Summit Therapeutics: Valuation Check After Q3 2025 Earnings and Insider Share Purchases.

Summit Therapeutics reported weak Q3 2025 earnings with deeper losses, but directors bought millions of dollars worth of shares. The stock price has fallen 8.73% in 30 days and 26.62% in 90 days, but its three-year total shareholder return is over 600%. Analysts see major upside, but fair value models flash caution and fundamentals are loss-making. The price-to-book ratio of 69.2x is richly priced compared to peers and the wider biotech space.