The Cost-Effectiveness of Ibrutinib in Treatment of Relapsed or Refractory Chronic Lymphocytic Leukemia

Abstract

Purpose: Treatment options for patients with previously-treated Chronic Lymphocytic Leukemia (CLL) are limited; no standard of care exists. In the Phase III RESONATE trial, oral, once-a-day, first-in-class covalent Bruton’s tyrosine kinase inhibitor ibrutinib was associated with improved Progression-Free Survival (PFS) (Hazard Ratio (HR) 0.106, 95% Confidence Interval (CI) 0.07-0.15) and Overall Survival (OS) compared with ofatumumab (crossover-adjusted HR 0.37, 95% CI 0.22-0.62). The current study evaluated the cost-effectiveness of ibrutinib compared to commonly-used therapies for Relapsed or Refractory (R/R) CLL. Patients and methods: A health state model simulated a cohort of R/R CLL patients receiving ibrutinib, ofatumumab, Idelalisib+Ofatumumab (IO), or Physician’s Choice (PC) (a mixed bag of treatments) until death or disease progression, at which point they received subsequent treatment or best supportive care. PFS and OS were extrapolated based on data from RESONATE (ibrutinib and ofatumumab) and from indirect treatment comparisons. The analysis was conducted over a 30-year time horizon from a Swedish healthcare payer perspective. Health outcomes and costs were discounted per Swedish guidelines. Costs, Life Years (LYs), Quality-Adjusted LYs (QALYs), and incremental costs per QALYs were evaluated. Results: Treatment with ibrutinib resulted in increased LYs and QALYs (6.44 and 4.69) compared to ofatumumab (2.79 and 1.94), IO (3.65 and 2.64), and PC (1.95 and 1.34). Ibrutinib was also associated with higher total costs (2,384,966 SEK) compared to ofatumumab (883,489 SEK), IO (1,242,742 SEK), and PC (503,370 SEK), largely due to ibrutinib’s longer PFS. Incremental costs per QALYs gained comparing ibrutinib to ofatumumab, IO, and PC were 546,904 SEK, 556,976 SEK, and 562,450 SEK, respectively. Model results are most sensitive to the PFS projection method, discount rates, and time horizon. Conclusions: Results demonstrate that ibrutinib is cost-effective and greatly improves long-term health outcomes over current treatments in this hard-to-treat population with very high unmet need.