OBJECTIVES: The MONALEESA-3 trial demonstrated the efficacy and safety of R+F vs. placebo plus FUL for patients with HR+/HER2- ABC. This analysis evaluated the cost-effectiveness of R+F vs. FUL 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 R+F vs. FUL, was estimated using a semi-Markov cohort model developed in Microsoft Excel with states for progression-free (PF), post-progression (PP), and dead. A 15-year time horizon was used. Survival distributions for PFS, PPS and time to discontinuation (TTD) were based on parametric survival distribution 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 ($ CAN) and QALYs were discounted at 1.5% annually.

RESULTS: In the base case, R+F was estimated to result in gains of 1.20 life years and 0.98 QALYs vs. FUL, at an incremental cost of $152,757. The ICER of R+F vs. FUL was $156,638 per QALY gained based on deterministic analyses and $157,293 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, R+F is projected to result in substantial gains in QALYs compared with FUL. At its current list price, Ribociclib used in combination with FUL is cost-effective in these patients at a threshold ICER of $156,638. These results may be useful in deliberations regarding reimbursement and access to this treatment.