Yttrium-90 Ibritumomab Tiuxetan is Cost-Effective Compared to Bendamustine + Rituximab in Low-grade Lymphomas

Background: Yttrium-90 ibritumomab tiuxetan [(90)Y-IT] is a CD20-targeted radio-immunotherapeutic agent. It has shown an excellent therapeutic activity with high tolerability against previously untreated follicular lymphoma (FL) and marginal zone B cell lymphoma (MZL). It is an attractive therapeutic option as the treatment schedule is short and convenient. The aim of our study is to determine the cost-effectiveness of (90)Y-IT in comparison to the standard-of-care bendamustine + rituximab (BR) in the first-line treatment of low-grade FL (LG-FL) and MZL in the real world. Patients and Methods: We included all patients who were treated with standard-dose (90)Y-IT for previously untreated LG-FL and MZL at the Mayo Clinic Cancer Center (N = 51). A comparator arm with a historical cohort of previously untreated LG-FL and MZL patients who received BR was used (N = 92). Results: Inverse propensity weighting was utilized to balance the 2 study arms. There were no differences in terms of overall response rate (100% vs. 98%, P =. 18), complete response rate (94% vs. 95%, P =. 91), or 5 years progression-free survival (76% vs. 75%, P =. 63) between patients who received (90)Y-IT and BR, respectively. Within the first year, patients who received (90)Y-IT required an average of 4.5 fewer oncology clinic visits (P <. 001), an average of 10 fewer days of therapeutic use (P <. 001), and 40% less use of growth factors (P <. 001) as compared to the BR group. The direct therapeutic cost of (90)Y-IT treatment was 54% less than that of 6 cycles of BR. Conclusion: The findings suggest that (90) Y-IT is more cost-effective than BR and is a viable alternative in up-front management of LG-FL and MZL.