GemVax Confirms Safety and Efficacy of GV1001 in Comprehensive PSP Clinical Trial Results

On November 24, GemVax & KAEL announced that the efficacy and safety of GV1001 had been confirmed in a long-term clinical trial for progressive supranuclear palsy (PSP).

According to GemVax, in the combined 72-week trial-which included both the preceding and extension studies-an analysis of the change in the total score of the PSP-rating scale in patients with the progressive supranuclear palsy Richardson's syndrome (PSP-RS) subtype showed statistically significant efficacy in the low-dose GV1001 group (0.56mg) compared to an external control group (p-value<0.0001). This data is separate from the primary endpoint disclosed on November 24.

This was the first PSP clinical trial conducted in Korea, consisting of a 24-week preceding trial followed by a 48-week extension, for a total of 72 weeks. The preceding trial was divided into three groups: placebo, GV1001 0.56mg, and GV1001 1.12mg. The extension trial administered GV1001 1.12mg to patients who wished to continue after the preceding trial.

Analysis of the clinical trial data showed that, in the PSP-RS subtype, the low-dose GV1001 group experienced only a 5.61-point worsening in the PSP-rating scale total score at week 72, as calculated by the least squares mean (LS mean) using the MMRM estimation method. Although PSP is a rapidly progressing form of parkinsonism, the results indicate that long-term administration of GV1001 continuously slowed the disease progression rate.

To address the absence of a placebo control group in the extension study and to objectively demonstrate efficacy, GemVax conducted a detailed analysis using an external control group. Data from placebo groups in three major international PSP clinical trial papers were used for comparative analysis, and the MAIC (Matching Adjusted Indirect Comparison) statistical method was applied to enhance objectivity. In the external studies, the placebo group showed a 10.66-point worsening over just 52 weeks. When compared with the score changes in the low-dose GV1001 group, the p-value was less than 0.0001, demonstrating a statistically significant difference.

Notably, the results were obtained despite the disadvantage of comparing the 72-week total score change in the GV1001 group with the 52-week total score change in the external control group. The GV1001 group was measured over a period 20 weeks longer than the external control group, yet still demonstrated statistical significance, drawing attention from experts both in Korea and abroad. The trial also reconfirmed the safety of GV1001, as tolerability and safety data were secured.

GemVax plans to proceed with a global Phase 3 clinical trial, reflecting all data from the 72-week trial and biomarker results confirmed in the preceding study.

Paek Jongmin, Professor of Neurology and Director of the Neurocognitive and Behavioral Center at Seoul National University Bundang Hospital, stated, "PSP is an intractable disease that causes great suffering for patients and families. When the PSP-rating scale score reaches 60, the two-year survival rate drops sharply to the 20% range." He added, "Because the disease progresses rapidly, a patient with a score of 40 can reach 60 in just two to three years," emphasizing the severity of PSP.

Professor Paek continued, "The 72-week GV1001 clinical trial showed the potential to delay the progression of patients from the 40-point range to the 60-point range not by two years, but by nearly 10 years. I hope GV1001 will become a new treatment option for patients and families suffering from PSP."

Lee Jiyoung, Professor of Neurology at Boramae Medical Center, Seoul National University Hospital, who led the clinical trial, explained, "The clinical effects I observed firsthand while treating patients seem to have been confirmed once again through statistical data." She added, "These are encouraging results, and I hope that, so patients do not have to wait any longer, the follow-up Phase 3 clinical trial can begin as soon as possible so that all patients can access the medication."