common stock pursuant to our ATM offering program. During the three months ended March 31, 2023, we issued and sold 26,302 shares of common stock under the ATM offering program resulting in net proceeds of approximately $0.3 million after deducting approximately $8,000 in issuance costs. The ATM offering program has terminated and is no longer effective.
In February 2023, we issued and sold 1,050,000 shares of common stock at a public offering price of $5.25 per share pursuant to the 2020 Shelf Registration Statement resulting in net proceeds of approximately $4.9 million, after deducting underwriting discounts and offering expenses of approximately $0.6 million.
On January 26, 2024, we filed a shelf registration statement, or the 2024 Shelf Registration Statement, with the SEC for the issuance of common stock, preferred stock, warrants, rights and debt securities and units up to an aggregate of $150 million, including a prospectus for the sale of $1 million of shares of our common stock under the ATM Agreement, as discussed below, which was declared effective on February 2, 2024. We subsequently filed a prospectus supplement to the 2024 Shelf Registration Statement for the sale of up to $2 million of shares of our common stock pursuant to the ATM Agreement.
On January 26, 2024, we entered into an At the Market Offering Agreement, or the ATM Agreement, with H.C. Wainright & Co., LLC, or HCW. Pursuant to the ATM Agreement and the prospectus supplement to the 2024 Shelf Registration Statement filed in connection therewith, we were able, from time to time, in our sole discretion, to issue and sell through HCW, acting as sales agent and/or principal, up to $2 million of shares of our common stock. We have not made any sales under the ATM Agreement to date. In March 2024, we terminated the ATM Agreement with HCW.
On March 11, 2024, we entered into a securities purchase agreement with certain purchasers, or the Purchasers, pursuant to which we agreed to issue and sell to the Purchasers in a private placement offering exempt from registration under the Securities Act, and the Purchasers agreed to purchase from us (i) 1,687,712 shares of our common stock at a purchase price of $7.29 per share (the “Shares”), (ii) pre-funded common stock purchase warrants to purchase an aggregate of up to 507,076 shares of our common stock at an exercise price of $0.001 per share (the “Pre-Funded Shares”), (iii) tranche A common stock purchase warrants to purchase up to 1,097,394 shares of our common stock at an exercise price of $7.29 per share, or the Tranche A Warrants, and (iv) tranche B common stock purchase warrants to purchase up to 1,097,394 shares of our common stock at an exercise price of $9.1125 per share, or the Tranche B Warrants. The Tranche A Warrants will be exercisable until the earlier of (i) the three-year anniversary of issuance and (ii) 30 days after we announce the recommended Phase 2 dose for ATRN-119, and, following such announcement, the daily volume weighted average price of our common stock equals or exceeds $14.58 for 30 consecutive trading days. The Tranche B Warrants will be exercisable until the earlier of (i) the five-year anniversary of issuance and (ii) 30 days after we announce the recommended Phase 2 dose for APR-1051 and, following such announcement, the daily volume weighted average price of our common stock equals or exceeds $18.225 for 30 consecutive trading days. To the extent that the exercise of a Tranche A Warrant or Tranche B Warrant would result in the holder beneficially owning greater than 4.99% (or, at the election of the holder, greater than 9.99%) of our outstanding common stock immediately following such exercise, the holder will instead receive pre-funded warrants in substantially the same form as the pre-funded warrants issued at closing. The aggregate gross proceeds from the issuance of common stock and warrants totaled approximately $16.0 million, before deducting placement agent fees and offering costs of approximately $1.3 million, and the gross proceeds from potential future warrant cash exercises is expected to be up to approximately $18.0 million, before deducting placement agent fees. In April 2024, we registered on Form S-3 the resale of the Shares, the Pre-Funded Shares and the shares underlying the Tranche A Warrants and Tranche B Warrants.
Recent accounting pronouncements
From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that we adopt as of the specified effective date.
We do not believe that any recently issued, but not yet effective accounting pronouncements, if adopted, would have a material impact on our financial statements.