FDA Extends Review Time for Genentech SMA Drug

Rare Daily Staff

The U.S. Food and Drug Administration has extended the date for its review of Genentech’s New Drug Application  for the spinal muscular atrophy drug risdiplam to August 24, 2020 following the submission of additional data by the company.

In November 2019, the FDA granted Priority Review for risdiplam with a decision for approval expected by May 24, 2020. Genentech, though, in February, following discussions with the agency, decided to submit additional data to support the approval of risdiplam for a broad range of people living with the condition. This included 12-month efficacy and safety data from the pivotal SUNFISH Part 2 study, the only placebo-controlled study ever undertaken in people aged 2-25 years with type 2 or type 3 SMA.

Because of the volume of additional data the company submitted, the FDA needs more time to conduct its review.

Spinal muscular atrophy (SMA) is a severe, inherited, progressive neuromuscular disease that causes devastating muscle atrophy and disease-related complications. It is the most common genetic cause of infant mortality and one of the most common rare diseases, affecting approximately one in 11,000 babies. SMA leads to the progressive loss of nerve cells in the spinal cord that control muscle movement. Depending on the type of SMA, an individual’s physical strength and their ability to walk, eat or breathe can be significantly diminished or lost.

Risdiplam is an experimental survival motor neuron-2 (SMN2) splicing modifier for SMA and is an orally administered liquid. It is designed to durably increase and sustain SMN protein levels both throughout the central nervous system and in peripheral tissues of the body. It is being evaluated for its potential ability to help the SMN2 gene produce more functional SMN protein throughout the body. Genentech leads the clinical development of risdiplam, an investigational, orally administered survival motor neuron-2 (SMN2) splicing modifier for SMA, as part of a collaboration with the SMA Foundation and PTC Therapeutics.

“We strongly believe in the potential of risdiplam as a new therapeutic option and recognize that unmet need remains in the treatment of SMA,” said Levi Garraway, chief medical officer and head of global product development. “We are working closely with the FDA to support the review of risdiplam. Our goal is to bring this therapy to infants, children and adults living with SMA as quickly as possible.”

Regulatory filings for approval of risdiplam have been submitted to health authorities in six other countries. The company said the risdiplam Marketing Authorization Application is also on track to be submitted to the European Medicines Agency in mid-2020.

Photo: Levi Garraway, chief medical officer and head of global product development for Genentech