Sec Form 13D Filing - ORBIMED ADVISORS LLC filing for Sionna Therapeutics, Inc. - 2025-02-13

601 Lexington Avenue, 54th Floor, New York, New York 10022.

OrbiMed Advisors is the managing member or general partner of certain entities as more particularly described in Item 6 below.OrbiMed GP is the general partner of a limited partnership as more particularly described in Item 6 below.Carl L. Gordon is a member of OrbiMed Advisors.Sven H. Borho is a member of OrbiMed Advisors.W. Carter Neild is a member of OrbiMed Advisors.Geoffrey C. Hsu is a member of OrbiMed Advisors.C. Scotland Stevens is a member of OrbiMed Advisors.David P. Bonita is a member of OrbiMed Advisors.Peter A. Thompson is a member of OrbiMed Advisors.Matthew S. Rizzo is a member of OrbiMed Advisors.Trey Block is the Chief Financial Officer of OrbiMed Advisors.

Not applicable.

Not applicable.

Item 2(a) is incorporated herein by reference.

In February 2022, OrbiMed Advisors and GP VIII, pursuant to their authority under the limited partnership agreement of OrbiMed Private Investments VIII, L.P. ("OPI VIII"), as more particularly described in Item 6 below, caused OPI VIII to purchase 2,560,951 shares of Series B convertible preferred stock, par value $0.001 per share ("Series B preferred stock"), at a purchase price of $9.762 per share of Series B preferred stock.In March 2024, OrbiMed Advisors and GP VIII, pursuant to their authority under the limited partnership agreement of OPI VIII, caused OPI VIII to purchase 2,048,760 shares of Series C convertible preferred stock, par value $0.001 per share ("Series C preferred stock"), at a purchase price of $9.762 per share of Series C preferred stock.Each outstanding share of Series B preferred stock and Series C preferred stock converted into Shares at a ratio of 1-for-1.4611 immediately prior to the completion of the Issuer's initial public offering (the "IPO").On and prior to the closing of the IPO, OrbiMed Advisors and GP VIII, pursuant to their authority under the limited partnership agreement of OPI VIII, caused OPI VIII to purchase 550,000 Shares in the IPO at purchase price of $18.00 per Share.The source of funds for such purchases was the working capital of OPI VIII.

This Statement on Schedule 13D relates to the acquisition of Shares by the Reporting Persons. The Shares acquired by the Reporting Persons were acquired for the purpose of making an investment in the Issuer and not with the intention of acquiring control of the Issuer's business on behalf of the Reporting Persons' respective advisory clients.The Reporting Persons from time to time intend to review their investment in the Issuer on the basis of various factors, including the Issuer's business, financial condition, results of operations and prospects, general economic and industry conditions, the securities markets in general and those for the Issuer's Shares in particular, as well as other developments and other investment opportunities. Based upon such review, the Reporting Persons will take such actions in the future as the Reporting Persons may deem appropriate in light of the circumstances existing from time to time. If the Reporting Persons believe that further investment in the Issuer is attractive, whether because of the market price of Shares or otherwise, they may acquire Shares or other securities of the Issuer either in the open market or in privately negotiated transactions. Similarly, depending on market and other factors, the Reporting Persons may determine to dispose of some or all of the Shares currently owned by the Reporting Persons or otherwise acquired by the Reporting Persons either in the open market or in privately negotiated transactions.Except as set forth in this Schedule 13D, the Reporting Persons have not formulated any plans or proposals which relate to or would result in: (a) the acquisition by any person of additional securities of the Issuer or the disposition of securities of the Issuer, (b) an extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries, (c) a sale or transfer of a material amount of the assets of the Issuer or any of its subsidiaries, (d) any change in the present Board of Directors or management of the Issuer, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the board, (e) any material change in the Issuer's capitalization or dividend policy of the Issuer, (f) any other material change in the Issuer's business or corporate structure, (g) any change in the Issuer's charter or bylaws or other instrument corresponding thereto or other action which may impede the acquisition of control of the Issuer by any person, (h) causing a class of the Issuer's securities to be deregistered or delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association, (i) a class of equity securities of the Issuer becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Act or (j) any action similar to any of those enumerated above.

