INTRODUCTION • Enzalutamide and abiraterone acetate plus prednisone (hereafter referred to as ‘abiraterone’) are both approved 1 for the treatment of both chemotherapy-naïve and post-chemotherapy metastatic castration-resistant prostate cancer (mCRPC) patients in Russia. • Currently, only abiraterone is included in the Vital and Essential Drug List in Russia. 2 OBJECTIVE • To compare the pharmacoeconomics of enzalutamide and abiraterone used prior to chemotherapy in patients with mCRPC from the Russian healthcare system perspective, using budget impact, cost-effectiveness and cost-utility analyses. METHODS • For the purpose of analyses, an mCRPC Markov chain stochastic process model ( Figure 1 ) was proposed based on PREVAIL (enzalutamide), 3,4 COU-AA-302 (abiraterone), 5-7 TAX327 (docetaxel) 8 and TROPIC (cabazitaxel) 9 trial data. • Medical costs (including cancer treatment-related medications, adverse events treatments, treatments of bone metastases, pre-medications before chemotherapy, pain relief and oncologist visits) associated with two options considered as best practice by Russian experts − consecutive use of enzalutamide or abiraterone, followed by docetaxel and then cabazitaxel after progression on docetaxel − were calculated. • The 8-year time horizon was used as 97% of patients in the model die by the end of this period. • Budget impact, cost-effectiveness and cost-utility analyses were conducted for enzalutamide and abiraterone compared with consecutive use of docetaxel and cabazitaxel alone. RESULTS • The Markov model predicts slightly greater mean overall survival and progression-free survival on enzalutamide compared to abiraterone ( Figure 2 ), which corresponds to the results of a recent indirect comparison of the study drugs. 10 • Enzalutamide was found to be a cost-saving option compared to abiraterone. − Monthly medication costs for enzalutamide (in US dollars) were $3760 per patient; 11.7% less than for abiraterone. − The 8-year discounted total medical costs for enzalutamide and abiraterone were $114,307 and $121,272 per patient, respectively, ( Table 1 ) indicating that the 8-year health budget could be cut by $696,500 per 100 mCRPC patients through treatment with enzalutamide. • Enzalutamide was also found to be cost-effective compared to abiraterone when both were compared against chemotherapy alone ( Table 2 and Table 3 ). ISPOR 20th Annual European Congress, 4−8 November 2017, Glasgow, Scotland CONCLUSION • Enzalutamide is a cost-saving and cost-effective option when compared to abiraterone and, therefore, should be recommended for inclusion into the Vital and Essential Drug List in Russia. Pharmacoeconomic analysis of enzalutamide and abiraterone for treatment of chemotherapy-naïve patients with metastatic castration-resistant prostate cancer Nikolay Alexandrovich Avxentyev, 1 Maxim Frolov 2 1 Research Institute of Finance of the Ministry of Finance of the Russian Federation and Russian Presidential Academy of National Economy and Public Administration, Moscow, Russia; 2 Volgograd State Medical University of the Ministry of Health, Russian Federation and Interregional Association of Clinical Pharmacologists, Volgograd, Russia Table 1. Budget impact analysis Enzalutamide Abiraterone Incremental cost (enzalutamide - abiraterone) Drug cost 102,376 110,246 -7870 Administration cost 537 506 31 Adverse events 1854 1803 51 Treatments of bone metastases 3797 3470 328 Pain relief 5315 4848 466 Oncologist visits 427 399 29 Total 114,307 121,272 -6965 Costs in US dollars, per patient, per 8-year cycle. Table 2. Cost-effectiveness analysis Enzalutamide Abiraterone Total per patient costs, $ 114,307 121,272 Incremental costs,* $ 59,382 66,360 Mean overall survival, months 40.0 37.8 Incremental mean overall survival,* months 7.3 5.1 Cost-effectiveness ratio, $/month 2854 3209 Incremental cost-effectiveness ratio,* $/month 8098 13,075 *Against chemotherapy alone. Table 3. Cost-utility analysis Enzalutamide Abiraterone Total per patient costs, $ 114,307 121,272 Incremental costs,* $ 59,382 66,360 Mean QALY, months 29.2 27.8 Incremental mean QALY*, months 8.7 7.4 Cost-utility ratio, $/QALY month 3921 4365 Incremental cost-utility ratio,* $/QALY month 6797 9011 *Against chemotherapy alone. QALY=quality-adjusted life-year. Figure 1. Consecutive health states of mCRPC patients in the Markov model Enzalutamide/ abiraterone Docetaxel Cabazitaxel Palliative care Death Abiraterone, docetaxel and cabazitaxel were used with prednisone. mCRPC=metastatic castration-resistant prostate cancer. Figure 2. Duration of health states 23.5 23.0 4.6 4.1 2.5 2.5 9.5 8.2 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 Enzalutamide Abiraterone Stable disease Docetaxel Cabazitaxel Palliative care Mean, months Stable disease refers to enzalutamide or abiraterone health state. PCN137 ACKNOWLEDGEMENTS This study was funded by Astellas Pharma Inc and Pfizer Inc, the co-developers of enzalutamide. Editorial assistance, funded by both sponsor companies, was provided by Stephanie Rippon and Lauren Smith from Complete HealthVizion. REFERENCES 1. State Drug Registry of Russia. Available at: https://grls.rosminzdrav.ru/Default.aspx. 2. Government of the Russian Federation. Available at: http://government.ru/docs/25924/. 3. Beer TM et al. N Engl J Med 2014; 371: 424-433. 4. Beer TM et al. Eur Urol 2017; 71: 151-154. 5. Rathkopf DE et al. Eur Urol 2014; 66: 815-825. 6. Ryan CJ et al. N Engl J Med 2013; 368: 138-148. 7. Ryan CJ et al. Lancet Oncol 2015; 16: 152-160. 8. Tannock IF et al. N Engl J Med 2004; 351: 1502-1512. 9. de Bono JS et al. Lancet 2010; 376: 1147-1154. 10. Chopra A et al. Prostate 2017; 77: 639-646.