SC 13D/A

0001193125-15-258672.txt : 20150722 0001193125-15-258672.hdr.sgml : 20150722 20150721180940 ACCESSION NUMBER: 0001193125-15-258672 CONFORMED SUBMISSION TYPE: SC 13D/A PUBLIC DOCUMENT COUNT: 2 FILED AS OF DATE: 20150722 DATE AS OF CHANGE: 20150721 GROUP MEMBERS: ANSBERT GADICKE GROUP MEMBERS: JAMES PAUL SCOPA GROUP MEMBERS: LUKE EVNIN GROUP MEMBERS: MEDICAL PORTFOLIO MANAGEMENT LLC GROUP MEMBERS: MPM ASSET MANAGEMENT INVESTORS BV5 LLC GROUP MEMBERS: MPM BIOVENTURES V GP LLC GROUP MEMBERS: MPM BIOVENTURES V LLC GROUP MEMBERS: MPM CAPITAL LLC GROUP MEMBERS: TODD FOLEY GROUP MEMBERS: VAUGHN M. KAILIAN SUBJECT COMPANY: COMPANY DATA: COMPANY CONFORMED NAME: ARATANA THERAPEUTICS, INC. CENTRAL INDEX KEY: 0001509190 STANDARD INDUSTRIAL CLASSIFICATION: PHARMACEUTICAL PREPARATIONS [2834] IRS NUMBER: 383826477 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: SC 13D/A SEC ACT: 1934 Act SEC FILE NUMBER: 005-87524 FILM NUMBER: 15998656 BUSINESS ADDRESS: STREET 1: 1901 OLATHE BOULEVARD CITY: KANSAS CITY STATE: KS ZIP: 66103 BUSINESS PHONE: 913.951.2130 MAIL ADDRESS: STREET 1: 1901 OLATHE BOULEVARD CITY: KANSAS CITY STATE: KS ZIP: 66103 FILED BY: COMPANY DATA: COMPANY CONFORMED NAME: MPM BIOVENTURES V, L.P. CENTRAL INDEX KEY: 0001482716 IRS NUMBER: 270793842 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: SC 13D/A BUSINESS ADDRESS: STREET 1: MPM ASSET MANAGEMENT STREET 2: 200 CLARENDON STREET, 54TH FLOOR CITY: BOSTON STATE: MA ZIP: 02116 BUSINESS PHONE: (617) 425-9200 MAIL ADDRESS: STREET 1: MPM ASSET MANAGEMENT STREET 2: 200 CLARENDON STREET, 54TH FLOOR CITY: BOSTON STATE: MA ZIP: 02116 SC 13D/A 1 d80965dsc13da.htm SC 13D/A SC 13D/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13D

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 3)*

Aratana Therapeutics, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

03874P 10 1

(CUSIP Number)

Ansbert Gadicke

MPM Asset Management

The John Hancock Tower

200 Clarendon Street, 54^th Floor

Boston, MA 02116

Telephone: (617) 425-9200

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

July 15, 2015

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

*	The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Page 1


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. MPM BioVentures V, L.P.
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 1,057,125
		8.	Shared Voting Power 0
		9.	Sole Dispositive Power 1,057,125
		10.	Shared Dispositive Power 0
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,057,125
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 3.0%(2)
14.	Type of Reporting Person (See Instructions) PN

(1)

This Amendment No. 3 to the statement on Schedule 13D is filed by MPM BioVentures V, L.P. (“BV V”), MPM Asset Management Investors BV5 LLC (“AM LLC”), MPM BioVentures V GP LLC (“BV V GP”), MPM BioVentures V LLC (“BV V LLC”), MPM Capital LLC (“MPM Capital”), Medical Portfolio Management LLC (“Med Portfolio”) (collectively, the “MPM Entities”) and Ansbert Gadicke, Luke Evnin, Todd Foley, James Paul Scopa and Vaughn Kailian (collectively, the “Listed Persons” and together with the MPM Entities, the “Filing Persons”). The Listed Persons are members of BV V LLC and AM LLC. Ansbert Gadicke and Luke Evnin are members of Med Portfolio. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)

This percentage is calculated based upon 34,909,737 shares of Aratana Therapeutics, Inc.’s (the “Issuer”) common stock, par value $0.001 per share (the “Common Stock”) outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission (the “Commission”) on May 8, 2015.

