Warrants (Tables)

12 Months Ended

Dec. 31, 2021

Summary of Warrants Activity, Outstanding Warrants Issued in Connection with Equity and Debt Financings and Consultants

Warrant activity is summarized as follows:

	Warrants			Weighted average exercise price

Outstanding at December 31, 2019		12,538,204		$	4.22
Issued		—
Exercised		—
Canceled		—
Outstanding at December 31, 2020		12,538,204		$	4.22
Issued		—
Exercised		(1,180,240	)	$	2.50
Canceled		(500,000	)	$	5.00
Outstanding at December 31, 2021		10,857,964		$	4.37

The following table summarizes information with regard to outstanding warrants issued in connection with equity and debt financings and consultants as of December 31, 2021.

Issued in Connection With	Number Issued		Exercise Price	Exercisable Date	Expiration Date
February 12, 2009 Series B-1 Transaction $3.00 Investor Warrants — Class B	1,200,000	$	3.00	February 12, 2009	February 12, 2024
May 13, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B	600,000	$	3.00	May 13, 2009	May 13, 2024
June 30, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B	333,333	$	3.00	June 30, 2009	June 30, 2024
August 12, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B	200,000	$	3.00	August 12, 2009	August 12, 2024
September 30, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B	216,666	$	3.00	September 30, 2009	September 30, 2024
November 4, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B	106,666	$	3.00	November 4, 2009	November 4, 2024
December 8, 2009 Series B-2 Transaction $3.00 Investor Warrants — Class B	133,143	$	3.00	December 8, 2009	December 8, 2024
January 29, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B	216,667	$	3.00	January 29, 2010	January 29, 2025
March 8, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B	223,334	$	3.00	March 8, 2010	March 8, 2025
April 30, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B	204,192	$	3.00	April 30, 2010	April 30, 2025
May 10, 2010 Series B-2 Transaction $3.00 Investor Warrants — Class B	143,166	$	3.00	May 10, 2010	May 10, 2025
September 22, 2016 Series B-3 Transaction $3.00 Investor Warrants	698,158	$	3.00	September 22, 2016	September 22, 2023
September 29, 2016 Series B-3 Transaction $3.00 Investor Warrants	846,100	$	3.00	September 29, 2016	September 29, 2023
December 22, 2016 Private placement warrants	1,466,204	$	5.00	December 22, 2016	December 23, 2023
December 23, 2016 Series B-3 Transaction $3.00 Investor Warrants	924,780	$	3.00	December 23, 2016	December 23, 2023
December 28, 2016 Private placement warrants	644,468	$	5.00	December 28, 2016	December 28, 2023
February 27, 2017 Private placement warrants	76,776	$	5.00	February 27, 2017	February 27, 2024
2018 and 2017 Warrants issued for services	2,157	$	5.00	Various dates in 2018 and 2017	Various dates in 2025 and 2024
May 23, 2019 Rights offering warrants	2,622,154	$	7.00	May 23, 2019	May 23, 2026
Total outstanding warrants	10,857,964