Warrants (Tables)

12 Months Ended

Dec. 31, 2020

Warrants And Rights Note Disclosure [Abstract]

Summary of Warrants Issued to Purchase Common Stock

As of December 31, 2020, the Company issued the following warrants to purchase shares of its common stock. These warrants are exercisable any time at the option of the holder until their expiration date.  

	Issuance Date	Term	Exercise Price Per Share		Warrants Exercised during the Year Ended December 31, 2019		Warrants Outstanding at December 31, 2019		Warrants Exercised during the Year Ended December 31, 2020		Warrants Outstanding at December 31, 2020
December 2020 Warrants	December 2020	5.5 years	$	3.00		—		—		—		2,618,658
December 2020 Placement Agent Warrants	December 2020	5 years	$	3.82		—		—		—		130,933
July 2020 Warrants	July 2020	5.5 years	$	3.85		—		—		—		641,416
July 2020 Placement Agent Warrants	July 2020	5.5 years	$	4.97		—		—		—		32,071
May 2020 Warrants	May 2020	5 years	$	4.78		—		—		—		1,392,345
May 2020 Placement Agent Warrants	May 2020	5 years	$	6.13		—		—		—		69,617
March 2020 Service and Performance Warrants	March 2020	3 years	$	2.50		—		—		—		18,350
February 12, 2020 Service and Performance Warrants	February 2020	2 years	$	4.71		—		—		—		150,000
February 3, 2020 Service and Performance Warrants	February 2020	2 years	$	4.91		—		—		—		10,000
September 2019 Placement Agent Warrants	September 2019	5 years	$	9.48		—		65,942		—		65,942
August 2019 Service and Performance Warrants	August 2019	2 years	$	1.92		—		20,000		—		20,000
July 2019 Service and Performance Warrants	July 2019	2 years	$	2.19		—		10,000		—		10,000
June 2019 Placement Agent Warrants	June 2019	5 years	$	6.29		—		74,479		—		74,479
April 2019 Service and Performance Warrants	April 2019	5 years	$	6.18		—		145,154		—		145,154
June 2018 Placement Agent Warrants	June 2018	5 years	$	12.57		—		69,617		—		69,617
March 2018 Placement Agent Warrants	March 2018	5 years	$	41.56		—		15,038		—		15,038
Total						—		400,230		—		5,463,620

Summary of Key Terms and Activity of Liability Classified Common Stock Warrants

The key terms and activity of the liability classified common stock warrants are summarized as follows: 

	Issuance Date	Term	Exercise Price Per Share		Warrants Exercised during the Year Ended December 31, 2019		Warrants Outstanding at December 31, 2019		Warrants Exercised during the Year Ended December 31, 2020		Warrants Outstanding at December 31, 2020
September 2019 Warrants	September 2019	5.5 years	$	7.52		—		659,414		—		659,414
June 2019 Warrants	June 2019	5.5 years	$	5.00		1,053,745		435,830		—		435,830
June 2018 Warrants	June 2018	5.5 years	$	9.94		—		1,392,345		1,392,345		—
March 2018 Warrants	March 2018	5 years	$	10.73		—		1,282,832		641,416		641,416
Total						1,053,745		3,770,421		2,033,761		1,736,660