X0306 4 2016-07-05 0 0001609989 Blue Buffalo Pet Products, Inc. BUFF 0001404570 Invus, L.P. C/O THE INVUS GROUP, LLC 750 LEXINGTON AVENUE, 30TH FLOOR NEW YORK NY 10022 1 0 1 0 0001218180 Artal International S.C.A. 10-12 AVENUE PASTEUR, L-2310 LUXEMBOURG N4 LUXEMBOURG 1 0 1 0 0001522131 Artal International Management S.A. 10-12 AVENUE PASTEUR, L-2310 LUXEMBOURG N4 LUXEMBOURG 1 0 1 0 0001053906 Artal Group S.A. 10-12 AVENUE PASTEUR, L-2310 LUXEMBOURG N4 LUXEMBOURG 1 0 1 0 0001283968 Westend S.A. 10-12 AVENUE PASTEUR, L-2310 LUXEMBOURG N4 LUXEMBOURG 1 0 1 0 0001460840 Stichting Administratiekantoor Westend IJSSELBURCHT 3 NL-6825 BS ARNHEM THE NETHERLANDS P7 NETHERLANDS 1 0 1 0 0001460839 Minne Pascal PLACE STE. GUDULE, 19 B-1000, BRUXELLES C9 BELGIUM 1 0 1 0 0001404553 Invus Advisors, L.L.C. C/O THE INVUS GROUP, LLC 750 LEXINGTON AVENUE, 30TH FLOOR NEW YORK NY 10022 1 0 1 0 Common Stock 2016-07-05 4 S 0 15014548 21.285 D 99972999 D This amount represents the $22.00 public offering price per share of common stock of the Issuer, less the underwriting discount of $0.715 per share. These securities are directly held by Invus, L.P. Invus Advisors, L.L.C. is the general partner of Invus, L.P. Artal International S.C.A. is the managing member of Invus Advisors, L.L.C. The managing partner of Artal International S.C.A. is Artal International Management S.A., which is a wholly owned subsidiary of Artal Group S.A., which is a wholly owned subsidiary of Westend S.A., which is a wholly owned subsidiary of Stichting Administratiekantoor Westend ("Stichting"). Mr. Pascal Minne is the sole member of the board of the Stichting. Each of the Reporting Persons (other than to the extent it directly holds securities reported herein) disclaims beneficial ownership of the securities held by the other Reporting Persons, except to the extent of such Reporting Person's pecuniary interest therein, and, pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), each of the Reporting Persons (other than to the extent it directly holds securities reported herein) states that the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 or for any other purpose. For purposes of Section 16 of the Exchange Act, the Reporting Persons may be deemed to be directors by deputization of the Issuer by virtue of Invus, L.P.'s right to designate certain members of the Issuer's board of directors pursuant to an amended and restated investor rights agreement among the Issuer, Invus, L.P. and certain other stockholders of the Issuer. INVUS, L.P., By: Invus Advisors, L.L.C., its general partner, By: /s/ Raymond Debbane, Name: Raymond Debbane, Title: President 2016-07-07 INVUS ADVISORS, L.L.C., By: /s/ Raymond Debbane, Name: Raymond Debbane, Title: President 2016-07-07 ARTAL INTERNATIONAL S.C.A., By: ARTAL INTERNATIONAL MANAGEMENT S.A., its managing partner, By: /s/ Anne Goffard, Name: Anne Goffard, Title: Managing Director 2016-07-07 ARTAL INTERNATIONAL MANAGEMENT S.A., By: /s/ Anne Goffard, Name: Anne Goffard, Title: Managing Director 2016-07-07 ARTAL GROUP S.A., By: /s/ Anne Goffard, Name: Anne Goffard, Title: Authorized Person 2016-07-07 WESTEND S.A., By: /s/ Pascal Minne, Name: Pascal Minne, Title: Director 2016-07-07 STICHTING ADMINISTRATIEKANTOOR WESTEND, By: /s/ Pascal Minne, Name: Pascal Minne, Title: Sole Member of the Board 2016-07-07 /s/ Pascal Minne 2016-07-07