[6][5][10] In clinical trials, the most common adverse events included fever, diarrhea, rash, ulcers of the mouth area, joint pain (arthralgia) and urinary tract infections.

[6][5] Additional adverse events observed in the infantile-onset population included upper respiratory tract infection, pneumonia, constipation and vomiting.

[6][5] In two clinical trials, the following adverse events occurred at least 5% more frequently in participants treated with risdiplam than in the placebo group: fever, diarrhea, rash, ulcers of the mouth area, joint pain (arthralgia) and urinary tract infections.

[6][5] Additional adverse events for the infantile-onset population included upper respiratory tract infection, pneumonia, constipation and vomiting.

[9][15] The compound is a pyridazine derivative that modifies the splicing of SMN2 messenger RNA to include exon 7,[9][10][16] resulting in an increase in the concentration of the functional SMN protein in vivo.

Although the study did not perform direct comparisons against children receiving a placebo (inactive treatment), these results compare favourably with the typical course of the untreated disease.