During the three months ended March 31, 2021, 150 shares of Preferred Stock were converted into 15,000 shares of the Company’s common stock.

As of March 31, 2021, there were an aggregate of 20,481 shares of Series E and Series E-1 Preferred Stock outstanding.

During the three months ended March 31, 2021, the Company issued 237,520 shares of common stock associated with the exercise of warrants.

In February 2021, the Company issued 2,636 shares of unregistered common stock in lieu of a cash payment of deferred accrued director fees to a former director.

As of March 31, 2021, there were 675,000 shares of the Company’s common stock reserved under the 2020 Plan, of which 95,000 remained available to be issued. On March 30, 2021, the Company’s Board of Directors approved an amendment of the 2020 Plan to increase the number of shares of the Company’s common stock available for issuance under the 2020 Plan by 1,800,000, subject to stockholder approval of the amendment. The amendment of the 2020 Plan was approved by the stockholders at the Company’s annual meeting of stockholders held on May 6, 2021 and, effective as of such date, the number of shares of the Company’s common stock available for issuance under the 2020 Plan increased by 1,800,000 resulting in a total share reserve of 2,475,000 shares of common stock.

The following is a summary of stock option activity under the 2019 Plan and the 2020 Plan for the three months ended March 31, 2021:

	Number of Option		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Outstanding at January 1, 2021		1,078,499	$	12.68
Granted		—		—
Exercised		—		—
Cancelled/Forfeited		—		—
Outstanding at March 31, 2021		1,078,499	$	12.68	9.5	$	710
Exercisable at March 31, 2021		175,164	$	13.05	9.5	$	131

The following table summarizes information for stock option shares outstanding and exercisable at March 31, 2021

			Options Exercisable
Range of Exercise Prices	Outstanding Number of Options		Weighted Average Remaining Option Term (in years)	Number of Options
$10 - $15		946,000	9.5		157,665
$15 - $20		81,000	9.5		8,500
$20 - $25		51,000	9.5		8,500
$25+		499	7.8		499
		1,078,499	9.5		175,164

The following is a summary of share-based compensation expense in the statement of operations for the three months ended March 31, 2021

	Three months ended March 31,
		2021		2020
Selling, general and administrative		$	1,466	$	49
Research and development			630		5
Cost of goods sold			52		—
Total		$	2,148	$	55

At March 31, 2021, there was $6,677 of aggregate unrecognized compensation expense related employee and board stock option grants. This will be recognized over the next 33 months.

The following is a summary of warrant activity for the three months ended March 31, 2021:

	Warrants			Weighted Average Exercise Price		Weighted Average Remaining Life (in years)		Aggregate Intrinsic Value
Outstanding at January 1, 2021		4,236,687		$	9.13
Warrants issued		—			—
Warrants exercised		(242,580	)		10.00
Warrants expired		—			—
Outstanding at March 31, 2021		3,994,107		$	9.07		3.9	$	13,372
Exercisable at March 31, 2021		3,994,107		$	9.07		3.9	$	13,372

The following table presents information related to stock warrants at March 31, 2021

				Warrants Exercisable
Range of Exercise Prices		Outstanding Number of Warrants		Weighted Average Remaining Warrant Term (in years)	Number of Warrants
$	0.01		371,000	4.1		371,000
$	10.00		3,623,107	3.9		3,623,107
			3,994,107	3.9		3,994,107

As of March 31, 2021, warrants to purchase 371,000 shares of the Company’s common stock were pre-funded, and the exercise price was $0.01 per share. The remaining warrants were exercisable at $10.00 per share.