Background:
Spinal muscular atrophy (SMA) is a severe, progressive neuromuscular disease caused by reduced levels of survival of motor neuron (SMN) protein due to deletions and/or mutations of the SMN1 gene. A second SMN gene, SMN2, produces only low levels of functional SMN protein. Risdiplam is a centrally and peripherally distributed oral SMN2 pre-mRNA splicing modifier that increases functional SMN protein levels. Risdiplam (EVRYSDI™) has been approved by the FDA for the treatment of patients with SMA, aged 2 months and older.
JEWELFISH (NCT03032172) is an ongoing, multicenter, open-label study evaluating the safety, tolerability, pharmacodynamics (PD) and pharmacokinetics relationship of daily oral risdiplam in non-naïve patients (previously treated with other SMA therapies) with SMA (inclusion criteria 6 months–60 years at enrollment). JEWELFISH participants previously received RG7800 (RO6885247), nusinersen (SPINRAZA®), olesoxime or onasemnogene abeparvovec-xioi (ZOLGENSMA®).
Objective:
To report updated safety and PD data from the JEWELFISH study.
Results:
We previously presented safety data from 173 patients with SMA (data-cut: 31st January 2020) who received risdiplam for up to 32.8 months (patients previously received RG7800 [n=13], nusinersen [n=76], onasemnogene abeparvovec [n=14] or olesoxime [n=70]). No treatment-related safety findings leading to withdrawal were reported. The overall adverse event profile of risdiplam treatment in non-naïve patients was consistent with that of treatment-naïve patients. Previously presented JEWELFISH PD data showed a ≥2-fold increase in median SMN protein levels versus baseline (data-cut: 1st June 2020), which was consistent with PD data from the SUNFISH study (NCT02908685) in treatment-naïve patients with Type 2/3 SMA. We will report updated safety and PD data from the JEWELFISH study.
Conclusion:
JEWELFISH is ongoing in sites across Europe and the US and will provide important data on the safety and PD of risdiplam in non-naïve patients with SMA.