Roche has reported that Evrysdi (risdiplam) lowered the mortality rate in infants aged two to seven months with symptomatic type 1 spinal muscular atrophy (SMA) in the FIREFISH trial.

The infants also achieved motor milestones, the two-year data from part one of the study revealed.

Evrysdi is a survival of the motor neuron 2 (SMN2) splicing modifier being developed to treat SMA caused by chromosome 5q mutations that are responsible for SMN protein deficiency.

In August, the US Food and Drug Administration (FDA) granted approval for Evrysdi to treat SMA patients aged two months and above.

FIREFISH, with two parts, is an open-label trial in infants with type 1 SMA.

The first part analysed the safety of risdiplam, while the second part assessed the proportion of infants who can sit without support following 12 months of treatment. The study met its primary endpoint.

According to the new data, 88% of infants were alive and did not need permanent ventilation at two years. It was observed that 59% of infants were able to sit without help for at least five seconds.

Furthermore, 65% maintained upright head control, 29% were able to turn over, and 30% were able to stand with or without support.

Additionally, 71% of infants showed a CHOP-INTEND score of 40 points or more and all infants increased their score from months 12 to 24.

All infants who were alive at two years were able to swallow and 93% were able to feed orally.

The drug’s safety profile was found to be consistent with previous data, with no new safety signals.

Roche chief medical officer and Global Product Development head Levi Garraway said: “These results build on the efficacy and safety demonstrated by Evrysdi in pivotal trials, and we look forward to continued assessments of both survival and motor function during long-term follow up for this first-of-its-kind treatment.”

In February this year, Roche reported one-year data from the second part of the SUNFISH clinical trial of risdiplam in type 2 or 3 SMA patients.