Biogen Inc. has announced that it has entered into a definitive agreement to acquire RayThera Inc., a privately held biotechnology company focused on developing small-molecule therapies for immune-mediated diseases.
The deal is valued at up to $1 billion and includes an upfront payment along with future milestone-based payments tied to clinical and regulatory achievements.
Once the transaction is completed, Biogen will take responsibility for the development, manufacturing, and global commercialization of RayThera’s pipeline assets.
The acquisition is aimed at expanding Biogen's presence in immunology by adding a portfolio of anti-inflammatory drug candidates that could potentially be used across multiple immune-mediated diseases.
RayThera has been developing a range of small-molecule therapies designed to address inflammation and immune system dysfunction. These assets are expected to complement Biogen's existing research efforts while opening opportunities in additional disease areas.
According to Biogen, the acquired portfolio has the potential to contribute significantly to the company's long-term development pipeline.
One of the key attractions of the acquisition is RayThera's lead drug candidate, which is expected to enter Phase 1 clinical development in early third quarter of 2026.
The candidate is part of a broader pipeline focused on immune-related disorders and represents an opportunity for Biogen to expand its clinical-stage immunology programs.
Biogen plans to use its global development capabilities to advance the asset through clinical testing and future regulatory stages.
Company Leaders Highlight Strategic Fit
Priya Singhal, Executive Vice President and Head of Development at Biogen, said the acquisition will help deepen the company's immunology pipeline and provide access to new therapeutic opportunities.
She noted that the addition of RayThera's assets could help Biogen expand into new disease areas while strengthening the company's long-term growth strategy.
Qing Dong, Co-founder, Chairman, and Chief Executive Officer of RayThera, stated that Biogen's experience in global immunology drug development makes it well positioned to advance the company's programs into clinical development and beyond.
He also highlighted the work of the RayThera team in building and rapidly advancing an innovative immunology-focused pipeline.
Financial Terms of the Deal
Under the agreement, Biogen will make an upfront payment to RayThera shareholders at closing.
In addition, shareholders will be eligible to receive future payments linked to the achievement of clinical and regulatory milestones. Together, these payments could bring the total value of the transaction to as much as $1 billion.
The acquisition remains subject to customary closing conditions, including required regulatory approvals. The companies expect the transaction to close during the third quarter of 2026.
About RayThera
RayThera is a biotechnology company focused on discovering and developing small-molecule therapies for immunological diseases.
Headquartered in San Diego, California, the company was co-founded by Qing Dong, Ph.D., and Gene Hung, M.D. The organization is led by a team with extensive experience in drug discovery and pharmaceutical development.
RayThera recently completed its Series A financing round, which was co-led by Foresite Capital and OrbiMed Advisors, with participation from TTM Capital.
About Biogen
Founded in 1978, Biogen is one of the world's leading biotechnology companies focused on developing innovative therapies for serious diseases.
The company applies expertise in human biology and multiple therapeutic technologies to develop treatments across several disease areas. Biogen continues to invest in research and development aimed at bringing new therapies to patients while supporting long-term business growth.
With the planned acquisition of RayThera, Biogen is further strengthening its position in immunology and expanding its pipeline of potential treatments for immune-mediated conditions.