In exchange for its investigational gene therapies, Regenxbio will receive $110 million upfront and up to $700 million in milestones. After hitting an all-time low of $6.95 at close of business yesterday, the stock surged on the news by nearly 20% before markets opened Tuesday.
Regenxbio on Tuesday entered into a strategic partnership with Kyoto-based Nippon Shinyaku to advance novel gene therapies for the rare metabolic disorder mucopolysaccharidosis.
Unlike many arrangements, where U.S.-based companies in-license promising candidates for further development, Tuesday’s contract flows the opposite way. Regenxbio will receive an upfront payment of $110 million once the transaction closes and is eligible for up to $700 million in potential development, regulatory and sales milestones.
The deal sent shares of the Maryland biotech surging by as much as 18% before the opening bell on Tuesday, according to Investing.com. This jump followed a closing price yesterday of $6.95—the lowest Regenexbio has traded since it began trading on the NASDAQ nearly a decade ago.
In return for its investment, Nippon Shinyaku will gain access to two of Regenxbio’s gene therapies. The most mature of the assets is RGX-121, which is being tested for mucopolysaccharidosis type II, also known as Hunter syndrome. The gene therapy works by delivering a functioning copy of the iduronate-2-sulfatase gene, which is faulty in Hunter syndrome, leading to hallmark symptoms of developmental delays, skeletal abnormalities and enlargement of several internal organs.
In February 2024, Regenxbio announced that RGX-121 had aced its pivotal trial, significantly reducing the cerebrospinal fluid levels of a key disease biomarker. The gene therapy also improved the acquisition of neurodevelopmental skills in treated children. A few months later, in June, the company revealed that it had had a “successful” meeting with the FDA to support an accelerated approval pathway for RGX-121.
The second asset involved in Tuesday’s agreement with Nippon Shinyaku is RGX-111, being developed for mucopolysaccharidosis type I, a rare metabolic disease caused by a mutation in the α-l-iduronidase (IDUA) gene and characterized by various physical abnormalities as well as intellectual and developmental delays. RGX-111 delivers a copy of the IDUA gene to the central nervous system (CNS), potentially stemming the cognitive deterioration assocated with the condition. RGX-111 is currently in a Phase I/II trial, interim data from which showed an encouraging safety profile and promising biomarker data indicative of CNS activity.
Under the terms of Tuesday’s collaboration, Regenxbio will be entitled to “meaningful” double-digit royalties on potential net sales of RGX-121 and RGX-111 in the U.S. and in Asia.
In a statement, Regenxbio CEO Curran Simpson called the Nippon Shinyaku deal “exciting,” noting that “it maximizes our collective strengths and enables access of two potentially transformational medicines to key markets.”
Also on Tuesday, Regenxbio announced that its AbbVie-partnered wet age-related macular degeneration program ABBV-RGX-314 is being assessed in the pivotal ATMOSPHERE and ASCENT trials, with data expected in 2026. The partners are also looking to run a Phase III program for the asset in diabetic retinopathy. In November 2024, Regenxbio said that it had aligned with the FDA on an accelerated approval track for RGX-202, an investigational gene therapy for Duchenne muscular dystrophy.
