Cost-effectiveness (CE) of regorafenib dose optimization schedule in metastatic colorectal cancer.

Abstract

e18367 Background: Regorafenib at 160mg daily 21/28 days is a standard therapeutic option in patients with metastatic colorectal cancer. However, the cost of treatment and management of its side-effects is more than the cost-effectiveness threshold for oncology drugs in US and many countries around the world. ReDOS (Regorafenib Dose Optimization Study), is a randomized phase II trial in refractory mCRC and established that weekly dose escalation of regorafenib over the conventional dosing is superior in the composite endpoint of safety and efficacy. We explored the impact of the new dosing strategy on CE of regorafenib. Methods: A Markov model was constructed to compare costs and effectiveness of regorafenib (standard), regorafenib (ReDOS), and best supportive care (BSC). Model inputs for clinical efficacy and safety were from the CORRECT trial for regorafenib (standard) and BSC, and the ReDOS study for regorafenib (ReDOS). The incremental cost-effectiveness ratios (ICERs) were reported to compare treatments. Model robustness was checked with univariate and probabilistic sensitivity analyses. The model used a US payer’s perspective with 5% annual discount rate, and all costs were measured in 2018 US dollars. Results: Regorafenib (ReDOS) dominated regorafenib (standard), producing higher quality-adjusted life years at a lower cost. When compared to BSC, regorafenib (ReDOS) resulted in the ICER of $112,705 while regorafenib (standard) resulted in the ICER of $384,687. The most influential parameters on the ICERs were efficacy and health state utility parameters under univariate sensitivity analysis. In probabilistic sensitivity analysis using cost-effectiveness acceptability curves, regorafenib (ReDOS) was more cost-effective than regorafenib (standard) and BSC in 70% of repetition at the willingness-to-pay threshold of $120,000 per QALY (Quality-Adjusted Life Year) and 98% at a WTP threshold of $150,000. Conclusions: Based on the outcomes demonstrated in the ReDOS study, the dose optimization strategy of regorafenib results in favorable cost-effectiveness under a typical US willingness-to-pay threshold of $150,000 per QALY.