Cost-Effectiveness of Newborn Screening for Spinal Muscular Atrophy in England

Cost-utility analysis of newborn screening for spinal muscular atrophy in Japan

AIMS

Spinal muscular atrophy (SMA) is a rare genetic disorder characterized by progressive muscle weakness, atrophy, respiratory failure, and in severe cases, infantile death. Early detection and treatment before symptom onset may substantially improve outcomes, allowing patients to achieve age-appropriate motor milestones and longer survival. We assessed the cost-utility of newborn screening (NBS) for SMA in Japan.

MATERIALS AND METHODS

A cost-utility model (decision tree and Markov model) compared lifetime health effects and costs between "NBS" for SMA (presymptomatic treatment) or "no NBS" (treatment initiated at symptom onset). Model inputs were sourced from literature, local data, and expert opinion. Sensitivity and scenario analyses were conducted to assess model robustness and data validity.

RESULTS

Based on the 1:10,000 SMA incidence, it was estimated that 43 newborns/year would have SMA, and a total of 39 patients with SMA would initiate presymptomatic treatment after NBS. An estimated 736 quality-adjusted life-years were gained per annual birth cohort with NBS. NBS for SMA was dominant compared with no NBS (i.e. less costly and more effective), with ¥8,856,960,096 reduced total costs with NBS versus no NBS (base-case). Sensitivity and scenario analyses supported cost effectiveness of NBS for SMA versus no NBS. A greater percentage of patients was estimated to enjoy longer survival and be without permanent assisted ventilation with NBS versus no NBS.

LIMITATIONS

Real-world observations may differ from single-arm clinical trial outcomes. It was assumed that patients with SMA identified via NBS were asymptomatic and would receive treatment prior to symptoms. Best supportive care was not considered, and Japan-specific variations in gene replacement therapy protocol were not fully reflected.

CONCLUSION

NBS for SMA allows for early identification of patients with SMA and treatment initiation before symptom onset, improving health outcomes and reducing total costs than without NBS.

Cost-Effectiveness of Newborn Screening for Spinal Muscular Atrophy in Australian Hospitals

INTRODUCTION

This analysis evaluated the cost-effectiveness of newborn screening (NBS) for spinal muscular atrophy (SMA) from the perspective of Australian state hospital payers.

METHODS

A cost-utility analysis consisting of a decision tree and Markov cohort designed to calculate the difference in costs and health outcomes between two scenarios: (1) disease-modifying treatment (DMT) for SMA after diagnosis through NBS, and (2) DMT for SMA after diagnosis as symptoms appear. A population of 295,906 newborns was modeled, based on the total number of live births in Australia in 2023. Inputs included screening parameters, epidemiology inputs, SMA natural history data and DMT parameters (nusinersen and onasemnogene abeparvovec), costs, and health-related quality of life parameters. Assumed participation in NBS was 100%. A one-way sensitivity analysis and probabilistic sensitivity analysis were conducted to examine the impact of parameter uncertainty.

RESULTS

There were 30 patients identified with SMA, of whom 25 patients would be eligible for presymptomatic treatment. NBS for SMA was dominant compared with no NBS for SMA. On a population level, NBS demonstrated a lifetime gain of 267 quality-adjusted life years (QALY) and incremental costs of -AUD$3,983,263 (i.e., cost savings). Every dollar invested in NBS would save hospitals $3.69. Deterministic and probabilistic sensitivity analyses demonstrated the robustness of the base-case results.

CONCLUSION

NBS for SMA was dominant compared with no NBS for SMA in Australia from a state and territory payer perspective. Universal implementation of NBS for SMA would support access equity, as well as early diagnosis and treatment in infants with SMA, potentially leading to improved outcomes.

Pushing the boundaries: future directions in the management of spinal muscular atrophy

Spinal muscular atrophy (SMA) is a devastating, degenerative, paediatric neuromuscular disease which until recently was untreatable. Discovery of the responsible gene 30 years ago heralded a new age of pioneering therapeutic developments. Three disease-modifying therapies (DMTs) have received regulatory approval and have transformed the disease, reducing disability and prolonging patient survival. These therapies - with distinct mechanisms, routes of administration, dosing schedules, side effect profiles, and financial costs - have dramatically altered the clinical phenotypes of this condition and have presented fresh challenges for patient care. In this review article we discuss potential strategies to maximise clinical outcomes through early diagnosis and treatment, optimised dosing, use of therapeutic combinations and state-of-the-art physiotherapy techniques, and the development of innovative therapies targeting alternative mechanisms.

