Treatments and Outcomes for Patients with Spinal Muscular Atrophy (SMA) Type 2: Findings from RESTORE Registry

Topic:

Clinical Management

Poster Number: 41

Author(s):

Laurent Servais, MD, PhD, Department of Pediatrics, MDUK Oxford Neuromuscular Center, University of Oxford, Kamal Benguerba, MD, MSc, Novartis Gene Therapies Switzerland GmbH, Darryl C. De Vivo, MD, Columbia University Irving Medical Center, Janbernd Kirschner, PhD, University Medical Center Freiburg, Francesco Muntoni, MD, UCL Institute of Child Health and Great Ormond Street Hospital for Children, Crystal Proud, MD, Children's Hospital of The King's Daughters, Eduardo Tizzano, MD, PhD, Hospital Vall d'Hebron, Susana Quijano-Roy, MD, Garches Neuromuscular Reference Center, APHP Raymond Poincare University Hospital, Isabelle Desguerre, MD, PhD, Hôpital Necker Enfants Malades, APHP, Kayoko Saito, MD, PhD, Institute of Medical Genetics, Tokyo Women’s Medical University, Dheeraj Raju, PhD, Novartis Gene Therapies, Inc., Nicole LaMarca, DNP, MSN, CPNP, Novartis Gene Therapies, Inc., Rui Sun, MD, PhD, Novartis Gene Therapies, Inc., Frederick A. Anderson, PhD, Center for Outcomes Research, University of Massachusetts Medical School, Eric Faulkner, MPH, Novartis Gene Therapies, Inc., Richard Finkel, MD, St. Jude Children's Research Hospital

Background: Real-world data describing treatment patterns and outcomes for patients with SMA type 2 (SMA2) are limited. Patients with untreated SMA2 typically have clinically identifiable disease symptoms between 6–18 months of age, and are able to sit independently, but are unable to walk without support.
Objective: We sought to describe real-world treatment patterns and outcomes for patients with SMA2 receiving onasemnogene abeparvovec (OA) monotherapy or who switched to OA from nusinersen.
Methods: RESTORE is an ongoing SMA patient registry that captures patient data from a variety of sources. We analyzed changes in motor milestones and motor function scores and assessed treatment-emergent adverse events (TEAEs) for patients who received OA monotherapy or switched to OA from nusinersen.
Results: As of Nov. 23, 2021, 34 patients with SMA2 were identified. Six (17.7%), 27 (79.4%), and 1 (2.9%) had two, three, or four SMN2 gene copies, respectively. Median age at SMA diagnosis was 13.0 months. Age at first DMT administration was 14.0 months. Median interval between diagnosis and first DMT was 1 month. Two-thirds (n=23/34) of patients received OA monotherapy; 11 patients switched to OA from nusinersen. Of 23 patients with ≥2 motor milestone assessments (≥1 post-DMT administration), all but three (OA only [n=3]) maintained or achieved new milestones: 14 (60.9%) received OA monotherapy and six (26.1%) switched to OA from nusinersen. Ten of 11 (90.9%) patients evaluable for CHOP INTEND improved/maintained score, with eight (72.7%) achieving a ≥4-point increase. Any-stage TEAEs were recorded for 11/23 (47.8%) patients who received OA monotherapy and 7/11 (63.6%) who switched to OA from nusinersen. AEs in RESTORE are consistent with overall OA experience. No new safety signals were identified.
Conclusions: Real-world data from RESTORE indicate that OA is effective and has an acceptable safety profile for patients with SMA2, regardless of prior treatment with nusinersen.