Page 2


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. MPM Asset Management Investors BV5 LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 41,156
		8.	Shared Voting Power 0
		9.	Sole Dispositive Power 41,156
		10.	Shared Dispositive Power 0
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 41,156
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 0.1%(2)
14.	Type of Reporting Person (See Instructions) OO

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 3


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. MPM BioVentures V GP LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,057,125(2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,057,125(2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,057,125(2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 3.0%(3)
14.	Type of Reporting Person (See Instructions) OO

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)	Represents shares of Common Stock held by BV V. BV V GP and BV V LLC are the direct and indirect general partners of BV V.

(3)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 4


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. MPM BioVentures V LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,098,281(2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,098,281(2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,098,281(2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 3.2%(3)
14.	Type of Reporting Person (See Instructions) OO

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)	Includes 1,057,125 shares of Common Stock held by BV V and 41,156 shares of Common Stock held by AM LLC. BV V GP and BV V LLC are the direct and indirect general partners of BV V and BV V LLC is the manager of AM LLC.

(3)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 5


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. MPM Capital LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 19,594
		8.	Shared Voting Power 0
		9.	Sole Dispositive Power 19,594
		10.	Shared Dispositive Power 0
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 19,594
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 0.1%(2)
14.	Type of Reporting Person (See Instructions) OO

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 6


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. Medical Portfolio Management LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 0
		8.	Shared Voting Power 19,594(2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 19,594(2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 19,594(2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 0.1%(3)
14.	Type of Reporting Person (See Instructions) OO

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)	Shares held by MPM Capital, of which the Reporting Person is the managing member.

(3)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 7


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. Ansbert Gadicke
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) OO
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,117,875(2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,117,875(2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,117,875(2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 3.2%(3)
14.	Type of Reporting Person (See Instructions) IN

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)

Includes 1,057,125 shares of Common Stock held by BV V, 41,156 shares of Common Stock held by AM LLC and 19,594 shares of Common Stock held by MPM Capital. BV V GP and BV V LLC are the direct and indirect general partners of BV V and BV V LLC is the manager of AM LLC. Med Portfolio is the managing member of MPM Capital. The Reporting Person is a member of BV V LLC and Med Portfolio.

(3)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 8


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. Luke Evnin
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) OO
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 38,386
		8.	Shared Voting Power 1,117,875(2)
		9.	Sole Dispositive Power 38,386
		10.	Shared Dispositive Power 1,117,875(2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,156,261(2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 3.3%(3)
14.	Type of Reporting Person (See Instructions) IN

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)

(3)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 9


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. Todd Foley
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) OO
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,098,281(2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,098,281(2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,098,281(2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 3.1%(3)
14.	Type of Reporting Person (See Instructions) IN

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)	Includes 1,057,125 shares of Common Stock held by BV V and 41,156 shares of Common Stock held by AM LLC. BV V GP and BV V LLC are the direct and indirect general partners of BV V and BV V LLC is the manager of AM LLC. The Reporting Person is a member of BV V LLC.

(3)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 10


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. James Paul Scopa
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) OO
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 7,767
		8.	Shared Voting Power 1,098,261(2)
		9.	Sole Dispositive Power 7,767
		10.	Shared Dispositive Power 1,098,261(2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,106,048(2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 3.2%(3)
14.	Type of Reporting Person (See Instructions) IN

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)	Includes 1,057,125 shares of Common Stock held by BV V and 41,156 shares of Common Stock held by AM LLC. BV V GP and BV V LLC are the direct and indirect general partners of BV V and BV V LLC is the manager of AM LLC. The Reporting Person is a member of BV V LLC.

(3)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 11


CUSIP No. 03874P 10 1


1.	Name of Reporting Persons. Vaughn M. Kailian
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a) ¨ (b) x (1)
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) OO
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)
6.	Citizenship or Place of Organization United States
Number of Shares Beneficially Owned by Each Reporting Person With:		7.	Sole Voting Power 0
		8.	Shared Voting Power 1,098,281(2)
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 1,098,281(2)
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,098,281(2)
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
13.	Percent of Class Represented by Amount in Row (11) 3.1%(4)
14.	Type of Reporting Person (See Instructions) IN

(1)	This Amendment No. 3 to the statement on Schedule 13D is filed by the MPM Entities and the Listed Persons. The MPM Entities and the Listed Persons expressly disclaim status as a “group” for purposes of this Schedule 13D.

(2)	Includes 1,057,144 shares of Common Stock held by BV V and 3,368 shares of Common Stock held by AM LLC. BV V GP and BV V LLC are the direct and indirect general partners of BV V and BV V LLC is the manager of AM LLC. The Reporting Person is a member of BV V LLC.

