Summit Therapeutics (US:SMMT) Globenewswire·2025-09-10 18:51Core Viewpoint - Pomerantz LLP is investigating potential securities fraud and unlawful business practices by Summit Therapeutics Inc. and its officers or directors, following disappointing clinical trial results and significant stock price declines [1][3][4]. Group 1: Clinical Trial Results - On May 30, 2025, Summit announced topline results from the Phase III clinical trial, HARMONi, indicating that patients treated with ivonescimab and chemotherapy were 48% less likely to progress or die compared to those receiving chemotherapy alone [3]. - However, the drug did not show a statistically significant difference in overall survival, which measures the duration patients live before dying from any cause [3]. Group 2: Stock Price Impact - Following the initial trial results announcement on May 30, 2025, Summit's stock price dropped by $7.99 per share, or 30.5%, closing at $18.22 per share [4]. - On September 7, 2025, additional data revealed weaker results for ivonescimab in North American and European patients compared to those from Europe, leading to a further decline of $6.54 per share, or 25.15%, with a closing price of $19.45 per share on September 8, 2025 [4].