Burden of illness of spinal muscular atrophy type 1 (SMA1)

Abstract

SMA1 is a rapidly progressing, genetic, neurologic disease. Cost burden data are limited and must be updated as the treatment landscape evolves. The first SMA treatment, nusinersen, was recently approved in the US (23/12/2016) and EU (30/05/2017). We undertook two retrospective claims analyses of real-world healthcare resource utilization (HCRU) and costs among SMA1 patients. SMA1 patients ≤1-year old were identified and matched (1:1) with a random sample of infants in the QuintilesIMS PharMetrics Plus Health Plan Claims Database (US; 02/2011–11/2016). SMA1 patients were identified in Symphony Health's Integrated Dataverse® (US; 09/2016–08/2018). HCRU and costs were described. Significantly more SMA1 patients in PharMetrics (n=119) had ≥1 all-cause HCRU claims vs matched patients (98.3% vs 54.6%, P<0.0001). Mean all-cause HCRU and costs were higher for SMA1 infants; extrapolated all-cause total annual costs (month 1 post-diagnosis), were $324,751 (SMA1) vs $3,294 (matched). SMA1 patients in Symphony (n=349, median follow-up of 7.9 months) had an average 59.4 days with medical visits/year (inpatient, 14.1; related to respiratory failure, 13.4). In nusinersen-treated patients (n=45), those values were 56.6, 4.6, and 11.4 days, respectively, following treatment initiation. Excluding nusinersen-related costs, mean healthcare costs per-patient-per-year were $137,627 (median: $43,167) for all patients and $92,618 (median: $29,425) for nusinersen-treated patients. Mean nusinersen-related costs were $191,909/month (median: $144,487) for the first 3 months (loading phase), $36,882/month (median: $16,132) thereafter. EU data (pooled and country-specific) available at the time of the congress will be presented. The economic burden of SMA1 is substantial, even among patients treated with nusinersen.