Common Stock Reserved for Issuance (Tables)

9 Months Ended

Sep. 30, 2018

Equity [Abstract]

Schedule of Common Stock Reserved for Issuance

The Company is required to reserve and keep available out of its authorized but unissued shares of common stock a number of shares sufficient to effect the conversion of all outstanding options granted and available for grant under the incentive plans, shares reserved for issuance under the employee stock purchase plan and issued warrant.

	September 30, 2018		December 31, 2017
Outstanding stock options under the 2015 equity incentive plan		10,719,737		7,470,601
Shares reserved for future option grants under equity plans		1,731,500		1,503,770
Shares reserved under the 2015 employee stock purchase plan		700,000		700,000
Shares reserved under warrant upon contingent events		147,059		—
Outstanding warrant		73,529		—
Total common stock reserved for issuance		13,371,825		9,674,371