Common Stock (Tables)

3 Months Ended

Mar. 31, 2020

Common Stock

Schedule of reserved shares of common stock for issuance

	March 31,	December 31,
	2020	2019
Options outstanding	2,798,122	2,898,977
Unvested restricted stock units outstanding	12,305,236	12,639,066
Unvested performance stock units outstanding	1,005,000	—
Shares available for grant under the 2014 Equity Incentive Plan and 2015 Inducement Plan	4,075,082	1,301,881
Shares available for purchase under the Employee Stock Purchase Plan	943,545	378,525
Total	21,126,985	17,218,449