Cost Effectiveness of Ribociclib in Combination with Fulvestrant for the Treatment of Postmenopausal Women with HR+/HER2- Advanced Breast Cancer Who Have Received No or Only One Prior Line of Endocrine Therapy: A Canadian Healthcare Perspective.

BACKGROUND: The MONALEESA-3 trial demonstrated the efficacy and safety of ribociclib plus fulvestrant versus placebo plus fulvestrant for patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC). This analysis evaluated the cost effectiveness of ribociclib plus fulvestrant versus fulvestrant in patients with HR+/HER2- ABC from a Canadian healthcare payer perspective. METHODS: The incremental cost-effectiveness ratio (ICER), expressed as incremental costs per quality-adjusted life-year (QALY) gained for ribociclib plus fulvestrant versus fulvestrant, was estimated using a semi-Markov cohort model developed in Microsoft Excel, with states for progression-free, post-progression, and dead. A 15-year time horizon was used. Survival distributions for progression-free survival (PFS), post-progression survival (PPS), and time to discontinuation (TTD) were based on parametric survival distributions fit to data from MONALEESA-3. Health-state utilities were estimated using EQ-5D index values collected in MONALEESA-3. Direct costs of ABC treatment (medication and administration costs, follow-up and monitoring, adverse events, subsequent treatments) were based on Canadian-specific values from published sources. Costs (2019 CAN$) and QALYs were discounted at 1.5% annually. RESULTS: In the base case, ribociclib plus fulvestrant was estimated to result in gains of 1.19 life-years and 0.96 QALYs versus fulvestrant, at an incremental cost of $151,371. The ICER of ribociclib plus fulvestrant versus fulvestrant was $157,343 per QALY gained based on the mean of probabilistic analyses. Results were sensitive to parametric distributions used for projecting long-term TTD, PFS, and PPS. CONCLUSIONS: For patients with HR+/HER2- ABC, ribociclib plus fulvestrant is projected to result in substantial gains in QALYs compared with fulvestrant. At its current list price, ribociclib used in combination with fulvestrant is likely to be cost effective in these patients at a threshold ICER of $157,343. These results may be useful in deliberations regarding reimbursement and access to this treatment.

Cost Effectiveness of Ribociclib Plus a Nonsteroidal Aromatase Inhibitor in Pre-/Perimenopausal, HR+ and HER2- Advanced Breast Cancer: A Canadian Healthcare Perspective.

BACKGROUND AND OBJECTIVES: The MONALEESA-7 trial demonstrated the efficacy and safety of ribociclib plus a nonsteroidal aromatase inhibitor (NSAI) [with goserelin] for pre-/perimenopausal women with hormone receptor-positive and human epidermal growth factor receptor 2-negative advanced breast cancer. This analysis evaluated the cost effectiveness of ribociclib plus NSAI vs NSAI monotherapy and tamoxifen monotherapy from the perspective of the Canadian healthcare system. METHODS: The incremental cost-effectiveness ratio expressed as incremental costs per quality-adjusted life-year (QALY) gained for ribociclib plus an NSAI vs an NSAI and vs tamoxifen was estimated using a semi-Markov cohort model developed in Microsoft Excel with a 15-year time horizon and states for progression-free survival, post-progression survival, and dead. Survival distributions for progression-free survival, post-progression survival, and time to discontinuation as well as health-state utilities were estimated using data from MONALEESA-7. Direct costs of advanced breast cancer treatment were based on Canadian-specific values from published sources. Costs ($CAN 2019) and QALYs were discounted at 1.5% annually. RESULTS: Ribociclib plus an NSAI was estimated to yield gains of 1.42 life-years and 1.17 QALYs vs an NSAI, and 2.61 life-years and 2.12 QALYs vs tamoxifen, at incremental costs of $209,701 and $220,836, respectively. In probabilistic analyses, the incremental cost-effectiveness ratio for ribociclib plus an NSAI was estimated to be $178,872 per QALY gained vs an NSAI and $104,400 per QALY gained vs tamoxifen. Results of deterministic analyses were similar (incremental cost-effectiveness ratios of $177,245 and $103,316 vs NSAI and tamoxifen, respectively). Results were sensitive to parametric distributions used for projecting progression-free survival and the time horizon. CONCLUSIONS: At its current list price, ribociclib used in combination with NSAI is likely to be co-effective relative to an NSAI alone or tamoxifen alone if the willingness-to-pay threshold is less than approximately $178,000 per QALY. These results have informed deliberations regarding reimbursement and access to this treatment in Canada and may be useful for decision makers in other settings.