Mabion has signed a letter of intent with French technology company Oddifact to evaluate and develop MabionCD20 for rare disease indications, reviving a programme that previously completed Phase 3 clinical trials as a biosimilar candidate.

The collaboration will explore new uses for MabionCD20, a monoclonal antibody originally developed as a biosimilar to rituximab for conditions including lymphoma and rheumatoid arthritis. Although the programme did not progress to registration in its original form, Mabion said it generated substantial clinical, scientific and manufacturing expertise that can now support development in orphan diseases.

Under the proposed collaboration, Oddifact will use its AI-enabled platform to help identify and prioritise potential rare disease indications, while Mabion will contribute its experience in biologics development and manufacturing.

The companies said MabionCD20 has already received two FDA orphan drug designations for membranous nephropathy and autoimmune haemolytic anaemia, providing a foundation for further development in rare diseases.

Gregor Kawaletz, chief executive officer of Mabion, said: “The reactivation of the MabionCD20 project in orphan diseases is not only an opportunity to unlock the commercial potential of this asset, but also an important step toward building a portfolio of innovative products developed in a co-development model, where both risks and future benefits are shared with our partners.”

The agreement reflects a growing trend across the biopharmaceutical industry to reposition existing assets with established clinical and safety data for new indications, potentially reducing development timelines and costs compared with creating therapies from scratch.

Pierre-Alexandre Teulié, president of Oddifact, said: “CD20 is exactly the type of molecule our platform was built for – one with a proven safety profile, existing clinical data and unexplored rare disease indications.”

Initially, the companies plan to develop a regulatory strategy and prepare materials for potential investors and regulators before seeking to finalise a binding cooperation agreement by the end of 2026 covering future development and commercialisation activities.