Cost-Effectiveness of Onasemnogene Abeparvovec Compared With Nusinersen and Risdiplam in Patients With Spinal Muscular Atrophy Type 1 in Brazil: Custo-Efetividade do Onasemnogeno Abeparvoveque (AVXS-101) em Comparação ao Nusinersena e Risdiplam em Pacientes com Atrofia Muscular Espinhal Tipo 1 no Brasil

Objectives: This study aimed to evaluate the cost-effectiveness of the onasemnogene abeparvovec in relation to nusinersen and risdiplam in the treatment of spinal muscular atrophy type 1 from the perspective of the Brazilian Unified Health System.

Methods: A Markov model was built on a lifetime horizon. Short-term data were obtained from clinical trials of the technologies and from published cohort survival curves (long term). Costs were measured in current 2022 local currency (R$) values and benefits in quality-adjusted life-years (QALYs). Utility values were derived from type 1 spinal muscular atrophy literature, whereas costs related to technologies and maintenance care in each health state were obtained from official sources of reimbursement in Brazil. Deterministic and probabilistic, as well as scenario, sensitivity analyses were performed.

Results: Compared with the less costly strategy (nusinersen), the use of onasemnogene abeparvovec resulted in an incremental cost of R$2.468.448,06 ($975 671.169 - purchasing power parity [PPP]) and a 3-QALY increment and incremental cost-effectiveness ratio of R$742.890,92 ($293 632.774 - PPP)/QALY. Risdiplam had an extended dominance from other strategies, resulting in an incremental cost-effectiveness ratio of R$926.586,22 ($366 239.612 - PPP)/QALY compared with nusinersen. Sensitivity analysis showed a significant impact of the follow-up time of the cohort and the cost of acquiring onasemnogene abeparvovec.

Conclusions: Over a lifetime horizon, onasemnogene abeparvovec seems to be a potentially more effective option than nusinersen and risdiplam, albeit with an incremental cost. Such a trade-off should be weighed in efficiency criteria during decision making and outcome monitoring from the perspective of the Brazilian Unified Health System.