Mortality of symptomatic children with spinal muscular atrophy in the era of disease-modifying therapies

With the availability of novel disease-modifying therapies (DMT), survival in spinal muscular atrophy (SMA) has significantly increased, but mortality is not rare in severely affected cases. To improve care further, we aimed to characterise causes of mortality in children with SMA over the last five years since the introduction of DMT. This was a retrospective review of all patients with SMA registered on SMA REACH UK database, who died between 2019 and 2023. In the last 5 years, 533 patients were registered with SMA REACH (6 pre-symptomatic; 1-SMA0; 247-SMA1; 188-SMA2; 91-SMA3). Twenty-five paediatric patients with SMA died in this period: 1 SMA0(4 %;1 copy-SMN2), 20 SMA1(80%;17 patients-2 copies of SMN2 and 1 with 3 copies of SMN2) and 4 SMA2(16%). In SMA 1 cohort, 7/20(35%) patients were treatment naïve (5 ineligible; 1 died prior to commencement; 1 declined). Twelve patients received nusinersen; median age at treatment initiation of 6 months (range:1 month-12.3 years old) and median treatment duration of 6 months (range:1 month-6.5 years). One patient switched from nusinersen to risdiplam at age 4 years (died 19 months later) and 1 received onasemnogene abeparvovec at 2 years old (died 10 months later). The median age of death was 10.5 months(range:8 weeks-13 years), and 80%(16/20) died from respiratory-related causes. In SMA 2 cohort, 2/4 patients were not eligible for DMT and one received risdiplam at age 13 years for duration of 2.7 years and died as result of traumatic brain injury. The median age of death was 18 years 4 months (range:16-21 years). Two deaths were respiratory-related and one of sudden cardiac arrest. In conclusion, over the last 5 years, 5% of SMA patients registered with SMA REACH died. The majority had symptomatic SMA1 with 2 SMN2 copies at the severe end of the spectrum and were either treatment naïve or had initiation of DMT after significant disease progression. Respiratory-related deaths occurred in 72% of known causes of death. Standard of care for respiratory management and ceiling of care discussions should continue to be a key part of the overall management particularly in those with severe disease at onset. These outcomes will be considerably improved once newborn screening will be available also in the UK.

Epidemiology of spinal muscular atrophy in Aotearoa-New Zealand

BACKGROUND

The advent of three effective disease modifying therapies for SMA has highlighted the need to understand the epidemiology of spinal muscular atrophy (SMA) and its disability impact.

OBJECTIVE

We aimed to establish the nationwide incidence and prevalence of SMA in Aotearoa-New Zealand, and to estimate the patients' disability and the impact of this on health resource utilisation.

METHODS

We used multiple sources to identify patients with SMA and verified the diagnosis, disabilities and resources utilisation by review of the individual patient notes and genetic results. The four year incidence period was from 1st July 2015 to 30th June 2019. Prevalence date was 1st March 2019. Of note, this time period pre-dated access to disease modifying therapy in New Zealand. Census data for 2018 was used for denominators. Descriptive statistics and capture-recapture were used to analyse the data. For context, we reviewed international SMA epidemiology.

RESULTS

The incidence per 100,000 live births was 8.0 (95% confidence interval (CI): 4.8-12.5). The standardised prevalence rate of SMA on 1st March 2019 was 1.78 per 100,000 (95% CI: 1.24, 2.33). Prevalence was significantly lower amongst Māori at 0.34 (95% CI: 0.08, 1.13; p = 0.006). Substantial decline from best motor milestone performance was seen; seven patients with SMA1 died without access to disease modifying therapy. 74% of the total cohort used wheelchairs. 23% required respiratory support. 62% had scoliosis, of whom 61% had had surgery. Surviving SMA1 patients had very high health service utilisation.

CONCLUSIONS

Incidence and prevalence figures match closely with international studies. This is the first record of low SMA rates in Māori. While the largest burden of disease falls on patients with SMA1 and 2 there is still substantial use of health resources among SMA3 and SMA4 patients.

