Solid Biosciences (SLDB) CEO logs tax sale after RSUs vest

Rhea-AI Filing Summary

Solid Biosciences Inc. President and CEO Alexander Cumbo reported a combination of RSU vesting and a related tax sale. On February 13, 2026, he acquired 30,031 shares of common stock at $0.00 per share through the conversion of restricted stock units, increasing his directly held common stock.

On February 18, 2026, he sold 16,644 shares of common stock in an open‑market transaction at a weighted average price of $5.8233 per share to cover withholding taxes following the RSU vesting, under a pre‑existing automatic sales instruction that is not a discretionary trade. After these transactions, he directly owned 235,405 shares of common stock and 60,063 RSUs that vest over four years from the February 13, 2024 grant date.

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).

X

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^*

Cumbo Alexander

(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)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and CEO

3. Date of Earliest Transaction (Month/Day/Year)
02/13/2026

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
Common Stock	02/13/2026		M		30,031	A	(1)	252,049	D
Common Stock	02/18/2026		S		16,644(2)	D	$5.8233(3)	235,405	D

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
Restricted Stock Units	(1)	02/13/2026		M			30,031	(4)	(4)	Common Stock	30,301	$0.00	60,063	D

Explanation of Responses:

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

2. This sale was made to cover withholding taxes following the vesting of the previously granted RSUs pursuant to a durable automatic sales instruction letter adopted by Mr. Cumbo on August 18, 2024 effecting the sell-to-cover election. The sale does not represent a discretionary trade by Mr. Cumbo.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $5.23 to $6.14, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (4) to this Form.

4. The RSUs were granted on February 13, 2024 (the "Grant Date") and vest over four years, with 25% of the original number of shares vesting on each anniversary of the Grant Date until the fourth such anniversary.

	/s/ Kimberly Cornwell as attorney-in-fact for Alexander Cumbo	02/18/2026
	** 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 insider transactions did SLDB CEO Alexander Cumbo report on this Form 4?

Alexander Cumbo reported RSU vesting and a related tax sale. He converted 30,031 restricted stock units into common shares, then sold 16,644 shares in the open market to cover withholding taxes under a pre-set automatic sales instruction.

How many Solid Biosciences (SLDB) shares did the CEO sell and at what price?

He sold 16,644 shares of Solid Biosciences common stock at a weighted average price of $5.8233 per share. The sale occurred in multiple trades between $5.23 and $6.14, executed to satisfy tax withholding obligations tied to vested RSUs.

Were the SLDB CEO’s stock sales discretionary trades or part of a plan?

The sale was not a discretionary trade by the CEO. It was executed under a durable automatic sales instruction letter adopted on August 18, 2024, specifically to sell enough shares to cover tax withholding from RSU vesting.

What RSU activity did Solid Biosciences (SLDB) disclose for its CEO?

The CEO exercised 30,031 restricted stock units into an equal number of common shares at $0.00 per share. These RSUs were part of a grant from February 13, 2024 that vests in four annual installments of 25% each year.

How many Solid Biosciences shares and RSUs does the CEO hold after these transactions?

Following the reported Form 4 transactions, the CEO directly owned 235,405 shares of Solid Biosciences common stock and 60,063 remaining restricted stock units. The RSUs continue to vest annually over four years from the February 13, 2024 grant date.

Why did the SLDB CEO sell shares shortly after RSU vesting?

He sold shares to cover withholding taxes triggered by the vesting of previously granted RSUs. The transaction followed a pre-established automatic sales instruction, so it was a planned sell-to-cover event rather than an elective sale for portfolio reasons.