Korean biopharma GemVax & KAEL has stumbled on its quest to develop new therapies for neurodegenerative diseases.
GemVax revealed Tuesday that its peptide drug candidate GV1001 missed the mark in a phase 2a study in progressive supranuclear palsy (PSP). PSP is a degenerative disease, not unlike Parkinson’s disease, that leads to symptoms like gait disturbances, early falls, vertical gaze palsy, rigidity, tremors and cognitive decline.
The disease advances faster than Parkinson’s, however, and patients currently have no dedicated treatment options, GemVax explained in a release.
Although GV1001 failed to show statistical significance on the trial’s primary endpoint—change from baseline in total score on the PSP-Rating Scale at 24 weeks—GemVax is standing firm behind its candidate’s potential in the rare neurodegenerative disease.
The company’s chief scientific officer, Hyungsik Moon, argued in a statement that the overall data were still “strong enough” to the company to consider advancing GV1001 into a pivotal trial. The company's share still dropped by around 4% mid-morning ET time on the data.
GemVax’s phase 2a study ran for 24 weeks and enrolled 78 patients with PSP across five centers in Korea. Patients received either placebo, GV1001 0.56 mg or GV1001 1.12 mg, the company said. Medication was administered once weekly during the first month of the trial, and then biweekly for the remaining 20 weeks.
The study enrolled patients with two distinct types of PSP—PSP-Richardson’s syndrome and PSP-Parkinsonism. According to GemVax, PSP-RS shows a greater accumulation of tau protein and affects larger areas of the brain, including the cerebellum, dentate nucleus, pontine nuclei, frontal lobe and parietal lobe.
PSP-RS also accounts for most PSP patients, progresses faster and has a shorter average survival time compared to other PSP types, GemVax added.
On the study’s primary endpoint, the 0.56-mg GV1001 dose saw patients experience deterioration by 2.14 points on the PSP rating scale at 24 weeks versus 4.10 points of deterioration in the placebo cohort. This amounted to a 48% reduction in disease progression, which was not statistically significant, GemVax said in its release.
In trying to salvage the readout, GemVax highlighted a subgroup analysis of PSP-RS patients that showed GV1001 0.56 mg saw patients experience 0.25 points of deterioration on the PSP rating scale (calculated using simple average) versus 5.19 points in the study’s placebo group.
Further, PSP-RS patients in the treatment group experienced symptom stabilization or even improvement during the clinical trial’s run, GemVax added.
The medicine was generally well tolerated and didn’t lead to any serious side effects or safety signals, GemVax added.
GV1001 is a synthetic peptide comprised of 16 amino acids based on telomerase. Aside from PSP, the drug has also been pitted against Alzheimer’s disease. The medicine has been shown to modulate phenotypes of glial cells and regulate neuroinflammation, GemVax said.
Currnetly, GemVax is running a phase 2 trial of GV1001 in Alzheimer’s in the U.S. and Europe.
And despite the miss in the phase 2a trial, GemVax noted in its release that “preparations are underway” to eventually run a global PSP study.