Warrants (Tables)

9 Months Ended

Sep. 30, 2020

Proceeds From Issuance Of Preferred Stock Preference Stock And Warrants [Abstract]

Summary of Outstanding Warrants

The following table shows the common stock warrants outstanding as of September 30, 2020:

Warrant Issuance Date	Shares of CommonStock Underlying Warrants		Exercise Price/Share		Expiration Date
August 2014		28,713	$	23.51	2024
December 2014		144,772		14.00	2022
March 2016		45,307		2.76	2026
March 2018		18,123		7.73	2028
September 2019		2,234,925		0.01	N/A
June 2020		643,413		0.7771	2030