Restoration of Nusinersen Levels Following Treatment Interruption in People With Spinal Muscular Atrophy: Simulations Based on a Population Pharmacokinetic Model

Consensus from the Brazilian Academy of Neurology for the diagnosis, genetic counseling, and use of disease-modifying therapies in 5q spinal muscular atrophy

Spinal muscular atrophy linked to chromosome 5 (SMA-5q) is an autosomal recessive genetic disease caused by mutations in the SMN1. SMA-5q is characterized by progressive degeneration of the spinal cord and bulbar motor neurons, causing severe motor and respiratory impairment with reduced survival, especially in its more severe clinical forms. In recent years, highly effective disease-modifying therapies have emerged, either acting by regulating the splicing of exon 7 of the SMN2 gene or adding a copy of the SMN1 gene through gene therapy, providing a drastic change in the natural history of the disease. In this way, developing therapeutic guides and expert consensus becomes essential to direct the use of these therapies in clinical practice. This consensus, prepared by Brazilian experts, aimed to review the main available disease-modifying therapies, critically analyze the results of clinical studies, and provide recommendations for their use in clinical practice for patients with SMA-5q. This consensus also addresses aspects related to diagnosis, genetic counseling, and follow-up of patients under drug treatment. Thus, this consensus provides valuable information regarding the current management of SMA-5q, helping therapeutic decisions in clinical practice and promoting additional gains in outcomes.

Effects of the COVID-19 Pandemic on SMA Screening and Care: Physician and Community Insights

OBJECTIVE

As part of efforts to reduce diagnostic delays and enhance clinical trials, Cure SMA evaluated the effects of COVID-19 on SMA care and clinical trial conduct.

INTRODUCTION

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by progressive, potentially debilitating muscle weakness and atrophy. Uninterrupted access to early diagnosis, disease-modifying treatment, and care for SMA is vital to avoiding irreversible motor neuron death and achieving optimal patient outcomes.

METHODS

Two surveys were conducted: a provider survey and a community survey. The Provider Impact Survey, distributed from November 24, 2020, through March 8, 2021, assessed COVID-19's effects on referrals for evaluation of suspected SMA, cancellations and delays of SMA-related care, and clinical trials. The Community Impact Survey was fielded in three waves between April 7, 2020 and July 19, 2021, in tandem with Cure SMA COVID-19 support programs.

RESULTS

A total of 48 completed provider surveys (22 from care sites, 26 from care-and-trial sites) reflected decreases in referrals for suspected SMA, increases in appointment cancellations and delays, and patient reluctance to attend in-person visits due to COVID-19. One-third of care-and-trial sites reported trial recruitment delays, and one-quarter reported pausing trial enrollment. Results of the Community Impact Survey, completed by 2047 individuals, showed similar disruptions, with 55% reporting changes or limitations in accessing essential SMA-related services.

CONCLUSIONS

This research evaluates the pandemic's interruption of SMA care and research. These insights can help mitigate and increase preparedness for future disruptive events. Expanded use of virtual tools including telehealth and remote monitoring may enhance continuity and access. However, additional research is required to evaluate their effectiveness. While this research was specific to SMA, its findings may have relevance for other patient communities.

Decision-making and challenges within the evolving treatment algorithm in spinal muscular atrophy: a clinical perspective

INTRODUCTION

The clinical application of disease modifying therapies has dramatically changed the paradigm of the management of people with spinal muscular atrophy (SMA), from sole reliance on symptomatic care directed toward the downstream consequences of muscle weakness, to proactive intervention and even preventative care.

AREAS COVERED

In this perspective, the authors evaluate the contemporary therapeutic landscape of SMA and discuss the evolution of novel phenotypes and the treatment algorithm, including the key factors that define individual treatment choice and treatment response. The benefits achieved by early diagnosis and treatment through newborn screening are highlighted, alongside an appraisal of emerging prognostic methods and classification frameworks to inform clinicians, patients, and families about disease course, manage expectations, and improve care planning. A future perspective of unmet needs and challenges is provided, emphasizing the key role of research.

EXPERT OPINION

SMN-augmenting therapies have improved health outcomes for people with SMA and powered the practice of personalized medicine. Within this new proactive diagnostic and treatment paradigm, new phenotypes and different disease trajectories are emerging. Ongoing collaborative research efforts to understand the biology of SMA and define optimal response are critical to refining future approaches.

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

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 of first evidence of nusinersen treatment (occurring after 1 July 2017) until the end of the study period (31 December 2019) or end of continuous pharmacy and medical benefit enrollment, whichever came first. Subgroup analyses for nusinersen adherence and persistence were performed on the basis of age and presence or absence of spinal complications.

RESULTS

The final cohort consisted of 179 patients with SMA treated with nusinersen. Adherence to nusinersen treatment was 41% at 56 weeks and 39% at 104 weeks. In the base-case persistence analysis, there was a decrease in persistence before 6 months (67%) and further decline at 1 (57%) and 2 years (55%). Patients with spinal complication versus without had numerically higher persistence with nusinersen.

CONCLUSIONS

The findings suggest that adherence and persistence to nusinersen treatment appear low. Demographic (age ≥ 18 years) and clinical factors (no spinal complications) may contribute to nusinersen treatment discontinuation. Future research should explore possible reasons for low adherence and persistence to nusinersen treatment, such as clinical or logistical factors, patient preferences, and payer restrictions.

Examining Real-World Adherence to Nusinersen for the Treatment of Spinal Muscular Atrophy Using Two Large US Data Sources

INTRODUCTION

Spinal muscular atrophy (SMA) is a rare neuromuscular disease characterized by progressive muscular atrophy and weakness. Nusinersen was the first treatment approved for SMA. Per the US label, the nusinersen administration schedule consists of three loading doses at 14-day intervals, a fourth loading dose 30 days later, and maintenance doses every 4 months thereafter. Using two large US databases, we evaluated real-world adherence to nusinersen with its unique dosing schedule among generalizable populations of patients with SMA.

METHODS

Patients with SMA treated with nusinersen, likely to have complete information on date of treatment initiation, were identified in the Optum^® de-identified electronic health records (EHR) database (7/2017-9/2019), and in the Merative™ MarketScan^® Research Databases from commercial (1/2017-6/2020) and Medicaid claims (1/2017-12/2019). Baseline demographics, number of nusinersen administrations on time, and distribution of inter-dose intervals were summarized.

RESULTS

Totals of 67 and 291 patients were identified in the EHR and claims databases, respectively. Most nusinersen doses were received on time (93.9% EHR, 80.5% claims). Adherence was higher during the maintenance phase (90.6%) than the loading phase (71.1%) in the claims analysis, in contrast with the EHR analysis (95.5% and 92.6%, respectively), suggesting that not all loading doses of nusinersen may be accurately captured in claims. Inter-dose intervals captured in both databases aligned with the expected dosing schedule.

CONCLUSION

Most nusinersen doses were received on time, consistent with the recommended schedule. Our findings also highlight the importance of careful methodological approaches when using real-world administrative databases for evaluation of nusinersen treatment patterns.