0001785530-24-000020 | 10-Q | XBRL Viewer | Werewolf Therapeutics INC

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Collaboration and License Agreement - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognized that was included in prior period deferred revenue	$ 0.4	$ 2.3
Jazz Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Collaboration agreement, term	2 years 1 month 6 days
Unbilled Accounts Receivables
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Contract with customer, asset, after allowance for credit loss	$ 0.3		$ 0.4
Accounts Receivable
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Contract with customer, asset, after allowance for credit loss	$ 0.4		$ 0.9

Common and Preferred Stock

3 Months Ended

Mar. 31, 2024

Equity [Abstract]

Common and Preferred Stock

7. Common and Preferred Stock

Common Stock

We are authorized to issue 200,000,000 shares of common stock. Common stockholders are entitled to dividends if and when declared by our board of directors. As of March 31, 2024, no dividends on common stock had been declared by us.

On May 10, 2022, we entered into a Sales Agreement (the “Sales Agreement”) with Leerink Partners LLC (“Leerink Partners”), formerly known as SVB Securities LLC, pursuant to which we may offer and sell shares of our common stock (the “ATM Offering”). The Sales Agreement provides that Leerink Partners will be entitled to a sales commission equal to 3.0% of the gross sales price per share of all shares sold under the ATM Offering. We were initially entitled to offer and sell shares of our common stock having an aggregate offering price of up to $50.0 million in the ATM Offering. On February 9, 2024, we filed a prospectus supplement (the “Prospectus Supplement”) under our shelf registration statement for the offer and sale of shares of our common stock having an offering price of up to an additional $25.0 million in the ATM Offering. Following our filing of the Prospectus Supplement, we are now entitled to offer and sell shares of our common stock with an aggregate offering price of up to $75.0 million pursuant to the Sales Agreement. During the three months ended March 31, 2024, we sold 4,169,324 shares of our common stock at an average price of $5.05 per share for net proceeds of $20.1 million after deducting sales commissions and offering expenses. During the three months ended March 31, 2023, we sold 3,824,249 shares of our common stock at an average price of $2.35 per share for net proceeds of $8.6 million after deducting sales commissions and offering expenses.

We have reserved shares of common stock for issuance as follows:


	As of March 31,	As of December 31,
	2024	2023
Shares reserved for exercises of outstanding stock options	7,450,864	5,700,070
Shares reserved for vesting of restricted stock units	361,500	361,500
Shares reserved for exercises of warrants	58,904	58,904
Shares reserved for future issuance under the 2021 Employee Stock Purchase Plan	507,113	507,113
Shares reserved for future issuance under the 2021 Stock Incentive Plan	2,110,219	1,911,660
Total shares reserved for future issuance	10,488,600	8,539,247

Preferred Stock

We are authorized to issue 5,000,000 shares of undesignated preferred stock in one or more series. As of March 31, 2024, no shares of preferred stock were issued or outstanding.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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Reference 19: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

+ Details

Common and Preferred Stock - Narrative (Details)		3 Months Ended
Common and Preferred Stock - Narrative (Details)	Feb. 09, 2024 USD ($)	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2023 shares	May 10, 2022 USD ($)
Class of Stock [Line Items]
Common stock authorized (in shares) \| shares		200,000,000		200,000,000
Dividends declared \| $		$ 0
Proceeds from at the market offering of common stock, net of issuance costs \| $		$ 20,247,000	$ 8,623,000
Preferred stock authorized (in shares) \| shares		5,000,000		5,000,000
Preferred stock outstanding (in shares) \| shares		0		0
Preferred stock issued (in shares) \| shares		0		0
ATM Offering
Class of Stock [Line Items]
Sales commissions, percentage					0.030
Sale of stock increase in offering amount \| $	$ 25,000,000
Issuance of common stock from at the market offering, net of issuance costs (in shares) \| shares		4,169,324	3,824,249
Price per share (in usd per share) \| $ / shares		$ 5.05	$ 2.35
Proceeds from at the market offering of common stock, net of issuance costs \| $		$ 20,100,000	$ 8,600,000
ATM Offering \| Maximum
Class of Stock [Line Items]
Common stock, amount authorized \| $	$ 75,000,000				$ 50,000,000

Collaboration and License Agreement (Tables)

3 Months Ended

Mar. 31, 2024

Business Combination and Asset Acquisition [Abstract]

Collaborative Arrangement and Arrangement Other than Collaborative

The following table summarizes research and development costs incurred and revenue recognized in connection with our performance under the Collaboration Agreement:


	Three Months Ended March 31,
	2024		2023
	(in thousands)
Revenue recognized	$	742	$	4,464
Cost incurred	$	335	$	2,121

Contract with Customer, Contract Asset, Contract Liability, and Receivable

The following table presents changes in our contract liabilities during the three months ended March 31, 2024:


	Balance as of December 31, 2023		Additions		Reductions		Balance as of March 31, 2024
	(in thousands)
Contract liabilities:
Deferred revenue	$	1,340	$	—	$	(407)	$	933
Total contract liabilities	$	1,340	$	—	$	(407)	$	933

Collaboration and License Agreement - Contract with Customer, Contract Asset, Contract Liability, and Receivable (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Contract liabilities:
Deferred revenue, beginning balance	$ 1,340
Additions	0
Reductions	(407)
Deferred revenue, ending balance	$ 933

Stock-based Compensation - Restricted Stock Award Activity (Details) - Unvested RSUs - 2021 Stock Incentive Plan - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested at beginning of period (in shares)	361,500
Granted (in shares)	0
Vested (in shares)	0	0
Forfeited (in shares)	0
Unvested at end of period (in shares)	361,500
Weighted-Average Grant Date Fair Value Per Share
Weighted Average Grant Date Fair Value - Unvested at beginning of period (in usd per share)	$ 3.92
Weighted Average Grant Date Fair Value - Granted (in usd per share)	0
Weighted Average Grant Date Fair Value - Vested (in usd per share)	0
Weighted Average Grant Date Fair Value - Forfeited (in usd per share)	0
Weighted Average Grant Date Fair Value - Unvested at end of period (in usd per share)	$ 3.92

Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock par value (in usd per share)	$ 0.0001	$ 0.0001
Preferred stock authorized (in shares)	5,000,000	5,000,000
Preferred stock issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0
Common stock par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock authorized (in shares)	200,000,000	200,000,000
Common stock issued (in shares)	43,282,371	39,107,048
Common stock outstanding (in shares)	43,282,371	39,107,048

Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Stock-based Compensation Expense Recognized

Total stock-based compensation expense recognized in the condensed consolidated statements of operations was as follows:


	Three Months Ended March 31,
	2024		2023
	(in thousands)
Research and development	$	1,182	$	1,020
General and administrative	1,123		1,088
Total stock-based compensation	$	2,305	$	2,108

Restricted Stock Awards Activity

The following table summarizes RSU activity during the three months ended March 31, 2024:


	Shares/Units	Weighted-Average Grant Date Fair Value Per Share
	(in thousands)
Unvested at December 31, 2023	361,500	$	3.92
Granted	—	$	—
Vested	—	$	—
Forfeited	—	$	—
Unvested at March 31, 2024	361,500	$	3.92

