AstraZeneca is investing $2 billion in Summit Therapeutics, buying a slice of the US biotech behind one of cancer medicine's most closely watched new drugs.
The FTSE 100 drug maker will hold the equivalent of about 12% of Summit's common stock, or 10.6% on a fully diluted basis.
The prize is ivonescimab, a bispecific antibody that hits two targets at once.
It blocks PD-1, a protein tumours use to hide from the immune system, and VEGF, which helps them build their own blood supply.
AstraZeneca wants to combine it with its antibody drug conjugates (ADCs), which act like guided missiles, carrying a toxic payload directly into cancer cells.
Trials to start imminently
The first test pairs ivonescimab with sonesitatug vedotin, or Sone-Ve, an AstraZeneca ADC aimed at gastrointestinal cancers.
Trials are due to begin imminently, with each company supplying its own drug and sharing the costs.
Both keep the rights to their own medicines.
The pair have also signed a memorandum of understanding for a wider global programme combining ivonescimab with more of AstraZeneca's cancer drugs.
Susan Galbraith, AstraZeneca's head of oncology research and development, said the combinations "could enable new regimens that raise the bar for patients".
She added that PD-1/VEGF bispecifics could improve on current immunotherapies, particularly in lung, breast and gastrointestinal cancers.
Momentum behind both drugs
Sone-Ve recently produced a statistically significant improvement in overall survival in a late-stage trial in advanced stomach cancer.
The full results will be presented at this year's European Society for Medical Oncology congress.
Ivonescimab, originally developed by China's Akeso, is already approved in China for certain patients with non-small cell lung cancer, the most common form of the disease.
A US application for its use in lung cancer driven by EGFR gene mutations is under review by the Food and Drug Administration.
Summit holds the rights to the drug in major markets outside China.
It is in phase III trials across eight cancers, including breast, bowel and pancreatic.
The investment is expected to close within a week.
