GSK has made another trip to China to build out its antibody-drug conjugate (ADC) pipeline, returning with an option on a preclinical Duality Biologics candidate that could ultimately cost the Big Pharma $1 billion.
DualityBio has given GSK a chance to license the ADC outside of mainland China, Hong Kong and Macau in return for $30 million in upfront and pre-option milestone payments. If GSK takes up its option, DualityBio will get another fee and the chance to pocket up to $975 million in development, regulatory and commercial milestones. GSK is also on the hook for tiered royalties on net sales in its territories.
Details of what GSK has snagged in return for the financial package are thin on the ground. DualityBio said the candidate, DB-1324, is a potentially best-in-class ADC against a gastrointestinal cancer target.
The wording suggests at least one ADC aimed at the same target is more advanced than DualityBio’s asset—because otherwise DB-1324 could be first in class—but details of which target the ADC engages are yet to emerge. Other companies have identified EGFR, HER2, HER3, CLDN18.2 and MUC1 as targets for ADCs designed to treat gastrointestinal cancers.
DualityBio included 12 ADCs in its pipeline when it filed to go public in Hong Kong earlier this year, but DB-1324 wasn’t on the list. The publicly disclosed pipeline included ADCs aimed at popular targets such as HER2, HER3, B7-H3, B7-H4 and TROP2.
DB-1324 is built on the same platform as the ADCs against those five disclosed targets. The platform uses topoisomerase-based payloads. ADCs such as AstraZeneca and Daiichi Sankyo’s Enhertu and and Gilead Sciences' Trodelvy deliver topoisomerase, but DualityBio says its use of proprietary payloads and enhanced linkers provide benefits such as improved systemic stability and tumor-specific payload release.
Companies including BioNTech, BeiGene and Adcendo have struck deals that could be worth more than $4 billion to access DualityBio’s technology. The deals are part of a large wave of agreements for ADCs discovered in China. GSK added to the wave last year by paying Hansoh Pharmaceutical $270 million upfront for rights to ADCs aimed at B7-H3 and B7-H4.