Prior to the Issuer's initial public offering (the "IPO"), (i) the Fund purchased an aggregate of 1,284,000 shares of Common Stock, 819,153 shares of Series Seed Preferred Stock, 1,229,830 shares of Series A Preferred Stock, 923,773 shares of Series B Preferred Stock and 4,364,874 shares of Series C Preferred Stock; (ii) the Nexus Fund purchased an aggregate of 500,000 shares of Common Stock, 319,069 shares of Series Seed Preferred Stock, and 451,580 shares of Series A Preferred Stock; (iii) the Nexus Fund III purchased an aggregate of 2,155,469 shares of Series B Preferred Stock and 1,091,219 shares of Series C Preferred Stock; and (iv) the Account purchased an aggregate of 216,000 shares of Common Stock, 138,054 Shares of Series Seed Preferred Stock and 124,908 shares of Series A Preferred Stock. The aggregate purchase price of the foregoing was $95,573,941. On January 31, 2025, the Issuer effected a 1-for-1.4611 reverse stock split of its common stock (the "Reverse Stock Split"). In connection with the closing of the IPO, on February 10, 2025, the Preferred Stock discussed above automatically converted into shares of Common Stock on a 1-for-1.4611 basis. The Fund and the Nexus Fund III also purchased 1,022,586 and 102,414 shares of Common Stock, respectively, from the underwriters of the IPO at the IPO price of $18.00 per share, for an aggregate purchase price of $20,250,000. All purchases of the securities described herein were for cash and were funded by working capital of the Fund, the Nexus Fund, the Nexus Fund III and the Account, as applicable.

Lock-up Agreements The holders of substantially all of the Issuer's pre-IPO capital stock, including the Fund, the Nexus Fund, the Nexus Fund III and the Account, and each of the Issuer's directors, entered into lock-up agreements (the "Lock-Up Agreements") with the representatives of the underwriters of the Issuer's IPO. Pursuant to the Lock-Up Agreements, none of the Fund, the Nexus Fund, the Nexus Fund III and the Account is permitted, with limited exceptions, for a period of 180 days from February 6, 2025, to dispose of or hedge any of the Issuer's securities, except with the prior written consent of Goldman Sachs & Co. LLC and TD Securities (USA) LLC. The description of the Lock-Up Agreements contained in this Item 6 is qualified in its entirety by reference to the full text of the form of Lock-up Agreement filed as Exhibit 99.2 to this Schedule 13D and incorporated by reference herein. Investors' Rights Agreement On March 4, 2024, the Issuer, the Fund, the Nexus Fund, the Nexus Fund III and the Account and certain other parties entered into an amended and restated investors' rights agreement (the "Investors' Rights Agreement"). The Investors' Rights Agreement provides the Fund, the Nexus Fund, the Nexus Fund III and the Account and other parties thereto with certain demand registration rights, including shelf registration rights, in respect of the shares of Common Stock issued to it upon conversion of the convertible preferred stock, subject to certain conditions. In addition, in the event that the Issuer registers additional shares of Common Stock for its own account or for the account of other holders of its securities, the Fund, the Nexus Fund, the Nexus Fund III and the Account and certain other parties are entitled to include their shares in the registration, subject to certain limitations. The registration rights will terminate on the earlier to occur of (a) the closing of certain liquidation events, or (b) the fifth anniversary of the completion of the IPO. The Investors' Rights Agreement contains customary cross-indemnification provisions, pursuant to which the Issuer is obligated to indemnify the Fund, the Nexus Fund, the Nexus Fund III and the Account and other parties in the event of material misstatements or omissions in the registration statement attributable to the Issuer or any violation or alleged violation whether by action or inaction by the Issuer under certain securities laws and each of the Fund, the Nexus Fund, the Nexus Fund III and the Account is obligated to indemnify the Issuer for material misstatements or omissions in the registration statement attributable to it, subject to certain limitations. The description of the Investors' Rights Agreement contained in this Item 6 is qualified in its entirety by reference to the full text of the Investors' Rights Agreement filed as Exhibit 99.3 to this Schedule 13D and incorporated by reference herein. Equity Awards Joshua Resnick, a Partner at RA Capital, is a member of the Board of Directors of the Issuer. From time to time, Dr. Resnick 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 RA Capital, Dr. Resnick is obligated to transfer any securities issued under any such stock options or other awards, or the economic benefit thereof, to RA Capital.

Exhibit 99.1 Joint Filing Agreement Exhibit 99.2 Form of Lock-up Agreement (incorporated by reference to Annex II to the Form of Underwriting Agreement filed as Exhibit 1.1 to the Issuer's Registration Statement on Form S-1, as amended (Registration No. 333-284352), filed with the SEC on February 3, 2025). Exhibit 99.3 Amended and Restated Investors' Rights Agreement, by and among the Issuer and certain of its stockholders (incorporated by reference to Exhibit 4.2 to the Issuer's Registration Statement on Form S-1, as amended (Registration No. 333-284352), filed with the SEC on February 3, 2025).