Erlotinib Monotherapy for the Maintenance Treatment of Non-Small Cell Lung Cancer after Previous Platinum-Containing Chemotherapy

The UK National Institute for Health and Clinical Excellence (NICE) invited the manufacturer of erlotinib (Roche) to submit evidence for the clinical and cost effectiveness of erlotinib as monotherapy for the maintenance treatment of patients with non-small cell lung cancer (NSCLC) and stable disease following previous treatment with four cycles of platinumcontaining therapy. The Liverpool Reviews and Implementation Group(LRiG) at the University of Liverpool was commissioned to act as the Evidence Review Group (ERG) for this appraisal.

The ERG reviewed the clinical- and cost-effectiveness evidence in two stages and in accordance with the decision problem defined by NICE. The analysis of the submitted models assessed the appropriateness of the approach taken by the manufacturer in modelling the decision problem. Analysis also included reliability of model implementation and the extent of conformity to published standards and prevailing norms of practice within the health economics modelling community. Particular attention was paid to issues likely to have substantial impact on the base-case cost-effectiveness results.

Clinical evidence was derived from a multi-centre, double-blind, randomized, phase III study designed to address the overall population of NSCLC patients. Outcomes included progression-free survival (PFS) and overall survival (OS). The recruited population was mainly from outside of Western Europe and no patients in the pivotal trial had received pemetrexed as a firstline therapy, which is now accepted clinical practice in the UK. The evidence considered in this article includes only the population for whom marketing authorizations has been received–that is, patients with stable disease following first-line therapy.

The trial reported a small but statistically significant increase in both PFS and OS in patients with stable disease receiving erlotinib compared with placebo. However, no significant difference was identified in OS when patients with non-squamous disease and stable disease were considered as a subgroup.

The economic evidence was focussed on the ERG’s assessment of three economic models that related to patients with stable disease and compared erlotinib with placebo in the squamous and non-squamous populations and erlotinib with pemetrexed in the non-squamous population. The incremental cost-effectiveness ratios (ICERs) reported by the manufacturer were £39 936 per QALY gained (stable disease, all); £35 491 per QALY gained (stable disease, squamous); and £40 020 per QALY gained (stable disease, nonsquamous). In comparison with pemetrexed, in the cases where erlotinib was considered to be superior or equivalent, erlotinib dominated. In the cases where erlotinib was considered to be slightly inferior, then the ICERs ranged between £91 789 and £511 351 per QALY gained; these ICERs appear in the south-west corner of a cost-effectiveness plane, i.e. erlotinib is cheaper but less effective than pemetrexed.

The ERG recalculated the base-case cost-effectiveness results in the manufacturer’s submission, considering nine key areas where corrections and/or adjustments were required, related to time horizon, discounting logic, costs of erlotinib and pemetrexed, cost of second-line chemotherapy, unit costs, utility values, PFS and OS. This resulted in ERG-revised ICERs for the stable disease squamous population of £44 812 per QALY gained, in the stable disease non-squamous population of £68 120 per QALY gained, and, when erlotinib was compared with pemetrexed, the result was £84 029 per QALY gained. All values were above NICE’s perceived willingness-to-pay threshold. After the second Appraisal Committee meeting, the Committee did not recommend the use of erlotinib in this patient population.