Three-year data from FIREFISH study of Evrysdi shows efficacy and safety in spinal muscular atrophy

The data showed an estimated 91% of infants (n=58) treated with Evrysdi were alive after three years of treatment. The Evrysdi-treated infants continued to improve or maintain motor functions, including the ability to swallow, sit without support, stand with support and walk while holding on, between two and three years of treatment. Without treatment, children with Type 1 SMA are never able to sit without support. The study also showed overall continued reductions in serious adverse events (SAEs) and hospitalizations over time. The FIREFISH study evaluated the efficacy and safety of Evrysdi in infants aged 1-7 months at the time of enrollment with Type 1 SMA. The study was in two parts, with Part 1 being the dose-finding period and Part 2 evaluating the efficacy and safety at the dose selected in Part 1. The pooled population includes participants treated with Evrysdi at the approved dose for a minimum of three years.

Infants treated with Evrysdi maintained or continued to improve in their ability to sit without support between 24-36 months. Among the infants with an available assessment (n=48) treated with Evrysdi, 32 infants maintained and 4 gained the ability to sit without support for at least 5 seconds since month 24, as assessed by the Gross Motor Scale of the Bayley Scales of Infant and Toddler Development Third Edition (BSID-III). In addition, 20 infants maintained and 15 gained the ability to sit without support for at least 30 seconds. No infant who gained the ability to sit without support lost this ability after three years of treatment. The majority of infants treated with Evrysdi maintained the ability to feed orally and swallow up to month 36.

Most of the infants treated with Evrysdi continued to improve or maintain measures of the Hammersmith Infant Neurological Examination 2 (HINE-2) between 24-36 months, including being able to hold their heads upright (36 maintained, 3 gained and none lost the ability since month 24), pivot while sitting (15 maintained, 11 gained and none lost the ability), stand with support (6 maintained, 5 gained and 1 lost the ability) and walk while holding on (1 maintained, 2 gained and none lost the ability). The most common adverse events (AEs) were pyrexia (60%), upper respiratory tract infection (57%), pneumonia (43%), constipation (26%), nasopharyngitis (24%), diarrhea (21%), rhinitis (19%), vomiting (19%) and cough (17%). These long-term data will be presented at the 14th European Paediatric Neurology Society (EPNS) Congress, April 28 – May 2, 2022.