Salanersen for Spinal Muscular Atrophy

(STELLAR-2 Trial)

This trial tests whether salanersen can safely assist babies with spinal muscular atrophy (SMA) who have already received onasemnogene abeparvovec (OA) therapy. SMA results from a deficiency of a specific protein, impairing muscle and nerve function. Salanersen aims to enhance a backup gene to increase production of this crucial protein. The study targets babies treated with OA before symptom onset and who have two copies of a specific gene linked to SMA. Researchers aim to determine if salanersen can improve movement and prevent symptom progression. As a Phase 3 trial, this study represents the final step before FDA approval, offering a chance to contribute to a potentially groundbreaking treatment for SMA.

Research has shown that salanersen is generally well tolerated by people with spinal muscular atrophy (SMA). In earlier studies, doses of 40 mg and 80 mg proved safe, with most side effects being mild to moderate. These side effects were not serious and did not cause major health problems for participants. Additionally, salanersen has received an FDA Breakthrough Therapy designation, often indicating promising early safety results. This suggests that, so far, it appears to be a safe option for treating SMA, but ongoing research will provide more information about its long-term safety.¹²³⁴⁵

Most treatments for Spinal Muscular Atrophy (SMA), like Spinraza or Zolgensma, focus on increasing SMN protein levels, which are crucial for motor neuron survival. However, Salanersen is unique because it introduces a new active ingredient administered intrathecally, directly into the spinal fluid, potentially enhancing its effectiveness in reaching the central nervous system. Researchers are excited about Salanersen because it offers a longer dosing interval, with doses given annually after the initial treatment, which could improve patient compliance and quality of life. Additionally, the novel delivery method might allow for more targeted action compared to existing therapies.

Research has shown that salanersen can increase levels of a protein called SMN, crucial for nerve and muscle health. Early results suggest that salanersen can slow nerve damage in children with spinal muscular atrophy (SMA), potentially leading to fewer or less severe symptoms. Specifically, studies with children who had already received gene therapy showed that salanersen significantly slowed nerve damage. Additionally, data indicates that children treated with salanersen reached new movement milestones, demonstrating improved motor skills. In this trial, participants will either receive salanersen or undergo a sham procedure. Overall, these findings suggest that salanersen may enhance treatment outcomes for SMA.¹⁶⁷⁸⁹