When SPTX insiders can sell

…will agree with the underwriters, subject to certain exceptions, not to dispose of or hedge any of our or their common stock or securities convertible into or exchangeable for shares of common stock, or collectively, the Lock-Up Securities, during the period from the date of this prospectus continuing through the date 180 days after the date of this prospectus, except with the 229 Table of Contents prior written consent of Goldman Sachs & Co. LLC and J.P. Morgan Securities LLC and the Company. This agreement does not apply to any existing employee benefit plans. See the section titled "Shares Available for Future Sale" for a discussion of certain transfer restrictions. The restrictions described in the immediately preceding paragraph do not apply to our officers, directors and holders of substantially all of our capital stock and securities convertible into or exchang…

Common stock to be outstanding immediately after this offering 53,027,817 shares (or 55,151,817 shares if the underwriters exercise their option to purchase additional shares of common stock in full) We will have two series of common stock authorized immediately following this offering: voting common stock and non-voting common stock. We are offering voting stock in this offering and unless otherwise noted, all references in this prospectus to our "common stock" refer to our voting common stock. The non-voting common stock will not be listed for trading on any securities exchange.

In addition, the lock-up party may (a) enter into a written plan meeting the requirements of Rule 10b5-1 under the Exchange Act relating to the transfer, sale or other disposition of the lock-up party's Lock-Up Securities, if then permitted by us, provided that none of the securities subject to such plan may be transferred, 230 Table of Contents sold or otherwise disposed of until after the expiration of the lock-up period and no public announcement, report or filing under the Exchange Act, or any other public fi…

…y to our officers, directors and holders of substantially all of our capital stock and securities convertible into or exchangeable for our common stock with respect to: Transfers of Lock-Up Securities (i) as one or more bona fide gifts or charitable contributions, or for bona fide estate planning purposes, (ii) upon death by will, testamentary document or intestate succession, (iii) if the lock-up party is a natural person, to any member of the lock-up party's immediate family or to any trust for the direct or indirect benefit of such lock-up party or the immediate family of such lock-up party or, if such lock-up party is a trust, t…

…nurse specialists, anesthesiologist assistants, certified registered nurse anesthetists, and certified nurse midwives), and teaching hospitals, as well as ownership and investment interests held by physicians and their immediate family members; federal government price reporting laws, which require manufacturers to calculate and report complex pricing metrics in an accurate and timely manner to government programs; federal consumer protection and unfair competition laws, which broadly regulate marketplace activities and activities that potentially harm consumers; and analogous state and foreign laws and regulations, such as state a…

See the section " Underwriting—Directed Share Program ." The underwriters expect to deliver the shares against payment on or about May 4, 2026. Goldman Sachs & Co. LLC J.P. Morgan Leerink Partners Citigroup Stifel Prospectus dated April 30, 2026 Table of Contents TABLE OF CONTENTS Page PROSPECTUS SUMMARY 1 RISK FACTORS 17 SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS 101 USE OF PROCEEDS 103 DIVIDEND POLICY 104 CAPITALIZATION 105 DILUTION 107 M…

…referred stock into an aggregate of 36,272,475 shares of common stock immediately prior to the completion of this offering, or the Preferred Stock Conversion, and excludes: 8,798,389 shares of common stock issuable upon exercise of outstanding stock options as of December 31, 2025, which includes 228,770 performance-based awards that have not yet been deemed granted for accounting purposes, under our 2024 Equity Incentive Plan, as amended, or the 2024 Plan, with a weighted-average exercise price of $4.68 per share; 962,655 shares of common stock issuable upon exercise of outstanding stock options granted after December 31, 2025 purs…