Exhibit 99.1
Joint Filing Agreement
The undersigned hereby agree that the Amended Statement on Schedule 13G dated August 21, 2014 with respect to the shares of Common Stock of Ligand Pharmaceuticals Incorporated, and any further amendments thereto executed by each and any of the undersigned shall be filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended.
Dated: August 21, 2014
| BIOTECHNOLOGY VALUE FUND, L.P. | INVESTMENT 10, L.L.C. | |||
| By: | BVF Partners L.P., its general partner | By: | BVF Partners L.P., its investment adviser | |
| By: | BVF Inc., its general partner | By: | BVF Inc., its general partner | |
| By: | /s/ Mark N. Lampert | By: | /s/ Mark N. Lampert | |
| Mark N. Lampert | Mark N. Lampert | |||
| President | President | |||
| BIOTECHNOLOGY VALUE FUND II, L.P. | MSI BVF SPV, LLC | |||
| By: | BVF Partners L.P., its general partner | By: | BVF Partners L.P., its investment adviser | |
| By: | BVF Inc., its general partner | By: | BVF Inc., its general partner | |
| By: | /s/ Mark N. Lampert | By: | /s/ Mark N. Lampert | |
| Mark N. Lampert | Mark N. Lampert | |||
| President | President | |||
| BVF INC. | ||||
| BVF PARTNERS L.P. | By: | /s/ Mark N. Lampert | ||
| Mark N. Lampert | ||||
| By: | BVF Inc., its general partner | President | ||
| By: | /s/ Mark N. Lampert | |||
| Mark N. Lampert | /s/ Mark N. Lampert | |||
| President | MARK N. LAMPERT | |||
| BVF INVESTMENTS, L.L.C. | ||||
| By: | BVF Partners L.P., its manager | |||
| By: | BVF Inc., its general partner | |||
| By: | /s/ Mark N. Lampert | |||
| Mark N. Lampert | ||||
| President | ||||