The SOLAR study: Phase 3 Study to Evaluate the Efficacy and Safety of Salanersen in Participants Aged 15–60 Years with Spinal Muscular Atrophy (SMA)

Topic:

Clinical Trials

Poster Number: 193 M

Author(s):

Perry Shieh, MD, University of California Los Angeles, Tim Hagenacker, MD, Department of Neurology Center for Translational, Neuro and Behavioral Sciences (C TNBS), Anna Kostera-Pruszczyk, MD, PhD, Department of Neurology, Medical University of Warsaw, Poland, Colleen O'Connell, Department of Rehabilitation, Stan Cassidy Centre for Rehabilitation, Horizon Health Network,, Orla Hardiman, Academic Unit of Neurology, School of Medicine, Trinity College Dublin, University of Dublin, Lauren Elman, MD, Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Stephanie Fradette, PharmD, Biogen, Peng Sun, PhD, Biogen, Sara Alexanian, Biogen, Cambridge, MA, USA, Jennifer Inra, Biogen, Cambridge, MA, USA, Julia Czerkowicz, Biogen, Cambridge, MA, USA, Natalie Schmitz, Biogen, Cambridge, MA, USA, Shirley Wu, Biogen, Cambridge, MA, USA, Alissa Verone-Boyle, Biogen, Cambridge, MA, USA, Giulia Gambino, MSc, Biogen, Maidenhead, UK, Yingying Liu, PhD, Biogen, Cambridge, MA, USA, Richard Foster, PhD, Biogen, Leeann Burton, MD, Biogen, Julia Heo, Pharm.D., Biogen

Salanersen (BIIB115) is an investigational, intrathecally administered antisense oligonucleotide being developed for the treatment of spinal muscular atrophy (SMA). Salanersen shares a similar mechanism with nusinersen but is designed with novel backbone chemistry to achieve higher potency relative to nusinersen, thus enabling the potential to maximize clinical outcomes with once yearly dosing.
The SOLAR study is an open-label, Phase 3 study designed to investigate the efficacy and safety of salanersen in participants aged 15–60 years with SMA. The study includes two cohorts (participants who are treatment-naive and those who have previously received risdiplam), and the eligibility criteria includes a baseline Hammersmith Functional Motor Scale Expanded (HFMSE) of between 10 and 54 in order to allow any decline or improvement in function to be possible to observe in all participants. All participants will receive salanersen 80 mg by intrathecal lumbar puncture every 12 months for up to approximately 5 years. The primary efficacy endpoint is change from baseline in HFMSE total score at 12 months of follow-up in the treatment-naive cohort, based on the progressive decline expected in this population without treatment. Key secondary efficacy endpoints will be evaluated in both treatment-naive and prior risdiplam cohorts and include change from baseline and responder analyses in HFMSE total score, Revised Upper Limb Module (RULM) total score, and 6-minute walk test (6MWT) distance walked. Other efficacy endpoints include compound muscle action potential (CMAP), respiratory function, bulbar function, fatigability, and activities of daily living assessed over the study period. Additionally, safety/tolerability and pharmacokinetics of salanersen will be evaluated. As the SOLAR study represents a broad SMA population, in both age and disease subtype, data from the study may help inform both initiation of therapy and transitions between therapies in clinical practice.