AstraZeneca has agreed to take a $2-billion equity stake in Summit Therapeutics, a Miami-based bio/pharmaceutical company, and the companies have formed a clinical collaboration to evaluate Summit’s lead drug candidate, ivonescimab, a bispecific antibody for treating certain solid tumors, with AstraZeneca’s sonesitatug vedotin (sone-ve), a late-stage antibody drug conjugate (ADC), for treating certain gastrointestinal (GI) cancers.  

Under the agreement, each company will contribute their respective medicines for planned combination trials and jointly contribute to trial costs. Each company will retain development and commercial rights to their respective medicines. The companies intend to initiate trials in GI cancers under the collaboration imminently (as reported on September 28, 2028).  

In addition, the companies have executed a Memorandum of Understanding with the intent to enter into an agreement initiating a global development program combining Summit’s ivonescimab with AstraZeneca’s cancer medicines, including additional ADCs. 

Under the deal, Summit Therapeutics will receive an equity investment of $2 billion from AstraZeneca. AstraZeneca will purchase an aggregate of approximately 109 thousand shares of preferred stock convertible into shares of common stock of Summit at a 1:1,000 ratio. Following completion of the investment, AstraZeneca will hold rights equivalent to approximately 12.0% of Summit Therapeutics outstanding common stock (approximately 10.6% on a fully diluted basis). 

Summit’s ivonescimab is a programmed cell-death protein 1 (PD-1)/ vascular endothelial growth factor (VEGF) bispecific antibody being evaluated in several solid tumors. It combines the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects associated with blocking VEGF into a single molecule. Summit is partnered with Aesko, a Hong Kong-based bio/pharmaceutical company, for ivonescimab. Summit has exclusive rights to develop and commercialize ivonescimab in major territories outside China while Akeso retains rights in China and other regions. 

Ivonescimab is approved to treat certain patients with non-small cell lung cancer (NSCLC) in China, and a biologics license application seeking approval in epidermal growth factor receptor (EGFR)-mutated NSCLC is under review by the US Food and Drug Administration (FDA) with a Prescription Drug User Fee Act goal action date of November 14, 2026. In addition, ivonescimab is currently being studied in Phase III trials in small-cell lung cancer, biliary tract cancer, bladder cancer, triple-negative breast cancer, head and neck squamous cell carcinoma, colorectal cancer, and pancreatic cancer.  

AstraZeneca’s sone-ve is a Claudin 18.2 (CLDN18.2)-positive-targeting ADC. CLDN18.2 is a protein found in the stomach lining and a validated therapeutic target in oncology, particularly for GI cancers. Sone-ve consists of an anti-CLDN18.2 monoclonal antibody, a protease-degradable linker, and a cytotoxic small-molecule monomethyl auristatin E (MMAE) payload.  

AstraZeneca has a global exclusive license agreement with KYM Biosciences, a Chengdu, China-based bio/pharmaceutical company, to develop and commercialize sone-ve. The drug is in Phase III development for treating advanced or metastatic gastric cancer, gastroesophageal junction (GEJ) cancer, or oesophageal adenocarcinoma (i.e., cancer of the esophagus). It received Orphan Drug Designation from FDA and the European Commission for treating gastric and GEJ cancers. It has also received Breakthrough Designation in China for the second-line treatment of gastric cancer. 

Source: AstraZeneca