COMPARATIVE PHARMACOECONOMIC EVALUATION OF THE USE OF AFATINIB AND GEFITINIB IN THERAPY FOR LUNG CANCER

Abstract

Background: Preliminary results of the study of clinical effectiveness and safety of afatinib in comparison with gefitinib as the first line therapy for the patients with the metastatic non-small-cell lung cancer (NSCLC) and activating EGFR mutation have been reported in December of 2015. According to this study afatinib has significantly increased the rate of progression-free survival (PFS) (RR = 0.73; 95% CI, 0.57, 0.95; р = 0.0165), as well as the time before treatment discontinuation (TTD) (RR = 0.73; 95% CI, 0.58, 0.92; р = 0.0073) in comparison with gefitinib and the objective response rate (ORR) (70% vs 56%, р = 0.0083). The aim of the present study: Economic evaluation of afatinib in comparison with gefitinib as the first line therapy during the long-term treatment of locally advanced or metastatic NSCLC in the patients with the activating EGFR mutation. Methods: The cost-effectiveness analysis has been performed using Markov model. The model has been constructed on the basis of the results of clinical study LUX-Lung 7, taking into account the results of the study LUX-Lung 3. The direct medical costs have been taken into account: the cost of drug treatment of metastatic NSCLC during the first and second line therapy, the expenses for palliative care, correction of adverse events, as well as for the follow-up of patients in the course of the treatment. The cost/effectiveness ratio (CER) (Rubles/ Quality adjusted life year, or QALY) has been calculated for afatinib and gefitinib. In the baseline scenario (all patients with frequent activating mutations) the cost-effectiveness of afatinib for all patients with activating EGFR mutation has been evaluated; in addition the costs and outcomes in patients with Del19 and L858R mutation have been analyzed separately. The probabilistic sensitivity analysis of the analysis results to the variability of initial parameters has been performed. Results: In the baseline scenario the cost of first year treatment with afatinib as the first line therapy has been by 13.56% cheaper than the cost of treatment with gefitinib and amounted to 1.058 million Rubles for afatinib and 1.224 million Rubles for gefitinib. The general expenses for the first year of treatment have amounted to 946 726 Rubles for afatinib, and 1 024 096 Rubles for gefitinib. In the baseline scenario the modeled progression-free survival for afatinib has amounted to 13.15 months and for gefitinib to 10.65 months. The total direct medical costs for first 3 years of treatment for afatinib have amounted to 1.577 million Rubles, for gefitinib 1.585 million Rubles, the number of QALY gained - 1.341 and 1.280 correspondingly. CER for afatinib has amounted to 1.176 million, for gefitinib - 1.239 million Rubles/QALY In the additional scenarios the same results have been demonstrated: CER for afatinib was less than for gefitinib. Conclusions: The administration of afatinib leads to the better clinical results, expressed by the increase of the rate of progression-free survival and longer-term therapy on retention of life quality of the patients in comparison with the administration of gefitinib accompanying by the cost advantage. Subsequently the cost - effectiveness ratio for afatinib is better than for gefitinib. Afatinib is the dominant alternative for the treatment of NSCLC during first line therapy in comparison with gefitinib. The prescription of afatinib offers the possibility to spare funds in the health system and is appropriate from pharmacoeconomic standpoint.