Adherence and Persistence to Nusinersen for Spinal Muscular Atrophy: A US Claims-Based Analysis

Abstract

Introduction: Spinal muscular atrophy (SMA) is a genetic, neuromuscular disease caused by deletions and/or mutations in the survival of motor neuron 1 (SMN1) gene leading to reduced SMN protein levels. Nusinersen, an intrathecally administered antisense oligonucleotide therapy that increases SMN protein levels, is approved for use in adult and pediatric patients with SMA. Data to inform real-world patient adherence and persistence to nusinersen are limited, with disparities in the population with SMA, study design, and results. The objective of this study is to characterize real-world nusinersen adherence and persistence in patients with SMA. Methods: This retrospective study examined nusinersen adherence and persistence over a 2-year period in patients with SMA in the USA from the IQVIA PharMetrics Plus claims database. Patients were followed from the date

Combination disease‐modifying treatment in spinal muscular atrophy: A proposed classification

“…Durations for bridging and switching were adopted as reasonable surrogates for distinguishing these two treatment patterns in the absence of direct knowledge of caregiver/provider intent. Definitions for discontinuation were adopted based on previously published/presented analyses 15,16 . Importantly, the actual time on nusinersen therapy before discontinuation is variable depending on phase of treatment (loading doses or maintenance doses).…”

“…Definitions for discontinuation were adopted based on previously published/presented analyses. 15,16 Importantly, the actual time on nusinersen therapy before discontinuation is variable depending on phase of treatment (loading doses or maintenance doses).…”

Adherence and Persistence Among Risdiplam-Treated Individuals with Spinal Muscular Atrophy: A Retrospective Claims Analysis

“…Compared with risdiplam, nusinersen had lower adherence and persistence values in prior real-world studies. There is evidence that repeated intrathecal injections and dosing schedule management has negative impacts on the adherence to and persistence with nusinersen [ 21 , 33 , 34 ]. These impacts may be more pronounced during the loading dose phase when dosing is the most frequent [ 33 ].…”

“…The differences observed between nusinersen and risdiplam in adherence and persistence may also be related to different study methodologies, including how adherence and persistence were defined, datasets used, number of individuals included, and length of follow-up. As a result of the nature of the dosing administration of nusinersen, adherence can be calculated at the patient level [ 21 ], dose level [ 22 ], or both [ 20 ]. Patient-level adherence considers the adherence of each individual within the study population to estimate a population’s overall adherence.…”

“…Dose-level adherence could be highly influenced by a small number of patients contributing more doses within the analysis [ 37 ]. For example, analyses of nusinersen adherence at the dose level (e.g., Youn et al) [ 22 ] have reported higher levels of adherence to nusinersen than studies analyzing adherence at the patient level (e.g., Fox et al) [ 21 ]. Differences in adherence at the dose level (e.g., 72–76%) versus at the patient level (e.g., 27–44%) are apparent even within the same study [ 20 ].…”