Arjunji R, Dean R, Jensen IS, Miller B, Menier M, Sproule DM, Feltner DE, Droege M, et al. 2019. Abstract PBI10: Type I spinal muscular atrophy patients treated with AVXS-101 have lower use of ventilatory support, hospitalization, and associated costs compared to those treated with nusinersen. Value in Health 22(Sup 2):S48; doi: 10.1016/j.jval.2019.04.093.
Abstract
Objectives: Spinal muscular atrophy type 1 (SMA1) is a rapidly progressing, debilitating neurodegenerative disease resulting from bi-allelic survival motor neuron 1 (SMN1) gene deletion/mutation and subsequent motor neuron loss, muscle weakness, respiratory failure, hospitalization, and early death. This study assessed the impact of onasemnogene abeparvovec (AVXS-101) on survival, hospitalization, ventilatory support, and associated costs in SMA1 patients (CL-101 study) contrasted with response to nusinersen (ENDEAR study). Methods: SMA1 patients (two SMN2 copies) were treated with AVXS-101 (CL-101; NCT02122952; cohort 2; N=12) or nusinersen (ENDEAR; NCT02193074; N=80). Survival (composite endpoint of time to death or permanent ventilation), hospitalization, and ventilatory support were contrasted (CL-101, ≥24 months post-dose; ENDEAR, ≥14 months of age). Costs were determined using published claims analysis data, itemized costing derived from literature and expert opinion using a multi-state Markov model. Results: The proportion of patients alive without permanent ventilation at 56 weeks was 66% in nusinersen-treated patients and 100% in AVXS-101-treated patients. In nusinersen-treated patients, 19% required permanent assisted ventilation, whereas no AVXS-101-treated patient required such support. The mean unadjusted annualized rate of hospitalizations (total hospitalizations/total number of subject-years followed) was 4.5 for nusinersen-treated patients (up to 13 months follow-up) and 2.1 for AVXS-101-treated patients (up to 24 months follow-up). The mean proportion of time hospitalized for nusinersen-treated patients was 11.4% (range, 0-50.0%); 59% were hospitalized <10% of the time, and 18% were hospitalized ≥20% of the time. For AVXS-101-treated patients, the mean proportion of time hospitalized was 4.4% (range, 0-18.3%); 83% were hospitalized <10% of the time; none were hospitalized ≥20% of the time. The 5-year direct medical costs of nusinersen-treated patients were $74,265 higher than AVXS-101-treated patients. Conclusions: Patients treated with AVXS-101 have higher survival rates and reduced healthcare utilization (reduced ventilatory support and hospitalization), resulting in decreased estimated direct medical costs compared to nusinersen.
