Vanqua Bio's VQ-101 Achieves Over 70% GCase Activation in Phase 1b Trial for GBA-Parkinson's Disease
Key Insights
VQ-101 demonstrated over 70% activation of lysosomal glucocerebrosidase (search) (GCase (search)) in GBA-Parkinson's disease (search) patients, exceeding the 50% target engagement goal at all tested doses.
The oral, brain-penetrant drug showed favorable safety and tolerability with no dose-limiting or serious adverse events reported during 28 days of dosing in the Phase 1b study.
VQ-101 achieved full CNS penetration with CSF:unbound plasma ratios ≥1, supporting once-daily oral dosing for potential disease-modifying treatment.
Vanqua Bio (search) announced positive interim results from its Phase 1b clinical trial of VQ-101, marking a significant milestone as the first small molecule to demonstrate over 70% activation of lysosomal glucocerebrosidase (search) (GCase (search)) in patients with GBA-associated Parkinson's disease (search) (GBA-PD). The orally administered, brain-penetrant allosteric activator exceeded its target engagement goal while maintaining a favorable safety profile.
Robust Target Engagement Achieved
In the Phase 1b portion of the double-blind, placebo-controlled study, VQ-101 surpassed the study's target engagement goal of 50% lysosomal GCase (search) activation at all doses tested following 28 days of once-daily dosing. According to Vanqua Bio (search), this level of activation is expected to restore patients' lysosomal GCase activity to healthy volunteer levels and block the accumulation of insoluble alpha synuclein (search), the pathologic hallmark of Parkinson's disease (search).
"We are pleased to announce that VQ-101 demonstrated robust activation of lysosomal GCase (search) and full CNS penetrance at doses that were safe and well tolerated following 28 days of dosing in patients with GBA-PD," said Jim Sullivan, Ph.D., CEO of Vanqua Bio (search). "By restoring GCase activity to at least healthy volunteer levels, we believe that VQ-101 has the potential to positively impact the lives of patients following longer term dosing."
Safety Profile and CNS Penetration
The trial demonstrated VQ-101's favorable safety and pharmacokinetics profile. No dose-limiting or serious adverse events were reported, and all treatment-emergent adverse events were mild or moderate in severity. Importantly, there were no study discontinuations due to adverse events.
VQ-101 achieved full CNS penetration, with mean cerebrospinal fluid (CSF) to unbound plasma ratios of ≥1, supporting the drug's potential for once-daily oral dosing. This level of brain penetration is crucial for treating neurodegenerative diseases where the therapeutic target resides in the central nervous system.
Addressing Genetic Mechanisms of Disease
VQ-101 aims to address the underlying genetic mechanism of disease in GBA-PD by restoring GCase (search) activity to healthy levels. In preclinical studies using patient-derived neurons, 50% GCase activation blocked the accumulation of alpha synuclein (search), suggesting potential disease-modifying effects.
The Phase 1b study enrolled Parkinson's patients with and without GBA mutations in a randomized, double-blind design. Participants received once-daily VQ-101 or placebo for 28 days, with the opportunity to enroll in an open-label extension for up to 6 months.
Clinical Significance and Future Development
Vanqua Bio (search) will present these interim Phase 1b results at the International Congress of Parkinson's Disease (search) and Movement Disorders in Honolulu, Hawaii, from October 5-9. The company will also present an analysis comparing progression of motor function and cognitive abilities in Parkinson's patients with and without GBA1 mutations using the Michael J. Fox Foundation (search)'s Parkinson's Progression Markers Initiative (PPMI) study database.
According to the analysis, motor function and cognitive abilities decline more rapidly in GBA-PD compared with idiopathic Parkinson's disease (search) participants, including in time-to-event outcomes that can be used as potential endpoints for late-phase clinical trials.
The open-label extension portion of the Phase 1b study in Parkinson's patients is ongoing, with additional data expected in early 2026. These results support the continued development of VQ-101 in Parkinson's disease (search) and may provide insights into the drug's longer-term effects on disease progression.