RegenXBio Strikes $110M Upfront Deal with Nippon Shinyaku for Gene Therapy Rights

RegenXBio, a leading developer of gene therapy technology, has entered into a significant licensing agreement with Japan's Nippon Shinyaku. The deal, announced on January 14, 2025, grants Nippon Shinyaku commercial rights to two of RegenXBio's experimental gene therapies in the United States and Asia.

Deal Structure and Financial Terms

Under the terms of the agreement, Nippon Shinyaku will pay RegenXBio $110 million upfront, with the potential for additional payments of up to $700 million in milestone fees, primarily tied to future sales. The deal encompasses two gene therapies: RGX-121 for Hunter syndrome and RGX-111 for Hurler syndrome.

RegenXBio stands to receive up to $40 million in development and regulatory milestones, as well as $660 million in sales milestones. Additionally, the company will be entitled to double-digit royalties on net sales of both therapies.

RGX-121: Potential First Gene Therapy for Hunter Syndrome

RGX-121, RegenXBio's most advanced wholly owned therapy, is currently under FDA review for the treatment of Hunter syndrome, also known as mucopolysaccharidosis type II. The company has been submitting its application on a rolling basis and expects to complete the process in the first quarter of 2025.

If approved, RGX-121 could become the first gene therapy for Hunter syndrome, a rare inherited disorder that affects the body's ability to break down sugar molecules, leading to organ damage and impaired physical and mental abilities. The therapy has shown promising results in a multi-phase trial that measured its effects on a biomarker associated with brain disease activity.

RegenXBio CEO Curran Simpson stated, "This partnership with Nippon Shinyaku is exciting in that it maximizes our collective strengths and enables access of two potentially transformational medicines to key markets."

RGX-111: Addressing Hurler Syndrome

The second therapy included in the deal, RGX-111, targets Hurler syndrome, another type of mucopolysaccharidosis. While earlier in clinical testing, RegenXBio reports that RGX-111 has demonstrated "very promising results" in a phase 1/2 study. The therapy uses an AAV9 vector to deliver the IDUA gene to patients.

Roles and Responsibilities

Under the agreement, Nippon Shinyaku will lead commercialization efforts for both RGX-121 and RGX-111 in the United States and Asia. RegenXBio will retain control of future clinical development for both candidates and will be responsible for manufacturing the products for Nippon Shinyaku. The company also maintains rights to sell either therapy in countries outside of the U.S. and Asia.

Importantly, RegenXBio will retain rights to any priority review voucher that may be issued by the FDA upon approval of RGX-121, as well as 100% of the proceeds related to its sale. Such vouchers can often be sold for around $100 million.