AstraZeneca will invest $2 billion in Summit Therapeutics to advance ivonescimab with Sone-Ve and other ADCs in gastrointestinal and other cancers.
Written By: Umesh Hanumante,
M.Pharm (Reg. Affairs)
Reviewed By: Pharmacally Editorial Team
AstraZeneca is investing $2 billion in Summit Therapeutics and entering a clinical collaboration to combine ivonescimab, a PD-1/VEGF bispecific antibody, with antibody-drug conjugates (ADCs) across cancer types. The initial programme will evaluate sonesitatug vedotin (Sone-Ve, AZD0901) with ivonescimab in gastrointestinal (GI) cancers.
$2 Billion Equity Investment
Under the transaction, AstraZeneca purchased 108,955 shares of newly issued convertible preferred stock in Summit Therapeutics. The preferred stock converts into common stock at a 1:1,000 ratio. Following completion, AstraZeneca will hold rights equivalent to approximately 12% of Summit’s outstanding common stock, or approximately 10.6% on a fully diluted basis.
The investment strengthens the companies’ broader collaboration around ivonescimab and ADC-based cancer therapies. AstraZeneca and Summit will each contribute their respective medicines to the planned combination studies and share study costs.
For the initial Sone-Ve and ivonescimab programme in GI cancers, AstraZeneca will sponsor the clinical trials. Both companies will retain development and commercial rights to their respective medicines.
The companies have also signed a memorandum of understanding with the intention of establishing a global development programme combining ivonescimab with additional AstraZeneca cancer medicines, including other ADCs.
Sone-Ve and Ivonescimab Bring Complementary Mechanisms
Sone-Ve is a CLDN18.2-directed ADC comprising a monoclonal antibody against CLDN18.2, a protease-cleavable linker and a monomethyl auristatin E (MMAE) payload. By binding CLDN18.2 on tumour cells, the ADC delivers the cytotoxic payload to the cancer cell.
AstraZeneca obtained global exclusive rights to develop and commercialize Sone-Ve from KYM Biosciences in 2023. The ADC is being developed across gastric, gastroesophageal junction, oesophageal adenocarcinoma and other GI cancers.
Ivonescimab combines PD-1 blockade and VEGF inhibition in a single bispecific antibody. The candidate was developed by Akeso, with Summit holding exclusive rights to develop and commercialize it across major territories outside China.
Ivonescimab is approved for certain patients with non-small cell lung cancer (NSCLC) in China, while a US Biologics License Application for EGFR-mutated NSCLC is under FDA review. Phase III studies are evaluating ivonescimab across several tumour types, including NSCLC, small-cell lung cancer, biliary tract cancer, bladder cancer, triple-negative breast cancer, head and neck squamous cell carcinoma, colorectal cancer and pancreatic cancer.
CLARITY-Gastric01 Supports Further Development of Sone-Ve
The combination programme follows positive Phase III data for Sone-Ve in CLARITY-Gastric01, which evaluated the ADC in patients with CLDN18.2-positive advanced gastric, gastroesophageal junction and oesophageal adenocarcinoma in the second-line and later settings.
Sone-Ve demonstrated a statistically significant and clinically meaningful improvement in overall survival compared with investigator’s choice of therapy. The study met its overall-survival endpoint in the prespecified later-line population, while the broader second-line and later-line analysis also showed an overall-survival benefit.
Progression-free survival favoured Sone-Ve but did not reach statistical significance in the reported analysis. AstraZeneca reported no new safety signals, with the safety profile remaining consistent with previous observations for the ADC.
The CLARITY-Gastric01 findings are scheduled for presentation at the 2026 European Society for Medical Oncology Congress in a Presidential Symposium.
Broader Clinical Development
Sone-Ve is also being evaluated in the Phase III CLARITY-Gastric02 trial as a first-line treatment for advanced or metastatic gastric cancer, gastroesophageal junction cancer and oesophageal adenocarcinoma. The study is evaluating Sone-Ve with capecitabine, with or without rilvegostomig.
Phase II studies are evaluating Sone-Ve in advanced solid tumours and in combination regimens across additional settings, including CLDN18.2-positive pancreatic and biliary tract cancers.
The new collaboration will extend this development strategy by testing Sone-Ve alongside ivonescimab. The combination brings targeted tumour-cell killing through an ADC together with simultaneous PD-1 and VEGF blockade, providing a clinical approach that can be evaluated across complementary components of the tumour microenvironment and antitumour immune response.
AstraZeneca and Summit intend to initiate the GI cancer combination trials imminently, while the broader memorandum of understanding could support additional studies pairing ivonescimab with AstraZeneca’s ADC portfolio.
Reference
AstraZeneca announces strategic equity investment and clinical collaboration with Summit Therapeutics to advance leading ADC combination strategy in cancer, Astra Zeneca, 28 September 2026
AstraZeneca Makes $2 Billion Strategic Equity Investment in Summit Therapeutics, Summit Therapeutics, 28 September 2026
About the Writer
Umesh Hanumante (M.Pharm) (LinkedIn) is a pharmacy professional and healthcare writer with a background in Regulatory Affairs, pharmaceutical innovation, and clinical research. He has around two years of industry experience as an Executive PMT at Troikaa Pharmaceuticals Ltd and qualified GPAT 2024. His areas of interest include regulatory compliance, dossier preparation, clinical trials, emerging therapies, and advancements in the global pharmaceutical and healthcare sector.