Risdiplam: A Review in Spinal Muscular Atrophy.

Risdiplam (Evrysdi) is the first oral drug developed to treat spinal muscular atrophy (SMA) and is approved in multiple countries worldwide. It is approved for the treatment of SMA in patients aged ≥ 2 months in the USA and the EU, with this approval further specified in the EU for the treatment of 5q-autosomal recessive SMA with a clinical diagnosis of SMA types 1, 2, or 3 or with one to four survival motor neuron 2 (SMN2) copies. As an SMN2 pre-mRNA splicing modifier, risdiplam increases the production of full-length SMN protein, the lack of which drives the pathophysiology of SMA. In phase 2/3 clinical trials, risdiplam significantly improved motor function in infants with SMA type 1 and in patients aged 2-25 years with SMA types 2 or 3. These motor improvements were maintained with up to 2 years of treatment with risdiplam. Risdiplam was generally well tolerated, with a favourable benefit to risk balance. As an oral drug, risdiplam provides a convenient and useful treatment option across a broad range of patient ages and subtypes of SMA.