An orphan disease is any disease that affects only a small percentage of the population. There can be as many as 7,000 rare diseases known to affect human life. The total number of Americans living with a rare disease is estimated at between 25-30 million. When it comes to the EU, all together, rare disease patients comprise 6% to 8 % of the EU population.
One such disease is Pompe disease, with an overall worldwide incidence estimated to be 1 in 40,000 live births. According to the US National Library of Medicine National Institutes of Health, the Pompe disease prevalence is approximately 1 in 28,000 in the United States. Pompe disease is mainly caused by pathogenic variations in the acid alpha-glucosidase (GAA) gene. Additionally, more than 500 different variations of the same gene have been identified in the families living with Pompe disease. The gene is required for an efficient breakdown of glycogen, required to produce energy. Mutations in the gene cause failure in doing so, thus resulting in accrual of sugars in heart and liver.
The Pompe disease therapies available are disease-specific, symptomatic, and supportive. At present, there exists no cure for treating Pompe disease. Genzyme, a Sanofi Corporation, Enzyme replacement therapy (ERT), which holds the title of first ever approved treatment for Pompe disease, is not a cure but can only slow down the progression. It involves the intravenous administration of recombinant human acid α-glucosidase. However, companies like Amicus Therapeutics and Actus therapeutics are developing drugs to enhance Pompe disease pipeline and finish it from its roots.
Pompe Disease Pipeline
Amicus Therapeutics has initiated the clinical trials to investigate the safety and pharmacokinetics of AT-GAA as a fixed-dose combination therapy in patients with Pompe disease. Consisting of ATB200, AT-GAA is a unique recombinant human acid alpha-glucosidase (rhGAA) enzyme with optimised carbohydrate structures, particularly mannose-6 phosphate (M6P), to enhance uptake, co-administered with AT2221, a pharmacological chaperone. The therapy is currently under Phase III of development and will occupy a dominant Pompe disease market share when it gets approved because of the use of chaperone as a part of the therapy, increasing its target specificity.
Another company, Actus Therapeutics, is also running trials for its candidate ACTUS-101, to assess its safety, bioactivity, and immune responses for Pompe disease treatment. This Pompe disease treatment is an adeno associated virus (AAV) gene therapy, administered intravenously, specifically transduces the liver, promoting the production of the GAA enzyme. However, it is in an early stage of development and recently dosed the first patient for the Phase I/II trial.
The increase in awareness about the Pompe disease and support from various organizations have assured many companies to carry forward their research in treating and developing treatments for Pompe disease. Although, Researchers from all over the World, have made significant progress in diagnosing, treating and even in finding ways to prevent rare diseases. But, even so, there is much more required to be done in the area. Many organizations such as FDA and the National Institutes of Health (NIH) are supporting and funding researches to help improve the rare disease patient pool.