PORTO, Portugal, June 9, 2026
Bial announced topline results from its Phase 2b ACTIVATE study evaluating BIA 28-6156 (pariceract) in patients with GBA-associated Parkinson’s disease (GBA-PD). The study failed to meet both its primary efficacy endpoint and key secondary endpoint, demonstrating that pariceract did not significantly slow disease progression compared with placebo. While the investigational therapy was generally well tolerated and showed no unexpected safety concerns, the lack of efficacy has led Bial to discontinue further development of the program for this indication. The results provide important scientific insights into Parkinson’s disease biology and future therapeutic development despite the clinical setback.
ACTIVATE Study Fails to Demonstrate Disease-Modifying Benefit
The Phase 2b ACTIVATE trial was designed to evaluate the efficacy, safety, tolerability, pharmacodynamics, and pharmacokinetics of pariceract in patients with genetically confirmed GBA-associated Parkinson’s disease. The multinational study enrolled 273 patients across 85 clinical sites in 11 countries throughout Europe and North America over approximately 18 months. Despite strong scientific rationale and encouraging preclinical data, treatment with pariceract did not achieve statistically significant improvement compared with placebo on the primary endpoint or key secondary efficacy measures. These findings indicate that the therapy was unable to demonstrate a disease-modifying effect in slowing Parkinson’s progression among patients carrying pathogenic GBA1 gene variants.
Safety Profile Remained Favorable Throughout the Trial
Although efficacy goals were not achieved, Bial reported that pariceract was generally well tolerated, with no unexpected safety signals identified during the study. The safety findings were consistent with previous clinical observations and support the compound’s acceptable tolerability profile. Researchers noted that while the treatment did not produce meaningful clinical benefits, the study generated a substantial amount of data that may help researchers better understand disease mechanisms and treatment challenges associated with GBA-related Parkinson’s disease, one of the most important genetic forms of Parkinson’s.
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First-in-Class GCase Activator Development Program Ends
Pariceract was being developed as a first-in-class oral allosteric activator of beta-glucocerebrosidase (GCase), an enzyme closely linked to the biology of GBA-associated Parkinson’s disease. Mutations in the GBA1 gene reduce GCase activity and are among the strongest known genetic risk factors for Parkinson’s disease. The therapy was designed to enhance enzyme function and potentially slow neurodegeneration through a disease-modifying mechanism. However, the ACTIVATE results failed to confirm the therapeutic hypothesis, prompting Bial to terminate further development of the candidate for GBA-PD.
Findings Contribute to Future Parkinson’s Research Efforts
Despite the disappointing outcome, Bial emphasized that the ACTIVATE study provides valuable scientific knowledge that may guide future Parkinson’s disease research. The company plans to share the complete dataset through peer-reviewed publications and scientific conferences to help advance understanding of genetic Parkinson’s disease and inform future drug development strategies. Bial stated that it remains committed to neuroscience innovation and continues to pursue new therapeutic approaches aimed at addressing significant unmet needs in Parkinson’s disease and other neurological disorders.
Source: Bial press release
