Parkinson Disease Gene Therapy Demonstrates Continued Improvement in 6-Month Data

June 14, 2019

Axovant reported positive safety data as well as improvements in a number of measurements of motor function and dyskinesias in patients with Parkinson disease who received treatment with their investigational gene therapy.

Gavin Corcoran, MD

Newly reported 6-month follow-up data on Axovant Gene Therapies’ investigational therapy for the treatment of Parkinson disease, AXO-Lenti-PD, was observed to be generally well tolerated, and patients were reported to show continued improvement in several measurements.

The phase 2 SUNRISE-PD clinical trial data show that, at 6 months, patients experienced an average improvement of 29% in Unified Parkinson’s Disease Rating Scale (UPDRS) III off scores, measuring motor function, for a change from baseline of 17 points. At 6 months, the individuals treated with the AXO-Lenti-PD gene therapy had UPDRS III score improvements of 14 and 20 points, respectively.

“We continue to be encouraged by the consistency of the data and improvements in quality of life seen at six months in the two low-dose cohort patients, as we enroll additional patients in the second cohort of the SUNRISE-PD study,” Gavin Corcoran, MD, FACP, chief research and development officer, Axovant, said in a statement. “Our patient-focused goal of improving motor function, reducing dyskinesia, lowering the requirement for oral levodopa, and improving quality of life is made possible by the continuous dopamine replacement strategy of AXO-Lenti-PD gene therapy.”

AXO-Lenti-PD is designed to deliver 3 genes: tyrosine hydroxylase, cyclohydrolase 1, and aromatic L-amino acid decarboxylase. It is administered by a single lentiviral vector to encode a set of enzymes necessary for dopamine synthesis, with the goal of lowering the variability and reinstating stable levels of dopamine. According to Axovant, the investigational treatment is expected to provide patient benefit for years after 1 administration.

Axovant announced in April 2019 that the first patient in the second cohort of the SUNRISE-PD clinical study had been dosed and that it expected to have its initial 3-month data by Q4 2019.

Additionally, in the SUNRISE-PD trial, investigators observed an average improvement of about 20 points from baseline on the UPDRS Part II off score, which measures activities of daily living. On the UPDRS Part IV off scores, measuring complications of therapy, patients had an average improvement of 3 points from baseline.

“These data at 6 months highlight the potential for a clinically meaningful improvement over the currently available standard of care for those patients with moderate to advanced Parkinson disease," Corcoran added. As for safety, there were no reported treatment-related serious adverse events.

Investigators reported that the average levodopa equivalent daily dose at baseline was 1117 mg, dropping to 884 mg at 6 months—a 21% decrease from baseline and a 233 mg change. According to Rush Dyskinesia Rating Scale scores, patients experienced an 18% average improvement in functional disability at month 6 during their activities of daily living, while taking oral levodopa.

At month 3, Parkinson’s Disease Questionnaire-39 (“PDQ-39”) Summary Index scores had improved from 50 at baseline to 31 points, and at month 6, it dropped a further 13 points to a score of 18 (reduction from baseline, 32 points). The percentage of improvements from baseline at month 3 and month 6 were 37% and 65%, respectively.

Patient-recorded diaries, collected at month 6, showed an improvement from baseline in on time without dyskinesia of 27 hours. As well, they reported a decrease of 2.4 hours in on time with non-troublesome dyskinesias, 1.5 hours of on time with troublesome dyskinesias, and an increase in off time of 0.9 hours.

Axovant also announced recently that its license and collaboration agreement with Benitec Biopharma Limited has been terminated in its entirety. The agreement in part encompassed AXO-AAV-OPMD, an investigational therapy in preclinical development for the treatment of oculopharyngeal muscular dystrophy (OPMD). Additionally, the agreement featured some discovery-stage research collaboration programs in such conditions as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia.

“We are committed to our mission of developing clinical-stage gene therapies for the treatment of neurological diseases,” said Pavan Cheruvu, MD, chief executive officer, Axovant. “Based on the encouraging data seen in the Parkinson’s disease and GM2 gangliosidosis programs, the team will focus its efforts on our clinical programs.”

REFERENCES

Axovant Announces 6-Month Follow-Up Data From First Cohort of SUNRISE-PD Phase 2 Trial of AXO-Lenti-PD and Pipeline Update [press release]. Basel, Switzerland: Axovant Gene Therapies, Ltd; Published June 6, 2019. finance.yahoo.com/news/axovant-announces-6-month-data-114000546.html. Accessed June 12, 2019.