Rituximab for the first-line treatment of stage III-IV follicular lymphoma (review of Technology Appraisal No. 110): a systematic review and economic evaluation.

BACKGROUND: Follicular lymphoma (FL) is a non-Hodgkin's lymphoma which typically presents when the disease is at an advanced stage. The majority of patients receive first-line therapy of rituximab in combination with chemotherapy, with two-thirds receiving cyclophosphamide, vincristine and prednisolone. The clinical and cost-effectiveness of other chemotherapies in combination with rituximab in first-line therapy is not known.

OBJECTIVE: To systematically evaluate and appraise the clinical effectiveness and cost-effectiveness of rituximab (MabThera(®), Roche Products) in combination with chemotherapy, compared with chemotherapy alone, for the first-line treatment of symptomatic stage III-IV FL.

DATA SOURCES: A systematic review of literature and an economic evaluation were carried out. Key databases [including MEDLINE In-Process & Other Non-Indexed Citations; Cumulative Index to Nursing and Allied Health Literature (CINAHL); EMBASE; The Cochrane Library, including the Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE), NHS Economic Evaluation Database (NHS EED) and Health Technology Assessment (HTA) databases; Science Citation Index (SCI); and BIOSIS], plus research registers and conference proceedings, were searched for relevant studies from inception up to October 2010.

REVIEW METHODS: One reviewer assessed titles and abstracts of studies identified by the search strategy, obtained the full text of relevant papers and screened them against inclusion criteria. Data from included studies were extracted by one reviewer using a standardised data extraction form and checked by a second reviewer. The quality of included studies was assessed by one reviewer and checked by a second. A patient-level simulation model was developed to estimate the costs and quality-adjusted life-year (QALY) gains from the perspective of the UK NHS and Personal Social Services, with costs and benefits discounted at 3.5% annually.

RESULTS: Four randomised controlled trials comparing rituximab plus chemotherapy (R-chemotherapy) with chemotherapy alone in untreated, symptomatic patients with stage III-IV FL were identified. R-chemotherapy compared with chemotherapy alone increased the likelihood of a response to treatment in all four trials, with no additional toxicity of clinical relevance. Overall response rates were significantly improved in all four trials, with a difference between the R-chemotherapy and chemotherapy arms of between 5% and 24%, respectively. Complete response rates were also improved, with a difference between the R-chemotherapy and chemotherapy arms of between 2% and 25%, respectively. Exploratory meta-analyses were conducted; the level of statistical heterogeneity was very high and thus we believe the response rates from the individual trials to be a more robust estimator of the efficacy of the specific R-chemotherapy regimens. Over a follow-up period of 4-5 years, R-chemotherapy significantly increased the overall survival rate compared with chemotherapy alone in three trials, although data for two trials were compromised owing to the use of additional treatments. The incremental cost-effectiveness ratio (ICER) for the addition of rituximab to CVP (cyclophosphamide, vincristine and prednisolone), CHOP (cyclophosphamide, doxorubicin/adriamycin, vincristine and prednisolone) and MCP [mitoxantrone, chlorambucil (Leukeran(®), Aspen) and prednisolone] was £7720, £10,834 and £9316 per QALY gained, respectively, when it was assumed that first-line rituximab maintenance was not used. A scenario analysis is also presented, assuming that responders to R-chemotherapy in first-line induction receive maintenance with rituximab, increasing the ICER to £14,959, £21,687 and £20,493 per QALY gained, respectively.

LIMITATIONS: These relate to the sources of data used for the effectiveness in first and second line and the assumed utility values; there is uncertainty about the effect of salvage treatment on patients who had been previously treated with an anthracycline regimen. There is uncertainty whether or not rituximab is as effective in second-line treatment when patients have been previously treated with rituximab.

CONCLUSIONS: The results from four randomised trials comparing R-chemotherapy with chemotherapy alone showed an improvement in clinical effectiveness outcomes, with minimal clinically relevant additional adverse events or toxicity. The cost per QALY gained is estimated to be < £25,000 for all three comparisons under our base-case assumption and is considerably lower if first-line rituximab maintenance is not assumed. More data on patients pre-treated with rituximab and on the effect of first-line maintenance with rituximab is required for future work.

FUNDING: The National Institute for Health Research Health Technology Assessment programme.