Weighted -average Valuation Assumptions

The fair value of stock options granted during the three months ended March 31, 2024 and 2023 was calculated on the date of grant using the following weighted-average assumptions:


	Three Months Ended March 31,
	2024		2023
Risk-free interest rate	3.9	%	3.9	%
Expected term (in years)	6.0		6.0
Expected annual dividend yield	—	%	—	%
Expected volatility	92.6	%	82.6	%

Summary of Stock Option Activity

The following table summarizes stock option activity during the three months ended March 31, 2024:


	Options Outstanding
	Number of Options	Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Life (in years)	Aggregate Intrinsic Value (in millions)
Outstanding at December 31, 2023	5,700,070	$	6.89
Granted	2,058,389	$	4.64
Exercised	(5,999)	$	2.05
Cancelled	(301,596)	$	5.38
Outstanding at March 31, 2024	7,450,864	$	6.33	7.91	$	15.2
Exercisable at March 31, 2024	3,583,777	$	7.48	6.84	$	6.5

Accrued Expenses and Other Current Liabilities

3 Months Ended

Mar. 31, 2024

Payables and Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

5. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities were comprised as follows:


	March 31, 2024		December 31, 2023
	(in thousands)
Manufacturing	$	2,119	$	2,772
Employee compensation and benefits	1,350		3,627
Contract research	915		1,049
Professional fees	910		655
Accrued interest	310		310
Other	611		447
Total accrued expenses and other current liabilities	$	6,215	$	8,860

Accrued Expenses and Other Current Liabilities (Tables)

3 Months Ended

Mar. 31, 2024

Payables and Accruals [Abstract]

Accrued Expenses

Accrued expenses and other current liabilities were comprised as follows:


	March 31, 2024		December 31, 2023
	(in thousands)
Manufacturing	$	2,119	$	2,772
Employee compensation and benefits	1,350		3,627
Contract research	915		1,049
Professional fees	910		655
Accrued interest	310		310
Other	611		447
Total accrued expenses and other current liabilities	$	6,215	$	8,860

Financial Instruments and Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Total assets	$ 153,810	$ 149,294
Money market funds
Assets:
Money market funds	153,810	149,294
Level 1
Assets:
Total assets	153,810	149,294
Level 1 \| Money market funds
Assets:
Money market funds	153,810	149,294
Level 2
Assets:
Total assets	0	0
Level 2 \| Money market funds
Assets:
Money market funds	0	0
Level 3
Assets:
Total assets	0	0
Level 3 \| Money market funds
Assets:
Money market funds	$ 0	$ 0

Collaboration and License Agreement

3 Months Ended

Mar. 31, 2024

Business Combination and Asset Acquisition [Abstract]

Collaboration and License Agreement

3. Collaboration and License Agreement

Detailed description of the contractual terms and our accounting for the agreement described below is included in our audited financial statements and notes in the 2023 Annual Report.

During the three months ended March 31, 2024, we continued to perform under our exclusive global collaboration and license agreement (the “Collaboration Agreement”) with Jazz Pharmaceuticals Ireland Limited ("Jazz"), pursuant to which we recognize revenue utilizing the cost-to-cost input method, which best depicts the research and development services performed for the customer. As a result, we recognize revenue from the transaction price over time as research and development services are performed. The following table summarizes research and development costs incurred and revenue recognized in connection with our performance under the Collaboration Agreement:


	Three Months Ended March 31,
	2024		2023
	(in thousands)
Revenue recognized	$	742	$	4,464
Cost incurred	$	335	$	2,121

The following table presents changes in our contract liabilities during the three months ended March 31, 2024:


	Balance as of December 31, 2023		Additions		Reductions		Balance as of March 31, 2024
	(in thousands)
Contract liabilities:
Deferred revenue	$	1,340	$	—	$	(407)	$	933
Total contract liabilities	$	1,340	$	—	$	(407)	$	933

The remaining deferred revenue is expected to be recognized as revenue over a term of approximately 2.1 years.

Unbilled receivables related to the Collaboration Agreement of $0.3 million and $0.4 million are included within other receivables in the accompanying condensed consolidated balance sheets as of March 31, 2024 and December 31, 2023, respectively. Receivables related to the Collaboration Agreement of $0.4 million and $0.9 million are included within other receivables in the accompanying condensed consolidated balance sheets as of March 31, 2024 and December 31, 2023, respectively. Revenue recognized during the three months ended March 31, 2024 and 2023, includes $0.4 million and $2.3 million of revenue that was included in deferred revenue as of December 31, 2023 and 2022, respectively.

At the end of each reporting period, we re-evaluate our estimate of the transaction price associated with the Collaboration Agreement and determine if variable consideration previously excluded from the transaction should be included in the transaction price based on changes in circumstances, if any. During the three months ended March 31, 2024 and 2023, we did not recognize any adjustment to the transaction price associated with variable consideration previously excluded from the transaction price.

As of March 31, 2024, we have not received any royalty payments under the Collaboration Agreement.

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating activities:
Net loss	$ (16,193)	$ (11,982)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,305	2,108
Depreciation expense	464	425
Non-cash interest expense	92	13
Non-cash lease expense	376	336
Change in fair value of success payment liability	0	(1,021)
Amortization of debt issuance costs	0	60
Changes in operating assets and liabilities:
Prepaid expenses and other assets	704	1,425
Other receivables	575	673
Accounts payable, accrued expenses and other liabilities	(2,469)	903
Deferred revenue	(407)	(2,343)
Operating lease liability	(744)	(495)
Net cash used in operating activities	(15,297)	(9,898)
Investing activities:
Purchases of property and equipment	(111)	(168)
Net cash used in investing activities	(111)	(168)
Financing activities:
Proceeds from at the market offering of common stock, net of issuance costs	20,247	8,623
Proceeds from drawdown of term loans	0	40,000
Proceeds from stock option exercises	12	0
Net cash provided by financing activities	20,259	48,623
Net increase in cash, cash equivalents and restricted cash and cash equivalents	4,851	38,557
Cash, cash equivalents and restricted cash and cash equivalents—beginning of period	155,577	130,529
Cash, cash equivalents and restricted cash and cash equivalents—end of period	160,428	169,086
Reconciliation of cash, cash equivalents and restricted cash and cash equivalents to the condensed consolidated balance sheets
Cash and cash equivalents	139,189	147,868
Prepaid expenses and other current assets	212	207
Restricted cash and cash equivalents, net of current portion	21,027	21,011
Cash, cash equivalents and restricted cash and cash equivalents	160,428	169,086
Supplemental disclosure of cash flow information:
Cash paid for interest	910	0
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment in accounts payable and accrued expenses	0	79
Issuance costs in accounts payable and accrued expenses	$ 194	$ 17

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Manufacturing	$ 2,119	$ 2,772
Employee compensation and benefits	1,350	3,627
Contract research	910	655
Professional fees	915	1,049
Accrued interest	310	310
Other	611	447
Total accrued expenses and other current liabilities	$ 6,215	$ 8,860

