Solid Biosciences (SLDB) CEO earns 169,401 RSUs tied to PSUs

Q: What did Solid Biosciences (SLDB) CEO Alexander Cumbo receive in this Form 4?

Alexander Cumbo received a grant of 169,401 restricted stock units (RSUs) , each representing one share of Solid Biosciences common stock. This award reflects a performance-based equity grant rather than an open-market stock purchase or sale.

Q: How are Alexander Cumbo’s RSUs from Solid Biosciences (SLDB) structured?

The RSUs stem from performance stock units granted on June 11, 2024 . The award is divided into four independent 25% tranches, each tied to specific performance milestones set by the Board and based on non-market, non-financial business objectives.

Q: Which performance milestone did Solid Biosciences (SLDB) recently certify for the CEO’s award?

The Board determined that the second Performance Milestone was achieved on January 29, 2026 . This certification triggers vesting eligibility for 25% of the target RSUs, subject to Alexander Cumbo’s continued service through a future Evaluation Date.

Q: Are the Solid Biosciences (SLDB) CEO’s performance criteria based on stock price or financial targets?

The filing states that Performance Milestones are non-market and non-financial in nature. They are tied to achieving specific business objectives certified by the Board on specified evaluation dates, rather than stock price or traditional financial metrics.

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

Solid Biosciences Inc. reported that President and CEO Alexander Cumbo acquired 169,401 restricted stock units (RSUs), each representing one share of common stock. These RSUs relate to performance stock units granted on June 11, 2024, which vest in four 25% performance tranches.

The Board determined that the performance criteria for the second Performance Milestone were met on January 29, 2026. Shares tied to this milestone will vest only if Cumbo continues serving with the company through the Evaluation Date, which is anticipated in the first quarter of 2027.

Insider Trade Summary 10b5-1

1 transaction reported

Mixed 1 txn

Insider Cumbo Alexander

Role President and CEO

Type	Security	Shares	Price	Value
Grant/Award	Restricted Stock Units	169,401	$0.00	--

Holdings After Transaction: Restricted Stock Units — 169,401 shares (Direct, null)

Footnotes (1)

Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock (the "RSUs"). Performance stock units ("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"). 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 second Performance Milestone was determined by the Board to be met on January 29, 2026, and the shares related to such Performance Milestone will vest subject to the grantee's continued service with the Company on the Evaluation Date, which is anticipated to occur in the first quarter of 2027.

Key Figures

RSUs granted: 169,401 units Underlying common shares: 169,401 shares Performance tranches: 4 tranches at 25% each +2 more

5 metrics

RSUs granted 169,401 units Restricted stock units acquired by CEO on January 29, 2026

Underlying common shares 169,401 shares Each RSU represents one share of common stock

Performance tranches 4 tranches at 25% each PSUs vest in four independent 25% performance milestones

Second milestone date January 29, 2026 Board determined second Performance Milestone was met on this date

Anticipated vesting evaluation Q1 2027 Evaluation Date for vesting requires continued service through this period

Key Terms

Restricted Stock Units, Performance stock units, Performance Milestones, non-market and non-financial

4 terms

Restricted Stock Units financial

"Each restricted stock unit represents a contingent right to receive one share"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

Performance stock units financial

"Performance stock units ("PSUs") were granted on June 11, 2024"

Performance stock units are a type of company award that grants employees shares of stock only if certain performance goals are met. They motivate employees to work toward specific company achievements, aligning their interests with those of shareholders. For investors, they can influence a company's future stock supply and reflect management’s confidence in reaching key targets.

Performance Milestones financial

"four independent performance milestones predetermined by the Board ("Performance Milestones")"

non-market and non-financial financial

"The Performance Milestones are tied to the achievement of certain business objectives ... and are non-market and non-financial in nature"

Form 4 Insider Transactions: What Each Field Means →

04/21/2026 - 04:05 PM

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^*

Cumbo Alexander

(Last)

(First)

(Middle)

C/O SOLID BIOSCIENCES INC.

500 RUTHERFORD AVENUE, THIRD FLOOR

(Street)

CHARLESTOWN

MASSACHUSETTS

02129

(City)

(State)

(Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
01/29/2026

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

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

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

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)

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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Restricted Stock Units	⁽¹⁾	01/29/2026		A		169,401		⁽²⁾	⁽²⁾	Common Stock	169,401	$0.00	169,401	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. Performance stock units ("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"). 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 second Performance Milestone was determined by the Board to be met on January 29, 2026, and the shares related to such Performance Milestone will vest subject to the grantee's continued service with the Company on the Evaluation Date, which is anticipated to occur in the first quarter of 2027.

	/s/ Kimberly Cornwell as attorney-in-fact for Alexander Cumbo	04/21/2026
	** 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.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR

FAQ

What did Solid Biosciences (SLDB) CEO Alexander Cumbo receive in this Form 4?

Alexander Cumbo received a grant of 169,401 restricted stock units (RSUs), each representing one share of Solid Biosciences common stock. This award reflects a performance-based equity grant rather than an open-market stock purchase or sale.

How are Alexander Cumbo’s RSUs from Solid Biosciences (SLDB) structured?

The RSUs stem from performance stock units granted on June 11, 2024. The award is divided into four independent 25% tranches, each tied to specific performance milestones set by the Board and based on non-market, non-financial business objectives.

Which performance milestone did Solid Biosciences (SLDB) recently certify for the CEO’s award?

The Board determined that the second Performance Milestone was achieved on January 29, 2026. This certification triggers vesting eligibility for 25% of the target RSUs, subject to Alexander Cumbo’s continued service through a future Evaluation Date.

When will Alexander Cumbo’s newly earned RSUs in Solid Biosciences (SLDB) actually vest?

Shares related to the second Performance Milestone will vest only if Alexander Cumbo remains in service on the Evaluation Date, anticipated in the first quarter of 2027. Until then, the RSUs represent a contingent right to receive common shares.

Are the Solid Biosciences (SLDB) CEO’s performance criteria based on stock price or financial targets?

The filing states that Performance Milestones are non-market and non-financial in nature. They are tied to achieving specific business objectives certified by the Board on specified evaluation dates, rather than stock price or traditional financial metrics.