X0306 4 2019-11-20 0 0001649904 RHYTHM PHARMACEUTICALS, INC. RYTM 0001473930 Foley Todd C/O MPM ASSET MANAGEMENT 450 KENDALL STREET CAMBRIDGE MA 02142 1 0 0 0 Common Stock 2019-11-20 4 S 0 141365 22.02 D 2933528 I See Footnote Common Stock 2019-11-21 4 S 0 59466 20.50 D 2874062 I See Footnote Common Stock 2019-11-21 4 S 0 5457 21.09 D 2868605 I See Footnote The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person. The shares were sold as follows: 136,079 by MPM BioVentures V, L.P. ("BV V") and 5,286 by MPM Asset Management Investors BV5 LLC ("AM BV5"). MPM BioVentures V GP LLC and MPM BioVentures V LLC ("BV LLC") are the direct and indirect general partners of BV V and BV LLC is the manager of AM BV5. Ansbert Gadicke, Luke Evnin and Todd Foley are the members of BV LLC. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein. The price in Column 4 is a weighted average sale price. The prices actually received ranged from $21.59 to $22.58. The Reporting Person will provide to the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Shares are held as follows: 2,823,827 by BV V and 109,701 by AM BV5. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein. Shares were sold as follows: 57,242 by BV V and 2,224 by AM BV5. The price in Column 4 is a weighted average sale price. The prices actually received ranged from $20.00 to $20.99. The Reporting Person will provide to the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Shares are held as follows: 2,766,585 by BV V and 107,477 by AM BV5. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein. Shares were sold as follows: 5,253 by BV V and 204 by AM BV5. The price in Column 4 is a weighted average sale price. The prices actually received ranged from $21.00 to $21.28. The Reporting Person will provide to the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Shares are held as follows: 2,761,332 by BV V and 107,273 by AM BV5. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein. /s/ Todd Foley 2019-11-22