Roche has received the US Food and Drug Administration (FDA) expanded approval for Evrysdi (risdiplam) to include infants below two months with spinal muscular atrophy (SMA).

The drug was already approved in the US to treat SMA in adult and paediatric patients, aged two months and older.

With the expanded approval, Evrysdi is now approved in the US to treat SMA in children and adults of all ages, said Roche.

Evrysdi is a survival motor neuron 2 (SMN2) splicing modifier designed to treat SMA caused by mutations in chromosome 5q that lead to SMN protein deficiency.

The drug works by increasing and sustaining the production of the survival motor neuron (SMN) protein in the central nervous system (CNS) and peripheral tissues.

It is currently approved in 81 countries and is under review in 27 other countries.

The FDA expanded approval is based on interim efficacy and safety data from the RAINBOWFISH trial in newborn babies.

In the study, most of the pre-symptomatic babies treated with Evrysdi achieved key milestones, including sitting and standing with half walking after 12 months.

All of the babies with 2 or 3 copies of the SMN2 gene were able to sit after treatment with Evrysdi for one year, while 67% could stand and 50% of infants could walk independently.

The label extension has enabled the update of Evrysdi prescribing information to include recent two-year pooled data from Parts 1 and 2 of the FIREFISH study.

FIREFISH trial showed long-term efficacy and safety in infants with Type 1 SMA.

RAINBOWFISH principal investigator and director Richard Finkel said: “The approval of Evrysdi for pre-symptomatic babies is particularly important, as early treatment of SMA, before symptoms start to arise, can help babies to achieve motor milestones.

“With the inclusion of SMA in newborn screening programmes, this approval provides the opportunity to start treating at home with Evrysdi soon after the diagnosis is confirmed.”

The most common adverse reactions observed in the RAINBOWFISH trial include nasopharyngitis, rhinitis, pneumonia, bronchitis, constipation, vomiting, and cough.

Roche chief medical officer and global product development head Levi Garraway said: “The priority review and subsequent approval of Evrysdi for babies under two months of age speaks to the urgent ongoing need for additional treatment options for babies with SMA.

“Because of its efficacy in multiple settings, Evrysdi is now available for people with SMA from pre-symptomatic newborns to older adults. We are proud of this achievement, which has the potential to make a real difference to those living with SMA and their caregivers.”

Roche is leading the clinical development of Evrysdi, under collaboration with the SMA Foundation and PTC Therapeutics.

It is currently studying Evrysdi in five SMA trials, including FIREFISH, SUNFISH, JEWELFISH, RAINBOWFISH, and MANATEE.