Background. Chronic lymphocytic leukemia (CLL) is a b-cell tumor of small b-lymphocytes. In CLL, significant lymphocytosis (5000 monoclonal b-lymphocytes) is observed in the blood, there are no morphological signs of bone marrow involvement. The 2020 Russian Clinical Guidelines “Chronic lymphocytic leukemia/Small lymphocyte lymphoma” approved several main chemotherapy regimens for the treatment of CLL patients.Aim. To perform a pharmacoeconomic analysis of the feasibility of fixed therapy regimens based on venetoclax in comparison with other targeted drugs registered in Russia, from the class of bruton kinase inhibitors, used until CLL progression or unacceptable toxicity.Materials and methods. A list of direct costs in the health care system was compiled. To assess the change in the cost structure and budget impact analyze, 4 mathematical models were constructed from a health care system perspective. Model 1 analyzed the direct costs of the health care system over 5 years, without taking into account the addition of new patients to the model. At the beginning of the modeling, the patients were equally divided between the strategies; later, there was a natural withdrawal of patients from the cycle. Models 2–4 analyze the economic impact of increasing the proportion of venetoclax-based fixed regimens.Results. with venetoclax + rituximab and venetoclax + obinutuzumab combinations used in 65 % of new patients, a cost reduction of 6.97 % would be observed in 2nd year of the budget impact analysis. In the case of an increase in the use of venetoclax in combination with rituximab or obinutuzumab to 80 % for new patients in the 5th year of the budget impact analysis, direct costs will decrease by 31.17 %, to 9,077,299,932 rubles.Conclusion. Increasing the proportion of fixed-dose venetoclax-based combinations compared to regimens prior to CLL progression or unacceptable toxicity in all models demonstrates cost-effectiveness.