Note 7 - Equity

On April 24, 2020, the Company issued and sold 4.3 million shares of common stock and 2.8 million pre-funded warrants to purchase shares of common stock. The price to the public in this offering for each share of common stock was $4.50 and for each pre-funded warrant was $4.497. Each pre-funded warrant had an exercise price of $0.003 per share and was exercisable immediately upon issuance. Gross proceeds from this offering were $31.6 million, before deducting underwriting discounts and commissions and other offering expenses payable by the Company. Net proceeds from this offering were $29.1 million.

During the year ended December 31, 2020, holders of all of the 2.8 million pre-funded April 2020 warrants exercised their warrants at $0.003 per share and received 2.8 million shares of common stock.

On June 19, 2020, the Company issued and sold 1.9 million shares of common stock and 0.7 million pre-funded warrants to purchase shares of common stock. The price to the public in this offering for each share of common stock was $9.75 and for each pre-funded warrant was $9.747. Each pre-funded warrant had an exercise price of $0.003 per share and was exercisable immediately upon issuance. Gross proceeds from this offering were $25.0 million, before deducting underwriting discounts and commissions and other offering expenses payable by the Company. Net proceeds from this offering were $23.0 million.

During the year ended December 31, 2020, holders of all of the 0.7 million pre-funded June 2020 warrants exercised their warrants at $0.003 per share and received 0.7 million shares of common stock.

In August 2020, the Company entered into the Capital on Demand™ Sales Agreement with JonesTrading Institutional Services LLC (“JonesTrading”), pursuant to which the Company may sell, from time to time, through or to JonesTrading, up to an aggregate of $200 million of its common stock. Shares of common stock are offered pursuant to the Company’s shelf registration statement on Form S-3 filed with the SEC on August 7, 2020. As of December 31, 2020, the Company had sold 2.1 million shares of common stock, resulting in gross proceeds of $22.6 million and net proceeds of $21.7 million. For the year ended December 31, 2021, the Company sold 4.6 million shares of common stock, resulting in gross proceeds of $36.5 million and net proceeds of $35.3 million.

2019 Amended and Restated Stock Plan

In December 2019, the Company’s 2019 Stock Plan was established. The expiration date of the plan is October 18, 2029 and the total number of shares of the Company’s common stock available for grant to employees, directors and consultants of the Company was 333,333 shares. At the Company’s Annual Meeting of Stockholders held on November 18, 2020, its stockholders authorized an increase in the number of shares authorized under the plan, resulting in the number of shares authorized in the plan to be 3,083,333 shares. At the Company’s Annual Meeting of Stockholders held on November 9, 2021, its stockholders authorized an increase in the number of shares authorized under the plan, resulting in the number of shares authorized in the plan to be 5,833,333 shares.

2013 Amended and Restated Stock Plan

In September 2013, the Company’s 2013 Stock Plan was established. The expiration date of the plan is September 9, 2023 and at the time of approval, the total number of shares of the Company’s common stock available for grant to employees, directors and consultants of the Company under the plan was 91,666 shares. After a number of amendments approved by stockholders, the number of shares authorized under the plan is 758,333 shares.

2013 Equity Incentive Plan

In September 2013, the Company’s 2013 Equity Incentive Plan was established. The expiration date of the plan is September 9, 2023 and the total number of shares of the Company’s common stock available for grant to employees, directors and consultants of the Company under the plan was 15,000 shares. In December 2013, the shareholders of the Company approved the plan and increased the number of shares authorized under the plan to 33,333 shares.

Stock Options

Following is a summary of stock option activity for the years ended December 31, 2021 and 2020:

During 2021, the Company granted its employees and members of the Board of Directors options to purchase 881 thousand shares of common stock with an exercise price ranging from $6.02 to $9.25 per share, a term of 10 years, and a vesting period from 4 to 4.2 years. The options have an aggregated fair value of $3.9 million that was calculated using the Black-Scholes option-pricing model. Variables used in the Black-Scholes option-pricing model include: (1) discount rate range from 0.65% to 1.28% (2) expected life of 6 years, (3) expected volatility range from 79.8% to 85.1%, and (4) zero expected dividends.

During 2020, the Company granted its employees and members of the Board of Directors options to purchase 458 thousand shares of common stock with an exercise price ranging from $6.63 to $12.41 per share, a term of 10 years, and a vesting period from 4 to 4.2 years. The options have an aggregated fair value of $3.2 million that was calculated using the Black-Scholes option-pricing model. Variables used in the Black-Scholes option-pricing model include: (1) discount rate range from 0.34% to 0.56% (2) expected life of 6 years, (3) expected volatility range from 83.6% to 85.5%, and (4) zero expected dividends.

During the years ended December 31, 2021 and 2020, options to purchase 333 thousand and 23 thousand common shares were cancelled, respectively, upon the termination of employment. During 2021, 1 thousand options were exercised for shares of common stock. There were no exercises of options during 2020.

The fair values of all options issued and outstanding are being amortized over their respective vesting periods. The unrecognized compensation expense at December 31, 2021 was $4.9 million related to unvested options, which is expected to be expensed over a weighted average of 3.3 years. During 2021 and 2020, the Company recorded total option expense of $1.5 million and $1.2 million, respectively.

Pre-funded Warrants

As part of the April 2020 offering and the June 2020 offering, the Company issued pre-funded warrants. Each pre-funded warrant had an exercise price of $0.003 per share and was exercisable immediately upon issuance. The pre-funded warrants did not have an expiration date. During 2020 all the pre-funded warrants were exercised for shares of common stock.

Warrants

Following is a summary of warrant activities for the years ended December 31, 2021 and 2020:

The Company has an outstanding warrant to purchase 1,907 shares of common stock, issued on March 14, 2017 to Sandesh Seth, the Company’s Chairman and Chief Executive Officer. The warrant included down-round protection up until it was amended on August 11, 2020. For warrants with down-round protection, a deemed dividend is recorded for the change in fair value of the warrants when the down-round provision is triggered. As a result of the April 2020 offering and June 2020 offering, the exercise price of the warrant was reset from $26.40 per share to $15.62 per share. The down-round protection provision in the above warrants created a deemed dividend to common stockholders of $1 thousand in the year ended December 31, 2020 which is reflected in the accompanying consolidated statement of operations and consolidated statement of changes in stockholders’ equity. On August 11, 2020, the Company and Mr. Seth agreed to amend the warrant to remove the anti-dilution provision that had been in the warrant. Accordingly, pursuant to the amendment, as of August 11, 2020, the exercise price of the warrant will no longer be subject to a proportional adjustment if and when the Company issues any shares of its common stock for a consideration less than the exercise price of the warrant. All other terms of the warrant remained the same.

During the years ended December 31, 2021 and 2020, the Company recorded stock-based compensation expense related to warrants of $16 thousand and $13 thousand, respectively.