| Exhibit 1 | ||||
Joint Filing Agreement
The undersigned hereby agree that they are jointly filing this statement on Schedule 13G. Each of them is responsible for the timely filing of such statement and any amendments thereto, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the completeness or accuracy of the information concerning the other persons making the filing, unless such person knows or has reason to believe that such information is inaccurate.
Dated: February 8, 2019
| ONYX THERAPEUTICS, INC. | ||
| By: | /s/ Mary A. Lehmann | |
| Name: | Mary A. Lehmann | |
| Title: | Vice President, Finance and Treasurer | |
| ONYX PHARMACEUTICALS, INC. | ||
| By: | /s/ Mary A. Lehmann | |
| Name: | Mary A. Lehmann | |
| Title: | Vice President, Finance and Treasurer | |
| AMGEN INC. | ||
| By: | /s/ Mary A. Lehmann | |
| Name: | Mary A. Lehmann | |
| Title: | Vice President, Finance and Treasurer | |
