AstraZeneca puts $2 billion into Summit Therapeutics and partners to test ivonescimab with its oncology pipeline

AstraZeneca announced a $2 billion equity investment in Summit Therapeutics, acquiring roughly 109,000 shares of convertible preferred stock. The deal will give AstraZeneca about a 12% stake in Summit, or around 10.6% on a fully‑diluted basis.

Alongside the cash infusion, the companies will evaluate Summit’s experimental antibody ivonescimab in combination with AstraZeneca’s cancer medicines. The first joint study will pair ivonescimab with AstraZeneca’s targeted therapy Sone‑Ve in gastrointestinal tumors, with plans to explore additional combinations, including other antibody‑drug conjugates.

Both firms will share development costs for the collaborative programs, while each retains its own ownership rights to the respective assets.