OBJECTIVES : CDK4/6 inhibitor, ribociclib in combination with an aromatase inhibitor (AI) was first approved for post-menopausal women with hormone receptor positive, human epidermal growth factor receptor-2 negative (HR+/HER2-) advanced or metastatic breast cancer (ABC). In 2018, ribociclib received expanded indication as first-line (1L) therapy in combination with AI for pre/peri-menopausal women and in combination with fulvestrant for post-menopausal women. A 3-year budget impact analysis from a US third-party commercial or Medicare payer perspective was developed to estimate the financial impact associated with ribociclib indication expansion.

METHODS : The budget impact was estimated for a hypothetical 1 million-member plan over each of the first 3 years with ribociclib expanded indication, comparing scenarios with and without expansion. Comparators included CDK4/6 inhibitors, endocrine therapy, fulvestrant, and chemotherapy; treatments varied in each population per label and clinical practices. Inputs were based on ribociclib MONALEESA-2, MONALEESA-3 and MONALEESA-7 trials, clinical trials for other comparators, publicly available data, and assumptions. In scenarios with and without indication expansion, costs (treatment, monitoring, adverse events [AE], other medical costs) were estimated (2019 USD) for each population, accounting for market share. Sensitivity analyses tested robustness of results.

RESULTS : In each modeled year, commercial (15 pre-menopausal, 45 post-menopausal) and Medicare (4 pre-menopausal, 421 post-menopausal) HR+/HER2- ABC patients were analyzed. The estimated plan total budget impact of ribociclib indication expansion for the combined pre- and post-menopausal populations in years 1, 2 and 3, was $111,155, $312,961, $472,947 (commercial) and $244,786, $914,939, $1,315,397 (Medicare), with PMPM of $0.009, $0.026, $0.039 and $0.020, $0.076, $0.110, respectively. Costs were offset by AE management and other medical costs. Results were robust to sensitivity analyses.

CONCLUSIONS : Initiating ribociclib for HR+/HER2- ABC patients is estimated to mildly increase commercial and moderately increase Medicare payers’ costs in the first 3 years, with costs partially offset by savings in AE management and other medical costs.