FDA Rejects Enzyvant’s Rare Disease Therapy over Manufacturing Issues

Enzyvant’s experimental tissue-based regenerative therapy RVT-802 for pediatric congenital athymia works—it’s been shown to be safe and effective—so the company was surprised when the U.S. Food and Drug Administration declined to grant the company approval to market the treatment based on an inspection of Enzyvant’s manufacturing facilities.

“Many of these are topics that we are very aware of and we anticipated those to be post-marketing commitments, not approval requirements,” CEO Rachelle Jacques told Reuters. “The good news is there’s no requirement for us to foresee any additional animal studies or any additional clinical trials.”

Pediatric congenital athymia is a rare and deadly condition associated with complete DiGeorge Anomaly, CHARGE syndrome, and FOXN1 deficiency. Children with the condition are born without a thymus, resulting in a severe immunodeficiency due to the inability to produce normally functioning T cells, which defend against infection and regulate essential processes in the immune system. Approximately 20 infants are born each year in the United States with congenital athymia, which is fatal if untreated. Death typically occurs in the first 24 months of life due to susceptibility to infection. Currently, there are no FDA-approved therapies for this condition.

RVT-802 is derived from infant thymus tissue and stimulates and facilitates the body’s production of naive, immunocompetent T cells, with the goal of bolstering the immune system and restoring the body’s ability to fight infection. Investigational RVT-802 is designed to be administered as a single treatment. The FDA had granted Enzyvant’s BLA priority review status in June 2019.

In 2016, Enzyvant entered into an exclusive worldwide licensing agreement with Duke University to develop RVT-802. Louise Markert, professor of pediatrics at Duke University School of Medicine, led research on the treatment of immunodeficiency in patients with congenital athymia.

More recently, Sumitomo Dainippon Pharma paid Roivant Sciences, Enzyvant’s main shareholder, $3 billion for Roivant’s interest in five “vants” that includes Enzyvant.

Photo: Rachelle Jacques, CEO of Enzyvant