Following its move to secure ex-China rights to the CD38-directed antibody felzartamab, Biogen is doubling down and building on an existing partnership with local drugmaker TJ Biopharma.
The Massachusetts Big Biotech has signed an $850 million biobucks agreement with TJ Biopharma, securing exclusive China rights to the multi-indication candidate.
In an April 20 release, Cambridge-based Biogen said it will pay TJ $100 million upfront to expand its rights to felzartamab. The drug is currently being evaluated in global phase 3 studies across multiple immune-related conditions. The deal could generate up to $750 million in commercial and sales milestone payments, along with mid single-digit to low double-digit royalties in Greater China.
Felzartamab was originally developed by German biopharma MorphoSys. Its ex-China rights were acquired by Human Immunology Biosciences (HIBio) in 2022 in a deal valued at up to $1 billion.
In 2024, Biogen obtained those ex-China rights through its $1.15 billion acquisition of HIBio, announcing plans to advance the anti-CD38 monoclonal antibody into phase 3 trials across several rare immune-mediated indications.
Since the acquisition, Biogen has initiated studies of the drug in antibody-mediated rejection (AMR) in kidney transplant recipients, IgA nephropathy (IgAN) and primary membranous nephropathy (PMN), with plans to expand into additional indications.
Biogen’s intercontinental region president, Fraser Hall, said in a statement that felzartamab has the potential to evolve from a single product into a broader pipeline asset due to its applicability across multiple indications.
The latest deal expands the partnership between Biogen and China-based TJ Biopharma, which began in April 2025 when TJ joined two Biogen-sponsored phase 3 trials evaluating felzartamab in IgAN and PMN in China. Under that deal, TJ was tasked with leading regulatory interactions on the candidate in China.
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With the new agreement, Biogen will continue to lead development in immunology indications and will assume responsibility for manufacturing and commercialization of felzartamab in Greater China. The drug is currently under review by China’s National Medical Products Administration after TJ submitted a Biologics License Application for multiple myeloma in 2024.
“This transaction sharpens our strategic focus and validates our ‘fast-to-market’ and ‘tiered value realization’ business models,” Dr. Lili Qian, general manager of TJ Biopharma, said in the release.
IgAN is a leading cause of end-stage kidney disease (ESKD) among young adults in China, which is believed to have one of the largest patient populations for both IgAN and PMN, according to the release.