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 139,189	$ 134,343
Prepaid expenses and other current assets	2,320	2,677
Other receivables	775	1,350
Total current assets	142,284	138,370
Property and equipment, net	7,529	7,958
Restricted cash and cash equivalents, net of current portion	21,027	21,023
Operating lease right of use asset	6,512	6,888
Other assets	248	594
Total assets	177,600	174,833
Current liabilities:
Accounts payable	1,594	1,336
Accrued expenses and other current liabilities	6,215	8,860
Operating lease liability, current	1,236	1,608
Deferred revenue, current	502	907
Note payable, current	11,667	6,667
Total current liabilities	21,214	19,378
Operating lease liability, net of current portion	10,620	10,992
Deferred revenue, net of current portion	431	433
Note payable, net of discount, issuance costs, and current portion	27,748	32,656
Total liabilities	60,013	63,459
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value, 5,000,000 shares authorized as of March 31, 2024 and December 31, 2023; no shares issued or outstanding as of March 31, 2024 and December 31, 2023	0	0
Common stock, $0.0001 par value, 200,000,000 shares authorized as of March 31, 2024 and December 31, 2023; 43,282,371 and 39,107,048 shares issued and outstanding as of March 31, 2024 and December 31, 2023, respectively	4	4
Additional paid-in capital	477,849	455,443
Accumulated deficit	(360,266)	(344,073)
Total stockholders’ equity	117,587	111,374
Total liabilities and stockholders’ equity	$ 177,600	$ 174,833

Condensed Consolidated Statements of Operations (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue:
Collaboration revenue	$ 742	$ 4,464
Operating expenses:
Research and development	12,908	11,706
General and administrative	4,996	4,981
Total operating expenses	17,904	16,687
Operating loss	(17,162)	(12,223)
Other income:
Interest income	1,973	1,519
Interest expense	(1,003)	(172)
Other expense, net	(1)	(1,106)
Total other income	969	241
Net loss	$ (16,193)	$ (11,982)
Net loss per share attributable to common stockholders, basic and diluted
Net loss per common share, basic (in usd per share)	$ (0.39)	$ (0.34)
Net loss per common share, diluted (in usd per share)	$ (0.39)	$ (0.34)
Weighted-average common shares outstanding, basic and diluted
Weighted-average common shares outstanding, basic (in shares)	41,607,279	34,784,682
Weighted -average common shares outstanding, diluted (in shares)	41,607,279	34,784,682

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying condensed consolidated financial statements as of March 31, 2024 and December 31, 2023, and for the three months ended March 31, 2024 and 2023, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) and generally accepted accounting principles in the United States of America (“GAAP”) as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”) for condensed consolidated financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, these condensed consolidated financial statements reflect all normal recurring adjustments which are necessary for a fair presentation of our financial position and results of our operations, as of and for the periods presented. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in our Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on March 7, 2024 (the “2023 Annual Report”).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, those related to revenue recognition, accrued expenses, assumptions used in the valuation of stock-based compensation expense and income taxes. Actual results could differ from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU No. 2023-09”), which enhances the transparency and decision usefulness of income tax disclosures primarily related to rate reconciliation and income taxes paid. The provisions of ASU No. 2023-09 are effective for fiscal years beginning after December 15, 2024, with early adoption permitted, and are required to be applied on a prospective basis. Our management is currently evaluating the impact that this standard will have on our consolidated financial statements. Other accounting standards that have been issued or proposed by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on our consolidated financial statements upon adoption.
Subsequent Events	Subsequent Events We have evaluated subsequent events and transactions that occurred after the balance sheet date up to the date that the financial statements were issued. Other than as described in these condensed consolidated financial statements, we did not identify any subsequent events that require adjustment or disclosure in the condensed consolidated financial statements.

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Consolidation The accompanying condensed consolidated financial statements as of March 31, 2024 and December 31, 2023, and for the three months ended March 31, 2024 and 2023, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) and generally accepted accounting principles in the United States of America (“GAAP”) as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”) for condensed consolidated financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, these condensed consolidated financial statements reflect all normal recurring adjustments which are necessary for a fair presentation of our financial position and results of our operations, as of and for the periods presented. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in our Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on March 7, 2024 (the “2023 Annual Report”). The information presented in the condensed consolidated financial statements and related notes as of March 31, 2024, and for the three months ended March 31, 2024 and 2023, is unaudited. The December 31, 2023 condensed consolidated balance sheet included herein was derived from the audited financial statements as of that date, but does not include all disclosures, including notes, required by GAAP for complete financial statements. Interim results for the three months ended March 31, 2024 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2024, or any future period. The accompanying condensed consolidated financial statements include the accounts of Werewolf Therapeutics, Inc. and its wholly owned subsidiary, Werewolf Therapeutics Mass Securities, Inc. All intercompany transactions and balances have been eliminated in consolidation. Summary of Significant Accounting Policies The significant accounting policies and estimates used in the preparation of the condensed consolidated financial statements are described in our audited financial statements as of and for the year ended December 31, 2023, and the notes thereto, which are included in the 2023 Annual Report. There have been no material changes in our significant accounting policies during the three months ended March 31, 2024. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, those related to revenue recognition, accrued expenses, assumptions used in the valuation of stock-based compensation expense and income taxes. Actual results could differ from those estimates. Recent Accounting Pronouncements In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU No. 2023-09”), which enhances the transparency and decision usefulness of income tax disclosures primarily related to rate reconciliation and income taxes paid. The provisions of ASU No. 2023-09 are effective for fiscal years beginning after December 15, 2024, with early adoption permitted, and are required to be applied on a prospective basis. Our management is currently evaluating the impact that this standard will have on our consolidated financial statements. Other accounting standards that have been issued or proposed by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on our consolidated financial statements upon adoption. Subsequent Events We have evaluated subsequent events and transactions that occurred after the balance sheet date up to the date that the financial statements were issued. Other than as described in these condensed consolidated financial statements, we did not identify any subsequent events that require adjustment or disclosure in the condensed consolidated financial statements.

Collaboration and License Agreement - Collaborative Arrangement and Arrangement Other than Collaborative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Revenue recognized	$ 742	$ 4,464
Cost incurred	$ 335	$ 2,121

