AstraZeneca agreed to invest $2 billion in Summit Therapeutics, taking an equity stake and setting up clinical collaborations aimed at advancing ivonescimab, a PD-1/VEGF bispecific. The partnership also plans to test ivonescimab in combination with AstraZeneca’s antibody-drug conjugate (ADC) portfolio, including a CLDN18.2-directed asset, with early focus on gastrointestinal cancers. AstraZeneca will purchase roughly 109,000 shares of Summit convertible preferred stock, representing a 12.0% stake in Summit’s common stock, subject to regulatory approvals for conversion. The companies say they will jointly contribute medicines for combination trials and share trial costs while keeping separate development and commercial rights. The move follows encouraging trial signals cited by AstraZeneca and adds to a growing trend of pairing PD-1/VEGF bispecifics with ADC backbones to build new combination regimens across tumor types.