AstraZeneca is to invest $2bn (£1.51bn) in US biopharma firm Summit Therapeutics as part of a strategic equity investment and clinical collaboration aimed at expanding its oncology portfolio.

The FTSE 100 company will receive rights equivalent to around 12% of New York-listed Summit’s outstanding common stock, or 10.6% on a fully diluted basis, through newly issued equity.

The companies will collaborate on trials combining Summit’s ivonescimab, a PD-1/VEGF bispecific antibody, with AstraZeneca’s sonesitatug vedotin (Sone-Ve), a Claudin-18.2-targeting antibody drug conjugate (ADC), initially in gastrointestinal cancers. They also intend to develop a broader global programme combining ivonescimab with AstraZeneca’s cancer medicines, including additional ADCs.

Susan Galbraith, executive vice president, Oncology Haematology R&D, AstraZeneca, said: “A core pillar of our oncology strategy is to broaden the reach of our ADC portfolio as the backbone of treatment across tumour types with combinations alongside next-generation immunotherapies. This opportunity to combine ivonescimab with AstraZeneca’s ADC portfolio, including with Sone-Ve, could enable new regimens that raise the bar for patients with cancer across the treatment landscape."

Dr. Maky Zanganeh, president and co-CEO of Summit Therapeutics, added: “The developments announced today with AstraZeneca open an exciting new chapter in the advancement of ivonescimab.”

Ivonescimab is approved for certain non-small cell lung cancer patients in China and is being assessed in Phase III trials across a range of cancers. Summit holds exclusive development and commercial rights outside China. AstraZeneca recently reported positive high-level results for Sone-Ve in a Phase III trial involving patients with advanced gastric cancer.

AstraZeneca’s investment is expected to close within a week, subject to customary conditions.

Summit shares rose 18% in extended-hours trading following news of the deal.

---