Subsequent Event	3 Months Ended
Subsequent Event	Mar. 31, 2024
Subsequent Events [Abstract]
Subsequent Event	11. Subsequent Event On May 2, 2024, we, as borrower, entered into a loan and security agreement (the “Loan Agreement”) with K2 HealthVentures LLC, or K2HV (“K2HV,” and together with any other lender from time to time, as the “Lenders”); K2HV, as administrative agent for the Lenders; and Ankara Trust Company, LLC, as collateral trustee for the Lenders. The Loan Agreement provides up to $60.0 million principal in term loans. We received $30.0 million in gross loan proceeds at closing, $25.0 million from the first tranche commitment upon closing and $5.0 million from the second tranche commitment. We used the $29.5 million in net loan proceeds received at closing, together with $10.5 million in existing cash, to repay all amounts outstanding under the PWB Loan Agreement in May 2024. A third tranche commitment of up to $10.0 million is available to be drawn at our option during certain availability periods, subject to the achievement, as determined by the administrative agent in its discretion, of certain time-based, clinical and regulatory milestones and receipt of not less than $60.0 million in net cash proceeds from certain financing activities, with at least $50.0 million from a single offering of common stock. A fourth tranche commitment of up to $20.0 million is available to be drawn down at our option through May 1, 2026 or if the third tranche is funded, May 1, 2027, subject to Lender’s review of our clinical, financial and operating plan and subject to Lender’s consent in its sole and absolute discretion. The term loan matures on May 1, 2028, and we are obligated to make interest only payments for the first 24 months, or 36 months if the third tranche is funded, and then interest and equal principal payments for the next 24 or 12 months, as applicable. The term loan bears a variable interest rate equal to the greater of (i) 10.3%, and (ii) the sum of (A) the prime rate last quoted in The Wall Street Journal (or a comparable replacement rate if The Wall Street Journal ceases to quote such rate) and (B) 1.8%. We may prepay, at our option, all, but not less than all, of the outstanding principal balance and all accrued and unpaid interest with respect to the principal balance being prepaid of the term loans, subject to a prepayment premium to which the Lenders are entitled and certain notice requirements. We were required to pay the Lenders’ certain customary fees and expenses at closing and will be required to pay additional fees that may be due upon maturity or prepayment such as final payment fees and prepayment fees. The Lenders may elect prior to the full repayment of the term loans to convert up to $5.0 million of outstanding principal of the term loans into shares of our common stock, at a conversion price of the lesser of $6.32 per share and the lowest effective price per share of our next equity financing, subject to customary adjustments and 9.99% and 19.99% beneficial ownership limitations. There will be no prepayment penalty for any principal amount converted into common stock. The Loan Agreement provides the Lenders with certain piggyback registration rights with respect to the shares of common stock issuable upon conversion of term loans under the Loan Agreement. The Loan Agreement contains customary representations and warranties, events of default and affirmative and negative covenants, including covenants that limit or restrict our ability to, among other things, dispose of assets, make changes to the our business, management, ownership or business locations, merge or consolidate, incur additional indebtedness, incur additional liens, pay dividends or other distributions or repurchase equity, make investments, and enter into certain transactions with affiliates, in each case subject to certain exceptions. As security for our obligations under the Loan Agreement, we granted the Lenders a first priority security interest on substantially all of our assets (other than intellectual property), subject to certain exceptions. Subject to certain conditions, we granted the Lenders the right, prior to repayment of the term loans, to invest up to $5.0 million in the aggregate in future offerings of capital stock subject to certain exceptions and conditions.

Common and Preferred Stock - Schedule of Common Stock Reserved for Issuance (Details) - shares	Mar. 31, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Common stock available for issuance (in shares)	10,488,600	8,539,247
Shares reserved for exercises of outstanding stock options
Class of Stock [Line Items]
Common stock available for issuance (in shares)	7,450,864	5,700,070
Shares reserved for vesting of restricted stock units
Class of Stock [Line Items]
Common stock available for issuance (in shares)	361,500	361,500
Shares reserved for exercises of warrants
Class of Stock [Line Items]
Common stock available for issuance (in shares)	58,904	58,904
Shares reserved for future issuance under the 2021 Employee Stock Purchase Plan
Class of Stock [Line Items]
Common stock available for issuance (in shares)	507,113	507,113
Shares reserved for future issuance under the 2021 Stock Incentive Plan
Class of Stock [Line Items]
Common stock available for issuance (in shares)	2,110,219	1,911,660

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 272
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-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483014/272-10-45-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 272
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-Name Accounting Standards Codification
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-Publisher FASB
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Section 50
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Subparagraph (h)
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
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-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Stock-based Compensation - Narrative (Details)			1 Months Ended	3 Months Ended		12 Months Ended
Stock-based Compensation - Narrative (Details)	Mar. 31, 2024 USD ($) shares	Mar. 31, 2023 shares	Apr. 30, 2021 shares	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 $ / shares shares	Dec. 31, 2021	Dec. 31, 2023 shares
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock available for issuance (in shares)	10,488,600			10,488,600				8,539,247
Total stock-based compensation \| $				$ 2,305,000	$ 2,108,000
Weighted-average grant date fair value of awards (in usd per share) \| $ / shares				$ 3.59	$ 1.48
Aggregate intrinsic fair value of options exercised \| $				$ 0
Stock option exercises (in shares)					0
Share-based compensation expense not yet recognized (less than) \| $	$ 14,100,000			$ 14,100,000
Unvested RSAs \| 2017 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Granted (in shares)				0
Share-based compensation expense not yet recognized, excluding option \| $	0			$ 0
Aggregate fair value of awards that vested \| $					$ 100,000
Shares reserved for vesting of restricted stock units \| 2021 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Granted (in shares)				0
Share-based compensation expense not yet recognized, excluding option \| $	$ 300,000			$ 300,000
Share-based compensation not yet recognized, recognition period				4 months 24 days
Vested (in shares)				0	0
Grant fair value (in usd per share) \| $ / shares				$ 0
Performance Shares
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Granted (in shares)				0		883,352
Vested (in shares)		0
Grant fair value (in usd per share) \| $ / shares						$ 3.36
Total stock-based compensation \| $					$ 0
Shares reserved for future issuance under the 2021 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation not yet recognized, recognition period				2 years 7 months 6 days
Stock option exercises (in shares)				5,999
2021 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Maximum number of shares to be added annually, as a percentage of outstanding shares (percent)			5.00%
Common stock available for issuance (in shares)	2,110,219			2,110,219
2021 Stock Incentive Plan \| Unvested RSAs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock authorized to be issued (in shares)			477,725
2021 Stock Employee Stock Purchase Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Offering period							6 months
Purchase period							6 months
ESPP purchase price, percent							0.85
Common Stock
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock authorized to be issued (in shares)			3,352,725
Stock option exercises (in shares)				5,999
Common Stock \| 2021 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock authorized to be issued (in shares)			2,843,116
Maximum number of shares to be added annually, as a percentage of outstanding shares (in shares)	4,911,502
Common Stock \| 2017 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock authorized to be issued (in shares)			31,884
Common Stock \| 2021 Stock Employee Stock Purchase Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Shares purchased by employees (in shares)				0	0

Financial Instruments and Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended
	Apr. 17, 2023	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Success fee liability paid	$ 1,600		$ 1,600
Change in fair value of success payment liability		$ 0		$ (1,021)
Success payment liability		$ 0			$ 0

Net Loss Attributable to Common Stockholders per Share (Tables)

3 Months Ended

Mar. 31, 2024

Earnings Per Share [Abstract]

Schedule of Antidilutive Securities Excluded from Computation of (Loss) Income per Share

For purposes of the diluted net loss attributable to common stockholders per share calculation, outstanding stock options, unvested RSAs, unvested RSUs and warrants to purchase common stock are considered to be potentially dilutive securities, however the following outstanding shares of common stock equivalents were excluded from the calculation of diluted net loss attributable to common stockholders per share because their effect would be anti-dilutive:


	March 31,
	2024	2023
Outstanding stock options	7,450,864	6,664,468
Unvested RSUs	361,500	322,725
Warrants to purchase common stock	58,904	58,904
Commons stock to be issued under the 2021 ESPP	34,227	32,679
Unvested RSAs	—	38,065
Total	7,905,495	7,116,841

Stock-based Compensation - Expense Recognized (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 2,305	$ 2,108
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	1,182	1,020
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 1,123	$ 1,088

Stock-based Compensation

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Stock-based Compensation

8. Stock-based Compensation

2017 Stock Incentive Plan

In December 2017, we adopted the 2017 Stock Incentive Plan (as amended and restated, the “2017 Plan”), under which we could grant incentive stock options (“ISOs”), non-qualified stock options, restricted stock awards (“RSAs”), restricted stock units (“RSUs”), stock appreciation rights and other stock-based awards to eligible employees, officers, directors and consultants. The terms of stock options and RSAs, including vesting requirements, were determined by our board of directors, subject to the provisions of the 2017 Plan.

