Christopher Paul German - 01 Feb 2026 Form 4 Insider Report for RHYTHM PHARMACEUTICALS, INC. (RYTM)

Role: Corporate Controller & CAO
Signature: /s/ Stephen Vander Stoep, attorney-in-fact for Christopher Paul German
Issuer symbol: RYTM
Transactions as of: 01 Feb 2026
Net transactions value: -$124,031
Form type: 4
Filing time: 03 Feb 2026, 16:32:43 UTC
Previous filing: 14 Aug 2025
Next filing: 13 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
German Christopher Paul	Corporate Controller & CAO	222 BERKELEY STREET, 12TH FLOOR, BOSTON	/s/ Stephen Vander Stoep, attorney-in-fact for Christopher Paul German	03 Feb 2026	0001260835

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	RYTM	Common Stock	Options Exercise		+3,613	+377%		4,571	01 Feb 2026	Direct	F1, F2
transaction	RYTM	Common Stock	Tax liability	$124,031	-1,138	-25%	$108.99	3,433	01 Feb 2026	Direct	F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	RYTM	Restricted Stock Units	Options Exercise	$0	-1,806	-33%	$0.000000	3,612	01 Feb 2026	Common Stock	1,806		Direct	F1, F4
transaction	RYTM	Restricted Stock Units	Options Exercise	$0	-1,807	-25%	$0.000000	5,418	01 Feb 2026	Common Stock	1,807		Direct	F1, F5

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Each restricted stock unit represents a contingent right to receive one share of Issuer common stock.
F2	Includes 36 shares of Common Stock purchased pursuant to the Rhythm Pharmaceuticals, Inc. Employee Stock Purchase Plan.
F3	These shares were withheld for payment of the withholding taxes upon the vesting of the restricted stock units reported herein.
F4	The restricted stock units vest as to 25% of the total shares on each of February 16, 2025, February 1, 2026, February 1, 2027 and February 1, 2028. The restricted stock units have no expiration date.
F5	The restricted stock units vest as to 25% of the total shares on each of February 1, 2026, February 1, 2027, February 1, 2028 and February 1, 2029. The restricted stock units have no expiration date.