Common Stock Reserved for Issuance

6 Months Ended

Jun. 30, 2018

Equity [Abstract]

Common Stock Reserved for Issuance

7. 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 and shares reserved for issuance under the employee stock purchase plan.

	June 30, 2018		December 31, 2017
Outstanding stock options		10,569,959		7,470,601
Shares reserved for future option grants		411,262		1,503,770
Shares reserved under the 2015 employee stock purchase plan		700,000		700,000
Total common stock reserved for issuance		11,681,221		9,674,371