The first trials will evaluate ivonescimab together with AstraZeneca’s sonesitatug vedotin (Sone-Ve), an ADC that targets Claudin-18.2 and is being studied in gastrointestinal cancers. The trials are expected to start shortly. Each company will provide its own drug, both will share the trial costs, and each will keep development and commercial rights to its own medicine. The two companies have also signed a memorandum of understanding that is intended to lead to a broader global program combining ivonescimab with more of AstraZeneca’s cancer medicines, including additional ADCs.

“A core pillar of our oncology strategy is to broaden the reach of our ADC portfolio as the backbone of treatment across tumor types with combinations alongside next-generation immunotherapies,” says Susan Galbraith, Executive Vice President, Oncology Hematology R&D, AstraZeneca. “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.”

Ivonescimab was developed by Akeso, which keeps the rights in China. Summit holds the rights in major markets outside China. The drug is approved in China for certain patients with non-small cell lung cancer, and it is under FDA review in the US for EGFR-mutated non-small cell lung cancer. It is also being tested in Phase III trials in several other cancers. AstraZeneca recently reported that Sone-Ve significantly improved overall survival in the Phase III CLARITY-Gastric01 trial in previously treated Claudin-18.2-positive advanced gastric cancer. The results will be presented at the ESMO Congress 2026.

After the investment, AstraZeneca will hold preferred stock equal to about 12% of Summit’s outstanding common stock, or about 10.6% on a fully diluted basis. The deal is expected to close within one week.