Rare Daily Staff
Roche subsidiary Genentech reported positive data from the pivotal second part of the SUNFISH study evaluating risdiplam in people aged 2 to 25 years with type 2 or type 3 spinal muscular atrophy that showed improved motor function after one year of treatment compared to placebo.
The data could put Roche in good standing with rivals’ approved therapies for SMA: Novartis’ gene therapy Zolgensma and Biogen’s Spinraza.
Spinal muscular dystrophy (SMA) is a rare genetic disease caused by a mutation in the SMN1 gene, which encodes the protein critical for the maintenance and function of specialized nerve cells called motor neurons. If there is not enough functional SMN protein, then the motor neurons die, leading to debilitating and often fatal muscle weakness. 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.
There are five types of SMA. Infantile-onset, or SMA type 1, is the most severe and most common subtype of SMA, accounting for 50 to 70 percent of cases. The onset of SMA type 2 occurs in children between the ages of 7 months and 18 months. Symptoms of SMA type 3 usually occur after 18 months and may not appear until early adulthood.
The pivotal SUNFISH study met its primary endpoint of change from baseline in the Motor Function Measure 32 (MFM-32) scale after one year of treatment with risdiplam, compared to placebo. No treatment-related safety findings leading to study withdrawal have been seen in any risdiplam trial to date. Safety for risdiplam was consistent with its known safety profile and no new safety signals were identified.
“The positive outcome of this trial is an important milestone for people with type 2 or 3 SMA, too many of whom remain untreated,” said Levi Garraway, chief medical officer and head of Global Product Development. “SUNFISH is the largest placebo-controlled study ever undertaken in Type 2 or 3 SMA patients.”
Risdiplam is an orally administered, experimental survival motor neuron-2 (SMN2) splicing modifier, designed to durably increase and sustain SMN protein levels both throughout the central nervous system and 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.
Roche and Genentech are leading the clinical development of risdiplam as part of a collaboration with the SMA Foundation and PTC Therapeutics. Data from the SUNFISH study will be presented at an upcoming medical congress.
Photo: Levi Garraway, chief medical officer and head of Global Product Development, Roche