EXHIBIT A
Joint Filing Statement
We, the undersigned, hereby express our agreement that the attached Schedule 13D is filed on behalf of each of us.
Dated: April 12, 2019
| THE COLUMN GROUP, LP | THE COLUMN GROUP GP, LP | |||||||
| By: | The Column Group GP, LP | |||||||
| By: | /s/ Jennifer J. Carlson,Attorney-in-Fact | By: | /s/ Jennifer J. Carlson,Attorney-in-Fact | |||||
| THE COLUMN GROUP II, LP | THE COLUMN GROUP II GP, LP | |||||||
| By: | The Column Group II GP, LP | By: | /s/ Jennifer J. Carlson,Attorney-in-Fact | |||||
| By: | /s/ Jennifer J. Carlson,Attorney-in-Fact | |||||||
| PONOI CAPITAL, LP | PONOI MANAGEMENT, LLC | |||||||
| By: | Ponoi Management, LLC | By: | /s/ Jennifer J. Carlson,Attorney-in-Fact | |||||
| By: | /s/ Jennifer J. Carlson,Attorney-in-Fact | |||||||
| PONOI CAPITAL II, LP | PONOI II MANAGEMENT, LLC | |||||||
| By: | Ponoi II Management, LLC | By: | /s/ Jennifer J. Carlson,Attorney-in-Fact | |||||
| By: | /s/ Jennifer J. Carlson,Attorney-in-Fact | |||||||
| THE COLUMN GROUP MANAGEMENT, LP | ||||||||
| By: | /s/ Jennifer J. Carlson,Attorney-in-Fact | |||||||
| By: | /s/ Jennifer J. Carlson,Attorney-in-Fact on behalf of Peter Svennilson | By: | /s/ Jennifer J. Carlson,Attorney-in-Fact on behalf of Tim Kutzkey | |||||
| By: | /s/ Jennifer J. Carlson,Attorney-in-Fact on behalf of David V. Goeddel | |||||||
