OBJECTIVES : To evaluate the cost-effectiveness of risdiplam, a novel at-home oral therapy, versus nusinersen in treating patients with Spinal Muscular Atrophy (SMA) type 1 in China.

METHODS : A six-state Markov model was constructed to evaluate the 10-year cost and effectiveness associated with the two therapies from a Chinese healthcare system perspective. Modelling of survival and motor-milestones (defined according to the Hammersmith Infant Neuromuscular Examination Module-2 [HINE-2]) with risdiplam were based on data from the FIREFISH clinical trial. Relative effects estimated from a matching-adjusted indirect comparison were used for the modelling of nusinersen. The cycle length of the Markov model was each month, and the modelled time horizon was 10 years. Utility values for patients were estimated from EQ-5D-3L responses from Chinese pediatric neurologists based on the case history descriptions of different disease states of SMA. Direct medical costs comprising administration, inpatient, outpatient, and medical devices costs, were estimated from expert clinical opinion and hospital information systems in China. Costs and quality-adjusted life-years (QALYs) were discounted by 5% annually.

RESULTS : Patients treated with risdiplam gained 1.42 more life-years and 1.41 more QALYs compared to nusinersen. The total direct medical costs of treating with risdiplam is CNY 207,486 lower than treating with nusinersen. Thus, risdiplam is dominant over nusinersen in treating patients with SMA type 1.

CONCLUSIONS : Risdiplam is a dominant alternative over nusinersen for patients with SMA type I in China, with increased QALYs and less costs.