0000950170-23-056121 | 10-Q | XBRL Viewer

Cash, Cash Equivalents and Restricted Cash

9 Months Ended

Sep. 30, 2023

Restricted Cash and Cash Equivalents [Abstract]

Cash, Cash Equivalents and Restricted Cash

3. Cash, Cash Equivalents and Restricted Cash

Cash includes cash in readily available checking accounts and cash equivalents include money market funds that invest in U.S. treasury securities and all highly liquid investments maturing within 90 days from the date of purchase.

Amounts included in restricted cash represent amounts pledged as collateral for letters of credit required for security deposits on the Company’s leased facilities.

Cash, cash equivalents and restricted cash consisted of the following:


	September 30,		December 31,
(in thousands)	2023		2022
Cash and cash equivalents	$	130,279	$	172,147
Restricted cash		2,325		2,319
Total	$	132,604	$	174,466

Property and Equipment

9 Months Ended

Sep. 30, 2023

Property, Plant and Equipment [Abstract]

Property and Equipment

5. Property and Equipment

Property and equipment consisted of the following:


	September 30,			December 31,
(in thousands)	2023			2022
Laboratory equipment	$	7,432		$	6,770
Office and computer equipment		2,080			1,898
Construction in process		490			906
Property and equipment—at cost		10,002			9,574
Less accumulated depreciation and amortization		(4,890	)		(3,629	)
Property and equipment—net	$	5,112		$	5,945

Depreciation and amortization expense for the three and nine months ended September 30, 2023 was $0.4 million and $1.3 million, respectively. Depreciation and amortization expense for the three and nine months ended September 30, 2022 was $0.4 million and $1.3 million, respectively.

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

The accompanying financial statements have been prepared in conformity with generally accepted accounting principles (“GAAP”) in the United States of America. 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 financial statements of the Company included herein have been prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). The unaudited interim financial statements have been prepared on the same basis as audited annual financial statements, except certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. In the opinion of management, the interim financial information reflects all adjustments, all of which are of a normal and recurring nature, necessary for a fair representation of the results for the reported periods. Accordingly, these financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s annual report on Form 10-K filed with the SEC on March 2, 2023. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period.

Fair value measurements

Certain assets and liabilities are carried at fair value. 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—Unadjusted quoted prices in active markets that are accessible to the reporting entity at the measurement date for identical assets and liabilities.

•

Level 2—Inputs other than quoted prices in active markets for identical assets and liabilities that are observable either directly or indirectly for substantially the full term of the asset or liability. Level 2 inputs include the following:

•

quoted prices for similar assets and liabilities in active markets;

•

quoted prices for identical or similar assets or liabilities in markets that are not active;

•

observable inputs other than quoted prices that are used in the valuation of the asset or liabilities (e.g., interest rate and yield curve quotes at commonly quoted intervals); and

•

inputs that are derived principally from or corroborated by observable market data by correlation or other means.

•

Level 3—Unobservable inputs for the assets or liability (i.e., supported by little or no market activity). Level 3 inputs include management’s own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk).

Net loss per share

Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. Diluted net loss is computed by adjusting net loss to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share is computed by dividing the diluted net loss by the weighted average number of shares of common stock outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents.

The following potentially dilutive common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:


	September 30,
	2023		2022
Options to purchase common stock		9,085,392		8,352,831
Unvested restricted common stock		—		2,462
Unvested restricted stock units		1,381,259		937,688
Total		10,466,651		9,292,981

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($)	3 Months Ended
	Jun. 30, 2023	Mar. 31, 2023
Common Stock
Stock issuance costs	$ 800	$ 1,000

Fair Value Measurements

9 Months Ended

Sep. 30, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

4. Fair Value Measurements

The following tables set forth marketable securities for the periods presented:


	As of September 30, 2023
(in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Total
Corporate debt securities		6,697		—		(13	)		6,684
U.S. treasury notes		20,860		1		(1	)		20,860
Total	$	27,557	$	1	$	(14	)	$	27,544


	As of December 31, 2022
(in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Total
Commercial paper	$	3,955	$	—	$	—		$	3,955
Corporate debt securities		57,231		—		(526	)		56,705
Certificates of deposit		4,984		—		—			4,984
U.S. treasury notes		18,266		1		(46	)		18,221
Total	$	84,436	$	1	$	(572	)	$	83,865

The scheduled maturity for the Company's marketable securities at September 30, 2023 was less than one year.