2021 Stock Incentive Plan

In April 2021, our board of directors adopted and our stockholders approved the 2021 Stock Incentive Plan (the “2021 Plan”), which became effective immediately prior to the effectiveness of our initial public offering (“IPO”). As a result of the adoption of the 2021 Plan, no further awards will be made under the 2017 Plan.

The 2021 Plan provides for the grant of ISOs, non-qualified stock options, RSAs, RSUs, stock appreciation rights and other stock-based awards. Our employees, officers, directors, consultants and advisors are eligible to receive awards under the 2021 Plan. The terms of awards, including vesting requirements, are determined by our board of directors, subject to the provisions of the 2021 Plan.

We initially registered 3,352,725 shares of common stock under the 2021 Plan, pursuant to a Registration Statement on Form S-8 filed with the SEC on April 30, 2021, which was comprised of (i) 2,843,116 shares of common stock reserved for issuance under the 2021 Plan, (ii) 31,884 shares of common stock originally reserved for issuance under the 2017 Plan that became available for issuance under the 2021 Plan upon the completion of the IPO, and (iii) 477,725 shares of unvested restricted stock subject to repurchase by us that may become issuable under the 2021 Plan following such repurchase. The 2021 Plan also provides that an additional number of shares will be added annually to the shares authorized for issuance under the 2021 Plan on the first day of each fiscal year, beginning with the fiscal year ended December 31, 2022 and continuing until, and including, the fiscal year ending December 31, 2031. The number of shares added each year will be equal to the lesser of (i) 5% of the number of outstanding common stock on such date and (ii) such amount as determined by our board of directors. As of March 31, 2024, a total of 4,911,502 additional shares have been added to the total shares authorized for issuance under the 2021 Plan in accordance with these terms.

As of March 31, 2024, there were 2,110,219 shares available for future issuance under the 2021 Plan.

2021 Employee Stock Purchase Plan

The 2021 ESPP permits eligible employees to purchase shares of our common stock at a discount and consists of consecutive six-month offering periods, each containing a single six-month purchase period. On the first day of each offering period, each employee who is enrolled in the 2021 ESPP will automatically receive an option to purchase up to a whole number of shares of our common stock. The purchase price of each of the shares purchased, in a given purchase period, will be equal to 85% of the lesser of the closing price of a share of our common stock on (i) the first day of the offering period, or (ii) the last day of the offering period. During the three months ended March 31, 2024 and 2023, no shares of our common stock were purchased by participants of the 2021 ESPP.

Stock-Based Compensation Expense

Total stock-based compensation expense recognized in the condensed consolidated statements of operations was as follows:


	Three Months Ended March 31,
	2024		2023
	(in thousands)
Research and development	$	1,182	$	1,020
General and administrative	1,123		1,088
Total stock-based compensation	$	2,305	$	2,108

RSA Activity

We may, at our discretion, repurchase unvested shares of restricted stock issued pursuant to the 2017 Plan at the initial purchase price if the employees or non-employees terminate their service relationship with us. The shares are recorded in stockholders’ deficit as they vest.

As of December 31, 2023, all RSAs granted to employees or non-employees had become fully vested or had been previously forfeited. No RSAs were granted during the three months ended March 31, 2024. Accordingly, we had no unrecognized stock-based compensation expense related to unvested RSAs as of March 31, 2024.

The aggregate fair value of RSAs that vested during the three months ended March 31, 2023, based upon the fair values of the stock underlying the RSAs on the date of vesting, was $0.1 million.

RSU Activity

We have granted RSUs to our employees under the 2021 Plan. The following table summarizes RSU activity during the three months ended March 31, 2024:


	Shares/Units	Weighted-Average Grant Date Fair Value Per Share
	(in thousands)
Unvested at December 31, 2023	361,500	$	3.92
Granted	—	$	—
Vested	—	$	—
Forfeited	—	$	—
Unvested at March 31, 2024	361,500	$	3.92

As of March 31, 2024, we had unrecognized stock-based compensation expense related to unvested RSUs of $0.3 million, which we expect to recognize over a weighted-average period of approximately 0.4 years.

No RSUs vested during the three months ended March 31, 2024 or 2023.

Stock Option Activity

During the year ended December 31, 2022, we granted performance-based stock options to certain executive officers for the purchase of an aggregate of 883,352 shares of common stock with a grant date fair value of $3.36 per share. These stock options would have vested only upon achievement of specified performance targets related to certain business objectives on or before December 31, 2023. As of March 31, 2023, none of these options were vested because none of the specified performance targets had been achieved. Because achievement of the specified performance targets was not deemed probable as of March 31, 2023, we did not record any expense for these stock options during the three months ended March 31, 2023. As of December 31, 2023, the specified performance targets had not been achieved, and accordingly, all outstanding performance-based stock options expired without vesting. No additional performance-based stock options have been granted during the three months ended March 31, 2024.

The fair value of stock options granted during the three months ended March 31, 2024 and 2023 was calculated on the date of grant using the following weighted-average assumptions:


	Three Months Ended March 31,
	2024		2023
Risk-free interest rate	3.9	%	3.9	%
Expected term (in years)	6.0		6.0
Expected annual dividend yield	—	%	—	%
Expected volatility	92.6	%	82.6	%

Using the Black-Scholes option pricing model, the weighted-average grant date fair value of stock options granted during the three months ended March 31, 2024 and 2023 was $3.59 and $1.48 per share, respectively.

The following table summarizes stock option activity during the three months ended March 31, 2024:


	Options Outstanding
	Number of Options	Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Life (in years)	Aggregate Intrinsic Value (in millions)
Outstanding at December 31, 2023	5,700,070	$	6.89
Granted	2,058,389	$	4.64
Exercised	(5,999)	$	2.05
Cancelled	(301,596)	$	5.38
Outstanding at March 31, 2024	7,450,864	$	6.33	7.91	$	15.2
Exercisable at March 31, 2024	3,583,777	$	7.48	6.84	$	6.5

The aggregate intrinsic fair value of stock options exercised during the three months ended March 31, 2024 was nominal. There were no stock options exercised during the three months ended March 31, 2023.

As of March 31, 2024, we had unrecognized stock-based compensation expense related to unvested stock options of $14.1 million, which we expect to recognize over a weighted-average period of approximately 2.6 years.

