Stockholders' Equity

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Stockholders' Equity

10. Stockholders’ Equity

On July 16, 2021, the Company completed a registered direct offering, in which the Company issued and sold 17,416,096 shares of its common stock, pre-funded warrants ("Pre-funded Warrants") to purchase up to an aggregate of 3,941,648 shares of its common stock in lieu of shares of common stock, and warrants ("Warrants") to purchase up to 10,678,872 shares of the Company’s common stock through a securities purchase agreement with several healthcare-focused institutional and accredited investors. The combined price of each share of common stock and accompanying Warrant to purchase one-half of a share of common stock was $1.311 per share. The purchase price of each Pre-funded Warrant was $1.301, which was the combined purchase price per share of common stock and accompanying Warrant to purchase one-half of a share of common stock, minus $0.01. Gross proceeds of the transaction were $28.0 million. As a result of the registered direct offering, the Company received approximately $25.4 million after deducting offering costs. Each Warrant is exercisable for one share of the Company’s common stock at an exercise price of $1.25 per share. The Warrants are immediately exercisable and expire on July 16, 2026. Each Pre-funded Warrant is exercisable for one share of our Common Stock at an exercise price of $0.01 per share. All Pre-funded Warrants were exercised on July 16, 2021.

The Company entered into the B. Riley ATM Agreement on March 29, 2021, under which the Company was authorized to issue and sell shares of its common stock having aggregate sales proceeds of up to $50 million from time to time through B. Riley, acting as sales agent and/or principal. The Company agreed to pay B. Riley a commission of 3.0% of the gross proceeds from any sales of shares of its common stock under this facility. During the year ended December 31, 2021, the Company issued and sold a total of 4,081,338 shares of its common stock under the B. Riley ATM Agreement at a weighted average price of $1.11 per share for net proceeds of approximately $4.2 million.

The Company entered into the Updated B. Riley ATM Agreement on December 23, 2021, under which the Company was authorized to issue and sell shares of its common stock having aggregate sales proceeds of up to $50 million from time to time through B. Riley, acting as sales agent and/or principal. During the first quarter of 2022 through the filing date of this Annual Report, the Company issued and sold 6,804,888 shares of its common stock under the Updated B. Riley ATM Agreement at a weighted average price of $0.62 per share for net proceeds of $4.1 million. The B. Riley ATM Agreement was terminated at the time the Company entered into the Updated B. Riley Agreement.

In December 2018, the Company entered into the Cowen ATM Agreement, under which the Company was authorized to issue and sell shares of its common stock having aggregate sales proceeds of up to $50 million from time to time through Cowen, acting as sales agent and/or principal. The Company agreed to pay Cowen a commission of 3.0% of the gross proceeds from any sales of shares of its common stock under this facility. On December 30, 2019, the Company completed an issuance and sale of 1,243,756 shares of common stock under the ATM Agreement. As a result of this issuance and sale of common stock, the Company received approximately $2.6 million in net proceeds after deducting offering costs. During the first quarter of 2021, the Company issued and sold 6,058,318 shares of its common stock under the Cowen ATM Agreement at a weighted average price of $1.99 per share for net proceeds of $11.7 million. The Cowen ATM Agreement was terminated at the time the Company entered into the B. Riley ATM Agreement.

On June 5, 2020, the Company completed another registered direct offering, in which it issued and sold 7,317,074 shares of its common stock, at a purchase price of $2.05 per share, for net proceeds of $13.7 million through a securities purchase agreement with certain institutional and accredited investors.

On July 30, 2020, the Company completed a public underwritten offering of 5,894,191 shares of its common stock, including the exercise in full of the underwriter’s option to purchase an additional 768,807 shares of common stock, at a price to the public of $1.30 per share, for net proceeds of $6.7 million.

On December 4, 2020, the Company completed another public underwritten offering of 11,960,000 shares of our common stock, including the exercise in full of the underwriter’s option to purchase an additional 1,560,000 shares of common stock, at a price to the public of $1.25 per share, for net proceeds of $13.5 million.

Common Stock

The holders of common stock are entitled to one vote for each share held. Common stockholders are not entitled to receive dividends, unless declared by the Board of Directors.

The Company has reserved for future issuances the following shares of common stock as of December 31, 2021 and 2020:

	December 31,
	2021		2020
Stock options and restricted stock units		8,372,313		5,359,736
Warrants		10,687,912		9,040
Common stock issuable upon conversion of outstanding debt		2,439,024		2,439,024
Employee stock purchase plan		306,527		336,910
Total		21,805,776		8,144,710

Warrants

At December 31, 2021, the Company had 10,687,912 warrants outstanding for the purchase of shares of common stock at a weighted average exercise price of $1.26. At December 31, 2020, the Company had 9,040 warrants outstanding for the purchase of shares of common stock at an exercise price of $11.06. 10,678,872 warrants with an exercise price of $1.25 expire on July 16, 2026. 9,040 warrants with an exercise price of $11.06 expire on May 1, 2026.