AstraZeneca announced a $2 billion equity investment in Summit Therapeutics alongside plans to run clinical collaboration trials pairing Summit’s PD-1/VEGF bispecific ivonescimab with AstraZeneca antibody-drug conjugates. The strategy targets combinations intended to broaden the ADC portfolio with next-generation immunotherapy regimens. AstraZeneca will purchase convertible preferred stock representing about a 12% stake in Summit’s outstanding common stock at closing terms, according to the deal announcement. The companies said the collaboration will evaluate ivonescimab with multiple AstraZeneca assets, starting with the company’s CLDN18.2-directed ADC in gastrointestinal cancers. The move follows separate clinical readouts from AstraZeneca and data from Summit’s ivonescimab development, reinforcing AstraZeneca’s emphasis on stacking mechanisms across tumor types. For the market, it underscores how quickly PD-1/VEGF bispecific programs are attracting large “platform-style” combination bets.