CSO of Pharmaceuticals, Inc. (RYTM) reports RSU vesting and tax share withholding

Rhea-AI Filing Summary

Pharmaceuticals, Inc.’s Chief Scientific Officer Alastair Garfield reported a routine equity compensation event. On February 1, 2026, 6,663 restricted stock units (RSUs) were converted into 6,663 shares of common stock at an exercise price of $0. Of these, 2,026 shares were withheld at $108.99 per share to cover tax withholding, leaving Garfield with 7,763 shares of common stock directly owned. He also directly holds 19,987 RSUs, which vest in four equal 25% installments on February 1 of 2026, 2027, 2028, and 2029, with no expiration date.

Insider Trade Summary

6,663 shares exercised/converted

Mixed 3 txns

Insider Garfield Alastair

Role Chief Scientific Officer

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Units	6,663	$0.00	--
Exercise	Common Stock	6,663	$0.00	--
Tax Withholding	Common Stock	2,026	$108.99	$221K

Holdings After Transaction: Restricted Stock Units — 19,987 shares (Direct); Common Stock — 9,789 shares (Direct)

Footnotes (1)

1. Each restricted stock unit represents a contingent right to receive one share of Issuer common stock. These shares were withheld for payment of the withholding taxes upon the vesting of the restricted stock units reported herein. 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.

Form 4 Insider Transactions: What Each Field Means →

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^*

Garfield Alastair

(Last) (First) (Middle)

222 BERKELEY STREET, 12TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
RHYTHM PHARMACEUTICALS, INC. [ RYTM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Scientific Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/01/2026

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	02/01/2026		M		6,663	A	(1)	9,789	D
Common Stock	02/01/2026		F(2)		2,026	D	$108.99	7,763	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)	02/01/2026		M			6,663	(3)	(3)	Common Stock	6,663	$0	19,987	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of Issuer common stock.

2. These shares were withheld for payment of the withholding taxes upon the vesting of the restricted stock units reported herein.

3. 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.

	/s/ Stephen Vander Stoep, attorney-in-fact for Alastair Garfield	02/03/2026
	** 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 transaction did RYTM Chief Scientific Officer Alastair Garfield report?

Alastair Garfield reported the vesting of 6,663 restricted stock units into common stock on February 1, 2026. The filing shows equity compensation being settled in shares with a portion withheld to cover tax obligations tied to the vesting.

How many Rhythm Pharmaceuticals (RYTM) shares did the CSO acquire and retain?

Garfield acquired 6,663 shares of common stock upon RSU vesting and had 2,026 shares withheld for taxes. After these transactions, he directly owned 7,763 shares of common stock, as disclosed in the beneficial ownership column of the Form 4.

What was the tax withholding transaction for RYTM shares on February 1, 2026?

The filing shows 2,026 shares of common stock disposed of at $108.99 per share with code F. Footnotes explain these shares were withheld by the issuer to pay withholding taxes related to the RSU vesting reported in the same Form 4.

How many restricted stock units does the RYTM CSO still hold after this Form 4?

After the reported transactions, Garfield beneficially owned 19,987 restricted stock units. Each RSU represents a contingent right to receive one share of common stock, according to the footnotes describing the equity award structure.

What is the vesting schedule of the CSO’s RYTM restricted stock units?

The restricted stock units vest in four equal installments of 25% of the total shares. Vesting dates are February 1, 2026, 2027, 2028, and 2029, and the RSUs have no expiration date, as specified in the explanatory footnote.

Were the RYTM insider transactions direct or indirect holdings?

All reported holdings and transactions are listed as directly owned by Alastair Garfield. The Form 4 shows ownership form as D for both common stock and restricted stock units, with no separate entity or indirect ownership structure disclosed.