FDA Grants Rare Pediatric Disease Designation to Versantis’ Treatment for Urea Cycle Disorders

Rare Daily Staff

The U.S. Food and Drug Administration granted Rare Pediatric Disease designation to Versantis’ lead candidate VS-01 for the treatment of urea cycle disorders, a rare life-threatening inborn error of metabolism.

Urea cycle disorders (UCD) are the result of a severe dysfunction of the enzymes or transporters involved in the urea cycle that converts ammonia to urea. The condition results in an accumulation of toxic levels of ammonia in the blood and brain of patients. Elevated ammonia levels can cause coma and irreparable brain damage, potentially resulting in cognitive impairment, seizures, cerebral palsy, and death if untreated. UCD predominantly affects children either shortly after birth (about 50 percent) or, later at any age. Current treatment options, often associated with poor outcomes, include dialysis to lower ammonia levels, which must be conducted at specialized clinics, and liver transplantation.

“The rare pediatric disease designation highlights the potential of using VS-01 to treat the serious and life-threatening manifestations of UCD,” said Meriam Kabbaj, chief operations officer and co-founder of Versantis. “It is valuable recognition that will help Versantis to ramp up its pediatric program by fostering collaborations with key opinion leader and patients’ associations.”

VS-01 is an innovative liposomal-based detoxification therapy that acts as a clearance enhancer for a large spectrum of toxic metabolites accumulated during liver and kidney failures. More specifically, VS-01 clears ammonia from the body, which is the main neurotoxic metabolite and can lead to brain edema. With its rapid onset, VS-01 could be the first-line medication of choice for acute hyperammonemia in an emergency setting. VS-01 is currently being evaluated in clinical trials in decompensated cirrhotic patients.

Versantis recently raised $16 million in a series B financing round and is currently raising new funds to fuel VS-01 clinical development in rare indications, including UCD.

“This recognition acknowledges the unmet medical needs of children with UCD. Importantly, with this designation, we may qualify to receive a priority review voucher from FDA, at the time of marketing approval of VS-01. It provides significant value to our current effort to develop effective treatments for this devastating rare disease,” said Vincent Forster, Versantis’ co-founder and CEO.

The FDA grants Rare Pediatric Disease designation for serious or life-threatening diseases with manifestations in individuals aged from birth to 18 years, including access to the FDA’s expedited review and approval process. The designation makes VS-01 eligible for a Rare Pediatric Disease Priority Review voucher upon approval of the therapy by the FDA.

The vouchers can be used to reduce the time of an FDA new drug approval review to six months from ten months. The vouchers are potentially lucrative because they are transferable. Most recently, Sarepta sold its priority review voucher to Vifor Pharma $111 million in February 2020.

The voucher program was due to expire at the end of September but Congress provided a short-term extension of the program. According to the current statutory sunset provisions, after December 11, 2020, FDA may only award a voucher for an approved rare pediatric disease product application if the sponsor has rare pediatric disease designation for the drug, and that designation was granted by December 11, 2020. After December 11, 2022, FDA may not award any rare pediatric disease priority review vouchers.

Going forward, requests for rare pediatric disease designation submitted will be reviewed in a timely manner but the FDA’s previous 60-day response time no longer applies.

Photo: Meriam Kabbaj, chief operations officer and co-founder of Versantis