Term Loan - Schedule of Long-Term Debt Instruments (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Debt Instrument [Line Items]
Net carrying amount of note payable	$ 40,000
Term Loans \| Term loan
Debt Instrument [Line Items]
Note payable	40,000
Unamortized debt discount and issuance costs	(585)
Net carrying amount of note payable	39,415
Less: current portion of note payable	(11,667)
Note payable, net, less current portion	$ 27,748

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

Term Loan (Tables)

3 Months Ended

Mar. 31, 2024

Debt Disclosure [Abstract]

Schedule of Long-Term Debt Instruments

The outstanding notes payable balance under the Term Loans consists of the following:


	March 31, 2024
	(in thousands)
Note payable	$	40,000
Unamortized debt discount and issuance costs	(585)
Net carrying amount of note payable	39,415
Less: current portion of note payable	(11,667)
Note payable, net, less current portion	$	27,748

Schedule of Total Principal Payments Maturities

The following table presents the total principal payments scheduled to become due during each of the years ended December 31:


	Principal Payments
	(in thousands)
2024 (remaining as of March 31, 2024)	$	6,667
2025	20,000
2026	13,333
	$	40,000

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

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+ Details

Stock-based Compensation - Weighted Average Assumptions (Details) - Stock options	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Risk-free interest rate	3.90%	3.90%
Expected term (in years)	6 years	6 years
Expected annual dividend yield	0.00%	0.00%
Expected volatility	92.60%	82.60%

Term Loan - Schedule of Total Principle Payments Maturities (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Principal Payments
2024 (remaining as of March 31, 2024)	$ 6,667
2025	20,000
2026	13,333
Net carrying amount of note payable	$ 40,000

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

Nature of Business	3 Months Ended
Nature of Business	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	1. Nature of Business Werewolf Therapeutics, Inc. was incorporated in the state of Delaware in October 2017. As used throughout these unaudited, condensed consolidated financial statements, the terms “Werewolf,” “we,” “us,” and “our” refer to the business of Werewolf Therapeutics, Inc., and its wholly owned subsidiary. We are an innovative biopharmaceutical company pioneering the development of therapeutics engineered to stimulate the body’s immune system for the treatment of cancer. Our headquarters are located in Watertown, Massachusetts. Since inception, we have devoted substantially all of our efforts and financial resources to organizing and staffing the company; business planning; raising capital; developing and optimizing our platform technology; identifying potential product candidates; enhancing our intellectual property portfolio; undertaking research, preclinical studies, and clinical trials; and enabling manufacturing for our development programs. We are subject to risks and uncertainties common to early-stage companies in the biotechnology industry including, but not limited to, technical risks associated with the successful research, development and manufacturing of product candidates, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Current and future programs will require significant research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure. Even if our product development efforts are successful, it is uncertain when, if ever, we will realize significant revenue from product sales. We had cash and cash equivalents of $139.2 million at March 31, 2024. We expect that our cash and cash equivalents will enable us to fund our operating expenses and capital expenditure requirements for at least twelve months from the date of issuance of the condensed consolidated financial statements in this Form 10-Q. However, additional funding will be necessary beyond this point to fund future preclinical and clinical activities. We expect to finance our future cash needs through a combination of equity or debt financings, collaboration agreements, strategic alliances and licensing arrangements.

Condensed Consolidated Statements of Stockholders’ Equity (unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Market Offering
Issuance costs	$ 985	$ 370

Common and Preferred Stock (Tables)

3 Months Ended

Mar. 31, 2024

Equity [Abstract]

Schedule of Common Stock Reserved for Issuance

We have reserved shares of common stock for issuance as follows:


	As of March 31,	As of December 31,
	2024	2023
Shares reserved for exercises of outstanding stock options	7,450,864	5,700,070
Shares reserved for vesting of restricted stock units	361,500	361,500
Shares reserved for exercises of warrants	58,904	58,904
Shares reserved for future issuance under the 2021 Employee Stock Purchase Plan	507,113	507,113
Shares reserved for future issuance under the 2021 Stock Incentive Plan	2,110,219	1,911,660
Total shares reserved for future issuance	10,488,600	8,539,247

Condensed Consolidated Statements of Stockholders’ Equity (unaudited) - USD ($) $ in Thousands	Total	Market Offering	Common Stock	Common Stock Market Offering	Additional Paid-in Capital	Additional Paid-in Capital Market Offering	Accumulated Deficit
Stockholders' equity, beginning balance (in shares) at Dec. 31, 2022			31,515,074
Stockholders' equity, beginning balance at Dec. 31, 2022	$ 122,337		$ 3		$ 429,039		$ (306,705)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from at the market offering, net of issuance costs (in shares)				3,824,249
Issuance of common stock from at the market offering, net of issuance costs		$ 8,610				$ 8,610
Stock-based compensation expense	$ 2,108				2,108
Stock option exercises (in shares)	0
Net loss	$ (11,982)						(11,982)
Stockholders' equity, ending balance (in shares) at Mar. 31, 2023			35,339,323
Stockholders' equity, ending balance at Mar. 31, 2023	121,073		$ 3		439,757		(318,687)
Stockholders' equity, beginning balance (in shares) at Dec. 31, 2023			39,107,048
Stockholders' equity, beginning balance at Dec. 31, 2023	111,374		$ 4		455,443		(344,073)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from at the market offering, net of issuance costs (in shares)				4,169,324
Issuance of common stock from at the market offering, net of issuance costs		$ 20,089				$ 20,089
Stock-based compensation expense	2,305				2,305
Stock option exercises (in shares)			5,999
Stock option exercises	12				12
Net loss	(16,193)						(16,193)
Stockholders' equity, ending balance (in shares) at Mar. 31, 2024			43,282,371
Stockholders' equity, ending balance at Mar. 31, 2024	$ 117,587		$ 4		$ 477,849		$ (360,266)

- Definition

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

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+ Details

- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

+ References + Details

- Definition

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

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+ Details

Stock-based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Number of Options
Exercised (in shares)		0
Stock options
Number of Options
Outstanding at beginning of period (in shares)	5,700,070
Granted (in shares)	2,058,389
Exercised (in shares)	(5,999)
Cancelled (in shares)	(301,596)
Outstanding at end of period (in shares)	7,450,864
Exercisable at end of period (in shares)	3,583,777
Weighted-Average Exercise Price per Share
Weighted-Average Exercise Price - Outstanding at beginning of period (in usd per share)	$ 6.89
Weighted-Average Exercise Price - Granted (in usd per share)	4.64
Weighted-Average Exercise Price - Exercised (in usd per share)	2.05
Weighted-Average Exercise Price - Cancelled (in usd per share)	5.38
Weighted-Average Exercise Price - Outstanding at end of period (in usd per share)	6.33
Weighted-Average Exercise Price - Exercisable at end of period (in usd per share)	$ 7.48
Weighted-Average Remaining Contractual Life (in years)
Weighted Average Remaining Contractual Life - Outstanding	7 years 10 months 28 days
Weighted Average Remaining Contractual Life - Exercisable	6 years 10 months 2 days
Outstanding, Aggregate Intrinsic Value	$ 15.2
Exercisable, Aggregate Intrinsic Value	$ 6.5

Financial Instruments and Fair Value Measurements

3 Months Ended

Mar. 31, 2024

Fair Value Disclosures [Abstract]

Financial Instruments and Fair Value Measurements

4. Financial Instruments and Fair Value Measurements

Our assets that are required to be measured at fair value on a recurring basis consist of money market funds, classified as cash, cash equivalents and restricted cash and cash equivalents on our condensed consolidated balance sheets as March 31, 2024 and December 31, 2023. We did not have any liabilities that are required to be measured at fair value on a recurring basis as of March 31, 2024 or December 31, 2023.