(3)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

Page 12

Explanatory Note:

This Amendment No. 3 (the “Amendment”) to the statement on Schedule 13D is being filed by the Filing Persons (as defined below) and amends the Schedule 13D filed with the Commission on August 7, 2013 as amended by Amendment No.1 filed March 13, 2014 and Amendment No. 2 filed April 20, 2014 (as amended, the “Original Schedule 13D”), and relates to shares of Common Stock, $0.001 par value per share (“Common Stock”), of Aratana Therapeutics, Inc., a Delaware corporation (the “Issuer”). This Amendment is being filed by the Filing Persons to report the open market sales of shares of the Issuer’s Common Stock by certain Filing Persons.

Items 4, 5 and 7 of the Original Schedule 13D are hereby amended and supplemented to the extent hereinafter expressly set forth and, except as amended and supplemented hereby, the Original Schedule 13D remains in full force and effect. All capitalized terms used in this Amendment but not defined herein shall have the meanings ascribed thereto in the Original Schedule 13D.

Item 4. Purpose of Transaction

Item 4 of the Original Schedule 13D is hereby amended and supplemented by adding the following paragraph at the end of Item 4:

The MPM Entities sold an aggregate of 1,000,970 shares of the Issuer’s Common Stock in open market transactions from July 2, 2015 through July 15, 2015 for aggregate proceeds of $16,193,095.

Item 5. Interest in Securities of the Issuer

Item 5 of the Original Schedule 13D is hereby amended and restated in its entirety as follows:

(a) – (b) The following information with respect to the ownership of the Common Stock of the Issuer by the Filing Persons is provided as of July 15, 2015:


Reporting Person	Shares Held Directly		Sole Voting Power		Shared Voting Power		Sole Dispositive Power		Shared Dispositive Power		Beneficial Ownership		Percentage of Class (1)
BV V		1,057,125		1,057,125		0		1,057,125		0		1,057,125		3.0	%
AM LLC		41,156		41,156		0		41,156		0		41,156		0.1	%
MPM Capital		19,594		19,594		0		19,594		0		19,594		0.1	%
BV V GP(2)		0		0		1,057,125		0		1,057,125		1,057,125		3.2	%
BV V LLC(3)		0		0		1,098,281		0		1,098,281		1,098,281		3.0	%
Med Portfolio(4)		0		0		41,156		0		41,156		41,156		0.1	%
Ansbert Gadicke(5)		0		0		1,117,875		0		1,117,875		1,117,875		3.2	%
Luke Evnin(5)		38,386		38,386		1,117,875		38,386		1,117,875		1,156,261		3.3	%
Todd Foley(6)		0		0		1,098,281		0		1,098,281		1,098,281		3.1	%
James Paul Scopa(6)		7,767		7,767		1,098,281		7,767		1,098,281		1,106,048		3.2	%
Vaughn Kailian(6)		0		0		1,098,281		0		1,098,281		1,098,281		3.1	%

(1)	This percentage is calculated based upon 34,909,737 shares of the Issuer’s common stock outstanding on May 4, 2015, as disclosed in the Issuer’s Quarterly Report on Form 10-Q, filed with the Commission on May 8, 2015.

(2)	Includes securities held by BV V. BV V GP and BV V LLC are the direct and indirect general partners of BV V.

(3)	Includes securities held by BV V and AM LLC. BV V GP and BV V LLC are the direct and indirect general partners of BV V and BV V LLC is the manager of AM LLC.

(4)	Securities held by MPM Capital, of which the Reporting Person is the managing member.

(5)	Includes securities held by BV V, AM LLC and MPM Capital. Med Portfolio is the managing member of MPM Capital. The Reporting Person is a member of BV V LLC and Med Portfolio.

(6)	Includes securities held by BV V and AM LLC. The Reporting Person is a member of BV V LLC.

Page 13

(c) The Reporting Persons sold the following shares of Common Stock in the open market in the sixty days preceding the date of this filing:


Date of Sale	Sold by BV V		Sold By AM LLC		Sold By MPM Capital		Price Per Share
7/2/2015		94,567		3,681		1,752	$	14.09
7/6/2015		189,134		7,362		3,504	$	14.15
7/14/2015		917		36		17	$	17.99
7/15/2015		661,990		25,760		12,250	$	17.05

The information provided and incorporated by reference in Item 3 and Item 6 is hereby incorporated by reference in this Item 5.

(d) Not applicable.