The following tables set forth by level, within the fair value hierarchy (see Note 2), the assets carried at fair value on a recurring basis for the periods presented:


	Fair value measurements as of September 30, 2023
(in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents
Money market funds	$	81,965	$	—	$	—	$	81,965
U.S. treasury notes		14,547		—		—		14,547
Marketable securities
Corporate debt securities		—		6,684		—		6,684
U.S. treasury notes		20,860		—		—		20,860
Total	$	117,372	$	6,684	$	—	$	124,056


	Fair Value Measurements as of December 31, 2022
(in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents
Money market funds	$	9,381	$	—	$	—	$	9,381
Corporate debt securities		—		3,852		—		3,852
U.S. treasury notes		811		—		—		811
Marketable securities
Commercial paper		3,955		—		—		3,955
Corporate debt securities		—		56,705		—		56,705
Certificates of deposit		—		4,984		—		4,984
U.S. treasury notes		18,221		—		—		18,221
Total	$	32,368	$	65,541	$	—	$	97,909

The fair value of U.S. treasury notes, money market funds and commercial paper were determined by the Company based on quoted market prices, which represent a Level 1 measurement within the fair value hierarchy. Certificates of deposit and corporate debt 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.

There were no transfers between Level 1, Level 2, or Level 3 during the periods presented.

Financial instruments not recorded at fair value

The carrying values of cash, cash equivalents, accounts payable and accrued expenses that are reported on the balance sheets approximate their fair value due to the short-term nature of these assets and liabilities.

- 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

Accrued Expenses and Other Current Liabilities

9 Months Ended

Sep. 30, 2023

Payables and Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

6. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following:


	September 30,		December 31,
(in thousands)	2023		2022
Payroll and benefits	$	5,984	$	5,935
Consulting services		657		776
Legal services		564		410
Research and development		14,221		11,097
Facility costs		—		1
Total	$	21,426	$	18,219

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	61,322,283	55,636,505
Common stock, shares outstanding	61,322,283	55,636,505

Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 400	$ 400	$ 1,274	$ 1,282

Stockholders' Equity - Summary of Assumptions Used to Determine Grant-Date Fair Value of Options Granted (Details)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Expected volatility	67.00%	71.00%
Risk-free interest rate, minimum	3.42%	1.47%
Risk-free interest rate, maximum	4.47%	4.11%
Expected term (in years)	6 years	6 years

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (169,299)	$ (129,272)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	14,242	11,346
Depreciation and amortization expense	1,274	1,282
Non-cash lease expense	620	1,448
Amortization (accretion) of premium on marketable securities	(908)	1,248
Loss on sale of marketable securities	23	30
Loss on disposal of property and equipment	118	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(781)	(4,654)
Accounts payable and other liabilities	1,559	(5,881)
Net cash used in operating activities	(153,152)	(124,453)
Cash flows from investing activities:
Purchases of property and equipment	(647)	(2,548)
Purchases of marketable securities	(44,262)	(94,712)
Maturities of marketable securities	100,195	162,466
Sales of marketable securities	1,829	2,759
Net cash provided by investing activities	57,115	67,965
Cash flows from financing activities:
Proceeds from issuance of common stock in public offering, net of issuance costs	52,370	0
Proceeds from exercise of stock options	1,805	187
Net cash provided by financing activities	54,175	187
Net decrease in cash, cash equivalents and restricted cash	(41,862)	(56,301)
Cash, cash equivalents and restricted cash, beginning of period	174,466	203,519
Cash, cash equivalents and restricted cash, end of period	132,604	147,218
Supplemental disclosures of cash flow information:
Purchase of property and equipment in accounts payable	$ 27	$ 0

Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

Potential Dilutive Securities Excluded From Calculation Of Net Loss Per Share


	September 30,
	2023		2022
Options to purchase common stock		9,085,392		8,352,831
Unvested restricted common stock		—		2,462
Unvested restricted stock units		1,381,259		937,688
Total		10,466,651		9,292,981

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Payroll and benefits	$ 5,984	$ 5,935
Consulting services	657	776
Legal services	564	410
Research and development	14,221	11,097
Facility costs	0	1
Total	$ 21,426	$ 18,219

