Ionis Pharmaceuticals announced that its partner Biogen presented new data highlighting the potential benefit of SPINRAZA® (nusinersen) in infants and toddlers living with spinal muscular atrophy (SMA). Interim results from the RESPOND study showed improved motor function in most participants treated with SPINRAZA following treatment with Zolgensma® (onasemnogene abeparvovec). The data were presented at the SMA Research & Clinical Care Meeting hosted by Cure SMA.

RESPOND is an ongoing two-year, Phase 4 open-label study to evaluate clinical outcomes and safety following treatment with SPINRAZA in infants and toddlers with SMA who have unmet medical needs after treatment with Zolgensma. Interim efficacy results at six months from 29 study participants treated with SPINRAZA show: Improvements in motor function in most participants as measured by increased mean total Hammersmith Infant Neurological Examination Section 2 (HINE-2) score from baseline. Participants with two SMN2 copies (n=24) improved by a mean of over 5 points on HINE-2. All participants with three SMN2 copies (n=3) improved; a mean change from baseline was not calculated due to the small number of participants.

Most participants (25/27) with investigator-reported suboptimal motor function at baseline improved. After a median of 230.5 days in the study, serious adverse events (AEs) were reported in 13/38 (34%) participants. No serious AEs were considered related to SPINRAZA or led to study withdrawal.

No new emerging safety concerns have been identified in enrolled participants who received SPINRAZA after Zolgensma. Additional interim clinical outcomes from the RESPOND study are being presented at the conference. New Analysis Evaluating Real-World Impact of SPINRAZA: A systematic literature review and meta-analysis evaluating real-world impact of SPINRAZA for infantile-onset SMA was presented and highlights the importance of generating real-world evidence to achieve a comprehensive understanding of the treatment benefits of SPINRAZA.

Improvements in motor function and motor milestones observed in real-world studies were greater than or comparable to those observed in clinical trials, and patients continued to improve with longer duration of SPINRAZA treatment.