Preclinical efficacy results with gene-based product for Parkinson's disease, ProSavin, were presented at 14th Annual Congress of the European Society of Gene Therapy (ESGT) in Athens, November 2006
The data showed, for the first time, that ProSavin outperformed the standard treatment for Parkinson's disease, L-Dopa, in terms of efficacy without inducing 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.
ProSavin is 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.
Dr Palfi, head of neurosurgery at Henri Mondor Hospital, Creteil is the principal researcher conducting the preclinical in vivo evaluation of ProSavin.
At the ESGT meeting, Palfi presented a comparison of ProSavin with L-Dopa In an industry standard model of Parkinson's disease.
In the early stages of treatment, ProSavin gave high levels of efficacy when evaluated by a series of clinically relevant parameters.
In addition, the benefit of a single administration of ProSavin was maintained after a prolonged period, whereas the benefit of continuous L-Dopa therapy waned significantly.
Palfi reported that ProSavin has been effective to the most recent time point of 15 months.
The higher efficacy of ProSavin combined with the absence of side effects suggest 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.
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.
Commenting on the ProSavin data, Oxford BioMedica's CEO, Alan Kingsman, said: "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.
"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."