Stockholders' Equity - Summary of Stock Option Activity and Related Information (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Options
Outstanding, beginning of period \| shares	9,381,429
Granted \| shares	764,400
Exercised \| shares	(790,379)
Canceled \| shares	(270,058)
Outstanding, end of period \| shares	9,085,392	9,381,429
Options exercisable as of September 30, 2023 \| shares	4,988,311
Options vested or expected to vest as of September 30, 2023 \| shares	9,085,392
Weighted Average Exercise Price
Outstanding, beginning of period \| $ / shares	$ 9.59
Granted \| $ / shares	12.38
Exercised \| $ / shares	2.28
Canceled \| $ / shares	10.58
Outstanding, end of period \| $ / shares	10.43	$ 9.59
Options exercisable as of September 30, 2023 \| $ / shares	9.63
Options vested or expected to vest as of September 30, 2023 \| $ / shares	$ 10.43
Weighted Average Remaining Life (in years)
Outstanding	7 years 8 months 12 days	8 years 2 months 12 days
Options exercisable as of September 30, 2023	7 years 1 month 6 days
Options vested or expected to vest as of September 30, 2023	7 years 8 months 12 days
Aggregate Intrinsic Value
Outstanding \| $	$ 15,506	$ 34,879
Options exercisable as of September 30, 2023 \| $	12,443
Options vested or expected to vest as of September 30, 2023 \| $	$ 15,506

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2023	Oct. 27, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Registrant Name	Dyne Therapeutics, Inc.
Entity Central Index Key	0001818794
Entity File Number	001-39509
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-4883909
Entity Address, Address Line One	1560 Trapelo Road
Entity Address, City or Town	Waltham
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02451
City Area Code	781
Local Phone Number	786-8230
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	DYN
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	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		61,375,598

Summary of Significant Accounting Policies - Net loss per share (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Total	$ 10,466,651	$ 9,292,981
Unvested Restricted Stock Units
Total	1,381,259	937,688
Options to purchase common stock
Total	9,085,392	8,352,831
Unvested restricted common stock
Total	$ 0	$ 2,462

Cash, Cash Equivalents and Restricted Cash (Tables)

9 Months Ended

Sep. 30, 2023

Restricted Cash and Cash Equivalents [Abstract]

Schedule of Cash, Cash Equivalents and Restricted Cash

Cash, cash equivalents and restricted cash consisted of the following:


	September 30,		December 31,
(in thousands)	2023		2022
Cash and cash equivalents	$	130,279	$	172,147
Restricted cash		2,325		2,319
Total	$	132,604	$	174,466

Property and Equipment (Tables)

9 Months Ended

Sep. 30, 2023

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment consisted of the following:


	September 30,			December 31,
(in thousands)	2023			2022
Laboratory equipment	$	7,432		$	6,770
Office and computer equipment		2,080			1,898
Construction in process		490			906
Property and equipment—at cost		10,002			9,574
Less accumulated depreciation and amortization		(4,890	)		(3,629	)
Property and equipment—net	$	5,112		$	5,945

Stockholders' Equity - Additional Information (Details) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($) Installment $ / shares shares	Sep. 30, 2022 USD ($) $ / shares	Dec. 31, 2022 shares	Nov. 30, 2021 USD ($)
Stock based compensation expense reversal
Common stock, shares issued \| shares	61,322,283		55,636,505
Weighted-average grant date fair value of options granted \| $ / shares	$ 7.79	$ 5.33
Intrinsic value of options exercised	$ 8.0	$ 0.4
Common Stock [Member]
Stock based compensation expense reversal
Common stock aggregate offer price				$ 150.0
Common stock, shares issued \| shares	4,509,063
Net proceeds from issuance of common stock	$ 52.4
Sale price per share \| $ / shares	$ 12.01
Stock Option
Stock based compensation expense reversal
Unrecognized compensation expense	$ 25.5
Unrecognized share based compensation expense, recognition period	2 years 2 months 12 days
Restricted Stock Units ("RSUs")
Stock based compensation expense reversal
Unrecognized compensation expense	$ 15.2
Unrecognized share based compensation expense, recognition period	2 years 8 months 12 days
Number of share of common stock receivable upon vesting \| shares	1
2020 Plan
Stock based compensation expense reversal
Number of shares available for future issuance \| shares	5,288,851
2020 Plan \| Restricted Stock Units ("RSUs")
Stock based compensation expense reversal
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights	The Company grants RSUs with service conditions that vest in four equal annual installments provided that the employee remains employed with the Company, RSUs with service conditions that vest in sixteen equal quarterly installments provided that the employee remains employed with the Company and RSUs with performance-based vesting conditions.
Share-based Compensation Arrangement By Share-based Payment Award Grant Service Conditions to Vest Number of Annual Installments \| Installment	4

