Summit Therapeutics Stock Plummets 30.50% Amidst Mixed Trial Results and 406th Ranking in Trading Volume

On May 30, 2025, Summit Therapeutics (SMMT) experienced a significant drop of 30.50% in its stock price, with a trading volume of 3.91 billion, ranking 406th in the day's market activity.

Summit Therapeutics' recent data release for its lead asset, ivonescimab, has sparked a heated debate among investors. The Phase III HARMONi trial showed a 48% reduction in the risk of disease progression or death, with a hazard ratio of 0.52 and a p-value of less than 0.00001. However, the lack of statistically significant overall survival (OS) data has raised concerns, despite a positive trend in OS results.

The FDA's requirement for statistically significant OS data poses a challenge, but the global consistency of PFS data and the drug's unique mechanism offer hope for conditional approval or an accelerated pathway. Citigroup has upgraded Summit to a Buy rating with a target price of $35, citing potential for OS data to become significant by the end of 2025, China's expanded approval, and the Pfizer partnership.

Summit's strategic partnership with Pfizer to evaluate ivonescimab with antibody-drug conjugates (ADCs) could expand indications, differentiate the drug, and accelerate approval. This collaboration adds credibility and resources to navigate regulatory hurdles.

While U.S.-China trade tensions are a concern, Summit's exposure is limited to supply chain diversification. The company's global trials and partnerships ensure data diversity and reduce reliance on any single market. Additionally, Summit's biologics are unlikely targets for punitive tariffs.

At a post-selloff price of $21.50, Summit trades at 6.3x its 2025 cash balance, with a runway to 2026. Citigroup's $35 target assumes a $2B+ peak sales scenario for ivonescimab, achievable with FDA approval, mature OS data, and secondary indications from the Pfizer collaboration.