- Amicus Therapeutics has become the latest rare disease biotech to turn its focus toward gene therapy. A deal announced Thursday will add a slate of 10 mostly preclinical programs to its pipeline of experimental drugs for metabolic diseases.
- The programs come via Celenex, which spun out of a gene therapy center at Nationwide Children's Hospital in Ohio. Per the deal, Amicus will pay $100 million upfront to acquire Celenex, with another $277 million in potential development and regulatory milestones.
- Headlining the deal are two clinical candidates for Batten disease, a rare and fatal lysosomal storage disorder that typically emerges in childhood. The more advanced of the two entered clinical testing two years ago and, so far, has been administered to 10 patients.
Amicus has focused most of its research work to date on lysosomal storage disorders, a broad category of inherited diseases characterized by the damaging buildup of toxic cellular waste in the body.
Earlier this year, Amicus identified 15 lysosomal storage disorders that it saw as attractive opportunities to expand into and complement its existing research in Fabry and Pompe. Thursday's deal covers 10 of those short-listed research targets and sets Amicus on a search for potentially curative one-time treatments.
Nationwide Children's, which licensed the programs to Celenex, has developed a gene therapy platform using an AAV9 vector. Previous work in spinal muscular atrophy supports the applicability of the approach to central nervous system disorders, Amicus said.
Batten disease is the near-term focus of the acquisition. In patients with the condition, a mutation in one of 13 different CLN genes triggers lysosomal dysfunction and toxic buildup of cellular waste in the central nervous system.
Three of the 10 experimental gene therapies acquired by Amicus target Batten disease. One of those three is aimed at patients with a mutation of the CLN6 gene and has generated initial clinical data.
The biotech's confidence in the program was boosted by a case report from two siblings treated with the therapy. After two years of follow-up, the younger sibling's motor and language function did not appear to have worsened, while disease progression in the older sibling seemed to stabilize.
Typically, children with Batten disease see steady loss of function. Preliminary safety findings from the 10 patients treated so far show treatment has been generally well-tolerated, Amicus said.
"I can tell you that the initial glimpse of these data in this sibling pair — this is part of what gives us reason to believe that this could be a transformative therapy," said Amicus CEO John Crowley on a Thursday morning conference call.
A clearer picture of the therapy's profile won't be available until next year, when Amicus expects to present additional data from the study.
All told, Amicus estimates the affected population of patients with one of the three targeted Batten mutations to number nearly 7,000 across the U.S., EU, Japan and other major markets.
Work on the gene therapies was driven in part by Gordon and Kristen Gray, parents of two daughters with CLN6 Batten disease. The two parents established a foundation that collaborated with Nationwide Children's Hospital and funded the current clinical study. Gordon Gray is also a co-founder of Celenex.
The Grays' work in advancing Batten disease research shares some parallels with that of Amicus' Crowley, who was motivated to search for Pompe treatments by the diagnosis of two of his children with the disease.