price of $7.47 per share. As of March 31, 2025, the SVB Warrant was exercisable for 6 shares of our common stock at an exercise price of $44,820 per share.
In April 2020, in connection with a securities purchase agreement, we issued to H.C. Wainwright & Co., LLC and certain of its designees in a private placement pursuant to Section 4(a)(2) of the Securities Act, a warrant to purchase up to 37,500 shares of our common stock, at an exercise price of $12.50 per share (the “April 2020 Warrant”). As of March 31, 2025, the April 2020 Warrant was exercisable for 159 shares of our common stock at an exercise price of $3,000 per share. The April 2020 Warrant expired unexercised, on April 13, 2025.
In January 2021, in connection with a securities purchase agreement, we issued to certain institutional investors in a private placement pursuant to Section 4(a)(2) of the Securities Act, a warrant to purchase up to 2,500,000 shares of our common stock, at an exercise price of $4.00 per share (the “January 2021 Warrant”). As of March 31, 2025, the January 2021 Warrant was exercisable for 10,421 shares of our common stock at an exercise price of $1,447.20 per share.
In October 2021, in connection with a securities purchase agreement, we issued to certain institutional investors in a private placement pursuant to Section 4(a)(2) of the Securities Act, a warrant to purchase up to 4,307,693 shares of our common stock, at an exercise price of $3.75 per share (the “October 2021 Warrant”). As of March 31, 2025, the October 2021 Warrant was exercisable for 15,390 shares of our common stock at an exercise price of $900 per share. The October 2021 Warrant expired unexercised, on April 7, 2025.
In June 2024, we issued to Armistice Capital Master Fund Ltd and Dong-A in a private placement pursuant to Section 4(a)(2) of the Securities Act, (i) pre-funded warrants to purchase up to 1,781,171 shares of common stock at an exercise price of $0.001 per share, (ii) Series A Warrants to purchase 5,089,060 shares of common stock at an exercise price of $3.93 per share, and (iii) Series B Warrants to purchase up to 7,633,591 shares of common stock at an exercise price of $3.93 per share. As of March 31, 2025, the pre-funded warrants were exercisable for up to 1,430,000 shares of our common stock at an exercise price of $0.0001 per share, the Series A Warrants were exercisable for up to 5,089,060 shares of our common stock at an exercise price of $3.93 per share, and our Series B Warrants were exercisable for 7,633,591 shares of our common stock at an exercise price of $3.93 per share. The pre-funded warrants were exercised in full on April 15, 2025, and the Series A Warrants expired unexercised, on June 14, 2025.
In June 2024, we issued to H.C. Wainwright & Co., LLC and certain of its designees in a private placement pursuant to Section 4(a)(2) of the Securities Act, a warrant to purchase up to 127,227 shares of common stock at an exercise price of $4.9125 per share (the “Placement Agent Warrants”). As of March 31, 2025, the Placement Agent Warrants were exercisable for 127,227 shares of our common stock at an exercise price of $4.9125 per share.
In May 2025, we issued to Dong-A Socio Holdings, pursuant to the Securities Purchase Agreement, pre-funded warrants to purchase up to 4,605,162 shares of our common stock at an exercise price of $0.001 per share. The pre-funded warrants were exercised for shares of our common stock on June 30, 2025.
Options and Restricted Stock Units
As of March 31, 2025, (i) no shares of common stock remain available for issuance under our 2019 Equity Incentive Plan (the “2019 Plan”), and 2,067,064 shares of common stock remain available for potential issuance under our Amended and Restated 2021 Inducement Plan and our Amended and Restated Equity Incentive Plan (“2022 Plan”), (ii) stock options to purchase an aggregate of 1,575 shares of common stock were outstanding under our 2019 Plan and stock options to purchase an aggregate of 3,125 shares of common stock were outstanding under our 2022 Plan, and (iii) 149,239 unvested shares of restricted stock units were outstanding under our 2022 Plan.
Anti-Takeover Effects of Delaware Law and Our Certificate of Incorporation and Bylaws
Our Certificate of Incorporation and Bylaws contain provisions that could make it more difficult to complete an acquisition of us by means of a tender offer, a proxy contest or otherwise or the removal and replacement of our incumbent officers and directors.