
2022	5,805
2023	6,341
2024	586
2025	0
Total	$ 14,106

Stock_Equity-Based Compensati_3

Stock/Equity-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Feb. 01, 2021	Feb. 03, 2016	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Jan. 01, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise price					$ 13.89
Amount of cost not yet recognized for nonvested award under share-based payment arrangement.			$ 12,500		$ 12,500
Stock-based compensation			1,292	$ 694	$ 3,958	$ 1,766
Weighted average remaining contractual term					7 years 11 months 1 day		8 years 3 months 14 days
Fair value of option					$ 13,700
Number of options outstanding, including both vested and non-vested options					2 years 7 months 24 days
Restricted Incentive Units RSU [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation			$ 200		$ 700
Fair value of share options granted	$ 2,200
Units granted					122,469
Number of incentive units			87,052		87,052
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual term					1 year
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual term					4 years
2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized			1,527,210		1,527,210
Common stock available for future issuance			330,609		330,609
2018 Plan | Service Based [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment award, expiration period					10 years
Share-based payment award, vest period					4 years
2016 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance		79,092	626,100		626,100
Common stock available for future issuance			136,329		136,329
Common stock reserved for issuance, percentage of number of shares of common stock outstanding		3.00%
2016 Plan [Member] | Service Based [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment award, expiration period					10 years
Share-based payment award, vest period					4 years
2016 Plan [Member] | Additional [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for future issuance								303,495
2016 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance		6,938	41,626		41,626
Common stock reserved for issuance, percentage of number of shares of common stock outstanding		1.00%
2016 ESPP [Member] | Additional [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for issuance								6,937
2021 Stock Option And Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized			504,000		504,000
Common stock available for issuance			233,600		233,600

Stock_Equity-Based Compensati_4

Stock/Equity-Based Compensation - Summary of Restricted Stock Unit Activity and Related Information (Detail)	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Number of Shares
Unvested balance at December 31, 2020 | shares	0
Issued | shares	122,469
Vested | shares	(23,146)
Forfeited | shares	(12,271)
Unvested balance at September 30, 2021 | shares	87,052
Weighted Average Grant Date Fair Value
Unvested balance at December 31, 2020 | $ / shares	$ 0
Issued | $ / shares	17.89
Vested | $ / shares	17.89
Forfeited | $ / shares	17.89
Unvested balance at September 30, 2021 | $ / shares	$ 17.89

Stock_Equity-Based Compensati_5

Stock/Equity-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Number of Shares/Units
Outstanding at December 31, 2020 | shares	944,961
Granted | shares	986,014
Exercised | shares	(9,241)
Forfeited | shares	(139,290)
Outstanding as of September 30, 2021 | shares	1,782,444	944,961
Vested and expected to vest at September 30, 2021 | shares	1,767,444
Weighted Average Exercise Price
Outstanding as of December 31, 2020 | $ / shares	$ 20.70
Granted | $ / shares	15.33
Exercised | $ / shares	8.97
Forfeited | $ / shares	13.70
Outstanding as of September 30, 2021 | $ / shares	19.01	$ 20.70
Vested and expected to vest at September 30, 2021 | $ / shares	$ 19.03
Weighted Average Remaining Contractual Term, Outstanding	7 years 11 months 1 day	8 years 3 months 14 days
Weighted Average Remaining Contractual Term,Granted	9 years 10 months 28 days
Weighted Average Remaining Contractual Term,Exercised	7 years 4 months 13 days
Weighted Average Remaining Contractual Term, Vested and expected to vest at September 30, 2021	7 years 10 months 24 days
Aggregate Intrinsic Value, Outstanding as of December 30, 2020 | $	$ 6,522
Aggregate Intrinsic Value,Granted | $	0
Aggregate Intrinsic Value,Exercised | $	9
Aggregate Intrinsic Value, Outstanding as of September 30, 2021 | $	1,521	$ 6,522
Aggregate Intrinsic Value, Vested and expected to vest at September 30, 2021 | $	$ 0

Stock_Equity-Based Compensati_6

Stock/Equity-Based Compensation - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Stock-based compensation expense	$ 1,292	$ 694	$ 3,958	$ 1,766
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Stock-based compensation expense	320	154	1,066	529
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Stock-based compensation expense	$ 972	$ 540	$ 2,892	$ 1,237

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net loss	$ (9,956)	$ (10,454)	$ (8,682)	$ (6,385)	$ (6,972)	$ (7,465)	$ (29,092)	$ (20,822)
Gain on extinguishment of Class B preferred units					$ 6,697
Net loss applicable to common shareholders	$ (9,956)			$ (6,385)			$ (29,092)	$ (14,125)
Denominator:
Weighted Average Number of Shares Outstanding, Basic and Diluted	10,304,775			2,159,403			10,239,502	2,155,276
Net loss per share/unit, basic and diluted	$ (0.97)			$ (2.96)			$ (2.84)	$ (6.55)
Class B Preferred Units [Member]
Numerator:
Gain on extinguishment of Class B preferred units								$ 6,697

Net Loss per Share - Schedule_2

Net Loss per Share - Schedule of Antidilutive Securities Excluded from Computation of Diluted Weighted-average Shares Outstanding (Detail) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding	1,882,430	1,063,988
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding	1,782,444	964,002
Warrants to purchase common stock or shares convertible into common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities outstanding	99,986	99,986

