OBJECTIVES: Until recently, spinal muscular atrophy (SMA), a rare, serious, and life-threatening autosomal recessive neuromuscular disorder, was a leading cause of infant mortality. Risdiplam is the first orally-administered small molecule to be marketed for the treatment of SMA patients. In Italy, risdiplam is currently reimbursed for the treatment of SMA 5q in patients from 2 months of age, with a clinical diagnosis of SMA type 1, type 2, or type 3, or having one to four copies of SMN2. The objective of this study was to evaluate the impact of risdiplam on the Italian National Healthcare Service (SSN) during the first 15 months of commercialization.

METHODS: A Cost Offset Calculator (COC) was developed using AIFA monitoring register and internal data. Two 1-month cycle Markov models were used to estimate clinical outcomes and costs of SMA patients receiving either risdiplam or nusinersen. Health-state occupancy was determined using risdiplam clinical data and indirect comparisons for nusinersen. Direct costs included drug acquisition, administration and disease monitoring. Resource use data and unit costs were retrieved from published literature and Italian sources. The COC compared expenses for risdiplam treatment to those that would have been incurred with nusinersen. In the nusinersen scenario, for patients coming from risdiplam compassionate use program (CUP) no costs were considered as they were deemed ineligible for nusinersen treatment.

RESULTS: During the initial 15 months of commercialization, 514 patients received treatment with risdiplam, with 33% coming from CUP. The COC estimated savings of €15.3 million for drug acquisition and administration along with savings of €256,000 for healthcare resource consumption.

CONCLUSIONS: The introduction of risdiplam during its first 15 months of commercialization led to significant overall savings for the SSN.