The carrying amounts reflected in the condensed consolidated balance sheets for cash, prepaid expenses and other current assets, accounts payable and accrued expenses approximate their fair values, due to their short-term nature.

Assets measured at fair value on a recurring basis as of March 31, 2024 were as follows:


	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets:
Money market funds	$	153,810	$	—	$	—	$	153,810
Total assets	$	153,810	$	—	$	—	$	153,810

Assets measured at fair value on a recurring basis as of December 31, 2023 were as follows:


	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets:
Money market funds	$	149,294	$	—	$	—	$	149,294
Total assets	$	149,294	$	—	$	—	$	149,294

There were no changes in valuation techniques during the three months ended March 31, 2024.

Success Payment Liability

We have entered into an amended and restated loan and security agreement (the “PWB Loan Agreement”) with Pacific Western Bank (“PWB”), as described below in Note 6. In conjunction with the PWB Loan Agreement, we became obligated to pay to PWB a one-time success payment of up to $1.6 million (the “Success Fee”) upon achieving certain conditions defined in the PWB Loan Agreement (the “Success Fee Event”). The Success Fee Event occurred during the second quarter of 2023, resulting in the immediate payment in full of the required Success Fee.

Prior to the occurrence of the Success Fee Event, we recognized a success payment liability that was stated at fair value and was considered Level 3 because its fair value measurement was based, in part, on significant inputs not observed in the market. Upon completion of the Success Fee Event, we paid the total $1.6 million success payment and removed the corresponding success payment liability. We remeasured the success payment liability at each reporting date and immediately prior to the Success Fee Event. During the three months ended March 31, 2023, we recognized expense of $1.0 million associated with the change in the fair value of the success payment liability which is included in other expense, net in the accompanying condensed consolidated statements of operations. We had no outstanding obligation associated with the Success Fee as of March 31, 2024 or December 31, 2023.

- Definition

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

+ References + Details

Related Parties	3 Months Ended
Related Parties	Mar. 31, 2024
Related Party Transactions [Abstract]
Related Parties	9. Related Parties In May 2022, we entered into a sublease agreement with Crossbow Therapeutics, Inc. (“Crossbow”), for which entities affiliated with MPM Capital (“MPM Capital”) are also beneficial owners, to sublease the entirety of our office and laboratory space in Cambridge, Massachusetts. Luke Evnin, Ph.D., the chair of our board of directors, co-founded MPM Capital and serves as Managing Director of MPM Capital. Briggs Morrison, who serves on our board of directors, serves as Executive Partner of MPM Capital and Chief Executive Officer of Crossbow. The term of the sublease agreement commenced in June 2022 and ended in March 2024, with no option to extend. We received cash payments under the sublease of approximately $0.4 million during the three months ended March 31, 2024. In addition, we received $0.2 million from Crossbow in June 2022 as a security deposit that is included within accrued expenses and other current liabilities in the accompanying condensed consolidated balance sheet as of March 31, 2024. Following the conclusion of the sublease agreement, the security deposit is expected to be remitted to Crossbow upon satisfactory inspection of the subleased premises.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

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+ Details

Net Loss Attributable to Common Stockholders per Share - Antidilutive Shares (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	7,905,495	7,116,841
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	7,450,864	6,664,468
Unvested RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	361,500	322,725
Warrants to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	58,904	58,904
Commons stock to be issued under the 2021 ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	34,227	32,679
Unvested RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	38,065

Subsequent Event (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended
	May 02, 2024	Apr. 30, 2022	Mar. 31, 2024	Mar. 31, 2023
Subsequent Event [Line Items]
Proceeds from drawdown of term loans			$ 0	$ 40,000
Floating rate spread in effect (greater than) (percent)		4.50%
Prime Rate
Subsequent Event [Line Items]
Floating rate spread in effect (greater than) (percent)		0.50%
Subsequent Event
Subsequent Event [Line Items]
Cash used to repay debt	$ 10,500
Subsequent Event \| Loan Agreement
Subsequent Event [Line Items]
Loan agreement, amount	60,000
Proceeds from drawdown of term loans	30,000
Net proceeds	29,500
Amount of net cash proceeds from certain financing activities	60,000
Minimum amount of offering of common stock	$ 50,000
Floating rate spread in effect (greater than) (percent)	1.80%
Conversion of outstanding principal	$ 5,000
Conversion price (in dollars per share)	$ 6.32
Allowable amount to invest in future offerings	$ 5,000
Subsequent Event \| Loan Agreement \| Minimum
Subsequent Event [Line Items]
Adjustment rate (as a percent)	9.99%
Subsequent Event \| Loan Agreement \| Maximum
Subsequent Event [Line Items]
Adjustment rate (as a percent)	19.99%
Subsequent Event \| Loan Agreement \| Prime Rate
Subsequent Event [Line Items]
Floating rate spread in effect (greater than) (percent)	10.30%
Subsequent Event \| Loan Agreement \| Tranche one
Subsequent Event [Line Items]
Proceeds from drawdown of term loans	$ 25,000
Subsequent Event \| Loan Agreement \| Tranche two
Subsequent Event [Line Items]
Proceeds from drawdown of term loans	5,000
Subsequent Event \| Loan Agreement \| Tranche three
Subsequent Event [Line Items]
Capacity available to draw on the Term Loans	10,000
Subsequent Event \| Loan Agreement \| Tranche four
Subsequent Event [Line Items]
Capacity available to draw on the Term Loans	$ 20,000

Nature of Business (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 139,189	$ 134,343	$ 147,868

Financial Instruments and Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2024

Fair Value Disclosures [Abstract]

Assets Measured at Fair Value on a Recurring Basis

Assets measured at fair value on a recurring basis as of March 31, 2024 were as follows:


	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets:
Money market funds	$	153,810	$	—	$	—	$	153,810
Total assets	$	153,810	$	—	$	—	$	153,810

Assets measured at fair value on a recurring basis as of December 31, 2023 were as follows:


	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets:
Money market funds	$	149,294	$	—	$	—	$	149,294
Total assets	$	149,294	$	—	$	—	$	149,294

Related Parties (Details) $ in Millions	3 Months Ended
Related Parties (Details) $ in Millions	Mar. 31, 2024 USD ($)
Related Party Transactions [Abstract]
Sublease cash payments received	$ 0.4
Security deposit liability	$ 0.2

Net Loss Attributable to Common Stockholders per Share

3 Months Ended

Mar. 31, 2024

Earnings Per Share [Abstract]