Cash, Cash Equivalents and Restricted Cash - Schedule of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 130,279	$ 172,147
Restricted cash	2,325	2,319
Total	$ 132,604	$ 174,466

Fair Value Measurements - Summary of Marketable Securities by Security Type (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 27,557	$ 84,436
Unrealized Gains	1	1
Unrealized Losses	(14)	(572)
Total	27,544	83,865
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		3,955
Total		3,955
Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		4,984
Total		4,984
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	6,697	57,231
Unrealized Losses	(13)	(526)
Total	6,684	56,705
U.S. treasury notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	20,860	18,266
Unrealized Gains	1	1
Unrealized Losses	(1)	(46)
Total	$ 20,860	$ 18,221

- 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/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

+ Details

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

Fair Value Measurements

Fair value measurements

•

Level 1—Unadjusted quoted prices in active markets that are accessible to the reporting entity at the measurement date for identical assets and liabilities.

•

quoted prices for similar assets and liabilities in active markets;

•

quoted prices for identical or similar assets or liabilities in markets that are not active;

•

observable inputs other than quoted prices that are used in the valuation of the asset or liabilities (e.g., interest rate and yield curve quotes at commonly quoted intervals); and

•

inputs that are derived principally from or corroborated by observable market data by correlation or other means.

•

Net Loss Per Share

Net loss per share


	September 30,
	2023		2022
Options to purchase common stock		9,085,392		8,352,831
Unvested restricted common stock		—		2,462
Unvested restricted stock units		1,381,259		937,688
Total		10,466,651		9,292,981

Nature of the Business and Basis of Presentation

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

Nature of the Business and Basis of Presentation

1. Nature of Business and Basis of Presentation

Dyne Therapeutics, Inc. (the “Company”) is a clinical-stage muscle disease company focused on advancing innovative life-transforming therapeutics for people living with genetically driven diseases. The Company was incorporated in Delaware on December 1, 2017 and has a principal place of business in Waltham, Massachusetts.

The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for its product candidates, fluctuations in operating results, compliance with government regulations, the ability to establish clinical- and commercial-scale manufacturing processes and the ability to secure additional capital to fund operations. Product candidates and programs currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization of a product. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

The accompanying condensed consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Since inception, the Company has funded its operations with proceeds from the sales of equity securities. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash, cash equivalents and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements for at least 12 months from the issuance of these condensed consolidated financial statements.

To continue its development efforts, the Company will need to obtain substantial additional funding through public or private equity offerings, debt financings, collaborations, strategic alliances and/or licensing arrangements in order to fund its research and development and ongoing operating expenses. The Company may not be able to obtain financing on acceptable terms, when needed or at all, and the Company may not be able to enter into collaborations, strategic alliances or licensing arrangements. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. Any collaborations, strategic alliances or licensing arrangements may require the Company to relinquish rights to certain of its technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to the Company. If the Company is unable to obtain funding, the Company could be forced to delay, limit, reduce or eliminate some or all of its research and development programs, pipeline expansion or future commercialization efforts or grant rights to develop and market product candidates, which could adversely affect its business prospects. Although management will continue to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations when needed or at all.

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 130,279	$ 172,147
Marketable securities	27,544	83,865
Prepaid expenses and other current assets	10,393	9,582
Total current assets	168,216	265,594
Property and equipment, net	5,112	5,945
Right-of-use assets	29,591	32,467
Restricted cash	2,325	2,319
Total assets	205,244	306,325
Current liabilities:
Accounts payable	3,553	5,259
Accrued expenses and other current liabilities	21,426	18,219
Lease liabilities	4,713	4,610
Total current liabilities	29,692	28,088
Lease liabilities, net of current portion	23,514	25,873
Total liabilities	53,206	53,961
Stockholders’ equity
Preferred stock, $0.0001 par value; 10,000,000 shares authorized at September 30, 2023 and December 31, 2022	0	0
Common stock, $0.0001 par value; 200,000,000 shares authorized at September 30, 2023 and December 31, 2022; 61,322,283 and 55,636,505 shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively	6	6
Additional paid-in capital	717,917	649,502
Accumulated other comprehensive loss	(13)	(571)
Accumulated deficit	(565,872)	(396,573)
Total stockholders’ equity	152,038	252,364
Total liabilities and stockholders’ equity	$ 205,244	$ 306,325

Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Assumptions Used to Determine Grant-Date Fair Value of Options Granted

The assumptions that the Company used to determine the grant-date fair value of options granted were as follows:


	Nine Months Ended September 30,
	2023		2022
Expected volatility	67%		71%
Risk-free interest rate	3.42% — 4.47%		1.47% — 4.11%
Expected term (in years)	6		6
Expected dividend yield		—		—

Summary of Stock Option Activity and Related Information

A summary of the Company’s stock option activity and related information for the nine months ended September 30, 2023 is as follows:


(in thousands, except share and per share data)	Options			Weighted Average Exercise Price		Weighted Average Remaining Life (in years)		Aggregate Intrinsic Value
Outstanding as of January 1, 2023		9,381,429		$	9.59		8.2	$	34,879
Granted		764,400			12.38
Exercised		(790,379	)		2.28
Canceled		(270,058	)		10.58
Outstanding as of September 30, 2023		9,085,392		$	10.43		7.7	$	15,506
Options exercisable as of September 30, 2023		4,988,311		$	9.63		7.1	$	12,443
Options vested or expected to vest as of September 30, 2023		9,085,392		$	10.43		7.7	$	15,506

Summary of RSU Activity

A summary of the Company’s RSU activity and related information for the nine months ended September 30, 2023 is as follows:


	Number of Shares Underlying RSUs			Weighted Average Grant Date Fair Value
Issued and unvested as of January 1, 2023		1,695,191		$	13.02
Granted		142,000			11.89
Vested		(386,336	)		14.39
Forfeited		(69,596	)		12.56
Issued and unvested as of September 30, 2023		1,381,259		$	12.54

Summary of Stock-based Compensation Expense

The Company recorded stock-based compensation expense in the following expense categories of its statements of operations:


	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands)	2023		2022		2023		2022
Research and development	$	2,868	$	2,097	$	8,202	$	6,087
General and administrative		2,007		1,730		6,040		5,259
Total	$	4,875	$	3,827	$	14,242	$	11,346

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning Balance at Dec. 31, 2021	$ 368,197	$ 6	$ 596,934	$ (269)	$ (228,474)
Beginning Balance, Shares at Dec. 31, 2021		51,569,381
Exercise of stock options	18		18
Exercise of stock options, Shares		9,583
Stock-based compensation	4,488		4,488
Vesting of restricted shares		20,504
Vesting of restricted stock units		49,955
Unrealized gain on marketable securities	(661)			(661)
Net loss	(35,583)				(35,583)
Ending Balance at Mar. 31, 2022	336,459	$ 6	601,440	(930)	(264,057)
Ending Balance, Shares at Mar. 31, 2022		51,649,423
Beginning Balance at Dec. 31, 2021	368,197	$ 6	596,934	(269)	(228,474)
Beginning Balance, Shares at Dec. 31, 2021		51,569,381
Unrealized gain on marketable securities	(714)
Net loss	(129,272)
Ending Balance at Sep. 30, 2022	249,744	$ 6	608,467	(983)	(357,746)
Ending Balance, Shares at Sep. 30, 2022		51,906,773
Beginning Balance at Mar. 31, 2022	336,459	$ 6	601,440	(930)	(264,057)
Beginning Balance, Shares at Mar. 31, 2022		51,649,423
Exercise of stock options	99		99
Exercise of stock options, Shares		32,367
Stock-based compensation	3,031		3,031
Vesting of restricted shares		10,664
Vesting of restricted stock units		41,907
Unrealized gain on marketable securities	(226)			(226)
Net loss	(52,304)				(52,304)
Ending Balance at Jun. 30, 2022	287,059	$ 6	604,570	(1,156)	(316,361)
Ending Balance, Shares at Jun. 30, 2022		51,734,361
Exercise of stock options	70		70
Exercise of stock options, Shares		19,354
Stock-based compensation	3,827		3,827
Vesting of restricted shares		4,511
Vesting of restricted stock units		148,547
Unrealized gain on marketable securities	173			173
Net loss	(41,385)				(41,385)
Ending Balance at Sep. 30, 2022	249,744	$ 6	608,467	(983)	(357,746)
Ending Balance, Shares at Sep. 30, 2022		51,906,773
Beginning Balance at Dec. 31, 2022	252,364	$ 6	649,502	(571)	(396,573)
Beginning Balance, Shares at Dec. 31, 2022		55,636,505
Issuance of stock, net of issuance costs	28,186		28,186
Issuance of stock, net of issuance costs, Shares		2,335,150
Exercise of stock options	587		587
Exercise of stock options, Shares		232,292
Stock-based compensation	4,617		4,617
Vesting of restricted shares		101,533
Unrealized gain on marketable securities	368			368
Net loss	(44,187)				(44,187)
Ending Balance at Mar. 31, 2023	241,935	$ 6	682,892	(203)	(440,760)
Ending Balance, Shares at Mar. 31, 2023		58,305,480
Beginning Balance at Dec. 31, 2022	$ 252,364	$ 6	649,502	(571)	(396,573)
Beginning Balance, Shares at Dec. 31, 2022		55,636,505
Exercise of stock options, Shares	790,379
Unrealized gain on marketable securities	$ 558
Net loss	(169,299)
Ending Balance at Sep. 30, 2023	152,038	$ 6	717,917	(13)	(565,872)
Ending Balance, Shares at Sep. 30, 2023		61,322,283
Beginning Balance at Mar. 31, 2023	241,935	$ 6	682,892	(203)	(440,760)
Beginning Balance, Shares at Mar. 31, 2023		58,305,480
Issuance of stock, net of issuance costs	24,184		24,184
Issuance of stock, net of issuance costs, Shares		2,173,913
Exercise of stock options	764		764
Exercise of stock options, Shares		432,626
Stock-based compensation	4,749		4,749
Vesting of restricted shares		101,967
Unrealized gain on marketable securities	147			147
Net loss	(64,902)				(64,902)
Ending Balance at Jun. 30, 2023	206,877	$ 6	712,589	(56)	(505,662)
Ending Balance, Shares at Jun. 30, 2023		61,013,986
Exercise of stock options	453		453
Exercise of stock options, Shares		125,461
Stock-based compensation	4,875		4,875
Vesting of restricted shares		182,836
Unrealized gain on marketable securities	43			43
Net loss	(60,210)				(60,210)
Ending Balance at Sep. 30, 2023	$ 152,038	$ 6	$ 717,917	$ (13)	$ (565,872)
Ending Balance, Shares at Sep. 30, 2023		61,322,283

