Parkinson's disease is a progressive neurodegenerative disease of the basal ganglia region of the brain, with tremor, rigidity and difficulty initiating movement being the most common symptoms.
The condition is associated with a deficiency of the chemical dopamine in the brain. The appropriate cell therapy treatment of patients suffering from Parkinson's disease is the introduction of purified dopamine-producing neurons into the patient's brain.
The worldwide market for Parkinson's disease is currently worth approximately $2bn and is dominated by drugs that raise the level of dopamine in the brain. In the US alone, some one million patients are affected and 50,000 new patients are added annually.
Presenting at the 14th Annual Congress of the European Society of Gene Therapy, in Athens, Greece, the company revealed details of ProSavin, a gene-based product for Parkinson's disease that showed, for the first time, that ProSavin outperformed the standard treatment for Parkinson's disease, L-DOPA.
The data additionally showed that in terms of efficacy, ProSavin did not induce any of the disabling dyskinesias (movement disorders) that occur following prolonged treatment with L-DOPA.
Also, long-term data showed that ProSavin's therapeutic benefit was maintained for at least 15 months, the most recent time point, without any loss of effect.
"These new results substantially strengthen the already impressive preclinical data set for ProSavin and confirm its potential as a treatment for Parkinson's disease, particularly when other therapies fail," said Oxford BioMedica's CEO, Professor Alan Kingsman.
"Its duration of action and lack of side effects are particularly promising. We are now working towards the start of human trials and have been encouraged by discussions with the regulatory agencies."
Oxford Biomedica commented that the higher efficacy of ProSavin combined with the absence of side effects suggested that ProSavin could be used to replace current standard therapy with L-DOPA in late-stage Parkinson's disease.
These new data add to the extensive preclinical data package that supports advancement of the product into human trials.
ProSavin is intended to be administered locally to the region of the brain called the striatum, delivering the genes for three enzymes that are required for the synthesis of dopamine.
These genes are able to reprogram the cells that they enter, enabling these cells to manufacture and secrete dopamine.
The treated brain region becomes a new endogenous source of dopamine, replacing the patient's own lost source of the neurotransmitter. Sustained expression of the genes is a key requirement for the product to be clinically successful.
Oxford BioMedica is planning to start a European Phase I/II trial of ProSavin in 2007 in patients with late-stage Parkinson's disease and has proposed a clinical plan to progress to a Phase III trial following success in the Phase I/II trial.
The Phase III trial, which is designed to support product registration, could commence in 2009. Discussions with relevant regulatory agencies are ongoing.