RHYTHM PHARMACEUTICALS, INC. — Director's Dealing 2017

Oct 10, 2017

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: RHYTHM PHARMACEUTICALS, INC. (RYTM)
CIK: 0001649904
Period of Report: 2017-10-10

Reporting Person: Flynn James E (10% Owner, Possible Member of 10% Group)
Reporting Person: Deerfield Mgmt L.P. (10% Owner, Possible Member of 10% Group)
Reporting Person: DEERFIELD MANAGEMENT CO (10% Owner, Possible Member of 10% Group)
Reporting Person: Deerfield Special Situations Fund, L.P. (10% Owner, Possible Member of 10% Group)
Reporting Person: Deerfield Mgmt III, L.P. (10% Owner, Possible Member of 10% Group)
Reporting Person: Deerfield Private Design Fund III, L.P. (10% Owner, Possible Member of 10% Group)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2017-10-10	Common Stock	C	291005	—	Acquired	291005	Indirect
2017-10-10	Common Stock	C	291005	—	Acquired	291005	Indirect
2017-10-10	Common Stock	P	177500	$17.00	Acquired	468505	Indirect
2017-10-10	Common Stock	P	177500	$17.00	Acquired	468505	Indirect

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2017-10-10	Series A Preferred Stock	$	C	2668518	Disposed		Common Stock (291005)	Indirect
2017-10-10	Series A Preferred Stock	$	C	2668518	Disposed		Common Stock (291005)	Indirect

Footnotes

F1: Each share of Series A Preferred Stock automatically converted into 0.1090513 shares of the Issuer's common stock upon the closing of the Issuer's initial public offering (on an adjusted basis, after giving effect to the 1-for-9.17 reverse stock split effected by the Issuer in connection with its initial public offering).

F2: This Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt, L.P. is the general partner of Deerfield Special Situations Fund, L.P. (collectively with Fund III, the "Funds"). Deerfield Management Company, L.P. is the investment manager of the Funds. James E. Flynn is the sole member of the general partner of each of Deerfield Mgmt III, L.P., Deerfield Mgmt, L.P. and Deerfield Management Company, L.P.

F3: In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.