The following disclosure is based upon 44,108,934 outstanding Shares of the Issuer, as set forth in the Issuer's Registration Statement on Form S-1, filed with the Securities and Exchange Commission (the "SEC") on February 3, 2025, as supplemented by the registration adding securities to prior Form S-1 registration, filed with the SEC on February 6, 2025.As of the date of this filing, OPI VIII, a limited partnership organized under the laws of Delaware, holds 3,704,959 Shares constituting approximately 8.4% of the issued and outstanding Shares. OrbiMed GP is the general partner of OPI VIII, pursuant to the terms of the limited partnership agreement of OPI VIII, and OrbiMed Advisors is the managing member of OrbiMed GP, pursuant to the terms of the limited liability company agreement of OrbiMed GP. As a result, OrbiMed Advisors and OrbiMed GP share power to direct the vote and disposition of the Shares held by OPI VIII and may be deemed directly or indirectly, including by reason of their mutual affiliation, to be the beneficial owners of the Shares held by OPI VIII. OrbiMed Advisors exercises this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the Shares held by OPI VIII.

Item 5(a) is incorporated by reference herein.

Except as disclosed in Item 3, the Reporting Persons have not effected any transactions during the past sixty (60) days in any Shares.

Not applicable.

Not applicable.

In addition to the relationships between the Reporting Persons described in Items 2 and 5 above, OrbiMed GP is the general partner of OPI VIII, pursuant to the terms of the limited partnership agreement of OPI VIII. Pursuant to this agreement and relationship, OrbiMed GP has discretionary investment management authority with respect to the assets of OPI VIII. Such authority includes the power to vote and otherwise dispose of securities held by OPI VIII. The number of outstanding Shares attributable to OPI VIII is 3,704,959 Shares. OrbiMed GP, pursuant to its authority under the limited partnership agreement of OPI VIII, may be considered to hold indirectly 3,704,959 Shares.In addition to the relationships between the Reporting Persons described in Items 2 and 5 above, OrbiMed Advisors is the managing member of OrbiMed GP, pursuant to the terms of the limited liability company agreement of OrbiMed GP. Pursuant to these agreements and relationships, OrbiMed Advisors and OrbiMed GP have discretionary investment management authority with respect to the assets of OPI VIII. Such authority includes the power of OrbiMed GP to vote and otherwise dispose of securities held by OPI VIII. The number of outstanding Shares attributable to OPI VIII is 3,704,959 Shares. OrbiMed Advisors, pursuant to its authority under the terms of the limited liability company agreement of OrbiMed GP, may also be considered to hold indirectly 3,704,959 Shares.Peter A. Thompson ("Thompson"), a member of OrbiMed Advisors, is a member of the Board of Directors of the Issuer and, accordingly, OrbiMed Advisors and GP VIII may have the ability to affect and influence control of the Issuer. From time to time, Thompson may receive stock options or other awards of equity-based compensation pursuant to the Issuer's compensation arrangements for non-employee directors. Pursuant to an agreement with OrbiMed Advisors and GP VIII, Thompson is obligated to transfer any securities issued under any such stock options or other awards, or the economic benefit thereof, to OrbiMed Advisors and GP VIII, who will in turn ensure that such securities or economic benefits are provided to OPI VIII.Investors' Rights AgreementIn addition, OPI VIII and certain other stockholders of the Issuer entered into a Third Amended and Restated Investors' Rights Agreement with the Issuer, dated as of March 4, 2024 (the "Investors' Rights Agreement"). Pursuant to the Investors' Rights Agreement and subject to the terms and conditions therein, the parties agreed that:Form S-1 Registration RightsUpon the completion of the IPO, certain holders of Shares, including those issuable upon the conversion of shares of Series B preferred stock and Series C preferred stock, will be entitled to certain demand registration rights. At any time beginning 180 days after the completion of the IPO, the holders of a majority of registrable securities then outstanding may request that the Issuer register all or a portion of their Shares on Form S-1 with respect to at least 40% of the registrable securities then outstanding. With certain exceptions, the Issuer is not required to effect the filing of a registration statement during the period starting with the date of