NNI-351 Earns Rare Pediatric Disease Designation From FDA

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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The U.S. Food and Drug Administration (FDA) has granted rare pediatric disease designation to Neuronascent‘s investigational therapy NNI-351 for the treatment of fragile X syndrome (FXS).

“With vast unmet need for novel therapies that can directly address pediatric FXS behavioral deficits, such as to improve education and social outcomes of these young patients, this designation puts a spotlight on the true potential of NNI-351,” Judith Kelleher-Andersson, PhD, founder and CEO of Neuronascent, said in a press release.

NNI-351 is an oral small molecule that in preclinical models has been shown to promote neurogenesis — the process by which immature progenitor cells grow into mature neurons (nerve cells). The therapy is specifically thought to work by simultaneously activating the protein p70S6kinase while blocking another protein, DYRK1A.

According to Neuronascent, experiments in preclinical animal models of fragile X showed treatment with NNI-351 promoted neurogenesis in the hippocampus, a brain region important for memory. This neurogenesis was associated with less anxious behavior, improved learning, and decreased hyperactivity in young animals.

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Neuronascent is developing NNI-351 to treat fragile X and other conditions marked by developmental delays and intellectual disabilities, such as Down syndrome.

The FDA’s Rare Pediatric Disease Priority Voucher Program is designed to help encourage companies to develop new treatments for rare disorders, defined as those affecting fewer than 200,000 people in the U.S., that mainly affect children younger than 18.

With the new designation, Neuronascent, as NNI-351’s developer, will receive a voucher the company can redeem to get priority review of this or another medication; the voucher also can be traded or sold to other companies. Priority review is a process in which the FDA directs additional resources toward reviewing an application, shortening the review process from the usual 10 months to about six months.

“The receipt of this rare pediatric designation from the FDA allows Neuronascent to become eligible for the pediatric priority review voucher, which provides significant value to our first-in-class therapeutic NNI-351 for FXS in young individuals,” Kelleher-Andersson said.

Fragile X, the most common cause of inherited intellectual disability and autism spectrum disorders, is estimated to affect 1 in every 4,000 males and 1 in every 8,000 females in the U.S. It currently has no targeted treatments, with symptoms managed through such programs as speech, occupational, and behavior therapy.