AstraZeneca has agreed to invest $2 billion in Summit Therapeutics to support the development of ivonescimab and explore new cancer treatment combinations involving antibody-drug conjugates (ADCs).
The investment will be made through newly issued preferred stock in Summit. Once completed, AstraZeneca will hold rights equivalent to about 12% of Summit’s outstanding common stock, or around 10.6% on a fully diluted basis. The investment is expected to close within one week, subject to customary conditions.
Alongside the equity investment, AstraZeneca and Summit have entered into a clinical collaboration to study ivonescimab in combination with sonesitatug vedotin, also known as Sone-Ve. Sone-Ve is an experimental ADC that targets Claudin-18.2 (CLDN18.2), a protein associated with several gastrointestinal cancers.
The companies plan to begin clinical trials of the combination in gastrointestinal cancers. Sone-Ve is already being tested in several studies, including the Phase 3 CLARITY-Gastric01 trial in patients with advanced gastric cancer. AstraZeneca recently reported positive results from the trial, showing an improvement in overall survival compared with investigator’s choice of treatment.
Ivonescimab is a bispecific antibody designed to target both PD-1 and VEGF. By combining these two targets in one medicine, the treatment is being studied as a potential new approach to cancer immunotherapy.
Summit has exclusive rights to develop and commercialize ivonescimab in major markets outside China, while its partner Akeso retains rights in China and certain other regions. Ivonescimab is already approved in China for certain patients with non-small cell lung cancer, while a U.S. Biologics License Application for EGFR-mutated non-small cell lung cancer is under review by the FDA.
The drug is also being investigated in Phase 3 trials across a range of cancers, including non-small cell lung cancer, small cell lung cancer, biliary tract cancer, bladder cancer, triple-negative breast cancer, head and neck cancer, colorectal cancer and pancreatic cancer.
The new agreement could also lead to a wider collaboration between the companies. AstraZeneca and Summit have signed a memorandum of understanding with the aim of creating a global development program combining ivonescimab with additional AstraZeneca cancer medicines, including other ADCs.
Under the clinical collaboration, each company will provide its respective medicine for the planned combination studies and jointly cover trial costs. Each company will retain development and commercial rights to its own medicines.
The partnership reflects AstraZeneca’s strategy of combining ADCs with newer immunotherapies to develop potential treatments across different types of cancer. For Summit, the deal provides significant new funding and expands opportunities to test ivonescimab with established and emerging cancer medicines.
AstraZeneca said the $2 billion investment is intended to help accelerate ivonescimab development and support clinical collaborations focused on combination therapies in oncology.