Researchers are testing gene therapy to treat Parkinson's
Gene therapy offers promising new approaches to the treatment of Parkinson's. For decades, scientists around the world have been looking for ways to treat the previously incurable degenerative neurological disease. A British-French research team has now published a study in the specialist magazine "The Lancet", which concludes that so-called ProSavin gene therapy can at least significantly improve the motor skills of Parkinson's patients.
To date, Parkinson's disease is usually treated with oral dopamine replacement therapy, but the long-term treatment leads to significant side effects, such as "impulse control disorders caused by intermittent stimulation of the dopamine receptors and side effects," reports the research team led by Professor Stéphane Palfi von der medical faculty of the University of Paris. In their current study, the effectiveness and tolerability of an alternative treatment based on ProSavin gene therapy was therefore examined. This has proven to be quite effective and well tolerated.
Gene therapy increases dopamine production in the brain In ProSavin gene therapy, the scientists use cored viruses as a means of transport for DNA sequences or genes that play an essential role in dopamine production. These are injected into the patient's brain and then automatically incorporated into certain brain cells, whereupon dopamine production in the brain increases significantly. As a result, the motor disorders of Parkinson's patients caused by dopamine deficiency, such as muscle twitching or the typical tremor and balance disorders, decrease significantly. The researchers have now tested the effectiveness of this method on 15 Parkinson's patients between the ages of 48 and 65. All subjects had suffered from the neurological disease for at least five years. Patients were given different doses of ProSavin (three received low doses, six medium, six high) and then followed up for at least 12 months.
No serious side effects The patients reported “54 drug-related adverse events (51 mild, three moderate)” within the follow-up period. The most common complaints were so-called dyskinesias (disturbances in the movement sequences). However, according to Palfi and colleagues, there were no serious adverse events as a result of the study medication or the surgical procedures. After six months, all patients showed a significant improvement in motor skills. The higher the dose administered, the clearer the improvement in the patient's motor skills. In some patients, the effect lasted up to four years. Subsequently, the limitations of the motor skills in view of the progression of the disease came to bear again clearly.
Other Aspects of Parkinson's Disease Not Considered In a commentary on the article in The Lancet, Jon Stoessl of Pacific Parkinson's Research Center at the University of British Columbia and Vancouver criticized the fact that the current gene therapy approach does have a proven effect on motor skills the patient had neglected the other symptoms of the clinical picture. For many patients, the cognitive failures and changes in character are a considerably greater impairment than the motor difficulties. A sensible treatment method should therefore also take these aspects into account. (fp)
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