Net Loss Attributable to Common Stockholders per Share

10. Net Loss Attributable to Common Stockholders per Share


	March 31,
	2024	2023
Outstanding stock options	7,450,864	6,664,468
Unvested RSUs	361,500	322,725
Warrants to purchase common stock	58,904	58,904
Commons stock to be issued under the 2021 ESPP	34,227	32,679
Unvested RSAs	—	38,065
Total	7,905,495	7,116,841

Term Loan - Narrative (Details) - USD ($) $ in Thousands			1 Months Ended	3 Months Ended
Term Loan - Narrative (Details) - USD ($) $ in Thousands	Apr. 17, 2023	Apr. 30, 2022	Apr. 30, 2022	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2023
Debt Instrument [Line Items]
Floating rate spread in effect (greater than) (percent)			4.50%
Non-cash interest expense				$ 1,003		$ 172
Success fee liability paid	$ 1,600				$ 1,600
Proceeds from at the market offering of common stock, net of issuance costs				20,247		8,623
Prime Rate
Debt Instrument [Line Items]
Floating rate spread in effect (greater than) (percent)			0.50%
Term loan
Debt Instrument [Line Items]
Non-cash interest expense				1,000		$ 200
Term loan \| Period One
Debt Instrument [Line Items]
Delayed draw fee			$ 200
Success Fee (percent)		2.00%	2.00%
Term loan \| Period Two
Debt Instrument [Line Items]
Delayed draw fee			$ 400
Success Fee (percent)		4.00%	4.00%
Tranche I Loan \| Term loan
Debt Instrument [Line Items]
Term loan available		$ 20,000	$ 20,000
Tranche II Loan \| Term loan
Debt Instrument [Line Items]
Term loan available		$ 20,000	$ 20,000
Term Loans \| Term loan
Debt Instrument [Line Items]
Drawings on term loans				40,000
Default payment fee (percent)		5.00%	5.00%
Maximum annual capital expenditures		1.25	1.25
Proceeds from at the market offering of common stock, net of issuance costs	50,000	$ 50,000
Restricted Cash	$ 20,000			20,000			$ 20,000
Note payable				$ 40,000

Term Loan

3 Months Ended

Mar. 31, 2024

Debt Disclosure [Abstract]

Term Loan

6. Term Loan

In April 2022, we entered into the PWB Loan Agreement with PWB. Under the terms of the PWB Loan Agreement, PWB made available a term loan in an aggregate principal amount of up to $20.0 million (“Tranche I Loan”) available at any time after the closing date until February 28, 2024 as extended to August 31, 2024 upon the satisfaction of certain conditions set forth in the PWB Loan Agreement (such date, the “Amortization Date”). Based on the satisfaction of certain conditions defined in the PWB Loan Agreement, PWB was also obligated to make available an additional term loan in the aggregate principal amount of up to $20.0 million (“Tranche II Loan”, or collectively with the Tranche I Loan, the “Term Loans”) available at any time after the closing date until the Amortization Date upon the acceptance by the U.S. Food and Drug Administration (the “FDA”) of two investigational new drug (“IND”) submissions on or before March 31, 2023. As of March 31, 2024, we have drawn down $40.0 million of the Term Loans.

The outstanding notes payable balance under the Term Loans consists of the following:


	March 31, 2024
	(in thousands)
Note payable	$	40,000
Unamortized debt discount and issuance costs	(585)
Net carrying amount of note payable	39,415
Less: current portion of note payable	(11,667)
Note payable, net, less current portion	$	27,748

Subsequent to the interest-only period, which ends on August 31, 2024, we are required to make equal monthly principal payments plus interest until the Term Loans mature on August 31, 2026. The Term Loans will bear interest on the outstanding daily balance at a floating annual rate equal to greater of: (i) 0.5% above the prime rate then in effect or (ii) 4.5%. If the prime rate changes throughout the term, the interest rate will be adjusted effective on the date of the prime rate change. All interest chargeable under the PWB Loan Agreement is computed on a 360-day year for the actual number of days elapsed, with interest payable monthly. We recognized interest expense related to the PWB Loan Agreement of $1.0 million and $0.2 million during the three months ended March 31, 2024 and 2023, respectively.

The following table presents the total principal payments scheduled to become due during each of the years ended December 31:


	Principal Payments
	(in thousands)
2024 (remaining as of March 31, 2024)	$	6,667
2025	20,000
2026	13,333
	$	40,000

We were obligated to pay PWB a one-time fee in the event of certain corporate transactions equal to either (i) the greater of (a) $0.2 million and (b) 2.0% of the amount drawn under the Term Loans, for a transaction occurring on or before March 31, 2023, or (ii) for any transaction occurring thereafter, the greater of (a) $0.4 million and (b) 4.0% of the amount drawn under the Term

Loans (the “Success Fee”). The Success Fee Event occurred during the second quarter of 2023, resulting in the immediate payment in full of the $1.6 million required Success Fee.

All outstanding obligations under the PWB Loan Agreement are secured by our personal property (exclusive of any intellectual property) and are subject to acceleration in the event of default. In the event of a late payment or default, we are obligated to pay a fee equal to 5.0% of such unpaid amounts. In connection with the PWB Loan Agreement, we are required to comply with certain negative covenants, which among other things, restrict us from (i) incurring future debt or granting liens, (ii) effectuating a merger or consolidation with or into any other business organization, (iii) paying dividends or making certain other distributions, (iv) selling or otherwise transferring our assets, (v) making investments in any entities or instruments other than certain investments specified in the PWB Loan Agreement and (vi) making capitalized expenditures in excess of 125% of the amount provided for in the annual budget approved by our board of directors. The PWB Loan Agreement also contains standard affirmative covenants, including with respect to the issuance of audited consolidated financial statements, insurance, and maintenance of good standing and government compliance in our state of formation. On or before September 30, 2023, we were required to raise aggregate gross cash process of at least $50.0 million from the sale or issuance of our equity or from strategic partnerships or any similar transaction. Since receipt of those proceeds, we are required to maintain at all times at least $20.0 million of otherwise unrestricted cash in accounts with PWB, which is included within restricted cash and cash equivalents, net of current portion on our condensed consolidated balance sheet as of March 31, 2024 and December 31, 2023. On April 17, 2023, we achieved the $50.0 million funding milestone, triggering the corresponding $20.0 million cash covenant, full payment of the Success Fee of $1.6 million, and the updated Amortization Date of August 31, 2024.

PWB has the right to accelerate all of our outstanding obligations under the PWB Loan Agreement or terminate any remaining Term Loan commitments in the event of a material adverse effect on (i) our operations, business or financial condition, (ii) our ability to repay any portion of the Term Loans or perform any of our other obligations under the PWB Loan Agreement, and (iii) our interest in, or the value, perfection or priority of PWB’s security interest in the collateral.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
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-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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-Paragraph 1
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 1B
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Paragraph 1B
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

Cover - shares	3 Months Ended
Cover - shares	Mar. 31, 2024	Apr. 29, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-40366
Entity Registrant Name	WEREWOLF THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3523180
Entity Address, Address Line One	200 Talcott Ave
Entity Address, Address Line Two	2nd Floor
Entity Address, City or Town	Watertown
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02472
City Area Code	617
Local Phone Number	952‑0555
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	HOWL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		43,455,367
Entity Central Index Key	0001785530
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false