 SAN DIEGO, Oct. 2, 2021 PRNewswire -- Shareholder rights law firm Johnson Fistel, LLP is investigating potential violations of the federal securities laws by Summit Therapeutics Inc. Summit or the Company NASDAQ: SMMT. On September 21, 2021, Summit disclosed in an SEC filing that the FDA disagrees with its proposed change to the primary endpoint and subsequently implemented in the ongoing Phase III Ri-CoDIFy trials. 