OBJECTIVES: To evaluate the clinical and cost-effectiveness of atezolizumab (ATZ) versus durvalumab (Durv) as first-line therapy in adult patients with extensive stage small cell lung cancer (ES-SCLC).

METHODS: pharmacoeconomic cost-effectiveness analysis (CEA) based on overall surveillance (OS) and progression free surveillance (PFS); sensitivity analysis to changes in the initial parameters of the model, budget impact analysis (BIA).

RESULTS: Direct medical costs amounted €25 672.7 for CP/ET+ATZ and €45 353.7 for CP/ET+Durv. The costs of complications treatment were almost comparable (€4735 and €4530 respectively), but the drugs cost for CP/ET+ATZ was 50% lower than for CP/ET+Durv, €19 886.2 difference. Taking into account the complications treatment, CP/ET+ATZ course was for €19 680.9 cheaper than CP/ET+Durv. According to CEA results the cost-effectiveness ratio for a month of a patient's life (OS) was €2087.2 for CP/ET+ATZ, compared to €3515.7 for CP/ET+Durv option. CER for a month of a PFS amounted €4937.06 and €8892.8 respectively. Thus, choosing CP/ET+ATZ strategy over CP/ET+Durv, would save €1427.9 for a OS month and €3955.8 for a PFS month. The sensitivity analysis showed that the model was resistant to: an increase in the price of CP/EP+ATZ up to +68%; decrease in CP/EP + ATZ OS up to -40%; decrease in CP/EP + ATZ PFS to -44%. BIA showed that in a cohort of 4448 people an increase in the proportion of patients receiving CP/EP+ATZ from 70% to 90% and decrease in the proportion of patients receiving CP/EP+Durv from 30% to 10% will reduce budget costs by €17 508 196.9 per year, which will allow to treat additionally 681.9 people with advanced SCLC per year (+15.3%) with CP/EP+ATZ combination.

CONCLUSIONS: The use of ATZ in combination with standard chemotherapy in adult patients with ES-SCLC as the first line of therapy is clinically effective and cost-effective therapy.