X0306 4 2016-09-14 0001485003 Eleven Biotherapeutics, Inc. EBIO 0001503559 Flagship Ventures Fund IV, L.P. 1 MEMORIAL DRIVE, 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001508052 Flagship Ventures Fund 2007, L.P. 1 MEMORIAL DRIVE, 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001590973 Flagship Ventures Fund IV-Rx, L.P. 1 MEMORIAL DRIVE, 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001508053 Flagship Ventures 2007 General Partner LLC 1 MEMORIAL DRIVE, 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001508051 Flagship Ventures Fund IV General Partner LLC 1 MEMORIAL DRIVE, 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001222012 AFEYAN NOUBAR 1 MEMORIAL DRIVE, 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001255927 KANIA EDWIN M JR 1 MEMORIAL DRIVE, 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 Common Stock 2016-09-14 4 S 0 35209 4.18 D 1092902 D Common Stock 2016-09-14 4 S 0 8802 4.18 D 273213 D Common Stock 2016-09-15 4 S 0 2145 4.16 D 1090757 D Common Stock 2016-09-15 4 S 0 536 4.16 D 272677 D Common Stock 1833802 D Held by Flagship Ventures Fund IV, L.P. ("Flagship IV"). Flagship Ventures Fund IV General Partner LLC ("Flagship IV LLC") is the general partner of Flagship IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship IV LLC. Flagship IV LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV. Each of the filing persons, other than Flagship IV, disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein. Held by Flagship Ventures Fund IV-Rx, L.P. ("Flagship IV-Rx"). Flagship IV LLC is the general partner of Flagship IV Rx. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship IV LLC. Flagship IV LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV-Rx. Each of the filing persons, other than Flagship IV-Rx, disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein. Held by Flagship Ventures Fund 2007, L.P. ("Flagship 2007"). Flagship Ventures 2007 General Partner LLC ("Flagship 2007 LLC") is the general partner of Flagship 2007. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship 2007 LLC. Flagship 2007 LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship 2007. Each of the filing persons, other than Flagship 2007, disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein. The transactions were executed in multiple trades at prices ranging from $4.15 to $4.24. The price above reflects the weighted average sales price. Detailed information regarding the number of shares sold at each separate price will be provided upon request by the Commission staff, the Issuer or a security holder of the Issuer. The transactions were executed in multiple trades at prices ranging from $4.15 to $4.18. The price above reflects the weighted average sales price. Detailed information regarding the number of shares sold at each separate price will be provided upon request by the Commission staff, the Issuer or a security holder of the Issuer. FLAGSHIP VENTURES FUND IV, L.P., By: Flagship Ventures Fund IV General Partner LLC, By: /s/ Noubar B. Afeyan, Ph.D., Title: Manager 2016-09-16 FLAGSHIP VENTURES FUND 2007, L.P., By: Flagship Ventures 2007 General Partner LLC, By: /s/ Noubar B. Afeyan, Ph.D., Title: Manager 2016-09-16 FLAGSHIP VENTURES FUND IV-RX, L.P., By: Flagship Ventures Fund IV General Partner LLC, By: /s/ Noubar B. Afeyan, Ph.D., Title: Manager 2016-09-16 FLAGSHIP VENTURES 2007 GENERAL PARTNER LLC, By: /s/ Noubar B. Afeyan, Ph.D., Title: Manager 2016-09-16 FLAGSHIP VENTURES FUND IV GENERAL PARTNER LLC, By: /s/ Noubar B. Afeyan, Ph.D., Title: Manager 2016-09-16 /s/ Noubar B. Afeyan, Ph.D. 2016-09-16 /s/ Edwin M. Kania, Jr. 2016-09-16