A Roche drug in development as a treatment for spinal muscular atrophy achieved the main goals of a key study, helping to build the case that the drug could challenge a Biogen therapy already approved for the rare disorder.
Roche announced Monday that its drug, risdiplam, met the main goal of showing improvement according to a scale used to assess motor function, compared to a placebo, after one year of treatment. The Basel, Switzerland-based company plans to present full data from the study at a future medical conference.
Spinal muscular atrophy (SMA) is caused by a genetic defect in the SMN1 gene, which governs the production of a key protein needed for the health and proper function of motor neurons. Patients who have the disease progressively lose muscle function, and in some cases the disease can lead to paralysis. The disease is categorized by four subtypes, ranging from type 1, the most severe form in which symptoms show at birth, to type 4, which becomes apparent in adulthood when patients progressively develop muscle weakness and other symptoms.
Biogen won the first SMA drug approval in 2016 for nusinersen (Spinraza), an RNA-based drug intended to boost production of the deficient protein that it developed with Ionis Pharmaceuticals (NASDAQ: IONS). The FDA approval of the drug, which is administered as an injection into the cerebrospinal fluid, covers all forms of SMA. In May, the regulator approved a Novartis (NYSE: NVS) gene therapy called Zolgensma. The intravenous therapy was approved for children under age 2 whose SMA is confirmed by newborn screening, regardless of the subtype of the disease. Novartis has been conducting additional clinical trials to support approval of the gene therapy for older SMA patients.
Like the Biogen and Novartis therapies, Roche’s drug is meant to boost the levels of the key protein that SMA patients lack. While risdiplam is a relative latecomer compared to the already commercialized SMA treatments, it could offer a dosing advantage. The drug is a liquid taken by mouth, a formulation that is familiar to physicians, patients, and the insurance companies that are evaluating whether to cover these new SMA treatments. Patients who have lost the ability to swallow can receive the Roche drug through a gastronomy tube.
Roche is testing risdiplam as a treatment for the type 2 and 3 forms of SMA in patients ranging in age from newborns to 60 years old, which the company says represents the spectrum of people living with the disease in the real world. The results announced Monday are from tests of the drug in patients ranging from 2 to 25 years of age. It is developing the drug in partnership with the SMA Foundation and South Plainfield, NJ-based PTC Therapeutics (NASDAQ: PTCT). Roche says that to date, no safety problems have led patients to withdraw from the study. It adds that the safety profile of the drug is consistent with the earlier part of the study, during which the most common side effects reported included fever, cough, vomiting, and upper respiratory tract infections.