LOS ANGELES, Sept. 16, 2025 (GLOBE NEWSWIRE) -- The Portnoy Law Firm advises Summit Therapeutics Inc. investors  ("Summit" or the "Company") (NASDAQ: SMMT) investors that the firm has initiated an investigation into possible securities fraud, and may file a class action on behalf of investors.  Investors are encouraged to contact attorney Lesley F. Portnoy, by phone 844-767-8529 or email: lesley@portnoylaw.com, to discuss their legal rights, or join the case via https://portnoylaw.com/summit-therapeutics-in ...