Warrants (Tables)

9 Months Ended

Sep. 30, 2021

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, 2021:

Warrant Issuance Date	Shares of Common Stock Underlying Warrants		Exercise Price/Share		Expiration Date
August 2014		1,914	$	352.65	2024
December 2014		9,651		210.00	2022
March 2016		3,021		41.40	2026
March 2018		1,208		115.95	2028
June 2020		42,894		11.6565	2030