Summit Therapeutics has signed a licensing deal worth up to $5bn with Chinese biopharma firm Akeso for the latter’s ivonescimab, a bispecific antibody candidate for cancer.

Ivonescimab is designed to block a protein called PD-1. It combines immunotherapy with the anti-angiogenesis benefits of an anti-VEGF into a single molecule.

The drug candidate has breakthrough therapy designation status in China for three cancer indications.

As per the terms of the deal, Summit Therapeutics will have the rights to develop and commercialise the bispecific antibody candidate in the US, Canada, Europe, and Japan. However, Akeso will retain rights for the candidate in other parts of the world, including China.

The deal involves an upfront payment of $500m to the Chinese biopharma company, which will also be eligible for regulatory and commercial milestone payments, totalling up to $4.5bn. Additionally, Akeso will be eligible to get low double-digit royalties on net sales.

Summit Therapeutics chairman and CEO Robert Duggan said: “The partnership between Summit Therapeutics and Akeso is a strategically compelling opportunity.

“It represents bringing together Akeso’s extraordinary team, which has built an innovation engine capable of creating novel bispecific technologies, and the talented members of Team Summit with their proven track record of success of global clinical development, regulatory approvals, and commercialisation, particularly in oncology.

“We believe the potential exists for enormous creation through this partnership. We are extremely encouraged by ivonescimab and the potential for improving the quality and duration of patients’ lives based on clinical data to support this point.”

In a phase 2 study in patients with non-small cell lung cancer (NSCLC), ivonescimab showed an overall response rate (ORR) of 68.4%.

The antibody candidate demonstrated a median progression-free survival (mPFS) time period of 8.2 months when used along with combination chemotherapy in the mid-stage study. This is in comparison to historical mPFS of 4.3 months in patients subjected to combination chemotherapy alone.