Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 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 that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Klein Matthew B. 2. Issuer Name and Ticker or Trading Symbol PTC THERAPEUTICS, INC. [PTCT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CHIEF EXECUTIVE OFFICER (Last) (First) (Middle) C/O PTC THERAPEUTICS, INC., 500 WARREN CORPORATE CENTER DRIVE 3. Date of Earliest Transaction (Month/Day/Year) 03/11/2026 (Street) WARREN, NJ 07059 4. If Amendment, Date 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 (City) (State) (Zip) 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 03/11/2026 A 12,500(1) A $ 0 399,582 D Common Stock 03/12/2026 S(2) 2,662 D $64.08 396,920 D

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 Underlying Securities (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 of Derivative Security: 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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Klein Matthew B. C/O PTC THERAPEUTICS, INC. 500 WARREN CORPORATE CENTER DRIVE WARREN, NJ 07059	X		CHIEF EXECUTIVE OFFICER

Signatures

/s/ Avraham S. Adler, Attorney-in-Fact		03/13/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Represents the number of shares of the Issuer's common stock underlying restricted stock units ("RSUs") earned upon the vesting of performance-based restricted stock units ("PSUs") granted in December 2024. The Issuer's compensation committee of the board of directors certified the Issuer's achievement of a pre-established milestone set forth in the PSUs, as of March 11, 2026, which resulted in the reported RSUs being earned. Each earned RSU represents the contingent right to receive one share of the Issuer's common stock upon vesting. The earned RSUs immediately vested as to 6,500 shares on March 11, 2026 in connection with being earned and are scheduled to vest with respect to the remaining 6,500 shares on March 11, 2027.
(2)	Represents shares automatically sold pursuant to an irrevocable sell to cover election entered into upon acceptance of the RSU grant to satisfy tax withholding obligations in connection with the vesting of the earned RSUs with respect to 6,500 shares on March 11, 2026.

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