Stockholders' Equity

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Stockholders' Equity

9. Stockholders’ Equity

Preferred and Common Stock Authorized

The Company is authorized to issue 10,000,000 shares of preferred stock as of December 31, 2021 and 2020, and 200,000,000 shares of common stock as of December 31, 2021 and 2020.

Common Stock Reserved for Future Issuance

As of December 31, 2021 and 2020, the Company had reserved shares of common stock for future issuances as follows:

	December 31,
	2021		2020
Prefunded warrants to purchase common stock		3,125,000		—
Equity award plans:
Options and incentive awards outstanding, all equity plans		10,892,613		8,913,071
Equity awards available for future grant—2013 Plan		1,588,613		167,159
Equity awards available for future grant—2020 Plan		—		750,000
Total shares of common stock reserved for future issuance		15,606,226		9,830,230

Sale of Common Stock and Prefunded Warrants

On November 22, 2021, pursuant to a shelf registration statement on Form S-3, the Company issued 15,625,000 shares of its common stock at $4.00 per share in an underwritten public offering. Concurrently, the Company sold to certain existing investors who did not participate in the common stock sale pre-funded warrants to purchase up to an aggregate of 3,125,000 shares of common stock at a purchase price of $3.9999 per pre-funded warrant, which represents the per share public offering price for the common stock less the $0.0001 per share exercise price for each pre-funded warrant. The aggregate net proceeds to the Company from this offering was $70.5 million, after deducting underwriting discounts and commissions and other offering expenses. The underwriters also were granted a 30-day option to purchase an additional 2,812,500 shares of common stock at the public offering price per share less underwriting discounts and commissions. This option was not exercised, and it expired on December 22, 2021.

The pre-funded warrants do not expire and are immediately exercisable at any time by either (i) payment in full in immediately available funds for the number of shares of common stock purchased upon such exercise or (ii) a cashless exercise in the event of certain fundamental transactions, in which case the holder would receive upon such exercise the net number of shares of common stock determined according to the formula set forth in the pre-funded warrant. A holder will not be entitled to exercise any portion of any pre-funded warrant if the holder’s ownership of the Company’s common stock would exceed 4.99% to 14.99% following such exercise.

In the event of certain fundamental transactions, the holders of the pre-funded warrants will be entitled to receive upon exercise of the pre-funded warrants the kind and amount of securities, cash or other property that the holders would have received had they exercised the pre-funded warrants immediately prior to such fundamental transaction without regard to any limitations on exercise contained in the pre-funded warrants.

The pre-funded warrants were determined to be equity classified; accordingly, proceeds received from their issuance were recorded as a component of stockholders’ equity within additional paid-in capital. None of the pre-funded warrants were exercised in 2021 and therefore remain outstanding as of December 31, 2021.

At-the-Market (ATM) Facility

In July 2020, the Company filed a $200.0 million registration statement on Form S-3 with the SEC and entered into an at-the-market facility (ATM) to sell up to $75.0 million of common stock under the registration statement. To date, the Company has not sold any shares of common stock under the ATM.