Roche recently announced that its product Evrysdi (risdiplam) was recommended for approval for the treatment of spinal muscular atrophy (SMA) in patients two months of age and older by the European Medicines Agency (EMA). Evrysdi targets the deficient survival motor neuron protein in SMA patients and its convenient oral administration is a key attribute that will significantly strengthen the drug’s position in the SMA market over the coming years.

The EMA’s positive recommendation is based on data from two Phase III multi-centre clinical trials, called FIREFISH and SUNFISH. The FIREFISH study was an open-label study to assess the efficacy and safety of Evrysdi in infants with type 1 SMA.

Investigators found that following a 12-month therapy with Evrysdi, 90% of patients did not require invasive ventilation treatment and 33% of patients could sit unsupported for at least five seconds, as assessed by Item 22 of the Gross Motor Scale of the Bayley Scales of Infant and Toddler Development Third Edition (BSID-III).

Similarly, the randomised, double-blind, placebo-controlled SUNFISH study, involving patients aged 2–25 years with types 2 or 3 SMA, found improved motor function with Evrysdi treatment, as assessed using the Motor Function Measure-32 (MFM-32) total score.

Currently, Roche is conducting two other ongoing clinical trials with Evrysdi in SMA patients, namely JEWELFISH (NCT03032172) and RAINBOWFISH (NCT03779334), to increase confidence in its efficacy. The estimated primary completion dates are in Q1 2022 and Q2 2021 respectively.

Evrysdi is set to compete with Biogen’s Spinraza, one of the two leading treatments for SMA, due to their similar mechanisms of action (MOA). Evrysdi offers positive clinical attributes, whereby the drug can be administered orally, an alternative to its competitor Spinraza, which is administered intrathecally via a lumbar puncture.

This invasive treatment requires institutional infrastructure and resources for the treatment to be carried out, including the post-procedural monitoring of patients. In particular, this route of administration presents a risk for patients who have undergone spinal fusions to remedy indication-specific scoliosis. With consideration of the ongoing Covid-19 pandemic and the infant patient population, the non-invasive oral treatment Evrysdi has the opportunity to provide a convenient at-home treatment.

Novartis’ branaplam is also employing the strategy of oral therapy with a similar MOA to Evrysdi. Branaplam is currently in Phase II development in the US and EU, and GlobalData expects its launch in 2024 in the US. Evrysdi is anticipated to have the first-to-market advantage over branaplam.

Evrysdi was approved by the Food and Drug Administration (FDA) in August last year and is a strong contender for SMA market share, given its potential to provide a convenient at-home treatment to a broad spectrum of SMA patients. GlobalData forecasts that Evrysdi will generate $1.8bn globally by 2026.