X0508 4 2024-03-19 0 0001649904 RHYTHM PHARMACEUTICALS, INC. RYTM 0001873517 Cramer Pamela J. 222 BERKELEY STREET, 12TH FLOOR BOSTON MA 02116 0 1 0 0 Chief Human Resources Officer 0 Common Stock 2024-03-19 4 S 0 15515 39.22 D 30005 D The sale reported in this Form 4 was effected pursuant to Rule 10b5-1 instruction adopted prior to February 27, 2023 solely with the intent to cover withholding taxes in connection with the vesting of certain previously reported restricted stock units. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at per share prices ranging from $39.07 to $39.25. 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 this footnote. /s/ Hunter Smith, Attorney-in-Fact for Pamela J. Cramer 2024-03-19