Earlier this year, I interviewed Dr. Arthur Suckow, the CEO and co-founder of DTx Pharma, about the innovative RNA therapeutics being developed for Charcot-Marie-Tooth disease type 1A (CMT1A). In an exciting update made via news release, the company DTx Pharma recently shared that its lead therapeutic candidate DTx-1252 was recently granted Orphan Drug designation by the FDA.
Orphan Drug designation was created to incentivize drug development in the rare disease field. Historically, it has been difficult to advance research and drug development into rare disease due to smaller population sizes and financial concerns from companies. However, this leaves many patients living without help and without options. The Orphan Drug program helps to overcome these barriers. This designation, granted to drugs or biologics intended to treat, diagnose, or prevent conditions affecting fewer than 200,000 people nationwide, comes alongside benefits such as fee waivers, tax credits, increased regulatory assistance, and up to seven years of market exclusivity upon drug approval.
DTx-1252 is described as an siRNA therapy developed using DTx Pharma’s Fatty Acid Ligand Conjugated OligoNucleotides (FALCON™) platform. It works by inhibiting PMP22, which is overexpressed in Schwann cells in people with CMT1A. So far, DTx-1252 has shown immense promise in mice models of this disorder. In fact, DTx-1252 treatment improved nerve myelination, reversed signs of CMT1A, and contributed to stronger grip, better coordination, and increased grip strength.
What is CMT1A?
There are multiple forms of Charcot-Marie-Tooth disease (CMT), which, though rare, is considered one of the most commonly inherited neurological disorders. Charcot-Marie-Tooth disease type 1a, or CMT1a, is the most common form of CMT, accounting for approximately 70% of cases. CMT1A results from duplications or point mutations in the PMP22 gene. These mutations cause peripheral nerve degeneration and muscle wasting. Typically, symptoms begin in adolescence and progress throughout adulthood. Symptoms may include:
- Arched feet and/or hammertoes
- Foot drop
- Leg and hand cramps
- Hearing loss
- Muscle weakness in the lower extremities
- Fatigue
- Impaired vision
- Neuropathic pain
- Breathing difficulties when lying flat
- Decreased reflexes
- Numbness or tingling in the hands and feet
- Frequent tripping and falling
Occupational and physical therapy, surgical intervention, and orthopedic devices can help manage this condition. At this time, there is no cure for CMT1A, nor is there any treatment that specifically targets the underlying genetic basis.