the filing of, and ending on a date 60 days following the effective date of the registration statement for the IPO.Piggyback Registration RightsAfter the IPO, in the event that the Issuer proposes to register any of its securities under the Securities Act of 1933, as amended, either for its own account or for the account of other security holders, the holders of such Shares will be entitled to certain piggyback registration rights allowing the holder to include their Shares in such registration, subject to certain marketing and other limitations.Form S-3 Registration RightsUpon the completion of the IPO, certain holders of Shares, including those issuable upon the conversion of shares of Series B preferred stock and Series C preferred Stock, will be entitled to certain Form S-3 registration rights. Holders of at least 10% of registrable securities then outstanding can make a request that the Issuer register their Shares on Form S-3 if the Issuer is qualified to file a registration statement on Form S-3 and if the reasonably anticipated aggregate net proceeds of the Shares offered would equal or exceed $5 million. The Issuer will not be required to effect more than two registrations on Form S-3 within any twelve-month period. The right to have such Shares registered on Form S-3 is further subject to other specified conditions and limitations.Expiration of Registration RightsThe demand registration rights and short-form registration rights granted under the Investors' Rights Agreement will terminate on the fifth anniversary of the completion of the IPO.Lock-Up AgreementIn addition, in connection with the IPO, OPI VIII and Thompson each entered into a lock-up agreement (the "Lock-Up Agreement") with the Issuer's underwriters pursuant to which, among other things, OPI VIII and Chimovits each agreed not to, except in limited circumstances, directly or indirectly, from the date of the Lock-Up Agreement until 180 days after the date of the final prospectus supplement relating to the IPO: (i) offer, sell, contract to sell, pledge, grant any option, right or warrant to purchase, purchase any option or contract to sell, lend or otherwise transfer or dispose of any Shares or any options or warrants to purchase any Shares or any securities convertible into, exchangeable for or that represent the right to receive Shares; (ii) engage in any hedging or other transaction or arrangement (including, without limitation, any short sale or the purchase or sale of, or entry into, any put or call option, or combination thereof, forward, swap or any other derivative transaction or instrument, however described or defined) which is designed to or which reasonably could be expected to lead to or result in a sale, loan, pledge or other disposition (whether by the undersigned or someone other than the undersigned), or transfer of any of the economic consequences of ownership, in whole or in part, directly or indirectly, of any Shares or any options or warrants to purchase any Shares or any securities convertible into, exchangeable for or that represent the right to receive Shares, whether any such transaction or arrangement (or instrument provided for thereunder) would be settled by delivery of Shares or other securities, in cash or otherwise; (iii) make any demand for, or exercise any right with respect to, the registration of any Shares or any options or warrants to purchase any Shares or any securities convertible into, exchangeable for or that represent the right to receive Shares.The foregoing description of the Registration Rights Agreement and the Lockup Agreement do not purport to be complete and are qualified in their entirety by reference to the full texts of the Registration Rights Agreement and the Lockup Agreement, which are filed as Exhibit 2 and Exhibit 3, respectively, and incorporated herein by reference.

Exhibit Description------------------------------------------------------------------------1. Joint Filing Agreement among OrbiMed Advisors LLC and OrbiMed Capital GP VIII LLC.------------------------------------------------------------------------2. Third Amended and Restated Investors' Rights Agreement, by and between the Issuer and certain of its stockholders, dated as of March 4, 2024 (incorporated by reference to Exhibit 4.2 to the Issuer's Registration Statement on Form S-1/A, filed with the SEC on February 3, 2025).------------------------------------------------------------------------3. Form of Lock-Up Agreement (incorporated by reference to Annex II to Exhibit 1.1 to the Issuer's Registration Statement on Form S-1/A, filed with the SEC on February 3, 2025).