• Transaction to include felzartamab, a potential first-in-class therapeutic candidate with promise as a pipeline-in-a-product across a range of immune-mediated diseases
• Felzartamab is an investigational anti-CD38 monoclonal antibody that, through its cell depletion approach, has demonstrated clinical proof of concept in rare immune-mediated indications, with plans to advance to Phase 3
• Proposed acquisition builds on Biogen capabilities in immunology with plans to combine Human Immunology Biosciences expertise in immune-mediated indications with Biogen’s global development and commercial experience in rare diseases

Biogen Inc. (Nasdaq: BIIB) and Human Immunology Biosciences (HI-Bio™), a privately-held clinical-stage biotechnology company focused on targeted therapies for patients with severe immune-mediated diseases (IMDs),  announced the companies have entered into a definitive agreement under which Biogen has agreed to acquire HI-Bio for $1.15 billion upfront and up to $650 million in potential milestone payments.

HI-Bio’s lead asset, felzartamab, is a fully human anti-CD38 monoclonal antibody that has been shown in clinical studies to selectively deplete CD38+ cells including plasma cells and natural killer, or NK, cells which may allow for additional applications that improve clinical outcomes in a broad range of immune-mediated diseases.

Felzartamab has received Breakthrough Therapy Designation (BTD) and Orphan Drug Designation (ODD) from the U.S. Food and Drug Administration (FDA) for development in the treatment of primary membranous nephropathy (PMN) and has received ODD in the treatment of antibody-mediated rejection (AMR) in kidney transplant recipients. Phase 2 studies have been completed in PMN and AMR and remain ongoing in IgA nephropathy (IgAN), and HI-Bio has plans to advance each indication to Phase 3. HI-Bio plans to present two abstracts at the upcoming European Renal Association (ERA) Congress in Stockholm, including the complete Phase 2 data from the AMR study in kidney transplant patients and interim data from the Phase 2 IgAN study. Felzartamab has clinical data in AMR, PMN and IgAN indications.

“We believe this late-stage asset, which has demonstrated impact on key biomarkers and clinical endpoints in three renal diseases with serious unmet needs, is a strategic addition to the Biogen portfolio as we continue to augment our pipeline and build on our expertise in immunology,” said Priya Singhal, M.D., M.P.H., Head of Development at Biogen. “We look forward to welcoming HI-Bio employees into Biogen and, together, working to advance potential therapies for patients with rare immune diseases with high unmet need.”

“With its deep development and commercialization capabilities, Biogen is in a position to accelerate the development of new medicines, including felzartamab, for patients with severe immune-mediated diseases,” said Travis Murdoch, M.D., Chief Executive Officer of HI-Bio. “We are excited to combine the HI-Bio team’s expertise with Biogen’s global footprint.”

Biogen plans to leverage its existing global development and commercialization capabilities in rare disease and its strong scientific expertise in immunology to support the advancement of felzartamab and the HI-Bio pipeline. Biogen seeks to retain expertise and talent from HI-Bio and establish a San Francisco Bay Area team focused on expanding our efforts in immune-mediated diseases.

In addition to lead program felzartamab, the HI-Bio pipeline includes izastobart/HIB210, an anti-C5aR1 antibody currently in a Phase 1 trial and with potential for continued development in a range of complement-mediated diseases. HI-Bio also has discovery stage mast cell programs with potential in a range of immune-mediated diseases.

Financial Details and Terms of the Transaction
Under the terms of the agreement, Biogen will make an upfront payment to HI-Bio of $1.15 billion. HI-Bio’s stockholders would also be eligible for payments of up to an additional $650 million, for a total potential deal value of up to $1.8 billion, should the felzartamab programs achieve certain development milestones. The acquisition of HI-Bio is not expected to impact Biogen’s previously issued 2024 guidance. Biogen expects to finance the acquisition with cash and may also draw on its revolving credit agreement. The transaction is subject to customary closing conditions, including receipt of necessary regulatory approvals and is currently anticipated to close in the third quarter of 2024.