Making a big splash, Biogen acquires TJ Biopharma’s felzartamab for $850M

Biogen Inc. (BIIB) has entered into a definitive agreement to acquire TJ Biopharma’s exclusive rights to felzartamab in the Greater China Region for up to $850 million, the companies announced. 

Under the terms, TJ Bio will receive a $100 million upfront payment and is eligible for up to $750 million in potential commercial and sales milestone payments, plus mid-single-digit to low-double-digit percentage royalties on potential net sales in the region. The upfront payment is expected to be recorded by Biogen as an Acquired In-Process Research and Development expense in the second quarter of 2026. 

The transaction gives Biogen exclusive worldwide rights to felzartamab, a CD38-directed antibody currently being evaluated in global Phase 3 clinical studies across multiple immune-mediated diseases. Biogen previously acquired worldwide rights excluding the Greater China Region through its acquisition of HI-Bio in July 2024.