AstraZeneca to Invest $2 Billion in Summit Therapeutics
The oncology developer also agreed to pair ivonescimab with AstraZeneca’s sonesitatug vedotin in gastrointestinal cancers.
AstraZeneca (AZN) agreed to a $2.0 billion strategic equity investment in Summit Therapeutics Inc. (SMMT), the oncology developer of ivonescimab, and entered a clinical collaboration to test the bispecific antibody with AstraZeneca’s antibody-drug conjugate sonesitatug vedotin.
Under a share purchase agreement, AstraZeneca will buy about 108,955 shares of convertible preferred stock that convert into common stock at a 1:1,000 ratio. At that conversion ratio, the investment equals a common-stock price of $18.36, which the companies described as a premium over Summit’s closing price on the announcement day and as the five-day volume-weighted average price from the prior week plus 10%. Closing is subject to customary conditions and is expected by the end of the week.
Summit also entered a clinical collaboration agreement to evaluate sonesitatug vedotin in combination with ivonescimab, with the intent to start studies in certain gastrointestinal cancer settings imminently. Each company will contribute its compound, jointly fund the studies, and retain development and commercial rights to its own molecule; AstraZeneca is intended to sponsor the trials.
The two companies also executed a non-binding memorandum of understanding to conduct later clinical trials combining ivonescimab with additional AstraZeneca cancer medicines, including other ADCs, with shared development costs and no milestones, royalties, or profit-sharing. Summit said there can be no assurance that the intended collaboration will come to fruition.
Ivonescimab is a potential first-in-class investigational PD-1/VEGF bispecific antibody. More than 5,000 patients have been treated with it in clinical studies globally, and 16 Phase III studies have been announced, are ongoing, or have been completed, including five Summit-sponsored global trials. Five Phase III readouts to date have been positive. A Biologics License Application for HARMONi in EGFR-mutated non-squamous NSCLC was accepted for FDA filing in January 2026, with a PDUFA goal of November 14, 2026.
Susan Galbraith, executive vice president of oncology haematology R&D at AstraZeneca, said a core pillar of the company’s oncology strategy is to broaden the reach of its ADC portfolio with combinations alongside next-generation immunotherapies, and that bispecifics targeting PD-1 and VEGF have the potential to improve on current immunotherapies.
Robert W. Duggan, chairman and co-chief executive officer of Summit, said the investment and collaboration are a powerful validation of the potential of ivonescimab. Summit has agreed to file an SEC registration statement for resale of the common stock after closing.