Nutritional Therapy in Children With Spinal Muscular Atrophy in the Era of Nusinersen

Nutrition outcomes of disease modifying therapies in spinal muscular atrophy: A systematic review

The nutritional implications of spinal muscular atrophy (SMA) are profound. Disease modifying therapies (DMT) have improved clinical outcomes. This review describes the impact of DMT on nutrition outcomes. A systematic search strategy was applied across seven databases until May 2023. Eligible studies measured nutrition outcomes in individuals with SMA on DMT (nusinersen, risdiplam or onasemnogene abeparvovec [OA]) compared to untreated comparators. Nutrition outcomes included anthropometry, feeding route, swallowing dysfunction, dietary intake, dietetic intervention, nutritional biochemistry, metabolism, gastrointestinal issues and energy expenditure. Articles retrieved were screened in duplicate, data were extracted and appraised systematically. Sixty three articles from 54 studies were included; 41% (n = 22) investigated nusinersen in pediatric participants with SMA type 1. Anthropometry (n = 18), feeding route (n = 39), and swallowing dysfunction (n = 18) were the most commonly reported outcomes. In combined pediatric and adult cohorts, BMI z-score remained stable post nusinersen therapy. The proportion of children with SMA requiring enteral nutrition was stable post nusinersen therapy. Ability to thrive at age 1.5 years was higher in children treated in early infancy with OA compared to historical controls. Significant heterogeneity existed across study population characteristics and outcome measures. Nusinersen may prevent deterioration in some nutrition outcomes; and OA in early infancy may be associated with improved nutrition outcomes. Timing of DMT initiation is an important consideration for future nutrition research. Studies investigating nutrition as a primary outcome of DMT, using consistent outcome measures are required for nutritional management strategies for this cohort to be appropriately tailored.

Real-world use of orphan medicinal products (OMPs) in rare disease (RD) patients: A population-based registry study

Background: Despite calls for the use of real-world data, the rare diseases (RD) treatment landscape suffers from a scarcity of data referred to orphan medicinal products (OMP) use at the population level.

Objectives: We aim to describe the characteristics and patterns of utilization of OMP in a sizable group of RD patients globally monitored by an area-based rare diseases registry located in the Veneto region, Italy, during a 3-year period (1 January 2019 to 31 December 2021).

Methods: A list of OMP (n = 60) was assembled for study purposes, according to extensive criteria with regard to the status of orphan designation and of national reimbursement decisions.

Results: OMP prescriptions involved 1,010 patients, corresponding to the 2.3% of all the patients monitored by the RD registry. Nearly one out of five (22.8%) was a pediatric patient at the time of the first prescription. OMP use interested a limited proportion (17.5%) of diseases approaching the rarity threshold, having a prevalence of less than five per 10,000, while individuals affected by these more common rare conditions represented 49% of all the patients receiving an OMP prescription. A clustering effect of OMP use was observed in selected groups of diseases, mainly, neurological, hematological, and hereditary metabolic ones. Medication plans including an OMP show in the 45.9% of the cases a high level of complexity, both in terms of nature and number of co-prescribed treatments. Off-label use interested 15.3% (n = 155) of all the RD patients with at least an OMP prescription during the study period.

Conclusion: Data collected in a real-world setting through population-based registries globally monitoring RD patients, including related medication plans, have the potential to identify which diseases, and thus patients, have less benefit from the advent of OMP so far. Furthermore, in the rapidly evolving RD therapeutic landscape, they can help understand which therapeutic areas are most in need of investment to address existing unmet care needs.

Nonrespiratory complications of nusinersen-treated spinal muscular atrophy type 1 patients

BACKGROUND

Emergence of new treatments for spinal muscular atrophy type 1 (SMA1) has led to dramatic improvements in respiratory failure and survival. However, these "treated" patients sustain major problems in other organ systems, which may directly or indirectly affect their respiratory function. We observed three main nonrespiratory manifestations in these patients comprised of facial deformities, feeding problems, and spinal deformities.

OBJECTIVE

To investigate these three main sequelae in nusinersen-treated SMA1 patients.

METHODS

Data on nusinersen-treated SMA1 patients were prospectively collected throughout a 3-year period, with special focus upon nonrespiratory features of the disease.

RESULTS

Twenty nusinersen-treated SMA1 patients were included (eight males, median age 13.5 months, interquartile range: 4-56.2 months), among whom 17 survived after 3 years of follow-up. At follow-up, 15 (88%) patients were diagnosed with facial weakness, hypoplasia, or deformity. All but one patient (94%) were fed invasively by percutaneous endoscopic gastrostomy or nasogastric tube feeding. Four patients (25%) had maintained oral feeding in parallel to gastrostomy feeding and had clinical and radiologic evidence of aspirations. Fifteen (88%) patients were diagnosed with scoliosis, of whom seven had undergone or were scheduled to undergo corrective surgery.

CONCLUSIONS

Nusinersen-treated SMA1 patients may sustain facial deformities, feeding problems, and severe scoliosis, all of which affect their respiratory system. Strict surveillance of these complications is essential to avoid further respiratory morbidity.

Nutritional, Gastrointestinal and Endo-Metabolic Challenges in the Management of Children with Spinal Muscular Atrophy Type 1

The management of patients with spinal muscular atrophy type 1 (SMA1) is constantly evolving. In just a few decades, the medical approach has switched from an exclusively palliative therapy to a targeted therapy, transforming the natural history of the disease, improving survival time and quality of life and creating new challenges and goals. Many nutritional problems, gastrointestinal disorders and metabolic and endocrine alterations are commonly identified in patients affected by SMA1 during childhood and adolescence. For this reason, a proper pediatric multidisciplinary approach is then required in the clinical care of these patients, with a specific focus on the prevention of most common complications. The purpose of this narrative review is to provide the clinician with a practical and usable tool about SMA1 patients care, through a comprehensive insight into the nutritional, gastroenterological, metabolic and endocrine management of SMA1. Considering the possible horizons opened thanks to new therapeutic frontiers, a nutritional and endo-metabolic surveillance is a crucial element to be considered for a proper clinical care of these patients.

Metabolic Dysfunction in Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is an autosomal recessive genetic disorder leading to paralysis, muscle atrophy, and death. Significant advances in antisense oligonucleotide treatment and gene therapy have made it possible for SMA patients to benefit from improvements in many aspects of the once devastating natural history of the disease. How the depletion of survival motor neuron (SMN) protein, the product of the gene implicated in the disease, leads to the consequent pathogenic changes remains unresolved. Over the past few years, evidence toward a potential contribution of gastrointestinal, metabolic, and endocrine defects to disease phenotype has surfaced. These findings ranged from disrupted body composition, gastrointestinal tract, fatty acid, glucose, amino acid, and hormonal regulation. Together, these changes could have a meaningful clinical impact on disease traits. However, it is currently unclear whether these findings are secondary to widespread denervation or unique to the SMA phenotype. This review provides an in-depth account of metabolism-related research available to date, with a discussion of unique features compared to other motor neuron and related disorders.