Swiss pharma giant Roche has joined its big pharma rivals in the emerging field of antibody‑drug conjugates (DACs), announcing an expansion of its collaboration with US biotech C4 Therapeutics (C4T). The companies have agreed to jointly develop a cancer drug. This is the third agreement between the two companies, expanding their partnership that began in 2016. The potential value of the deal could exceed $1 billion. C4T’s shares rose 10% on the news.
C4T will receive a $20 million upfront payment for two programmes. If Roche exercises its option for a third project, C4T will receive an additional payment. Moreover, C4T is eligible for development, regulatory and commercial milestone payments totalling more than $1 billion, as well as royalties on future sales.
The collaboration focuses on developing DACs for two oncology targets, with the option to add a third. DACs are a new class of cancer drugs that combine antibody‑drug conjugate technology with targeted protein degradation.
Roche will identify two cancer targets and generate antibodies against them. C4T will use its Torpedo platform to develop degraders – molecules that destroy target proteins. Roche will then link the antibodies to the degraders and take the resulting DACs through all stages of testing, from the lab to the clinic. A third target can be added at Roche’s option.
Roche’s rivals have also shown interest in DACs. In 2023, US‑based MSD paid C4T $10 million for a partnership, gaining exclusive rights to one target and options for three more. However, in November 2025, MSD terminated the deal, depriving C4T of $600 million in anticipated milestone payments. That same year, Bristol Myers Squibb paid Orum Therapeutics $100 million upfront for a CD33‑targeting DAC (now BMS‑986497), which is in Phase I trials for blood cancer.
Seagen (now part of Pfizer) paid Nurix Therapeutics $60 million in 2023 to develop a DAC. Pfizer maintained the collaboration after acquiring Seagen. While most DACs target cancer, Nurix is also exploring the approach in inflammatory and autoimmune diseases.
