Warrants (Tables)

3 Months Ended

Mar. 31, 2022

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 March 31, 2022:

Warrant Issuance Date	Shares of Common Stock Underlying Warrants		Exercise Price/Share		Expiration Date
August 2014		1,914	$	352.65	2024
March 2016		3,021		41.40	2026
March 2018		1,208		115.95	2028
June 2020		42,894	11.6565		2030
March 2022		2,410,933		0.001	None
March 2022		3,244,987		2.062	2024
March 2022		3,244,987		2.062	2027