GSK forks out $85m for Hansoh gynecology cancer ADC

Hansoh Pharma has sold ex-China rights for its B7-H4 ADC to GSK in a $1.57 billion deal ($85 million upfront), plus royalties on any sales.

The antibody drug conjugate (ADC) candidate, HS-20089, targets B7-H4, a transmembrane glycoprotein in the B7 superfamily that is highly expressed in various cancers but limited in normal tissues.

Hansoh has started a China Phase I clinical study of HS-20089 for gynecologic cancers, especially ovarian and endometrial cancers with possibilities in other solid tumors.

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Under the agreement, GlaxoSmithKline (GSK) will own exclusive worldwide rights excluding mainland China, Hong Kong, Macau, and Taiwan for development and commercialization of HS-20089. The company said the ADC adds to GSK’s strategic R&D focus on tumor-cell targeting modalities as well its portfolio of gynecologic cancers. It will form combination therapies using HS-20089 and its own candidates. GSK plans to begin Phase I trials of the candidate outside of China in 2024.

The B7-H4 surface antigen, which is overexpressed in ovarian and endometrial cancers, is often associated with poor prognosis. For a payload, HS-20089 uses a topoisomerase inhibitor, a validated mechanism of action in approved anti-cancer medicines and a proven standard of care in the treatment of breast and ovarian cancers.

Hesham Abdullah, senior vice president, Global Head Oncology, R&D, GSK, said: “Given early clinical data, we believe that HS-20089 has best-in-class potential in ovarian and endometrial cancer. This agreement is in line with our approach to advancing novel treatment options for patients with gynecological cancers.”

Eliza Sun, executive director of board, Hansoh, said: “In line with our commitment to deliver first- or best-in-class medicines to address unmet medical needs, Hansoh is excited to explore further development of HS-20089 to bring breakthrough medicines to cancer patients. GSK’s R&D expertise and commercial footprint in developing therapies for gynecologic cancers make them the ideal licensee to bring HS-20089 to patients outside of China.”

Hansoh Pharma, one of China’s largest biopharmas, develops medicines for serious diseases and disorders. Founded in 1995, Hansoh has products for a broad range of therapeutic areas, including oncology, central nervous system disorders, metabolic diseases, infectious diseases and autoimmune diseases. In 2021, Hansoh announced a $1.3 billion deal to develop three short interfering ribonucleic acids (siRNA) candidates from London’s Silence Therapeutics.

A version of this article was first published in ChinaBio Today on October 23, 2023.