Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2017

Accounting Policies [Abstract]

Summary of Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share

The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because to do so would be anti-dilutive.

	June 30,
	2017		2016
Warrants to purchase common stock		149,704		149,704
Common stock options issued and outstanding		4,328,744		3,564,732
Shares issuable upon conversion of convertible note payable		2,465,647		—
Common stock subject to repurchase		—		13,011
ESPP shares pending issuance		3,886		2,472
Total		6,947,981		3,729,919