Leases - Additional Information

Leases - Additional Information (Detail)	Jan. 07, 2021	Dec. 22, 2020USD ($)ft²	May 23, 2020USD ($)	May 01, 2020USD ($)	Feb. 29, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset						$ 19,864,000	$ 19,864,000	$ 23,678,000
License term					3 years
Operating lease assets						19,864,000	19,864,000	$ 23,678,000
Moma Therapeutics Inc [Member]
Operating Lease, Right-of-Use Asset
Lessee, operating sub lease, term of contract	18 months
Operating sub lease, cost						500,000	1,500,000
Sublease Income						$ 500,000	$ 1,300,000
Old Premises Cambridge [Member]
Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset					$ 100,000
Increase (decrease) in operating lease liability					(100,000)
Lease expiration date							May 1, 2020
Operating lease assets					$ 100,000
New Premises Boston [Member]
Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset				$ 10,600,000
Increase (decrease) in operating lease liability				10,200,000
Percentage of escalation of License fee					3.00%
Total Amount of License fee					$ 12,000,000
Operating lease assets				$ 10,600,000
Merger Laboratory Boston [Member]
Operating Lease, Right-of-Use Asset
Operating lease, initial term						10 years	10 years
Operating lease, option to extend additional term						7 years	7 years
Operating Lease, Right-of-Use Asset		$ 10,200,000
Increase (decrease) in operating lease liability		$ 10,200,000
Number of Square Feet | ft²		30,000
Operating lease, payments		$ 14,200,000
Operating lease assets		10,200,000
Merger Laboratory Boston [Member] | Portion of Excess Merger Purchase Price [Member]
Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset		1,900,000
Operating lease assets		1,900,000
Merger Laboratory Boston [Member] | Value Attributable to Below Market Lease [Member]
Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset		3,100,000
Operating lease assets		$ 3,100,000
Maximum [Member] | Moma Therapeutics Inc [Member]
Operating Lease, Right-of-Use Asset
Operating leases, rent expense, sublease rentals							$ 1,997,520
Maximum [Member] | Old Premises Cambridge [Member]
Operating Lease, Right-of-Use Asset
Operating leases, rent expense			$ 100,000
Minimum [Member] | Moma Therapeutics Inc [Member]
Operating Lease, Right-of-Use Asset
Operating leases, rent expense, sublease rentals							$ 1,939,340

Leases - Summary of lease cost

Leases - Summary of lease cost (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Lease cost
Operating lease cost	$ 4,721	$ 2,085
Variable lease cost	458	244
Finance lease cost, amortization of lease assets	133	280
Finance lease cost, interest on lease liabilities	6	16
Total finance lease cost	$ 139	$ 296

Leases - Summary of supplementa

Leases - Summary of supplemental disclosure of cash flow information related to leases (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Schedule of Supplemental disclosure of cash flow information related to leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities (operating cash flows)	$ 4,484	$ 1,428
Cash paid for amounts included in the measurement of finance lease liabilities (operating cash flows)	6	16
Cash paid for amounts included in the measurement of finance lease liabilities (financing cash flows)	140	264
Operating lease liabilities arising from obtaining right-of-use assets	0	10,219
Finance lease liabilities arising from obtaining right-of-use assets	$ 0	$ 0

Leases - Schedule of weighted-a

Leases - Schedule of weighted-average remaining lease term and discount rate (Detail)	Sep. 30, 2021	Sep. 30, 2020
Schedule of weighted average remaining lease term and discount rate [Abstract]
Weighted-average remaining lease term (in years) used for Operating leases	5 years 5 months 19 days	2 years 6 months 29 days
Weighted-average remaining lease term (in years) used for Finance leases	11 months 26 days	9 months 29 days
Weighted-average discount rate for Operating leases	9.10%	8.80%
Weighted-average discount rate used for Finance leases	5.59%	6.90%

Leases - Summary of future annu

Leases - Summary of future annual Operating lease payments (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Operating Leases
2021	$ 1,514
2022	6,173
2023	2,977
2024	1,931
2025	1,985
Thereafter	4,840
Total future lease payments	19,420
Less: Imputed interest	(3,773)
Total lease liabilities	15,647
Finance Leases
2021	26
2022	50
2023	0
2024	0
2025	0
Thereafter	0
Total future lease payments	76
Less: Imputed interest	(2)
Total lease liabilities	$ 74

Leases - Summary of table pres

Leases - Summary of table presents lease assets and liabilities and their classification on the condensed consolidated balance sheet (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets:
Operating lease assets	$ 19,864	$ 23,678
Finance lease assets	66
Total leased assets	19,930
Current:
Operating lease liabilities	4,909	4,468
Finance lease liabilities	65	166
Non-current:
Operating lease liabilities	10,738	14,479
Finance lease liabilities	9	$ 48
Total lease liabilities	$ 15,721

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Long-term Purchase Commitment [Line Items]
Period of agreement	9 months
Contingent Value Rights Agreement [Member] | Shareholder Representative Series LLC [Member]
Long-term Purchase Commitment [Line Items]
Business combination contingent consideration agreement	$ 0	$ 0
Whitehead Institute for Biomedical Research [Member]
Long-term Purchase Commitment [Line Items]
Common unit issued	300,000
Common Unit, Issuance Value	$ 800
Whitehead Institute for Biomedical Research [Member] | Maximum [Member]
Long-term Purchase Commitment [Line Items]
Payment of license fees	100
Annual cost maintenance	100
Whitehead Institute for Biomedical Research [Member] | Maximum [Member] | Developmental and Regulatory [Member] | First Two Licensed Products [Member]
Long-term Purchase Commitment [Line Items]
Contractual Obligation	$ 1,900

Related Parties - Additional In

Related Parties - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Related Party Transaction [Line Items]
Related party transaction, amounts of transaction	$ 0		$ 0
Investor [Member]
Related Party Transaction [Line Items]
Operating lease expense		$ 0.4
Amounts paid under lease agreement				$ 0.6