Accrued Expenses and Other Current Liabilities (Tables)

9 Months Ended

Sep. 30, 2023

Payables and Accruals [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following:


	September 30,		December 31,
(in thousands)	2023		2022
Payroll and benefits	$	5,984	$	5,935
Consulting services		657		776
Legal services		564		410
Research and development		14,221		11,097
Facility costs		—		1
Total	$	21,426	$	18,219

Nature of the Business and Basis of Presentation - Additional Information (Details)	9 Months Ended
	Sep. 30, 2023
Nature Of Business And Basis Of Presentation [Line Items]
Entity incorporation date	Dec. 01, 2017

Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment—at cost	$ 10,002	$ 9,574
Less accumulated depreciation and amortization	(4,890)	(3,629)
Property and equipment—net	5,112	5,945
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment—at cost	7,432	6,770
Office and Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment—at cost	2,080	1,898
Construction in Process
Property Plant And Equipment [Line Items]
Property and equipment—at cost	$ 490	$ 906

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2023

Fair Value Disclosures [Abstract]

Summary of Marketable Securities by Security Type

The following tables set forth marketable securities for the periods presented:


	As of September 30, 2023
(in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Total
Corporate debt securities		6,697		—		(13	)		6,684
U.S. treasury notes		20,860		1		(1	)		20,860
Total	$	27,557	$	1	$	(14	)	$	27,544


	As of December 31, 2022
(in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Total
Commercial paper	$	3,955	$	—	$	—		$	3,955
Corporate debt securities		57,231		—		(526	)		56,705
Certificates of deposit		4,984		—		—			4,984
U.S. treasury notes		18,266		1		(46	)		18,221
Total	$	84,436	$	1	$	(572	)	$	83,865

Summary of Assets Carried at Fair Value on Recurring Basis

The following tables set forth by level, within the fair value hierarchy (see Note 2), the assets carried at fair value on a recurring basis for the periods presented:


	Fair value measurements as of September 30, 2023
(in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents
Money market funds	$	81,965	$	—	$	—	$	81,965
U.S. treasury notes		14,547		—		—		14,547
Marketable securities
Corporate debt securities		—		6,684		—		6,684
U.S. treasury notes		20,860		—		—		20,860
Total	$	117,372	$	6,684	$	—	$	124,056


