CytomX Therapeutics and Regeneron Pharmaceuticals have expanded their ongoing research collaboration focused on developing tumor-activated bispecific cancer therapy candidates, broadening the scope of an agreement that was originally established in 2019. The expanded collaboration introduces additional bispecific targets into the partnership framework and significantly increases the potential milestone and royalty payments available under the deal.
Under the terms of the expanded agreement, CytomX will apply its proprietary Probody therapeutics platform to engineer conditionally activated bispecific antibodies designed to preferentially activate within the tumor microenvironment. This approach is intended to improve the therapeutic window of bispecific cancer therapy candidates by limiting systemic exposure and off-tumor toxicity challenges that have historically complicated the development of potent oncology biologics. Regeneron will retain rights to develop and commercialize products arising from the collaboration, while CytomX is eligible to receive research funding, option fees, development and commercial milestones, as well as royalties on net sales.
The Probody therapeutics platform, which forms the backbone of CytomX’s contribution to the collaboration, works by masking antibody binding domains with a cleavable substrate that becomes active in protease-rich tumor environments. This selective activation mechanism is central to the bispecific cancer therapy strategy that both companies are pursuing together. With the addition of new targets under the expanded agreement, the collaboration now covers a broader landscape of oncology indications, reflecting the continued interest from large biopharmaceutical companies in conditional activation technologies as a means of improving the safety profile of next-generation cancer immunotherapies.
Financial terms specific to the expansion including the precise number of additional targets and the updated total potential deal value were disclosed in connection with the announcement, reinforcing the growing scale of the partnership between CytomX and Regeneron as they advance their shared pipeline of conditionally activated oncology candidates.
