Roche's Genentech, which could bring the third spinal muscular atrophy (SMA) treatment to market in just over three years, must wait a little longer.
The FDA promised the company a speedy review for risdiplam in November, thanks to the drug’s performance in children and young adults with multiple types of SMA. But since then, the company has submitted additional data, and, to give it ample time to look things over, the agency is extending that timeline by three months. The move pushes its decision date from May 24 to Aug. 24.
The new data, submitted in February—three months after risdiplam scored priority review status—“could help ensure access to risdiplam for a broad range of people living with the condition,” the company said in a statement Tuesday.
Those data included results from a yearlong study testing the drug in 180 patients aged two to 25 with type 2 and type 3 forms of the muscle-wasting disease. Risdiplam beat placebo at improving patients’ motor function scores, especially in the youngest patients aged two to five. Genentech has also tested risdiplam in infants with type 1 SMA.
The application for the PTC Therapeutics-partnered drug covers the use of risdiplam in patients with types 1, 2 and 3 forms of SMA. Patients with type 1 SMA typically don’t live past age two, but those with the less severe forms, type 2 and type 3, can live long lives. However, the less severe forms of the disease are still linked to mobility problems, respiratory infections and death.
“We strongly believe in the potential of risdiplam as a new therapeutic option and recognize that unmet need remains in the treatment of SMA,” Levi Garraway, M.D., Ph.D., chief medical officer and head of global product development at Genentech, said in the statement. “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."
An approval would tee risdiplam up to challenge Biogen’s Spinraza, an antisense oligonucleotide, and Novartis’ Zolgensma, a gene therapy, in a patient population that has historically been left unserved. Risdiplam may not offer the one-shot benefits of Zolgensma, but, thanks to its oral delivery, it may have a leg up on Spinraza, which is injected into spinal fluid.
Genentech has submitted risdiplam for review in six other countries and plans to add the EU to that list in mid-2020.