British drugmaker GSK has entered into an exclusive licence agreement with Chinese biopharmaceutical company Hansoh Pharma for HS-20093, a cancer drug candidate.

HS-20093 is a B7-H3 targeted antibody-drug conjugate (ADC) that uses a clinically validated topoisomerase inhibitor (TOPOi) payload.

It is currently in multiple Phase I and II clinical trials in China for the treatment of lung cancer, sarcoma, head and neck cancers and other solid tumours.

Under the terms of the agreement, GSK will gain exclusive worldwide rights to progress clinical development and commercialisation of the candidate.

The deal excludes regions like China’s mainland, Hong Kong, Macau, and Taiwan.

In return, GSK will make an upfront payment of $185m. Additionally, Hansoh will be qualified to receive success-based milestones for HS-20093 worth up to $1.525bn.

Upon commercialisation of the asset, GSK will pay tier-based royalties on worldwide net sales that aren’t made in Taiwan, Hong Kong, Macau, or the Chinese mainland.

The deal is subject to customary conditions, including applicable regulatory agency clearances.

GSK R&D oncology global head and senior vice president Hesham Abdullah said: “B7-H3 is highly expressed in a broad range of solid tumours where there remains a significant need for novel treatment options.

“We look forward to progressing this potential new treatment across several indications and in future potential combination approaches with our established portfolio.”

The latest agreement will help GSK gain access to a second clinical-stage ADC, which enhances the company’s drug development capabilities to address unmet medical needs in a variety of solid tumours.

The Chinese biopharmaceutical company presented data from the ARTEMIS-001 Phase I trial for HS-20093 in advanced solid tumours.

The candidate has shown initial clinical activity in small cell lung cancer, non-small cell lung cancer and sarcoma with multiple confirmed responses and a manageable safety profile.

Hansoh Pharma board executive director Eliza Sun said: “We are excited to enter this new licence agreement with GSK, our existing licensee on HS-20089, furthering Hansoh’s goal of bringing a potentially transformative treatment option to cancer patients globally.”

GSK intends to start Phase I trials for HS-20093 outside of China next year.

Earlier, both firms signed a contract in October this year for HS-20089, an ADC that targets B7-H4 and is presently undergoing Phase 2 trials in China.