OrbiMed Capital GP III Form 4 Sientra / SAMUEL D ISALY 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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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^*

ORBIMED ADVISORS LLC

(Last) (First) (Middle)

601 LEXINGTON AVENUE, 54TH FLOOR

(Street)

NEW YORK NY 10022

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Sientra, Inc. [ SIEN ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
09/24/2015

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, par value $0.01 per share	09/24/2015		S		6	D	$9.78	3,155,254	I	See Footnotes(5)(7)
Common Stock, par value $0.01 per share	09/24/2015		S		148	D	$11(1)	29,900	I	See Footnotes(6)(7)
Common Stock, par value $0.01 per share	09/24/2015		S		8,152	D	$11(1)	3,147,102	I	See Footnotes(5)(7)
Common Stock, par value $0.01 per share	09/25/2015		S		64,400	D	$10.07(2)	3,082,702	I	See Footnotes(5)(7)
Common Stock, par value $0.01 per share	09/25/2015		S		800	D	$10.07(2)	29,100	I	See Footnotes(6)(7)
Common Stock, par value $0.01 per share	09/25/2015		S		66,489	D	$11.07(3)	3,016,213	I	See Footnotes(5)(7)
Common Stock, par value $0.01 per share	09/25/2015		S		311	D	$11.07(3)	28,789	I	See Footnotes(6)(7)
Common Stock, par value $0.01 per share	09/28/2015		S		10,513	D	$10.3(4)	3,005,700	I	See Footnotes(5)(7)
Common Stock, par value $0.01 per share	09/28/2015		S		89	D	$10.3(4)	28,700	I	See Footnotes(6)(7)

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

1. Name and Address of Reporting Person^*

ORBIMED ADVISORS LLC

(Last) (First) (Middle)

601 LEXINGTON AVENUE, 54TH FLOOR

(Street)

NEW YORK NY 10022

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

OrbiMed Capital GP III LLC

(Last) (First) (Middle)

601 LEXINGTON AVENUE, 54TH FLOOR

(Street)

NEW YORK NY 10022

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

ISALY SAMUEL D

(Last) (First) (Middle)

601 LEXINGTON AVENUE, 54TH FLOOR

(Street)

NEW YORK NY 10022

(City) (State) (Zip)

Explanation of Responses:

1. The price reported in Column 4 is a weighted average price. These shares of the Issuer's common stock ("Shares") were sold in multiple transactions at prices ranging from $11.00 to $11.03 inclusive. Upon request, the Reporting Persons undertake to provide the Issuer, any security holder of the Issuer, or the Securities and Exchange Commission (the "SEC") full information regarding the Shares sold at each separate price within the range set forth in this footnote.

2. The price reported in Column 4 is a weighted average price. These Shares were sold in multiple transactions at prices ranging from $10.00 to $10.18 inclusive. Upon request, the Reporting Persons undertake to provide the Issuer, any security holder of the Issuer, or the SEC full information regarding the Shares sold at each separate price within the range set forth in this footnote.

3. The price reported in Column 4 is a weighted average price. These Shares were sold in multiple transactions at prices ranging from $11.00 to $11.24 inclusive. Upon request, the Reporting Persons undertake to provide the Issuer, any security holder of the Issuer, or the SEC full information regarding the Shares sold at each separate price within the range set forth in this footnote.

4. The price reported in Column 4 is a weighted average price. These Shares were sold in multiple transactions at prices ranging from $10.30 to $10.35 inclusive. Upon request, the Reporting Persons undertake to provide the Issuer, any security holder of the Issuer, or the SEC full information regarding the Shares sold at each separate price within the range set forth in this footnote.

5. These shares are held of record by OrbiMed Private Investments III, LP ("OPI III"). OrbiMed Capital GP III LLC ("GP III") is the general partner of OPI III, and OrbiMed Advisors LLC ("Advisors") is the managing member of GP III. Samuel D. Isaly ("Isaly"), a natural person, is the managing member of and owner of a controlling interest in Advisors. By virtue of such relationships, GP III, Advisors and Isaly may be deemed to have voting and investment power over the securities held by OPI III and as a result may be deemed to have beneficial ownership over such securities.

6. These shares are held of record by OrbiMed Associates III, LP ("Associates III"). Advisors is the general partner of Associates III. Isaly is the managing member of and owner of a controlling interest in Advisors. By virtue of such relationships, Advisors and Isaly may be deemed to have voting and investment power over the securities held by Associates III and as a result may be deemed to have beneficial ownership over such securities.

7. This report on Form 4 is jointly filed by GP III, Advisors, and Isaly. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its or his pecuniary interest therein, if any. This report shall not be deemed an admission that any of the Reporting Persons is a beneficial owner for the purpose of Section 16 of the Exchange Act, or for any other purpose.

	/s/Samuel D. Isaly	09/28/2015
	** Signature of Reporting Person	Date
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