Yuhan Corporation Presents Phase 1 Clinical Trial Results for Gaucher Disease Treatment at International Academic Conference

3rd International Working Group on Gaucher Disease Symposium 2026
Phase 1 Clinical Trial Results of Gaucher Disease Treatment Candidate 'YH35995' Announced

Yuhan Corporation announced on the 8th that it had delivered an oral presentation on the results of the Phase 1 single ascending dose trial for YH35995, a glucosylceramide synthase (GCS) inhibitor being developed as a treatment for Gaucher disease, at the 3rd International Working Group on Gaucher Disease (IWGGD) Symposium 2026, held in Trieste, Italy, on the 6th. IWGGD is an international academic conference specializing in Gaucher disease research.

Gaucher disease is a rare genetic disorder in which a mutation in the GBA1 gene causes decreased function of the lysosomal enzyme glucocerebrosidase, resulting in the accumulation of glucosylceramide (GL1) in various organs throughout the body. In particular, neuronopathic Gaucher disease (types 2 and 3) is accompanied by central nervous system (CNS) symptoms. Existing treatments have difficulty sufficiently crossing the blood-brain barrier (BBB), leading to a significant unmet medical need for therapies addressing CNS symptoms.

YH35995 is a novel drug candidate secured through a joint research agreement with GC Green Cross in 2018. Yuhan Corporation is currently conducting clinical development independently. The candidate is an oral, small-molecule GCS inhibitor classified as substrate reduction therapy (SRT), with a key feature of being able to cross the BBB. In preclinical studies, YH35995 significantly reduced GL1 levels in plasma and brain, improved abnormal behaviors, and suppressed increases in neuroinflammation-related markers, such as glial cell activation in brain tissue. These findings suggest the potential for expanding treatment options for Gaucher disease patients with neurological symptoms.

This oral presentation focused on the First-in-Human (FIH) Phase 1 single ascending dose (SAD) part involving healthy adult male subjects, sharing results on safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD). The clinical trial employed a randomized, double-blind, placebo-controlled design.

In these results, YH35995 demonstrated an overall favorable safety profile within the dosing range. No serious adverse events (SAEs) or drug-related adverse events of Grade 3 or higher were reported, and the incidence of adverse events did not increase in proportion to the dose.

Pharmacokinetically, drug exposure in the body increased proportionally with the dose, inter-individual variability was low, and, unusually for an oral drug, the half-life was relatively long, at approximately 21 to 24 days. Pharmacodynamically, plasma GL1, used as a biomarker, decreased in a dose-dependent manner. In dose groups 4 and 5, the targeted GL1 inhibition rate was achieved, confirming a strong and sustained GL1 inhibition effect. Based on these PK and PD results, the company anticipated that a dosing regimen with 4-week intervals (Q4W) or longer could be established.

Based on these SAD results, Yuhan Corporation plans to conduct repeated administration in the multiple ascending dose (MAD) part at 4-week intervals (Q4W), evaluate safety and tolerability, and assess changes in GL1 in plasma and cerebrospinal fluid (CSF), as well as target engagement in the CNS.

Yeolhong Kim, Head of Research and Development at Yuhan Corporation, stated, "This announcement marks an important achievement in confirming the potential for new treatment options to address the unmet medical needs of Gaucher disease patients, especially those with neuronopathic Gaucher disease." He added, "We will continue to actively communicate with global experts and patient groups and work closely with regulatory agencies in each country to accelerate clinical development and provide patients with tangible treatment alternatives."