ProSavin® – Initial Gene Therapy Shows Hope for PARKINSON’S Motor Function
Researchers in France have injected 15 volunteers who were diagnosed with advanced PARKINSON’S DISEASE with a unique gene cocktail and initial results have been exciting and promising. Using a modified and deactivated virus for a carrier, three genes necessary for the production of dopamine were injected directly into the dopamine deficient brain regions of the subjects and within 12 hours the defective brain cells began producing dopamine.
Subjects were given three different doses of ProSavin® and followed for up to four years. Motor improvements were noted in all of them, with better coordination and balance and speech improvements. The improvements did depend upon the dose, with higher doses giving better response. However there were problems with development of dyskinesias and also periods of “on-off”. The gene injection appears to encourage long term production of dopamine and improvement in motor symptoms, up to four years.
It cannot be considered a cure, as the disease process does continue and symptoms can only be controlled. But even a four year improvement of symptoms would provide an amazing benefit to the quality of life of people with PARKINSON’S DISEASE. This study did not address the non-motor symptoms of PARKINSON’S DISEASE, or the effects of this therapy on cognitive function, apathy or depression.
This therapy was a very preliminary test and shows that gene therapy can be delivered effectively and safely. This was not a clinical trial as none of the subjects were given placebo treatments for comparison. The researchers are excited by the results and have begun preparing a newer version of the therapy, which will provide even more dopamine production. This could last longer than four years and be better tolerated than the first therapy test. This new version is presently being evaluated in animal studies for safety before it can be approved for use in humans.
ProSavin® is a registered trademark for the gene based treatment developed by Oxford BioMedica, a pharmaceutical company from the United Kingdom. It uses a patented process called LentiVector® to deliver the gene based enzymes directly to the striatum to restore dopamine production.
Long-term safety and tolerability of ProSavin, a lentiviral vector-based gene therapy for Parkinson’s disease: a dose escalation, open-label, phase 1/2 trial
Prof Stéphane Palfi MD,Jean Marc Gurruchaga MD,G Scott Ralph PhD,Helene Lepetit PhD,Sonia Lavisse PhD,Philip C Buttery PhD,Colin Watts PhD,James Miskin PhD,Michelle Kelleher PhD,Sarah Deeley MSc,Hirokazu Iwamuro MD,Jean Pascal Lefaucheur MD,Claire Thiriez MD,Gilles Fenelon MD,Cherry Lucas BA,Pierre Brugières MD,Inanna Gabriel MD,Kou Abhay MD,Xavier Drouot MD,Naoki Tani MD,Aurelie Kas MD,Prof Bijan Ghaleh MD,Philippe Le Corvoisier MD,Patrice Dolphin MSc,David P Breen MRCP,Sarah Mason BSc,Natalie Valle Guzman MSc,Prof Nicholas D Mazarakis PhD,Pippa A Radcliffe PhD,Richard Harrop PhD,Susan M Kingsman PhD,Prof Olivier Rascol MD,Stuart Naylor PhD,Prof Roger A Barker PhD,Philippe Hantraye PhD,Prof Philippe Remy MD,Prof Pierre Cesaro MD,Kyriacos A Mitrophanous PhD The Lancet – 10 January 2014
Review by Marcia McCall