[Form 4] Solid Biosciences Inc. Insider Trading Activity

Rhea-AI Filing Summary

Solid Biosciences Inc. reported that its Chief Operating Officer, David T. Howton, was granted equity awards on 08/14/2025 consisting of an employee stock option to buy 150,000 shares at an exercise price of $6.17 per share with an expiration date of 08/14/2035, and 75,000 restricted stock units (RSUs) that each convert into one share. After these grants, Mr. Howton beneficially owns 150,000 option shares and 75,000 RSUs, all held directly. The RSUs and the option vest over four years: 50% vests on the second anniversary of the grant and 25% vests on each of the third and fourth anniversaries.

Insights

Corporate Compensation Analyst

TL;DR: The filing documents standard executive equity compensation: long-dated options plus RSUs with back-loaded vesting, aligning retention incentives.

The award package pairs a ten-year option with RSUs and a vesting schedule weighted toward the second year, which may be intended to retain the COO through multi-year operational milestones. The $6.17 exercise price sets the strike level for the option; the grant size (225,000 total equity-linked units) is meaningful for a senior officer but must be assessed relative to company headcount and outstanding shares to judge dilution. All holdings are reported as direct ownership, simplifying governance considerations.

Securities Compliance Specialist

TL;DR: Form 4 properly discloses grant details and direct ownership; vesting terms and option life are clearly stated.

The disclosure includes requisite details: transaction date, exercise price, quantity, expiration, and vesting schedule for RSUs and options. Signature indicates filing by attorney-in-fact, which is acceptable when authorized. No derivative dispositions, sales, or complex indirect holdings are reported, reducing immediate compliance risk. This is a routine insider compensation disclosure rather than a market-moving transaction.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Howton David T

Role Chief Operating Officer

Type	Security	Shares	Price	Value
Grant/Award	Employee Stock Option (Right to Buy)	150,000	$0.00	--
Grant/Award	Restricted Stock Units	75,000	$0.00	--

Holdings After Transaction: Employee Stock Option (Right to Buy) — 150,000 shares (Direct); Restricted Stock Units — 75,000 shares (Direct)

Footnotes (1)

1. The RSUs (as defined in footnote 2) together with this option were granted on August 14, 2025 (the "Grant Date") and vest over four years, with 50% of the original number of shares vesting on the second anniversary of the Grant Date and 25% of the original number of shares annually thereafter until the fourth such anniversary. Each restricted stock unit represents a contingent right to receive one share of the issuer's common stock (the "RSUs").

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Howton David T

(Last) (First) (Middle)

C/O SOLID BIOSCIENCES INC.

500 RUTHERFORD AVENUE, THIRD FLOOR

(Street)

CHARLESTOWN MA 02129

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Solid Biosciences Inc. [ SLDB ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Operating Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/14/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (Right to Buy)	$6.17	08/14/2025		A		150,000		(1)	08/14/2035	Common Stock	150,000	$0.00	150,000	D
Restricted Stock Units	(2)	08/14/2025		A		75,000		(1)	(1)	Common Stock	75,000	$0.00	75,000	D

Explanation of Responses:

1. The RSUs (as defined in footnote 2) together with this option were granted on August 14, 2025 (the "Grant Date") and vest over four years, with 50% of the original number of shares vesting on the second anniversary of the Grant Date and 25% of the original number of shares annually thereafter until the fourth such anniversary.

2. Each restricted stock unit represents a contingent right to receive one share of the issuer's common stock (the "RSUs").

	/s/ Kimberly Cornwell as attorney-in-fact for David Tyronne Howton	08/18/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What equity awards did SLDB COO receive on 08/14/2025?

The COO was granted an employee stock option for 150,000 shares at an exercise price of $6.17 and 75,000 RSUs.

When do the RSUs and options vest for the SLDB grant?

The awards vest over four years: 50% of the original shares vest on the second anniversary of the grant, then 25% annually on the third and fourth anniversaries.

How long is the option exercisable for SLDB COO's grant?

The option has an expiration date of 08/14/2035, giving a ten-year potential term from the grant date.

Does the Form 4 show indirect ownership or complex transactions?

No; the Form 4 reports these awards as direct ownership and contains no dispositions or indirect holdings.

Who signed the Form 4 for David T. Howton?

The Form 4 was signed by Kimberly Cornwell as attorney-in-fact for David T. Howton on 08/18/2025.