Cost-Effectiveness Analysis of Obinutuzumab for Previously Untreated Chronic Lymphocytic Leukaemia in Portuguese Patients who are Unsuitable for Full-Dose Fludarabine-Based Therapy.

BACKGROUND Chronic lymphocytic leukaemia (CLL) mostly affects patients with comorbidities and limited therapeutic options. Obinutuzumab in combination with chlorambucil (GClb) is a new therapeutic option for previously untreated CLL patients who are unsuitable for full-dose fludarabine-based therapy. This combination delays disease progression but incurs additional costs; thus, an assessment of its value for money is relevant. OBJECTIVE To estimate the incremental cost-utility ratio of GClb in comparison with (i) rituximab in combination with chlorambucil (RClb), and (ii) chlorambucil alone (Clb) from the perspective of the Portuguese National Health Service (NHS). METHODS A Markov model was used to predict disease progression. Pre-progression clinical data were based on the latest CLL11 trial data, and post-progression clinical data were obtained from CLL5 trial data. Utility values are from Kosmas et al. (Leuk Lymphoma 56:1320-1326, 14). Only direct medical costs were included. The resource consumption was estimated by a panel of Portuguese experts, and the unit costs were obtained from official sources. A discount rate of 5% was applied to costs and consequences. RESULTS GClb and RClb were associated with an increase of 1.06 and 0.39 quality-adjusted life-years (QALY) at an additional cost of €21,720 and €9836 when compared to Clb, respectively. The cost-utility ratio of GClb versus Clb was €20,397/QALY, while RClb was extendedly dominated. CONCLUSIONS The use of GClb for previously untreated CLL patients who are unsuitable for full-dose fludarabine-based therapy incurs an incremental cost per QALY that is generally accepted in Portugal. Therefore, although there is some uncertainty, obinutuzumab is probably a cost-effective therapy in the Portuguese setting.