(e) On July 15, 2015, the Reporting Persons ceased to be beneficial owners of more than 5% of the issued and outstanding Common Stock of the Company. The reporting obligations of the Reporting Persons with respect to the Common Stock pursuant to Section 13(d) of the Exchange Act and the rules and regulations promulgated thereunder are therefore terminated.

Item 7. Material to Be Filed as Exhibits

A. Agreement regarding filing of joint Schedule 13D.

Page 14

Signatures

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: July 21, 2015


MPM BIOVENTURES V GP LLC

By: MPM BioVentures V LLC,
		its Managing Member

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

MPM BIOVENTURES V LLC

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

MPM BIOVENTURES V, L.P.

By:		MPM BioVentures V GP LLC, its General Partner

By:		MPM BioVentures V LLC, its Managing Member

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

MPM ASSET MANAGEMENT INVESTORS BV5 LLC

By:		MPM BioVentures V LLC
		Its: Manager

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

MPM CAPITAL LLC

By: Medical Portfolio Management LLC,
		its Managing Member

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

Page 15


MEDICAL PORTFOLIO MANAGEMENT LLC

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke

By:		/s/ Luke Evnin
Name:		Luke Evnin

By:		/s/ Todd Foley
Name:		Todd Foley

By:		/s/ James Paul Scopa
Name:		James Paul Scopa

By:		/s/ Vaughn M. Kailian
Name:		Vaughn M. Kailian

Page 16

Schedule I

General Partners/Members

Ansbert Gadicke

c/o MPM Asset Management

The John Hancock Tower

200 Clarendon Street, 54^th Floor

Boston, MA 02116

Principal Occupation: Member of the managing member of the general partner of MPM BioVentures V, L.P. and member of the manager of MPM Asset Management Investors BV5 LLC.

Citizenship: USA

Luke Evnin

c/o MPM Asset Management

The John Hancock Tower

200 Clarendon Street, 54^th Floor

Boston, MA 02116

Principal Occupation: Member of the managing member of the general partner of MPM BioVentures V, L.P. and member of the manager of MPM Asset Management Investors BV5 LLC.

Citizenship: USA

Todd Foley

c/o MPM Asset Management

The John Hancock Tower

200 Clarendon Street, 54^th Floor

Boston, MA 02116

Principal Occupation: Member of the managing member of the general partner of MPM BioVentures V, L.P. and member of the manager of MPM Asset Management Investors BV5 LLC.

Citizenship: USA

James Paul Scopa

c/o MPM Asset Management

601 Gateway Blvd. Suite 350

S. San Francisco, CA 94080

Principal Occupation: Member of the managing member of the general partner of MPM BioVentures V, L.P. and member of the manager of MPM Asset Management Investors BV5 LLC.

Citizenship: USA

Vaughn M. Kailian

c/o MPM Asset Management

The John Hancock Tower

200 Clarendon Street, 54^th Floor

Boston, MA 02116

Principal Occupation: Member of the managing member of the general partner of MPM BioVentures V, L.P. and member of the manager of MPM Asset Management Investors BV5 LLC.

Citizenship: USA

Page 17

Exhibit Index

A. Agreement regarding filing of joint Schedule 13D.

Page 18

EX-99.A 2 d80965dex99a.htm EX-99.A EX-99.A

Exhibit A

Joint Filing Statement

I, the undersigned, hereby express my agreement that the attached Schedule 13D (and any amendments thereto) relating to the beneficial ownership by the undersigned of the equity securities of Aratana Therapeutics, Inc. is filed on behalf of each of the undersigned.


Date: July 21, 2015

MPM BIOVENTURES V GP LLC

By:		MPM BioVentures V LLC,
		its Managing Member

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

MPM BIOVENTURES V LLC

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

MPM BIOVENTURES V, L.P.

By:		MPM BioVentures V GP LLC, its General Partner

By:		MPM BioVentures V LLC, its Managing Member

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

MPM ASSET MANAGEMENT INVESTORS BV5 LLC

By:		MPM BioVentures V LLC
		Its: Manager

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

MPM CAPITAL LLC

By:		Medical Portfolio Management LLC,
		its Managing Member

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

Page 19


MEDICAL PORTFOLIO MANAGEMENT LLC

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke
Title:		Member

By:		/s/ Ansbert Gadicke
Name:		Ansbert Gadicke

By:		/s/ Luke Evnin
Name:		Luke Evnin

By:		/s/ Todd Foley
Name:		Todd Foley

By:		/s/ James Paul Scopa
Name:		James Paul Scopa

By:		/s/ Vaughn M. Kailian
Name:		Vaughn M. Kailian

Page 20