Four-Year Follow-Up Data for Genentech’s Evrysdi Show Continued Increase in Number of Children With a Severe Form of Spinal Muscular Atrophy (SMA) Able to Sit, Stand and Walk

  • Data from ongoing FIREFISH study confirm long-term efficacy and safety profile of Evrysdi in children with Type 1 SMA
  • Ninety-one percent of children were alive at month 48
  • More than 95% maintained the ability to swallow – without treatment they would have required feeding support and majority would have died within 2 years
  • Evrysdi is now approved in 99 countries with more than 8,500 patients treated globally

Genentech, a member of the Roche Group, announced today new long-term data for Evrysdi® (risdiplam) from the open-label extension (n=50) of the pivotal FIREFISH study, reinforcing its sustained efficacy and safety profile in children with Type 1 spinal muscular atrophy (SMA). FIREFISH is a two-part study in babies aged 1-7 months at the time of enrollment. After four years of treatment with Evrysdi, many of the babies, now young children, continued to improve their ability to sit, stand and walk without support. All the Evrysdi-treated children who were alive at the time of the primary analysis were still alive at month 48. 

Additionally, the majority of infants maintained their ability to feed by mouth and swallow up to month 48. Motor function was assessed by the Gross Motor Scale of the Bayley Scales of Infant and Toddler Development Third Edition (BSID-III) and Hammersmith Infant Neurological Examination 2 (HINE-2) and abilities were either maintained or improved over four years of Evrysdi treatment. Without treatment, children with Type 1 SMA are not expected to live past two years of age and are never able to sit without support.

These data were presented at the Cure SMA Research & Clinical Care Meeting, June 28 – 30, 2023.

Among the infants treated with Evrysdi (n=58), 37 were able to sit without support for at least 5 seconds at month 48, compared to 35 at month 24 (BSID-III). In addition, 36 infants were able to sit without support for at least 30 seconds at month 48, up from 23 infants at month 24. Between month 24 and month 48, three infants gained the ability to stand alone and one infant gained the ability to walk alone.

Evrysdi is the first and only small molecule pre-mRNA splicing modifier that targets survival motor neuron-2 (SMN2) for the treatment of SMA, and can be administered at home in liquid form by mouth or by feeding tube. 

No treatment-related adverse events (AEs) led to treatment discontinuation or withdrawal from the study, and the rate of AEs decreased by 71% between the first and fourth 12 month periods. The most common AEs were pyrexia (62%), upper respiratory tract infection (62%) and pneumonia (48%). The rate of hospitalizations decreased over the study period. 

Genentech leads the clinical development of Evrysdi as part of a collaboration with the SMA Foundation and PTC Therapeutics.

About Evrysdi® (risdiplam)

Evrysdi is a survival motor neuron 2 (SMN2) splicing modifier designed to treat SMA caused by mutations in chromosome 5q that lead to survival motor neuron (SMN) protein deficiency. Evrysdi is administered daily at home in liquid form by mouth or by feeding tube.

Evrysdi is designed to treat SMA by increasing and sustaining the production of SMN protein in the central nervous system (CNS) and peripheral tissues as demonstrated in animal models. SMN protein is found throughout the body and is critical for maintaining healthy motor neurons and other functions such as swallowing, speaking, breathing and movement.

Evrysdi was granted PRIME designation by the European Medicines Agency (EMA) in 2018 and Orphan Drug Designation by the U.S. Food and Drug Administration in 2017. In 2021, Evrysdi was awarded Drug Discovery of the Year by the British Pharmacological Society as well as the Society for Medicines Research award for Drug Discovery. Evrysdi is currently approved in 99 countries and the dossier is under review in a further 18 countries.

Evrysdi is currently being evaluated in five multicenter trials in people with SMA:

  • FIREFISH (NCT02913482) – an open-label, two-part pivotal clinical trial in infants with Type 1 SMA. The study met its primary endpoint.
  • SUNFISH (NCT02908685) – a two-part, double-blind, placebo-controlled pivotal study in people aged 2-25 years with Types 2 or 3 SMA. The study met its primary endpoint.
  • JEWELFISH (NCT03032172) – an open-label exploratory trial designed to assess the safety, tolerability, pharmacokinetics and pharmacodynamics in people with SMA aged 6 months to 60 years who received other investigational or approved SMA therapies for at least 90 days prior to receiving Evrysdi. The study has completed recruitment (n=174).
  • RAINBOWFISH (NCT03779334) – an open-label, single-arm, multicenter study, investigating the efficacy, safety, pharmacokinetics, and pharmacodynamics of Evrysdi in babies (~n=25), from birth to six weeks of age (at first dose) with genetically diagnosed SMA who are not yet presenting with symptoms. The study is fully enrolled.
  • MANATEE (NCT05115110) – a global Phase II/III clinical study to evaluate the safety and efficacy of GYM329 (RG6237), an anti-myostatin molecule targeting muscle growth, in combination with Evrysdi for the treatment of SMA in patients 2-10 years of age. The FDA Office of Orphan Products Development granted GYM329 Orphan Drug Designation for the treatment of patients with SMA in December 2021. The study is currently recruiting.

About Genentech in Neuroscience

Neuroscience is a major focus of research and development at Genentech. Our goal is to pursue groundbreaking science to develop new treatments that help improve the lives of people with chronic and potentially devastating diseases.

Genentech and Roche are investigating more than a dozen medicines for neurological disorders, including multiple sclerosis, spinal muscular atrophy, neuromyelitis optica spectrum disorder, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease and Duchenne muscular dystrophy. Together with our partners, we are committed to pushing the boundaries of scientific understanding to solve some of the most difficult challenges in neuroscience today.

About Genentech

Founded more than 40 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious and life-threatening medical conditions. The company, a member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit

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