	Fair Value Measurements as of December 31, 2022
(in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents
Money market funds	$	9,381	$	—	$	—	$	9,381
Corporate debt securities		—		3,852		—		3,852
U.S. treasury notes		811		—		—		811
Marketable securities
Commercial paper		3,955		—		—		3,955
Corporate debt securities		—		56,705		—		56,705
Certificates of deposit		—		4,984		—		4,984
U.S. treasury notes		18,221		—		—		18,221
Total	$	32,368	$	65,541	$	—	$	97,909

- Definition

Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-9

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

+ Details

Fair Value Measurements - Summary of Assets Carried at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Assets:
Total	$ 124,056	$ 97,909
Level 1
Assets:
Total	117,372	32,368
Level 2
Assets:
Total	6,684	65,541
Cash Equivalents \| Money Market Funds
Assets:
Total	81,965	9,381
Cash Equivalents \| Corporate Debt Securities
Assets:
Total		3,852
Cash Equivalents \| U.S. treasury notes
Assets:
Total	14,547	811
Cash Equivalents \| Level 1 \| Money Market Funds
Assets:
Total	81,965	9,381
Cash Equivalents \| Level 1 \| U.S. treasury notes
Assets:
Total	14,547	811
Cash Equivalents \| Level 2 \| Corporate Debt Securities
Assets:
Total		3,852
Marketable Securities \| Commercial Paper
Assets:
Total		3,955
Marketable Securities \| Certificates of Deposit
Assets:
Total		4,984
Marketable Securities \| Corporate Debt Securities
Assets:
Total	6,684	56,705
Marketable Securities \| U.S. treasury notes
Assets:
Total	20,860	18,221
Marketable Securities \| Level 1 \| Commercial Paper
Assets:
Total		3,955
Marketable Securities \| Level 1 \| U.S. treasury notes
Assets:
Total	20,860	18,221
Marketable Securities \| Level 2 \| Certificates of Deposit
Assets:
Total		4,984
Marketable Securities \| Level 2 \| Corporate Debt Securities
Assets:
Total	$ 6,684	$ 56,705

Fair Value Measurements - Additional Information (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair value assets, transfers among level 1, level 2 or level 3	$ 0	$ 0

Stockholders' Equity - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 4,875	$ 3,827	$ 14,242	$ 11,346
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	2,868	2,097	8,202	6,087
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,007	$ 1,730	$ 6,040	$ 5,259

Cash, Cash Equivalents and Restricted Cash - Additional Information (Details)	9 Months Ended
	Sep. 30, 2023
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalent maturity period	90 days

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ 55,251	$ 34,670	$ 151,918	$ 109,570
General and administrative	7,022	7,609	22,556	21,247
Total operating expenses	62,273	42,279	174,474	130,817
Loss from operations	(62,273)	(42,279)	(174,474)	(130,817)
Other (expense) income:
Interest income	2,189	903	5,890	1,575
Other income (expense), net	(126)	(9)	(715)	(30)
Total other (expense) income, net	2,063	894	5,175	1,545
Net loss	$ (60,210)	$ (41,385)	$ (169,299)	$ (129,272)
Net loss per share - basic	$ (0.99)	$ (0.8)	$ (2.86)	$ (2.5)
Net loss per share - diluted	$ (0.99)	$ (0.8)	$ (2.86)	$ (2.5)
Weighted-average common shares outstanding, basic	61,109,917	51,795,446	59,107,795	51,692,899
Weighted-average common shares outstanding, diluted	61,109,917	51,795,446	59,107,795	51,692,899
Comprehensive loss:
Net loss	$ (60,210)	$ (41,385)	$ (169,299)	$ (129,272)
Other comprehensive loss:
Unrealized gains (losses) on marketable securities, net	43	173	558	(714)
Comprehensive loss	$ (60,167)	$ (41,212)	$ (168,741)	$ (129,986)

Stockholders' Equity

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Stockholders' Equity

7. Stockholders' Equity

Common Stock

In November 2021, the Company entered into an Open Market Sale Agreement (the "Sales Agreement") with Jefferies LLC as the Company's sales agent, pursuant to which, from time to time, the Company may offer and sell shares of its common stock having an aggregate offering price of up to $150.0 million in an "at-the-market" offering. During the nine months ended September 30, 2023, the Company issued and sold an aggregate of 4,509,063 shares of common stock pursuant to the Sales Agreement for aggregate net proceeds of $52.4 million, after deducting fees. The Company sold such shares at a weighted average price of $12.01 per share.

