Therapies for rare diseases face peculiar challenges, especially as they affect small patient populations and are surrounded by a lack of understanding about the disease pathology compared to diseases that occur more frequently.
Gene therapies represent a viable treatment option with the potential to redefine the treatment landscape for many rare diseases. Metachromatic leukodystrophy (MLD) could be the next indication to witness the impact of gene therapy.
On 18 November, Orchard Therapeutics’ OTL-200 was granted an accelerated review from the European Medicines Agency (EMA) due to its potential to treat MLD.
MLD is a rare disease caused by a faulty gene that results in abnormal accumulation of substances in the nerve cells. This accumulation blocks messages from the brain to other parts of the body, preventing the body from working properly. The therapy is being developed as an ex-vivo autologous option for pediatric patients who are pre-symptomatic. Ongoing clinical trials are evaluating both fresh and cryopreserved formulations. The latter option is understood to help optimise the quality control of the final product and to address the time constraints that are associated with a typical ex-vivo gene therapy procedure. At present, there are no approved therapies for patients with MLD while currently available treatment options are aimed at alleviating the symptoms of the disease. Therefore, accelerated review status means it is more likely that an effective treatment option will become available earlier than anticipated.
Rare monogenic diseases represent easier opportunities for gene therapy solutions compared to frequent diseases. According to GlobalData’s Gene Therapies in Neurology report, there are 18 neurology indications for which gene therapies are being developed, specifically in Phases I, II, or III of development. Half of these indications are identified as rare diseases. More gene therapies are expected to become available for rare diseases based on their clinical profiles. GlobalData expects that these therapies will be offered at a price range that ensures access to a wider patient population.