PHARMACOECONOMIC EVALUATION OF RIBOCICLIB FOR THE FIRST-LINE TREATMENT OF HR-POSITIVE HER2-NEGATIVE ADVANCED BREAST CANCER

Background. Breast cancer is the most common malignant tumor and accounts for the most number of cancer-related deaths among Russian women. Combination of cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor ribociclib and aromatase inhibitor is approved for the first-line treatment of postmenopausal women with HR-positive HER2-negative advanced breast cancer.

Objective: to conduct pharmacoeconomic evaluation of using ribociclib + aromatase inhibitor for the first-line treatment of HR-positive HER2- negative advanced breast cancer from the Russian healthcare system perspective.

Materials and methods. The comparator was palbociclib + aromatase inhibitor, because ribociclib and palbociclib have similar mechanism of action and are the only available CDK4/6 inhibitors that could be used for treatment of HR-positive HER2-negative advanced breast cancer in Russia. Using clinical trials data and published results of matching adjusted indirect comparison (MAIC), we proposed Markov chain model of breast cancer progression and estimated direct medical costs associated with two considered options (first and subsequent lines of drug therapy, adverse events treatment, inpatient and outpatient care). Budget impact and cost-effectiveness analyses were conducted. Mean duration of treatment in the model was 21,9 and 20,2 months on ribociclib and palbociclib for five year time horizon respectively.

Results and conclusion. Monthly medication costs of ribociclib (270 814.18 RUB) were 9 % less than for palbociclib (296 517.21 RUB). Driven by less monthly medication costs and potential of cost reduction due to dose reduction, five-year total medical per patient costs for ribociclib were 4 991 168 RUB, which were 1 162 666 RUB or 19 % less than for palbociclib. Ribociclib also had better (lower) cost/effectiveness ratio (1 244 906 vs 1 595 867 RUB per life year). As the result, ribociclib was considered a cost-saving option. If 8 162–8 270 women receive ribociclib, public healthcare expenditures will decrease by 20.1 billion RUB (21 %) within 3 years, compared to palbociclib.