The clinical effectiveness and cost-effectiveness of rituximab for the first-line treatment of chronic lymphocytic leukaemia: an evidence review of the submission from Roche

Abstract

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of rituximab for the first-line treatment of chronic lymphocytic leukaemia (CLL) based upon a review of the manufacturer’s submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The manufacturer’s searches for clinical effectiveness and cost-effectiveness data were appropriate and included all relevant studies. The submission’s evidence came from a single, unpublished, well-conducted randomised controlled trial (RCT) comparing rituximab in combination with fludarabine and cyclophosphamide (R-FC) with fludarabine and cyclophosphamide (FC) alone for the first-line treatment of CLL. There was a statistically significant increase in progression-free survival (PFS) with R-FC compared with FC alone {median 39.8 months vs 32.2 months; hazard ratio [HR] 0.56 [95% confidence interval (CI) 0.43 to 0.72]}. However, the initial significant treatment benefit for R-FC compared with FC for overall survival was not maintained at a slightly longer follow-up time [median 25.4 months; adjusted HR 0.72 (95% CI 0.48 to 1.09)]. Response rates, numbers of patients with event-free survival and duration of response all favoured treatment with R-FC. Additional evidence from a mixed-treatment comparison model indicated R-FC to be significantly superior to chlorambucil alone for both PFS and overall and complete response rates. The incidence of grade 3 or 4 adverse events was higher in the R-FC arm (77%) than in the FC arm (62%). Dose modifications were also more frequent in this arm, but this did not lead to differences in treatment discontinuation. Roche used a three-state Markov model (PFS, progressed and death) to model the cost-effectiveness of R-FC compared with FC and chlorambucil alone. The model used a cycle length of 1 month and a lifetime time horizon. The approach taken to modelling was reasonable and the sources and justification of estimates were generally sound. The base-case analysis produced an incremental cost-effectiveness ratio (ICER) of £13,189 per quality-adjusted life-year (QALY) for R-FC versus FC, and £6422 per QALY for the comparison of R-FC versus chlorambucil, suggesting that R-FC is cost-effective at normal willingness-to-pay thresholds. One-way sensitivity analyses produced a range of ICERs from £10,249 to £22,661 per QALY for R-FC versus FC, and £5612 and £6921 per QALY for R-FC versus chlorambucil. Probabilistic sensitivity analysis results matched the deterministic results very closely. However, the sensitivity analysis did not fully investigate the uncertainty associated with differential values across arms or with the structural assumptions of the model, and utility values were not drawn from an empirical study. The NICE guidance issued as a result of the STA states that: Rituximab in combination with fludarabine and cyclophosphamide (R-FC) is recommended as an option for the first-line treatment of chronic lymphocytic leukaemia in people for whom fludarabine in combination with cyclophosphamide (FC) is considered appropriate. Rituximab in combination with chemotherapy agents other than fludarabine and cyclophosphamide is not recommended for the first-line treatment of chronic lymphocytic leukaemia.