Axovant Releases Positive Interim Updates for Parkinson's and Tay-Sachs Gene Therapy Trials
Axovant has been busy, releasing interim results from two different clinical trials, one for Tay-Sachs, the other for Parkinson’s disease.
For Parkinson’s disease, Axovant released positive interim results from the first cohort of its SUNRISE-PD Phase II clinical trial of AXO-Lenti-PD. AXO-Lenti-PD is a gene therapy that delivers three genes, tyrosine hydroxylase, cyclohydrolase 1, and aromatic L-amino acid decarboxylase, by way of a single lentiviral vector. These genes code for a group of enzymes required for dopamine synthesis.
The cohort involved two patients with advanced Parkinson’s disease. They both received a single administration of the lowest dose of the therapy. It was well-tolerated, and no serious adverse events were observed.
At three months after receiving the therapy, improvements of an average of 55 percent from baseline were observed, based on the Unified Parkinson’s Disease Rating Scale (UPDRS) Total OFF score.
“Our focus in this first cohort of the SUNRISE-PD study was on the safety and tolerability of AXO-Lenti-PD, as well as the evaluation of efficacy using well-validated, objective measures,” stated Gavin Corcoran, Axovant’s executive vice president of Research and Development. “These early data support the safety of the lowest dose of AXO-Lenti-PD, similar to what was observed with the earlier generation construct, ProSavin, and also suggest substantially greater biological activity than the highest dose of ProSavin previously tested. These findings are highly encouraging, and we look forward to advancing to higher dose cohorts where we will explore the full clinical potential of AXO-Lenti-PD in patients with Parkinson’s disease.”
The bottom line appears to be that AXO-Lenti-PD is safe at the lower dosage and appears at least as effective as an early version, ProSavin, significantly improving motor function in patients with advanced Parkinson’s disease.
Axovant also announced a clinical update on its first patient dosed with AXO-AAV-GM2 gene therapy for advanced infantile Tay-Sachs disease. AXO-AAV-GM2 is a gene therapy for GM2 gangliosidosis, also known as Tay-Sachs and Sandhoff diseases. They are a group of rare and fatal pediatric neurodegenerative diseases caused by mutations in the HEXA gene, which causes Tay-Sachs, and the HEXB gene, which causes Sandhoff disease. These genes code for two subunits of the ß-hexosaminidase A (Hex A) enzyme.
The announcement described three-month data from the trial evaluating dose of the therapy in a 30-month-old child with advanced infantile Tay-Sachs. It was administered into the cisterna magna and lumbar spinal canal only. Because of the patient’s advanced disease, the intrathalamic injection wasn’t administered. The company indicates that future patients, who are expected to be treated earlier in the disease, will also receive the therapy into the thalamus bilaterally in addition to into the cisterna magna and spinal canal.
The therapy was generally well-tolerated. No serious adverse events were reported as of the three-month visit. The patient’s clinical condition was stable from baseline to the third month without any neurological clinical deterioration observed in either the neurological exam or the MRI. There was also an increase of ß-Hexosaminidase A to 1.44 percent of normal.
“Our first priority has been to identify a vector construct and route of delivery that can reconstitute a clinically important level of enzyme activity in a safe manner,” stated Terence R. Flotte, professor of pediatrics and dean of the School of Medicine at the University of Massachusetts Medical School. Flotte is the principal investigator of the trial. “This first demonstration of the feasibility of human gene therapy for Tay-Sachs disease is a tribute to the tremendous collaborative effort between the research teams at UMass Medical School and Auburn University, and provides a strong foundation for the transition of this program to the team at Axovant.”