Comprehensive newborn screening for severe combined immunodeficiency, X-linked agammaglobulinemia, and spinal muscular atrophy: the Chinese experience

BACKGROUND

Newborn screening (NBS) for severe combined immunodeficiency (SCID), X-linked agammaglobulinemia (XLA), and spinal muscular atrophy (SMA) enables early diagnosis and intervention, significantly improving patient outcomes. Advances in real-time polymerase chain reaction (PCR) technology have been instrumental in facilitating their inclusion in NBS programs.

METHODS

We employed multiplex real-time PCR to simultaneously detect T-cell receptor excision circles (TRECs), kappa-deleting recombination excision circles (KRECs), and the absence of the survival motor neuron (SMN) 1 gene in dried blood spots from 103,240 newborns in Zhejiang Province, China, between July 2021 and December 2022.

RESULTS

Of all the samples, 122 were requested further evaluation. After flow cytometry evaluation and/or genetic diagnostics, we identified one patient with SCID, two patients with XLA, nine patients with SMA [one of whom also had Wiskott-Aldrich Syndrome (WAS)], and eight patients with other medical conditions. The positive predictive values (PPVs) of NBS for SCID, XLA, and SMA were 2.44%, 2.78%, and 100%, respectively. The estimated prevalence rates in the Chinese population were 1 in 103,240 for SCID, 1 in 51,620 for XLA, and 1 in 11,471 for SMA.

CONCLUSION

This study represents the first large-scale screening in mainland China using a TREC/KREC/SMN1 multiplex assay, providing valuable epidemiological data. Our findings suggest that this multiplex assay is an effective screening method for SCID, XLA, and SMA, potentially supporting the universal implementation of NBS programs across China.

Why should a 5q spinal muscular atrophy neonatal screening program be started?

Spinal muscular atrophy (SMA) is a genetic neuromuscular progressive disorder that is currently treatable. The sooner the disease-modifying therapies are started, the better the prognosis. Newborn screening for SMA, which is already performed in many countries, has been scheduled to begin in the near future. The development of a well-organized program is paramount to achieve favorable outcomes for the child who is born with the disease and for the costs involved in health care. We herein present a review paper hoping to point out that SMA neonatal screening is urgent and will not increase the cost of its care.

Cost-Effectiveness Analysis of Newborn Screening for Spinal Muscular Atrophy in Italy

BACKGROUND AND OBJECTIVE: Untreated spinal muscular atrophy (SMA) is the leading genetic cause of death in children younger than 2 years of age. Early detection through newborn screening allows for presymptomatic diagnosis and treatment of SMA. With effective treatments available and reimbursed by the National Health Service, many regions in Italy are implementing newborn screening for SMA. We evaluated the cost effectiveness of universal newborn screening for SMA in Italy.

METHODS

A decision-analytic model assessed the cost effectiveness of newborn screening from the National Health Service perspective in 400,000 newborns. Newborn screening enabling early identification and presymptomatic treatment of SMA was compared with no newborn screening, symptomatic diagnosis, and treatment. Transition probabilities between health states were estimated from clinical trial data. Higher-functioning health states were associated with increased survival, higher utility values, and lower costs. Long-term survival and utilities were extrapolated from scientific literature. Health care costs were collected from official Italian sources. A lifetime time horizon was applied, and costs and outcomes were discounted at an annual rate of 3%. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

Newborn screening followed by presymptomatic treatment yielded 324 incremental life-years, 390 incremental quality-adjusted life-years, and reduced costs by €1,513,375 over a lifetime time horizon compared with no newborn screening. Thus, newborn screening was less costly and more effective than no newborn screening. Newborn screening has a 100% probability of being cost effective, assuming a willingness-to-pay threshold of > €40,000.

CONCLUSIONS

Newborn screening followed by presymptomatic SMA treatment is cost effective from the Italian National Health Service perspective.

One-Year Pilot Study Results of Newborn Screening for Spinal Muscular Atrophy in the Republic of Croatia

Spinal muscular atrophy (SMA) is a neuromuscular and neurodegenerative disease caused by the homozygous deletion of SMN1 exon 7 in 95% of cases. The prognosis for SMA patients has improved with the development of disease-modifying therapies, all of which are available in Croatia. The best treatment outcomes occur when therapy is applied before symptoms appear, making newborn screening (NBS) for SMA a crucial factor. Since SMA NBS is the first genetic test performed in our laboratory, for successful implementation of the program, we had to overcome logistical and organizational issues. Herein, we present the results of the SMA NBS during the one-year pilot project in Croatia and verify the suitability of the Targeted qPCR™ SMA assay for SMA NBS. The pilot project started on 1 March 2023 in the Department for Laboratory Diagnostics of the University Hospital Center Zagreb. A total of 32,655 newborns were tested. Five SMA patients were detected, and their diagnoses were confirmed by the multiplex ligation-dependent probe amplification (MLPA) assay. There have been no false positive or false negative results, to our knowledge so far. The incidence of SMA determined during the pilot study is consistent with the SMA incidence data from other European countries.

