Stockholders' equity	12 Months Ended
Dec. 31, 2023
Stockholders' equity
Stockholders' equity	8. Stockholders’ equity The total number of shares of all classes of capital stock that the Company is authorized to issue is 440,000,000 shares, consisting of 400,000,000 shares of common stock, par value $0.001 per share and 40,000,000 shares of preferred stock, par value $0.001 per share. Reverse Stock Split On February 10, 2023, the Company effectuated a one-for-twenty reverse stock split of its outstanding shares of common stock (the “Reverse Stock Split”). The Reverse Stock Split reduces the Company’s shares of outstanding common stock, stock options and RSU’s. Fractional shares of common stock that would have otherwise resulted from the Reverse Stock Split were rounded down to the nearest whole share and cash in lieu of payments were made to stockholders. All share and per share data for all periods presented in the accompanying financial statements and the related disclosures have been adjusted retrospectively to reflect the Reverse Stock Split. The number of authorized shares of common stock and the par value per share remains unchanged. Conversion of Series A Preferred Stock As discussed in Note 1 and Note 3, the Company issued to the shareholders of Atrin 2,949,630 shares of Series A Preferred Stock as partial consideration of the Atrin acquisition. Each share of Series A Preferred Stock is convertible into 10 shares of common stock on a pre-Reverse Stock Split basis. The Company held a stockholders’ meeting on July 28, 2022 where approval of the conversion of the Series A Preferred Stock into shares of the Company’s common stock in accordance with Nasdaq Listing Rule 5635(a) was received. As of December 31, 2023, a total of 2,893,403 shares of Series A Preferred Stock was converted into 1,446,701 shares of common stock. As of December 31, 2023, a total of 56,227 shares of Series A Preferred Stock remained outstanding. Common Stock The holders of common stock are entitled to one vote for each share of common stock. In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company, after the payment or provision for payment of all debts and liabilities of the Company, the holders of common stock shall be entitled to share in the remaining assets of the Company available for distribution, if any. Shelf Registration Statement On November 12, 2020, the Company filed a universal shelf registration statement with the SEC for the issuance of common stock, preferred stock, warrants, rights, debt securities and units up to an aggregate of $350.0 million (the “2020 Shelf Registration Statement”). On November 30, 2020, the 2020 Shelf Registration Statement was declared effective by the SEC and on November 30, 2023 the 2020 Shelf Registration Statement expired. The 2023 Shelf Registration Stated included an at-the-market offering program with SVB Leerink LLC (the “SVB ATM Program”) and the Company filed a Prospectus Supplement dated September 2, 2022, for the sale of up to $14,744,728 of shares of the Company’s common stock pursuant to its SVB ATM Program. The Company agreed to pay a commission of 3% of the gross proceeds of any common stock sold in connection with the SVB ATM Program. During the years ended December 31, 2023, 2022 and 2021, the Company issued and sold 26,302 shares, 38,481 shares and 18,338 shares, respectively, of common stock under the SVB ATM Program resulting in net proceeds to the Company of approximately $0.3 million, $0.7 million and $1.5 million, respectively. The SVB ATM Program has terminated is no longer effective. In February 2023, the Company 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 to the Company of approximately $4.9 million, after deducting underwriting discounts and offering expenses of approximately $0.6 million. On January 26, 2024, the Company filed a new shelf registration statement (the “2024 Shelf Registration Statement”) with the SEC for issuance of up to $150 million, including a prospectus for the sale of $1 million under the ATM Agreement, as discussed below, which was declared effective on February 2, 2024. The Company subsequently filed a prospectus supplement to the 2024 Shelf Registration Statement for the sale of up to $2 million of shares of common stock pursuant to the ATM Agreement. On January 26, 2024, the Company entered into an At the Market Offering Agreement (the “ATM Agreement”) with H.C. Wainright & Co., LLC (“HCW”). Pursuant to the ATM Agreement and the prospectus supplement filed in connection therewith, the Company may, from time to time, in its sole discretion, issue and sell through HCW, acting as sales agent and/or principal, up to $2 million of shares of common stock. The Company has not made any sales under the ATM Agreement to date. In March 2024, the Company terminated the ATM Agreement with HCW.

