Orano Med announced that its long-standing collaboration with the multinational pharmaceutical company Roche is entering the next phase. Over the past years, the companies have conducted extensive preclinical research to develop a potential novel cancer treatment approach called "two-step pretargeted radioimmunotherapy" (or PRIT). This innovative technology, which pretargets the tumor with an antibody that is subsequently able to capture chelated lead-212 (212Pb) to target tumor cells, is now ready to advance into clinical development in humans.
Orano Med will be responsible for the manufacturing of 212Pb, utilizing its industrial manufacturing platform in France and the US. Under the terms of the agreement, Orano Med and Roche have committed to develop this new therapeutic solution targeting a specific antigen known as carcinoembryonic (CEA), a cell surface glycoprotein overexpressed in several cancers. This antigen serves as a marker for various types of cancer, such as colorectal, pancreatic, and gastric cancers, as well as certain lung cancers.
These are cancers for which the current therapeutic options are often limited or insufficient to meet patients' needs. CEA shows restricted expression in normal tissues, making it a very suitable target for antibody-based therapies and radioimmunotherapy. The Roche sponsored phase 1 clinical trial is expected to start in the first half of 2026, initiating the development of a broader platform dedicated to alpha radioimmunotherapies, underscoring Orano Med's global leading position in the field of targeted alpha therapies.
Compared with conventional radioligand therapies (RLT), where the isotope and targeting moiety are co-delivered, pretargeted radioimmun therapy (PRIT) uses a sequential approach. A tumor-targeting bispecific antibody (bsAb) is first administered, followed by a radioligand carrying the radioactive payload. The delay gives the bsAb the necessary time to accumulate on the tumor cells while unbound radioligand is rapidly cleared.
It thus enables highly specific antibody targeting while remaining compatible with the relatively short half-life of 212Pb (10.6 hours). By introducing the cytotoxic radioligand only after the bsAb has largely cleared from circulation, radiation is concentrated in the tumor. This sequential approach is designed to minimize systemic radiation exposure, achieve high tumor-to-nontumor ratios, and thus improve safety and tolerability compared to otherRLT.
