Deerfield Special Situations Fund Form 4 RHYTHM PHARMACEUTICALS / James E Flynn ownership change

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

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X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Flynn James E

(Last) (First) (Middle)

780 THIRD AVENUE, 37TH FLOOR

(Street)

NEW YORK NY 10017

(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	X	10% Owner
	Officer (give title below)	X	Other (specify below)
Possible Member of 10% Group

3. Date of Earliest Transaction (Month/Day/Year)
10/10/2017

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	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	10/10/2017		C		291,005	A	(1)	291,005	I	Through Deerfield Private Design Fund III, L.P.(2)(3)
Common Stock	10/10/2017		C		291,005	A	(1)	291,005	I	Through Deerfield Special Situations Fund, L.P.(2)(3)
Common Stock	10/10/2017		P		177,500	A	$17	468,505	I	Through Deerfield Private Design Fund III, L.P.(2)(3)
Common Stock	10/10/2017		P		177,500	A	$17	468,505	I	Through Deerfield Special Situations Fund, L.P.(2)(3)

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
Series A Preferred Stock	(1)	10/10/2017		C			2,668,518	(1)	(1)	Common Stock	291,005	(1)	0	I	Through Deerfield Private Design Fund III, L.P.(2)(3)
Series A Preferred Stock	(1)	10/10/2017		C			2,668,518	(1)	(1)	Common Stock	291,005	(1)	0	I	Through Deerfield Special Situations Fund, L.P.(2)(3)

1. Name and Address of Reporting Person^*

Flynn James E

(Last) (First) (Middle)

780 THIRD AVENUE, 37TH FLOOR

(Street)

NEW YORK NY 10017

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Deerfield Mgmt L.P.

(Last) (First) (Middle)

780 THIRD AVENUE

37TH FLOOR

(Street)

NEW YORK NY 10017

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

DEERFIELD MANAGEMENT CO

(Last) (First) (Middle)

780 THIRD AVENUE, 37TH FLOOR

(Street)

NEW YORK NY 10017

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Deerfield Special Situations Fund, L.P.

(Last) (First) (Middle)

780 3RD AVENUE

37TH FLOOR

(Street)

NEW YORK NY 10017

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Deerfield Mgmt III, L.P.

(Last) (First) (Middle)

780 THIRD AVENUE, 37TH FLOOR

(Street)

NEW YORK NY 10017

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Deerfield Private Design Fund III, L.P.

(Last) (First) (Middle)

780 THIRD AVENUE, 37TH FLOOR

(Street)

NEW YORK NY 10017

(City) (State) (Zip)

Explanation of Responses:

1. 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).

2. 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.

3. 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.

Remarks:

Jonathan Isler, Attorney-in-Fact: Power of Attorney, which is hereby incorporated by reference to Exhibit 24 to a Form 3 with regard to Proteon Therapeutics, Inc. filed with the Securities and Exchange Commission on August 4, 2017 by Deerfield Special Situations Fund, L.P., Deerfield Partners, L.P., Deerfield International Master Fund, L.P., Deerfield Private Design Fund III, L.P., Deerfield Private Design Fund IV, L.P., Deerfield Mgmt, L.P., Deerfield Mgmt III, L.P., Deerfield Mgmt IV, L.P., Deerfield Management Company, L.P., and James E. Flynn.

	/s/ Jonathan Isler, Attorney-in-Fact	10/10/2017
	** Signature of Reporting Person	Date
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