OBJECTIVES: WM is a rare B-cell lymphoma that is relapsing and remitting and remains incurable. Treatment options are limited and data informing their effectiveness in the RR setting is sparse. We present a cost-utility model from the English National Health Service (NHS) perspective using an indirect treatment comparison to assess health outcomes of ibrutinib, the only licensed treatment for RR WM, versus PC, an assortment of commonly-used treatments.

METHODS: A chart review (CR) of 454 symptomatic WM patients from more than 10 European countries was used to estimate efficacy of PC. A mixed-line cohort with median lines of prior lines of treatments matched to the PCYC1118e ibrutinib trial population was created by randomly sampling from the CR population (n = 175). A five-state cost-utility model with a 30-year time horizon was developed; progression-free survival (PFS) for ibrutinib was extrapolated from PCYC118e Kaplan-Meier data and a hazard ratio derived from a multivariate Cox proportional hazard model was applied to estimate the PFS of PC. Probability of death was informed by the CR for PC and assumed to be the general population mortality rate for ibrutinib based on PCYC1118e observation. Due to lack of WM utility data, a proxy was used from the ibrutinib RR CLL trial and a utility decrement from published literature was applied per expert opinion.

RESULTS: Ibrutinib was associated with higher quality-adjusted PFS of 2.65 years per patient compared to 1.10 years associated with PC. The life-time health gain for ibrutinib was 4.94 quality-adjusted life years (QALYs) versus 2.76 QALYs for PC, an incremental 2.18 QALY survival benefit.

CONCLUSIONS: The model demonstrates a substantial clinical benefit of ibrutinib over PC. The high unmet clinical need and limited data demonstrate the difficulties in assessing effectiveness in rare indications and suggests the need for real world evidence generation in WM.