Stockholders' equity

12 Months Ended

Dec. 31, 2023

8. Stockholders’ equity

The total number of shares of all classes of capital stock that the Company is authorized to issue is 440,000,000 shares, consisting of 400,000,000 shares of common stock, par value $0.001 per share and 40,000,000 shares of preferred stock, par value $0.001 per share.

Reverse Stock Split

On February 10, 2023, the Company effectuated a one-for-twenty reverse stock split of its outstanding shares of common stock (the “Reverse Stock Split”). The Reverse Stock Split reduces the Company’s shares of outstanding common stock, stock options and RSU’s. Fractional shares of common stock that would have otherwise resulted from the Reverse Stock Split were rounded down to the nearest whole share and cash in lieu of payments were made to stockholders. All share and per share data for all periods presented in the accompanying financial statements and the related disclosures have been adjusted retrospectively to reflect the Reverse Stock Split. The number of authorized shares of common stock and the par value per share remains unchanged.

Conversion of Series A Preferred Stock

As discussed in Note 1 and Note 3, the Company issued to the shareholders of Atrin 2,949,630 shares of Series A Preferred Stock as partial consideration of the Atrin acquisition. Each share of Series A Preferred Stock is convertible into 10 shares of common stock on a pre-Reverse Stock Split basis. The Company held a stockholders’ meeting on July 28, 2022 where approval of the conversion of the Series A Preferred Stock into shares of the Company’s common stock in accordance with Nasdaq Listing Rule 5635(a) was received. As of December 31, 2023, a total of 2,893,403 shares of

Series A Preferred Stock was converted into 1,446,701 shares of common stock. As of December 31, 2023, a total of 56,227 shares of Series A Preferred Stock remained outstanding.

Common Stock

The holders of common stock are entitled to one vote for each share of common stock. In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company, after the payment or provision for payment of all debts and liabilities of the Company, the holders of common stock shall be entitled to share in the remaining assets of the Company available for distribution, if any.

Shelf Registration Statement

On November 12, 2020, the Company filed a universal shelf registration statement with the SEC for the issuance of common stock, preferred stock, warrants, rights, debt securities and units up to an aggregate of $350.0 million (the “2020 Shelf Registration Statement”). On November 30, 2020, the 2020 Shelf Registration Statement was declared effective by the SEC and on November 30, 2023 the 2020 Shelf Registration Statement expired. The 2023 Shelf Registration Stated included an at-the-market offering program with SVB Leerink LLC (the “SVB ATM Program”) and the Company filed a Prospectus Supplement dated September 2, 2022, for the sale of up to $14,744,728 of shares of the Company’s common stock pursuant to its SVB ATM Program. The Company agreed to pay a commission of 3% of the gross proceeds of any common stock sold in connection with the SVB ATM Program. During the years ended December 31, 2023, 2022 and 2021, the Company issued and sold 26,302 shares, 38,481 shares and 18,338 shares, respectively, of common stock under the SVB ATM Program resulting in net proceeds to the Company of approximately $0.3 million, $0.7 million and $1.5 million, respectively. The SVB ATM Program has terminated is no longer effective.

In February 2023, the Company 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 to the Company of approximately $4.9 million, after deducting underwriting discounts and offering expenses of approximately $0.6 million.

On January 26, 2024, the Company filed a new shelf registration statement (the “2024 Shelf Registration Statement”) with the SEC for issuance of up to $150 million, including a prospectus for the sale of $1 million under the ATM Agreement, as discussed below, which was declared effective on February 2, 2024. The Company subsequently filed a prospectus supplement to the 2024 Shelf Registration Statement for the sale of up to $2 million of shares of common stock pursuant to the ATM Agreement. On January 26, 2024, the Company entered into an At the Market Offering Agreement (the “ATM Agreement”) with H.C. Wainright & Co., LLC (“HCW”). Pursuant to the ATM Agreement and the prospectus supplement filed in connection therewith, the Company may, from time to time, in its sole discretion, issue and sell through HCW, acting as sales agent and/or principal, up to $2 million of shares of common stock. The Company has not made any sales under the ATM Agreement to date. In March 2024, the Company terminated the ATM Agreement with HCW.