Treatment Options in Spinal Muscular Atrophy: A Pragmatic Approach for Clinicians

Spinal muscular atrophy (SMA) is a rare neurodegenerative neuromuscular disorder with a wide phenotypic spectrum of severity. SMA was previously life limiting for patients with the most severe phenotype and resulted in progressive disability for those with less severe phenotypes. This has changed dramatically in the past few years with the approvals of three disease-modifying treatments. We review the evidence supporting the use of currently approved SMA treatments (nusinersen, onasemnogene abeparvovec, and risdiplam), focusing on mechanisms of action, side effect profiles, published clinical trial data, health economics, and pending questions. Whilst there is robust data from clinical trials of efficacy and side effect profile for individual drugs in select SMA populations, there are no comparative head-to-head clinical trials. This presents a challenge for clinicians who need to make recommendations on the best treatment option for an individual patient and we hope to provide a pragmatic approach for clinicians across each SMA profile based on current evidence.

2024 update: European consensus statement on gene therapy for spinal muscular atrophy

Spinal muscular atrophy (SMA) is one of the most common genetic diseases and was, until recently, a leading genetic cause of infant mortality. Three disease-modifying treatments have dramatically changed the disease trajectories and outcome for severely affected infants (SMA type 1), especially when initiated in the presymptomatic phase. One of these treatments is the adeno-associated viral vector 9 (AAV9) based gene therapy onasemnogene abeparvovec (Zolgensma®), which is delivered systemically and has been approved by the European Medicine Agency for SMA patients with up to three copies of the SMN2 gene or with the clinical presentation of SMA type 1. While this broad indication provides flexibility in patient selection, it also raises concerns about the risk-benefit ratio for patients with limited or no evidence supporting treatment. In 2020, we convened a European neuromuscular expert working group to support the rational use of onasemnogene abeparvovec, employing a modified Delphi methodology. After three years, we have assembled a similar yet larger group of European experts who assessed the emerging evidence of onasemnogene abeparvovec's role in treating older and heavier SMA patients, integrating insights from recent clinical trials and real-world evidence. This effort resulted in 12 consensus statements, with strong consensus achieved on 9 and consensus on the remaining 3, reflecting the evolving role of onasemnogene abeparvovec in treating SMA.

Exploring the Cost-Effectiveness of Newborn Screening for Metachromatic Leukodystrophy (MLD) in the UK

Metachromatic leukodystrophy (MLD) is a fatal inherited lysosomal storage disease that can be detected through newborn bloodspot screening. The feasibility of the screening assay and the clinical rationale for screening for MLD have been previously demonstrated, so the aim of this study is to determine whether the addition of screening for MLD to the routine newborn screening program in the UK is a cost-effective use of National Health Service (NHS) resources. A health economic analysis from the perspective of the NHS and Personal Social Services was developed based on a decision-tree framework for each MLD subtype using long-term outcomes derived from a previously presented partitioned survival and Markov economic model. Modelling inputs for parameters related to epidemiology, test characteristics, screening and treatment costs were based on data from three major UK specialist MLD hospitals, structured expert opinion and published literature. Lifetime costs and quality-adjusted life years (QALYs) were discounted at 1.5% to account for time preference. Uncertainty associated with the parameter inputs was explored using sensitivity analyses. This health economic analysis demonstrates that newborn screening for MLD is a cost-effective use of NHS resources using a willingness-to-pay threshold appropriate to the severity of the disease; and supports the inclusion of MLD into the routine newborn screening programme in the UK.

