STOCK TITAN

Solid Biosciences (SLDB) CEO awarded options and RSUs, sells shares

Filing Impact
(Very High)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

Solid Biosciences Inc.’s President and CEO Alexander Cumbo reported multiple equity compensation events and a tax-related share sale. On January 29, 2026, 169,401 performance stock units vested into common shares, he received an option grant for 509,850 shares at $6.60, and was granted 254,900 RSUs.

On January 31, 2026, 100,400 RSUs from a prior grant vested into common stock. On February 2, 2026, Cumbo sold 80,258 shares at a weighted average price of $6.4369 to cover withholding taxes under an automatic sell-to-cover instruction, leaving him with 270,931 directly held common shares plus unvested RSUs and options.

Positive

  • None.

Negative

  • None.
Insider Cumbo Alexander
Role President and CEO
Sold 80,258 shs ($517K)
Type Security Shares Price Value
Sale Common Stock 80,258 $6.4369 $517K
Exercise Restricted Stock Units 100,400 $0.00 --
Exercise Common Stock 100,400 $0.00 --
Exercise Performance Stock Units 169,401 $0.00 --
Grant/Award Employee Stock Option (Right to Buy) 509,850 $0.00 --
Grant/Award Restricted Stock Units 254,900 $0.00 --
Exercise Common Stock 169,401 $0.00 --
Holdings After Transaction: Common Stock — 270,931 shares (Direct); Restricted Stock Units — 301,200 shares (Direct); Performance Stock Units — 0 shares (Direct); Employee Stock Option (Right to Buy) — 509,850 shares (Direct)
Footnotes (1)
  1. Each performance stock unit ("PSUs") converts to common stock on a one-for-one basis. Each restricted stock unit ("RSUs") converts to common stock on a one-for-one basis. This sale was made to cover withholding taxes following the vesting of previously granted PSUs pursuant to a durable automatic sale 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. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.295 to $6.580, 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. The PSUs were granted on June 11, 2024 and provide for the vesting of 25% of the target number of underlying RSUs granted upon the achievement of each of four independent performance milestones predetermined by the Board ("Performance Milestones"), subject to the grantee's continued service with the Company (the "Approval Conditions"). The Performance Milestones are tied to the achievement of certain business objectives, as certified by the Board on specified evaluation dates, and are non-market and non-financial in nature. The performance criteria specified for the first Performance Milestone was determined to be met on January 29, 2026 (the "2026 Grant Date") resulting in the vesting of the PSUs as to 25% of the underlying shares. This option was granted on the 2026 Grant Date and vests over four years, with 25% of the original number of shares vesting on the first anniversary of the 2026 Grant Date and 2.0833% of the original number of shares monthly thereafter until the fourth such anniversary. The RSUs were granted on the 2026 Grant Date and vest over four years, with 25% of the original number of shares vesting on each anniversary of the 2026 Grant Date until the fourth such anniversary. On January 31, 2025 (the "2025 Grant Date"), the reporting person was granted 401,600 RSUs, with 25% of the original number of shares vesting on each anniversary of the 2025 Grant Date until the fourth such anniversary.
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)
01/29/2026
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 01/29/2026 M 169,401 A (1) 250,789 D
Common Stock 01/31/2026 M 100,400 A (2) 351,189 D
Common Stock 02/02/2026 S 80,258(3) D $6.4369(4) 270,931 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
Performance Stock Units (1) 01/29/2026 M 169,401 (5) (5) Common Stock 169,401 $0.00 0 D
Employee Stock Option (Right to Buy) $6.6 01/29/2026 A 509,850 (6) 01/29/2036 Common Stock 509,850 $0.00 509,850 D
Restricted Stock Units (2) 01/29/2026 A 254,900 (7) (7) Common Stock 254,900 $0.00 254,900 D
Restricted Stock Units (2) 01/31/2026 M 100,400 (8) (8) Common Stock 100,400 $0.00 301,200 D
Explanation of Responses:
1. Each performance stock unit ("PSUs") converts to common stock on a one-for-one basis.
2. Each restricted stock unit ("RSUs") converts to common stock on a one-for-one basis.
3. This sale was made to cover withholding taxes following the vesting of previously granted PSUs pursuant to a durable automatic sale 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.
4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.295 to $6.580, 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.
5. The PSUs were granted on June 11, 2024 and provide for the vesting of 25% of the target number of underlying RSUs granted upon the achievement of each of four independent performance milestones predetermined by the Board ("Performance Milestones"), subject to the grantee's continued service with the Company (the "Approval Conditions"). The Performance Milestones are tied to the achievement of certain business objectives, as certified by the Board on specified evaluation dates, and are non-market and non-financial in nature. The performance criteria specified for the first Performance Milestone was determined to be met on January 29, 2026 (the "2026 Grant Date") resulting in the vesting of the PSUs as to 25% of the underlying shares.
6. This option was granted on the 2026 Grant Date and vests over four years, with 25% of the original number of shares vesting on the first anniversary of the 2026 Grant Date and 2.0833% of the original number of shares monthly thereafter until the fourth such anniversary.
7. The RSUs were granted on the 2026 Grant Date and vest over four years, with 25% of the original number of shares vesting on each anniversary of the 2026 Grant Date until the fourth such anniversary.
8. On January 31, 2025 (the "2025 Grant Date"), the reporting person was granted 401,600 RSUs, with 25% of the original number of shares vesting on each anniversary of the 2025 Grant Date until the fourth such anniversary.
/s/ Kimberly Cornwell as attorney-in-fact for Alexander Cumbo 02/02/2026
** 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 did Solid Biosciences (SLDB) CEO Alexander Cumbo report in this Form 4?

Alexander Cumbo reported vesting of performance and restricted stock units, a new stock option grant, and a related tax sale. PSUs and RSUs converted into common stock, he received 509,850 options, and some shares were sold automatically to satisfy withholding tax obligations.

How many Solid Biosciences shares did CEO Alexander Cumbo sell and at what price?

Alexander Cumbo sold 80,258 shares of Solid Biosciences common stock at a weighted average price of $6.4369 per share. The sale occurred on February 2, 2026, through multiple trades between $6.295 and $6.580, to cover tax withholding from vested performance stock units.

Why did Solid Biosciences CEO Alexander Cumbo sell shares on February 2, 2026?

The sale was executed solely to cover withholding taxes triggered by vesting of previously granted performance stock units. It followed a durable automatic sell-to-cover instruction Cumbo adopted on August 18, 2024 and, according to the disclosure, did not represent a discretionary trade by him.

What new equity awards did Solid Biosciences grant to CEO Alexander Cumbo?

Cumbo received a stock option for 509,850 shares at a $6.60 exercise price and a grant of 254,900 restricted stock units on January 29, 2026. Both awards vest over four years, with 25% vesting after one year and the remainder vesting in periodic installments.

How many Solid Biosciences shares does CEO Alexander Cumbo own after these transactions?

After the reported transactions, Cumbo directly owns 270,931 shares of Solid Biosciences common stock. He also holds 301,200 restricted stock units and 509,850 employee stock options, providing additional potential future equity exposure subject to vesting and exercise conditions described in the filing.

How do the performance stock units and RSUs for SLDB’s CEO vest and convert to shares?

Each performance stock unit and restricted stock unit converts into one share of common stock. PSUs vest upon achieving four board-certified performance milestones, 25% each. RSUs from the 2025 and 2026 grant dates vest in 25% annual installments over four years, contingent on continued service.