Axovant pushes on with Parkinson's gene therapy, despite investor cynicism

Axovant has said it plans to continue developing its Parkinson’s Disease gene therapy after reporting supportive data from a small cohort of patients from a phase 2 trial.

However shares in Axovant were down sharply after the announcement because of market sentiment that the New York biotech had been selective with the data it had shared in its update.

The data came from a second cohort of just four patients in the phase 2 clinical trial SUNRISE-PD, although the improvement in symptoms was dramatic.

Chief R&D officer Gavin Corcoran said that the therapy known as AXO-Lenti-PD could transform treatment of patients with Parkinson’s through a one-time shot of gene therapy.

The company plans to begin EXPLORE-PD, a randomised, sham-controlled study next year, which will evaluate safety and tolerability at higher volumes of infusion.

Latest results showed that in two evaluable patients in the cohort, there was a 21-point mean improvement in a score measuring motor function during “off” periods, a 40% improvement from the baseline average score of 52 in these patients.

There was also evidence of dose response when compared with results at lower doses.

However the company said that COVID-19 and a patient refusal in the cohort at UK trial sites meant that two of the patients could not be scored at the six-month follow-up.

All four subjects were able to complete all other efficacy assessments at six months, including the patient-recorded symptom diaries.

Axovant is working with sites and investigators to ensure safe and ethical data collection at future time points through the pandemic in accordance with regulatory guidance.

It added that the gene therapy was generally well-tolerated in four patients receiving gene therapy, with no serious adverse events at six months after a single administration in the four subjects.

The subjects had an average age of 57 years and an average duration of Parkinson’s disease of 13 years, the company said.

In patients with PD specialised neurons in the brain producing the neurotransmitter dopamine die and the patient's movements become erratic and uncontrolled, progressively declining over time.

Parkinson’s is not a true genetic disease, although certain genes have been linked to an increased likelihood of onset.

But Axovant is using a gene therapy approach to treat the disease – Axo-Lenti-PD works by turning other neurons in the brain into dopamine factories to replace those lost as the disease progresses.

The company hopes that by taking this approach it will solve the problem of “off” periods that occur with conventional therapies.