Summit Therapeutics Files Prospectus Supplement for Resale of up to 108.95M Common Shares

Executive Summary

On November 4, 2026, Summit Therapeutics Inc. ($SMMT) submitted a Current Report on Form 8-K under Item 8.01 (Other Events) and Item 9.01 (Financial Statements and Exhibits).

The report incorporates by reference a legal opinion from Baker & Hostetler LLP (Exhibit 5.1) related to a prospectus supplement filed under the company's Form S-3 shelf registration statement (File No. 333-296642).

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Key Filing Details

• Underlying Transaction: Resale from time to time by an identified selling stockholder of up to 108,955,369 shares of common stock ($0.01 par value per share).
• Mechanism: The common shares are issuable upon the conversion of 108,955.3686 shares of Class A Convertible Preferred Stock held by the selling stockholder.
• Legal Status: Counsel confirmed that upon due registration and issuance pursuant to the terms of the Preferred Shares, the common shares will be validly issued, fully paid, and non-assessable.

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Market and Trading Implications

• Potential Dilution / Float Increase: Although this filing covers a secondary offering/resale (the company does not directly receive proceeds from selling stockholder share sales), the registration of up to ~108.96 million common shares represents potential additional public float and market supply upon conversion.
• Trading Significance: Medium — Investors often monitor resale registration statements of preferred stock conversions for potential overhang or market supply dynamics.