Callio gets in on the dual payload action

Dual-payload ADCs have emerged as a recent trend, and the latest contender is Callio Therapeutics, with a $187m series A financing announced Monday. Still, Callio’s lead project might look familiar – the group has primarily licensed Hummingbird Bioscience’s HMBD-802, which hits HER2 and employs topoisomerase 1 and ATR inhibitor warheads. It’s hoped that two could be better than one by overcoming payload resistance. Callio also picked up HMBD-803 and HMBD-804, against undisclosed targets. The group isn’t the only one with this idea – a recent analysis by ApexOnco found various players including Adcoris, which also has a preclinical HER2-targeting project, ADC2202. Singapore-headquartered Hummingbird will continue developing its monoclonal antibodies, HMBD-001 and HMBD-002, and also retains rights to its ADC technology for non-oncology uses, a spokesperson for Seattle-based Callio told ApexOnco. The companies will share chief executive and chief scientific officers, and also have various investors in common, including Frazier Life Sciences and Novo Holdings. This raises the question of why a separate company has been formed, but given the sum just raised there’s clearly an appetite for dual-payload ADCs. Hummingbird has also farmed out a regular HER3 ADC to Endeavor, and recently licensed undisclosed antibodies to Immunome.

Hummingbird’s pipeline

Source: OncologyPipeline & company communications.