GSK struck a deal worth up to $1.7 billion with China-based Hansoh Pharma to pick up the rights to an antibody-drug conjugate (ADC), HS-20093, which is being investigated in cancer.

The exclusive license agreement announced Wednesday morning has GSK paying $185 million upfront, with Hansoh able to receive up to $1.5 billion in additional milestones.

HS-20093 is a B7-H3 targeted ADC that uses a topoisomerase inhibitor (TOPOi) payload and has shown promise in treating lung cancer. The drug may also hold potential in treating sarcoma, head and neck cancers as well as broader solid tumor indications, GSK stated.

Data from a Phase 1 trial, the ARTEMIS-001 in advanced solid tumors, showed that HS-20093 resulted in initial clinical activity in small cell lung cancer, non-small cell lung cancer and sarcoma.

“B7-H3 is highly expressed in a broad range of solid tumors where there remains a significant need for novel treatment options,” said Hesham Abdullah, SVP, global head oncology, R&D at GSK, in a statement. “We look forward to progressing this potential new treatment across several indications and in future potential combination approaches with our established portfolio.”

The deal follows on the heels of another exclusive license agreement between GSK and the Chinese biotech. 

In October, GSK paid $85 million upfront for Hansoh’s HS-20089, an ADC that targets B7-H4 and is being developed to treat gynecological cancers.

With HS-20093 under its belt as well, GSK said the two ADC candidates will bolster its pipeline in addressing unmet needs in solid tumors. HS-20093 is currently in Phase 1 and 2 trials in China, while GSK will launch Phase 1 trials outside of China in 2024.

“HS-20093 is a novel B7-H3 targeting ADC showing encouraging early clinical signals in lung cancer,” said Eliza Sun, executive director of board at Hansoh Pharma, in a statement. “We are excited to enter this new license 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 joins a flurry of other major pharma players who have invested in ADCs recently, including AbbVie, which acquired ADC manufacturer ImmunoGen for $10.1 billion in November.

Bristol Myers Squibb also recently picked up SystImmune’s ADC, BL-B01D1, which targets metastatic or unresectable non-small cell lung cancer (NSCLS). Earlier this year, BioNTech also delved into a $170 million deal with DualityBio for two of its ADC candidates.