Yuhan's Gaucher disease drug candidate wins EMA orphan drug designation

Yuhan announced Tuesday that its drug candidate YH35995, under development as a treatment for Gaucher disease, has received orphan drug designation from the European Medicines Agency. The designation follows a similar nod from the US Food and Drug Administration in April, and the company said recognition in both major markets is expected to accelerate its push into the global arena.

Orphan drug designation is a regulatory regime designed to encourage the development of treatments for diseases with small patient populations and limited therapeutic options. Designated drugs benefit from scientific advisory support and reduced regulatory fees during development, and are guaranteed market exclusivity upon marketing approval. In Europe, that exclusivity extends up to 10 years after approval — longer than the maximum seven years available in the United States. The company said the difference carries significant weight for its global commercialization strategy.

Gaucher disease is a hereditary rare disorder caused by mutations in the GBA1 gene, leading to the accumulation of glycolipids in the body. Symptoms include enlarged liver and spleen, anemia, low platelet counts and skeletal abnormalities. Type 3 Gaucher disease, which involves neurological symptoms, has no approved treatment, leaving a substantial unmet medical need.

YH35995 is a small-molecule glucosylceramide synthase inhibitor that Yuhan secured through a joint research collaboration with GC Biopharma in 2018 and is now developing independently in clinical trials. The drug belongs to the substrate reduction therapy class, which works by suppressing GL-1 production, and is notable for its ability to cross the blood-brain barrier. Yuhan said preclinical research confirmed reductions in GL-1 levels in both plasma and the brain, suggesting the drug can deliver therapeutic effects to the central nervous system — a target that existing treatments have struggled to reach. The company expects YH35995 to offer a new treatment option for Type 3 Gaucher disease patients with neurological involvement.

Clinical development is progressing on schedule. Yuhan conducted a first-in-human study in healthy adults and presented single ascending dose results at the third International Working Group on Gaucher Disease symposium held in Italy in May. The program has since advanced to the multiple ascending dose stage.

Yuhan said it plans to use the EMA orphan drug designation as a springboard to refine its global clinical and regulatory strategy and expand patient access. Kim Yeol-hong, president and head of research and development at Yuhan, said the company would "work closely with global regulators to accelerate development and provide patients with rare diseases a meaningful treatment alternative."