In August 2020, the Company filed a prospectus supplement, pursuant to which it sold $20.0 million of its common stock in At-The-Market (ATM) offerings. In February 2021, the Company filed a prospectus supplement pursuant to which it can issue and sell an aggregate of up to an additional $30.0 million of its common stock from time to time in ATM offerings. During the three months ended March 31, 2021, the Company sold 1,149,820 shares under the ATM program for net proceeds of $19.6 million, net of commissions and offering expenses. There were no ATM sales during the three months ended March 31, 2020.

On May 7, 2021, the Company filed a prospectus supplement, pursuant to which it can issue and sell an aggregate of up to an additional $50.0 million of its common stock from time to time in the ATM offerings.

The Company is required to reserve and keep available out of its authorized but unissued shares of common stock a number of shares sufficient to effect the conversion of all outstanding options granted and available for grant under the incentive plans, shares reserved for issuance under the employee stock purchase plan and issued warrants.

	March 31, 2021		December 31, 2020
Shares reserved under Series A warrant		7,802,241		7,802,241
Shares reserved under Series B warrant		2,524,732		2,574,727
Shares reserved for future option grants under equity plans		1,521,028		1,117,796
Outstanding stock options under equity incentive plans		4,667,173		4,146,928
Outstanding warrants		727,122		727,122
Shares reserved under the 2015 employee stock purchase plan		17,500		17,500
Total common stock reserved for issuance		17,259,796		16,386,314

Preferred Stock

On November 13, 2019, the Company completed an underwritten public offering whereby it issued 103,000 shares of Series A Convertible Voting Preferred Stock together with Series A warrants and Series B warrants for a combined purchase price of $1,000. The aggregate proceeds received by the Company was $97.7 million, net of underwriting discounts and commissions and offering expenses. Each share of Series A Preferred Stock was convertible into shares of the Company’s common stock equal to the stated value of the Series A Preferred Stock of $1,000 divided by the voting conversion price of $13.20. On January 29, 2020, all shares of Series A Preferred Stock converted into 7,803,273 shares of the Company’s common stock.

Common Stock Warrants

In connection with the Company’s November 2019 public offering of the Series A Preferred Stock, the Company issued Series A warrants to purchase up to 7,802,241 shares of common stock at an exercise price equal to $13.20, and Series B warrants to purchase up to 2,574,727 shares of common stock at an exercise price equal to $13.20. Both Series A and Series B warrants are exercisable following stockholder approval in January 2020 of an increase in authorized common stock sufficient to allow for the exercise of the warrants, subject to certain beneficial ownership limitations. The Series A warrants will expire five years from the date they first became exercisable or on January 22, 2025 and contain a cash and/or cashless exercise provision. The Series B warrants will expire on the 75^th day anniversary following the announcement of top-line data from the Company’s MOMENTUM Phase 3 clinical trial of momelotinib and may only be exercised by paying the exercise price in cash. During the three months ended March 31, 2021, 151,500 Series B warrants to purchase 49,995 shares of common stock were exercised for proceeds of $0.7 million. There were no warrants exercised during the three months ended March 31, 2020.

In connection with obligations under the amendment to the Asset Purchase Agreement (See Note 7), the Company issued to Gilead 725,283 shares of the Company’s common stock and a warrant to purchase 725,283 shares of common stock at a price per share of $13.20 on January 31, 2020. The warrant is immediately exercisable, will expire on January 31, 2025 and contains a cash and/or cashless exercise provision.

In August 2018, in connection with a Loan and Security Agreement (Loan Agreement) with Silicon Valley Bank (SVB), the Company issued a warrant to SVB to purchase 1,839 of the Company’s common stock at a price per share of $74.80. The warrant is immediately exercisable, will expire on August 21, 2028 and contains a cashless exercise provision.