The gene therapy era can be said to have begun in 1990, when the first gene therapy clinical trial took place. Some 3,000 clinical trials have followed that first study, a resounding affirmation of innovators’ increasing recognition of gene therapy’s breakthrough possibilities for treating a diverse range of disorders — especially afflictions with limited or no established treatments.
Patients with Parkinson’s disease (PD) are among the potential beneficiaries of gene therapy. Although there are currently numerous available treatments for PD, these merely target symptomatic relief, leaving disease onset or progression largely unmet and sometimes producing significant adverse effects. Those limitations underscore the need for novel therapeutic approaches.
Compared to conventional pharmacological and surgical approaches to treating PD, gene therapy has several potential advantages including preservation or restoration of dopaminergic neurons; addressing underlying pathophysiological imbalances, possibly resulting in less fluctuation in response and reduced risk of dyskinesias. In vivo gene therapy — the direct, vector-delivered, intra-cerebral injection of genetic material — appears to hold great promise in PD. Its success depends on efficient uptake of the therapeutic gene by the target cells and on the gene’s expression capability. Viral vector-based in vivo gene therapy is less invasive than transplantation techniques, leaving the striatal circuitry undisturbed by cellular implants.