2020 Stock Incentive Plan

In August 2020 the Company’s board of directors adopted and the Company’s stockholders approved the 2020 Stock Incentive Plan, (the "2020 Plan"), which became effective on September 16, 2020. The 2020 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards to employees, directors, consultants and advisors of the Company. The 2020 Plan is administered by the Company’s board of directors or by a committee appointed by the board of directors. Upon the effectiveness of the 2020 Plan, the Company ceased granting awards under the 2018 Stock Incentive Plan.

As of September 30, 2023, 5,288,851 shares remained available for future issuance under the 2020 Plan.

Stock option valuation

The fair value of stock option grants is estimated using the Black-Scholes option-pricing model. The fair value is determined based upon the quoted price of the Company’s common stock. The Company lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical

volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. For options with service-based vesting conditions, the expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. 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.

The assumptions that the Company used to determine the grant-date fair value of options granted were as follows:


	Nine Months Ended September 30,
	2023		2022
Expected volatility	67%		71%
Risk-free interest rate	3.42% — 4.47%		1.47% — 4.11%
Expected term (in years)	6		6
Expected dividend yield		—		—

Stock option activity

A summary of the Company’s stock option activity and related information for the nine months ended September 30, 2023 is as follows:


(in thousands, except share and per share data)	Options			Weighted Average Exercise Price		Weighted Average Remaining Life (in years)		Aggregate Intrinsic Value
Outstanding as of January 1, 2023		9,381,429		$	9.59		8.2	$	34,879
Granted		764,400			12.38
Exercised		(790,379	)		2.28
Canceled		(270,058	)		10.58
Outstanding as of September 30, 2023		9,085,392		$	10.43		7.7	$	15,506
Options exercisable as of September 30, 2023		4,988,311		$	9.63		7.1	$	12,443
Options vested or expected to vest as of September 30, 2023		9,085,392		$	10.43		7.7	$	15,506

The intrinsic value of options exercised for the nine months ended September 30, 2023 and 2022 totaled $8.0 million and $0.4 million, respectively. The weighted-average grant date fair value of the options granted during the nine months ended September 30, 2023 and 2022 was $7.79 and $5.33 per share, respectively. As of September 30, 2023 there was $25.5 million of unrecognized compensation expense, which the Company expects to recognize over a weighted-average period of 2.2 years.

Restricted stock units

A restricted stock unit (“RSU”) represents the right to receive one share of common stock upon vesting of the RSU. The Company grants RSUs with service conditions that vest in four equal annual installments provided that the employee remains employed with the Company, RSUs with service conditions that vest in sixteen equal quarterly installments provided that the employee remains employed with the Company and RSUs with performance-based vesting conditions. The fair value of each RSU is based on the closing price of the Company’s common stock on the date of grant. A summary of the Company’s RSU activity and related information for the nine months ended September 30, 2023 is as follows:


	Number of Shares Underlying RSUs			Weighted Average Grant Date Fair Value
Issued and unvested as of January 1, 2023		1,695,191		$	13.02
Granted		142,000			11.89
Vested		(386,336	)		14.39
Forfeited		(69,596	)		12.56
Issued and unvested as of September 30, 2023		1,381,259		$	12.54

As of September 30, 2023, there was $15.2 million of unrecognized compensation costs related to unvested RSUs, which are expected to be recognized over a weighted-average period of 2.7 years.

The Company recorded stock-based compensation expense in the following expense categories of its statements of operations:


	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands)	2023		2022		2023		2022
Research and development	$	2,868	$	2,097	$	8,202	$	6,087
General and administrative		2,007		1,730		6,040		5,259
Total	$	4,875	$	3,827	$	14,242	$	11,346

Stockholders' Equity - Summary of RSU Activity (Details) - Restricted Stock Units ("RSUs") - 2020 Plan	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Number of Shares Underlying RSUs
Issued and unvested as of January 1, 2023 \| shares	1,695,191
Granted \| shares	142,000
Vested \| shares	(386,336)
Forfeited \| shares	(69,596)
Issued and unvested as of September 30, 2023 \| shares	1,381,259
Weighted Average Grant Date Fair Value
Issued and unvested as of January 1, 2023 \| $ / shares	$ 13.02
Granted \| $ / shares	11.89
Vested \| $ / shares	14.39
Forfeited \| $ / shares	12.56
Issued and unvested as of September 30, 2023 \| $ / shares	$ 12.54