A new analysis of real-world outcomes in young children with spinal muscular atrophy (SMA) suggests that the use of onasemnogene abeparvovec (Zolgensma) results in lower healthcare resource utilization (HCRU) compared with nusinersen (Spinraza).
However, the data also showed that patients receiving onasemnogene abeparvovec had higher total healthcare costs than patients receiving nusinersen due to higher pharmacy costs. The paper was presented as a poster at the 2023 Academy of Managed Care Pharmacy Annual Meeting.
The study authors explain that SMA, a rare genetic neuromuscular disease caused by a deletion or mutation of SMN1 gene, was the leading genetic cause of childhood mortality before the development of disease-modifying therapies (DMTs). However, in 2016, the FDA approved the antisense oligonucleotide nusinersen for the treatment of SMA. This therapy, along with subsequent approvals of the gene replacement therapy onasemnogene abeparvovec in 2019 and the small molecule SMN2-targeted RNA-splicing modifier risdiplam (Evrysdi) in 2020 led to significant improvements in the prognosis of patients with the disease.
Yet, despite strong clinical trial evidence and successful use of the therapies, there is little in the scientific literature tracking how the therapies have affected health care utilization.
Researchers consulted a medical claims database to identify patients aged 0 to 2 years with SMA who received 1 of 3 approved therapies between January 2017 and March 2021. 62 patients receiving monotherapy with nusinersen who met the inclusion criteria. Twelve patients were found taking onasemnogene abeparvovec; 9 received it as monotherapy and 3 patients received the therapy after nusinersen. No patients on risdiplam met the study inclusion criteria.
Patients who took onasemnogene abeparvovec were more likely to be older at the study index date and when they received their diagnosis. They are also less likely to be female or have type 2 SMA. SMA is categorized based on age of onset and severity; type 1 is the most severe form.
The study authors used propensity score weighting to account for differences in baseline characteristics between the two treatment groups. However, the researchers found that patients receiving nusinersen had a higher HCRU both before and after the weigh-in.
All patients were followed for at least 2 months before the index date. After weighting, the researchers calculated the costs of health care provider visits, hospital care and skilled nursing care, which averaged $78,446 annually for people taking nusinersen monotherapy versus $29,438 for patients receiving omnasmnogene abeparvovec.
The data showed that patients in the nusinersen monotherapy group were more likely than patients taking onasemnogene abeparvovec to have spent some time as an inpatient (72.9% vs. 48.1%), to have visited the emergency department ( 70.5% vs 69.0%), spent time in a skilled nursing facility (10.0% vs 0.0%) or received home visits from skilled nurses (5.7% vs 0.0 %).
In contrast, patients taking onasemnogene abeparvovec had significantly higher total health care costs than patients taking nusinersen monotherapy, the researchers found, due to differences in the cost of the therapies themselves.
“Patients treated with nusinersen monotherapy incurred significantly lower SMA treatment costs than those treated with onasemnogene abeparvovec, with a mean difference of $1,548,684 after weighting (P < 0.05), they said.
The authors note that the time frame of their data set includes years when nusinersen was the only approved therapy for SMA, and as such, most patients enrolled in the study were taking nusinersen. Although their study offers a first look at real-world health care utilization in the DMT era, they said additional studies will be needed to better understand how the new therapies affect the economics of treating these patients over the long term. plan.
reference
Toro U., Jan M., Georgieva M. and others. Treatment patterns and outcomes in patients with spinal muscular atrophy: real-world findings of a retrospective analysis of the US claims database. Poster presented at: AMCP 2023; March 21-24, 2023; San Antonio, Texas. https://www.medicalcongressposters.com/FileUpload/QRPDF/AMCP2023_Toro_HealthVerity_Analysis_FINAL.pdf