Forecasting US ivacaftor outcomes and cost in cystic fibrosis patients with the G551D mutation

Abstract

Ivacaftor, a breakthrough treatment for cystic fibrosis (CF) patients with the G551D genetic mutation, lacks long-term clinical and cost projections. This study forecasted outcomes and cost by comparing ivacaftor plus usual care versus usual care alone.A lifetime Markov model was conducted from a US payer perspective. The model consisted of five health states: 1) forced expiratory volume in 1 s (FEV1) % pred ≥70%, 2) 40%≤ FEV1 % pred <70%, 3) FEV1 % pred <40%, 4) lung transplantation and 5) death. All inputs were extracted from published literature. Budget impact was also estimated. We estimated ivacaftor's improvement in outcomes compared with a non-CF referent population.Ivacaftor was associated with 18.25 (95% credible interval (CrI) 13.71-22.20) additional life-years and 15.03 (95% CrI 11.13-18.73) additional quality-adjusted life-years (QALYs). Ivacaftor was associated with improvements in survival and QALYs equivalent to 68% and 56%, respectively, for the survival and QALY gaps between CF usual care and their non-CF peers. The incremental lifetime cost was $3 374 584. The budget impact was $0.087 per member per month.Ivacaftor increased life-years and QALYs in CF patients with the G551D mutation, and moved morbidity and mortality closer to that of their non-CF peers. Ivacaftor costs much more than usual care, but comes at a relatively limited budget impact.

Medical and Surgical Advancements in the Management of Cystic Fibrosis Chronic Rhinosinusitis

“…98,99 The drug is also exceptionally expensive, costing upwards of $300,000 per year. 100 Nevertheless, the clinical benefits afforded to this subset of CF patients are enormous and it is likely they will experience a lower rate of lung transplantation compared to those receiving traditional care as a consequence of less severe pulmonary involvement. 100 A recent case report by Chang et al 101 demonstrated reversal of CF CRS with both subjective and objective findings after treatment with ivacaftor.…”

“…100 Nevertheless, the clinical benefits afforded to this subset of CF patients are enormous and it is likely they will experience a lower rate of lung transplantation compared to those receiving traditional care as a consequence of less severe pulmonary involvement. 100 A recent case report by Chang et al 101 demonstrated reversal of CF CRS with both subjective and objective findings after treatment with ivacaftor. The patient experienced rapid resolution of sinonasal symptoms within four weeks, but encountered prompt recurrence of sinus disease upon treatment cessation.…”

Healthcare expenditures for privately insured US patients with cystic fibrosis, 2010‐2016

“…11 No studies have reported the contribution of spending on these products to overall expenditures for insured patients with CF, although one modeling study was published in 2016. 12 In this study, we describe current trends in health care expenditures for commercially insured patients with CF in the US.…”

Rapid therapeutic advances in CFTR modulator science

“…Furthermore, ivacaftor monotherapy did not demonstrate clinical efficacy in CF subjects homozygous for the F508del CFTR variant, indicating it's requirement for appreciable CFTR at the plasma membrane for drug effect . In addition to these acute effects, prolonged treatment of CF patients with the G551D CFTR mutation reduces the loss of lung function over time relative to untreated controls and reduces mortality in patients with advanced disease . Thus, ivacaftor has the capacity to modify the course of CF disease in certain CF populations.…”

“…49 In addition to these acute effects, prolonged treatment of CF patients with the G551D CFTR mutation reduces the loss of lung function over time relative to untreated controls and reduces mortality in patients with advanced disease. 50,51 Thus, ivacaftor has the capacity to modify the course of CF disease in certain CF populations.…”