Three Biotechs Receive FDA Designations to Facilitate Their Drug Development

Rare Daily Staff

The U.S. Food and Drug Administration granted designations to Avidity Biosciences, PepGen, and Otsuka Pharmaceutical that can facilitate the development of their investigational therapies to treat rare diseases.

FDA granted Rare Pediatric Disease designation to Avidity Biosciences’ investigational therapy for the treatment of Duchenne muscular dystrophy (DMD) in people living with mutations amenable to exon 44 skipping (DMD44).

DMD is a rare genetic condition that is characterized by progressive muscle damage and weakness due to the loss of dystrophin protein that typically starts at a very young age. Currently, there are no therapies approved targeting exon 44. AOC 1044 is designed to deliver phosphorodiamidate morpholino oligomers (PMOs) to skeletal muscle and heart tissue to specifically skip exon 44 of the dystrophin gene to enable dystrophin production in people living with DMD44. It is being assessed in the phase 1/2 EXPLORE44 trial for people living with DMD44 and is the first of multiple AOCs the company is developing for DMD.

The FDA defines a “rare pediatric disease” as a serious or life-threatening disease in which the serious or life-threatening manifestations primarily affect individuals aged from birth to 18 years. Under the FDA’s Rare Pediatric Disease Priority Review Voucher program, a sponsor who receives an approval for a drug or biologic for a rare pediatric disease may qualify for a voucher that can be redeemed to receive a priority review of a subsequent marketing application for a different product. Recently, vouchers have been sold for as much as $100 million.

In addition to receiving Rare Pediatric Disease designation, AOC 1044 has been granted Orphan designation by the FDA and the European Medicines Agency (EMA), and Fast Track designation by the FDA.

FDA granted Fast Track designation to PepGen’s PGN-EDODM1, an investigational peptide-conjugated antisense oligonucleotide in development for the treatment of myotonic dystrophy type 1 (DM1). PepGen is evaluating PGN-EDODM1 in the ongoing FREEDOM-DM1 phase 1 trial and expects to report preliminary data later this year.

DM1 (also known as Steinert’s disease), is a progressively disabling, life-shortening genetic disorder estimated to affect 40,000 people in the U.S., and more than 74,000 people in Europe. People living with DM1 typically present with myotonia (stiff or contracted muscles), muscle weakness, and cardiac and respiratory abnormalities. There are currently no available treatment options that target the root cause of the disease.

The FDA’s Fast Track designation is a process designed to facilitate the development and expedite the review of drug candidates that treat serious conditions and fill an unmet medical need, with the goal of getting important new drugs to the patient earlier. Once a drug candidate receives Fast Track designation, early and frequent communication between the FDA and the drug company is encouraged throughout the entire drug development and regulatory review process. The frequency of communication assures that questions and issues are resolved quickly, often leading to earlier drug approval and access by patients.

FDA granted Breakthrough Therapy designation to Otsuka Pharmaceutical and Visterra, an Otsuka group company, for the investigational drug sibeprenlimab for the treatment of immunoglobulin A nephropathy (IgAN), also known as Berger’s disease.

IgAN is the most common form of primary glomerulonephritis worldwide and is the most common cause of kidney failure in young adults. The disease is associated with a reduction in life expectancy of 10 years, with at least 30 percent of affected patients progressing to kidney failure within 20 to 30 years, despite optimized standard of care therapy. Current standard of care management is based on renin-angiotensin aldosterone system (RAAS) blockers and adequate blood pressure control, but the risk of kidney failure remains high.

Sibeprenlimab is a humanized monoclonal antibody that blocks the action of the B-cell growth factor, APRIL (an acronym for a proliferation-inducing ligand), which plays a key role in the development and progression of IgAN. Otsuka and Visterra announced positive results of the phase 2 ENVISION trial for IgAN in November 2023. The trial results were also published in The New England Journal of Medicine.

Breakthrough therapy designation is granted by the FDA for a drug intended to treat a serious condition when preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on at least one clinically significant endpoint.  Breakthrough therapy designation allows the agency to prioritize and focus resources on the most promising products for which no satisfactory treatment option exists.