Disease Burden in Patients with Spinal Muscle Atrophy (SMA) Treated with Survival Motor Neuron (SMN)-Targeted Therapies: A Targeted Literature Review


Clinical Management

Poster Number: S90


Diana Castro, MD, Neurology and Neuromuscular Care Center

Diana Castro1, Joe Healy2, Allen Su2, Christabella Cherubino2, Amal Jamaleddine3
1 Neurology and Neuromuscular Care Center, Denton, TX; 2 Scholar Rock, Inc., Cambridge, MA; 3PRECISIONheor, Los Angeles, CA
Introduction: Spinal muscular atrophy is a neuromuscular disease resulting in muscle atrophy and associated muscle weakness. Approved SMA treatments include 3 SMN targeted therapies that improve survival and motor function. However, these therapies only address the neuronal component of disease and not the muscle directly. This review of the literature aims to understand the ongoing burden in SMA in patients who are treated with SMN targeted therapies.

Methods: A targeted literature review was conducted in PubMed®, Embase®, and Northern Light® (2011-2023) databases to identify data on clinical and economic benefit in SMA Types 1 to 3 from systematic literature reviews. An assessment of unmet needs was conducted based on relevant reviews and associated publications.
Results: From 14 relevant systematic literature reviews, 42 of 500 publications were included in the assessment. Notably, significant improvements in disease course, including longer survival, decreased hospitalizations, and improved motor function were reported in patients with SMA, treated with SMN-targeted therapies. These improvements varied across patients (Hammersmith Functional Motor Score-Expanded [HFMSE] change, generally ranging from -1 to +6 points). Additionally, this assessment showed that data on increased motor strength and its impact on motor function are limited (1 publication). Consistent with patient-reported unmet needs, relevant reviews and associated publications also highlight the need for improvements in daily activities (7 publications), fatigue (4 publications), and quality of life (14 publications) within SMA.
Conclusions: Our analysis describes significant unmet medical needs in SMA despite advancements in treatment. Data are warranted to further describe activities of daily living, fatigue, and quality of life in patients with SMA.