Biogen Completes RayThera Acquisition

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Biogen announced the completion of its acquisition of RayThera, a deal previously reported to be worth up to $1 billion. RayThera, a privately held biotechnology company, focused on discovery and development of small molecule therapies in immunology.

Considering RayThera’s background, Biogen views the acquisition as a boost to its immunology portfolio. Multiple RayThera assets, Biogen says, show potential to treat immune-mediated conditions over a range of indications.

RayThera Acquisition Background

When Biogen announced the pending acquisition, in June, RayThera’s lead program was about to enter Phase I development. That happened early in the third quarter of 2026—in July, as expected.

The acquisition itself also had an anticipated closing date of Q3 2026. That has now happened as well.

Biogen Looks Forward

Biogen Executive Vice President and Head of Development Priya Singhal, MD, said this positions the company’s pipeline for long-term growth.

“We are excited about the potential of these immunology assets,” Singhal said. “With the lead program in Phase I, this highlights strong execution on our open innovation model in sourcing external opportunities. [It] reflects our continued investment in immunology as a strategic growth area.”

Biogen will lead development, manufacturing, and global commercialization of all acquired RayThera assets moving forward.