Ideaya Biosciences has decided to go ahead with its plans to grab a bispecific antibody-drug conjugate (ADC) from Biocytogen, exercising an option to pick up a preclinical asset from the Chinese biotech that Ideaya hopes can turbocharge the effect of its DNA damage repair molecules.
Biocytogen has been using a B7H3xPTK7 bispecific to deliver a topoisomerase I inhibitor payload to tumor cells. Back in July, West Coast-based Ideaya signed a $406.5 million biobucks deal for the option to license this ADC so the U.S. biotech could partner it with its own PARG inhibitor IDE161 to expand into additional indications beyond endometrial and colorectal cancers.
Monday morning, Ideaya confirmed that it has decided to take up its option for the global license for the ADC, which has been named IDE034. The plan now is to submit an application to the FDA next year for permission to begin first-in-human trials.
The decision means Biocytogen will receive a $6.5 million option payment and brings closer the potential for up to $400 million in milestone payments, including $100 million tied to development and regulatory events.
“We are pleased to nominate IDE034 as a development candidate,” Ideaya Chief Scientific Officer Michael White, Ph.D., said in the release. “This promising, potential first-in-class B7H3/PTK7 topo-I-payload bispecific ADC has shown significant tumor regression in preclinical models.”
“The high prevalence of B7H3/PTK7 co-expression in solid tumors such as lung, colorectal, and head and neck cancers underscore its potential as both a monotherapy and in combination with our PARG inhibitor, IDE161,” White added.
The bispecific nature of IDE034 sets it apart from other B7H3-directed ADCs being developed by the likes of Daiichi Sankyo, which now falls under the remit of its collaboration with Merck & Co. MacroGenics also has two ADCs aimed at the same target, although the biotech recently paused work on the most advanced of these.