Edgar Filing: ARATANA THERAPEUTICS, INC.

Ownership Submission

FORM 4

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

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person ^*

MPM BIOVENTURES V, L.P.

2. Issuer Name and Ticker or Trading Symbol
ARATANA THERAPEUTICS, INC. [PETX]

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

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

(Last)

(First)

(Middle)

C/O MPM ASSET MANAGEMENT, 200 CLARENDON STREET, 54TH FLOOR

3. Date of Earliest Transaction (Month/Day/Year)
03/03/2014

(Street)

BOSTON, MA 02116

4. If Amendment, Date 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

(City)

(State)

(Zip)

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)
1.Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	03/03/2014		J⁽¹⁾		1,000,000 ⁽²⁾	D	$ 0	3,351,048	I	See Footnote ⁽³⁾
Common Stock	03/03/2014		J⁽¹⁾		20,876	A	$ 0	26,713	I	By Ansbert Gadicke
Common Stock	03/03/2014		J⁽¹⁾		20,876	A	$ 0	38,386	I	By Luke Evnin
Common Stock	03/03/2014		J⁽¹⁾		20,876	A	$ 0	22,767	I	By James Paul Scopa
Common Stock	03/03/2014		J⁽¹⁾		15,310	A	$ 0	17,937	I	By Vaughn Kailian ⁽⁴⁾
Common Stock	03/03/2014		J⁽¹⁾		12,247	A	$ 0	12,393	I	By The Todd Foley Trust
Common Stock	03/03/2014		J⁽¹⁾		37,117	A	$ 0	37,117	I	By MPM Capital LLC ⁽⁵⁾

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
	Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.		SEC 1474 (9-02)

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 Underlying Securities
(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 of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)

11. Nature of Indirect Beneficial Ownership
(Instr. 4)

Code

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
MPM BIOVENTURES V, L.P. C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
Scopa James Paul C/O MPM ASSET MANAGEMENT 601 GATEWAY BOULEVARD, SUITE 350 SOUTH SAN FRANCISCO, CA 94080		X
EVNIN LUKE C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
Foley Todd C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
GADICKE ANSBERT C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
KAILIAN VAUGHN M C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM ASSET MANAGEMENT INVESTORS BV5 LLC C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM BIOVENTURES V GP LLC C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X
MPM BIOVENTURES V LLC C/O MPM ASSET MANAGEMENT 200 CLARENDON STREET, 54TH FLOOR BOSTON, MA 02116		X

Signatures

By Ansbert Gadicke, member of MPM BioVentures V LLC, the managing member of MPM BioVentures V GP LLC, the general partner of MPM BioVentures V, L.P. /s/ Ansbert Gadicke		03/05/2014
^**Signature of Reporting Person		Date
/s/ James Paul Scopa		03/05/2014
^**Signature of Reporting Person		Date
/s/ Luke Evnin		03/05/2014
^**Signature of Reporting Person		Date
/s/ Todd Foley		03/05/2014
^**Signature of Reporting Person		Date
/s/ Ansbert Gadicke		03/05/2014
^**Signature of Reporting Person		Date
/s/ Vaughn Kailian		03/05/2014
^**Signature of Reporting Person		Date
By Ansbert Gadicke, member of MPM BioVentures V LLC, the manager of MPM Asset Management Investors BV5 LLC /s/ Ansbert Gadicke		03/05/2014
^**Signature of Reporting Person		Date
By Ansbert Gadicke, member of MPM BioVentures V LLC, the managing member of MPM BioVentures V GP LLC /s/ Ansbert Gadicke		03/05/2014
^**Signature of Reporting Person		Date
By Ansbert Gadicke, member of MPM BioVentures V LLC /s/ Ansbert Gadicke		03/05/2014
^**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Pro-rata distribution of partnership interests.
(2)	The shares were distributed as follows: 962,533 by MPM BioVentures V, L.P. ("BV V") and 37,467 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, Vaughn M. Kailian, James Paul Scopa and Todd Foley are the members of BV LLC. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.
(3)	The shares are held as follows: 3,225,494 by BV V and 125,554 by AM BV5. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.
(4)	Includes 2,627 shares held by The Vaughn and Patricia Kailian Revocable Trust u/a/dtd 12/18/1992, of which the Reporting Person is trustee.
(5)	MPM Founders LLC ("MPM Founders") is the managing member of MPM Capital LLC, and Messrs. Evnin and Gadicke are members of MPM Founders. Messrs. Evnin and Gadicke disclaim beneficial ownership of the shares held by MPM Capital LLC except to the extent of their respective pecuniary interests therein.

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