A consensus survey of neurologists and clinical geneticists on spinal muscular atrophy treatment in Singapore

Just a decade ago, spinal muscular atrophy (SMA) was considered a debilitating, progressive neuromuscular disease that inevitably led to chronic disability and a shortened lifespan. Now, it is treatable with nusinersen, onasemnogene abeparvovec (OAV) and risdiplam—the 3 disease-modifying drugs approved by the US Food and Drug Administration, the European Medicines Agency and most recently, the Health Science Authority in Singapore.1 Clinical trials and real-world data have consistently shown improvement in motor milestones for all 3 drugs, especially if introduced early in the disease course.2-4 More significantly, presymptomatic treatment has enabled age-appropriate development of motor milestones, leading to improved respiratory, orthopaedic and nutritional outcomes.

Multiplex Real-Time PCR-Based Newborn Screening for Severe Primary Immunodeficiency and Spinal Muscular Atrophy in Osaka, Japan: Our Results after 3 Years

In newborn screening (NBS), it is important to consider the availability of multiplex assays or other tests that can be integrated into existing systems when attempting to implement NBS for new target diseases. Recent developments in innovative testing technology have made it possible to simultaneously screen for severe primary immunodeficiency (PID) and spinal muscular atrophy (SMA) using quantitative real-time polymerase chain reaction (qPCR) assays. We describe our experience of optional NBS for severe PID and SMA in Osaka, Japan. A multiplex TaqMan qPCR assay was used for the optional NBS program. The assay was able to quantify the levels of T-cell receptor excision circles and kappa-deleting recombination excision circles, which is useful for severe combined immunodeficiency and B-cell deficiency screening, and can simultaneously detect the homozygous deletion of SMN1 exon 7, which is useful for NBS for SMA. In total, 105,419 newborns were eligible for the optional NBS program between 1 August 2020 and 31 August 2023. A case each of X-linked agammaglobulinemia and SMA were diagnosed through the optional NBS and treated at early stages (before symptoms appeared). Our results show how multiplex PCR-based NBS can benefit large-scale NBS implementation projects for new target diseases.

Newborn Screening for Spinal Muscular Atrophy: A 2.5-Year Experience in Hyogo Prefecture, Japan

Newborn screening (NBS) for spinal muscular atrophy (SMA) is necessary, as favorable outcomes can be achieved by treatment with disease-modifying drugs in early infancy. Although SMA-NBS has been initiated in Japan, its clinical results have not been fully reported. We report the findings of the initial 2.5 years of a pilot SMA-NBS of approximately 16,000 infants conducted from February 2021 in Hyogo Prefecture, Japan. Clinical data of 17 infants who tested positive were retrospectively obtained from the NBS follow-up centers participating in this multicenter cohort observational study. Genetic testing revealed 14 false positives, and three infants were diagnosed with SMA. Case 1 had two copies of survival motor neuron (SMN) 2 and showed SMA-related symptoms at diagnosis. Case 2 was asymptomatic, with two copies of SMN2. Asymptomatic case 3 had four copies of SMN2 exon 7, including the SMN1/2 hybrid gene. Cases 1 and 2 were treated within 1 month and case 3 at 8 months. All the patients showed improved motor function scores and did not require respiratory support. The identification of infants with SMA via NBS and early treatment improved their motor and respiratory outcomes. Thus, implementation of SMA-NBS at a nationwide scale should be considered.

Newborn screening for spinal muscular atrophy - what have we learned?

INTRODUCTION

Over the last decade, the treatment of spinal muscular atrophy (SMA) has become a paradigm of the importance of early and accurate diagnosis and prompt treatment. Three different therapeutic approaches that aims to increase SMN protein are approved now by Food and Drug Administration (FDA) and European Medicines Agency (EMA) for treatment of SMA; their efficacies have been demonstrated in pivotal trials.

AREAS COVERED

The authors report on the two controlled studies and real-world evidence that have demonstrated that the treatment of patients pre-symptomatically ensures normal or only slightly sub-normal motor development in children who would otherwise develop a severe form of the disease. Furthermore, the authors highlight the several newborn screening (NBS) methods that are now available, all of which are based on real-time PCR, that reliably and robustly diagnose SMA except in subjects with disease caused by a point mutation.

EXPERT OPINION

Pre-symptomatic treatment of SMA has been clearly demonstrated to prevent the most severe forms of the disease. NBS constitutes more than a simple test and should be considered as a global process to accelerate treatment access and provide global management of patients and parents. Even though the cost of NBS is low and health economics studies have clearly demonstrated its value, the fear of identifying more patients than the system can treat is often reported in large middle-income countries.