Subcutaneous Rituximab Demonstrates Superior Outcomes Compared to Intravenous Administration: Enhanced Complete Response Rates and Prolonged Progression-Free Survival – phase III trial (FLIRT) in low tumor burden follicular lymphoma.
Introduction: Rituximab, a monoclonal antibody targeting CD20-positive B-cells, has been widely used in the treatment of various lymphoid malignancies. Recent studies have investigated the efficacy and safety of subcutaneous rituximab (trade name: Rituxan Hycela) compared to intravenous rituximab. This analysis aims to evaluate the impact of subcutaneous rituximab on progression-free survival, complete response rates, and time to next treatment, while also considering the rituximab exposure during the initial three months of therapy.
The use of subcutaneous rituximab has demonstrated notable improvements in progression-free survival, complete response rates, and time to next treatment compared to intravenous rituximab. Multivariate analysis, complete response vs no complete response at month 12, revealed a significant association between achieving a complete response at month 12 and prolonged progression-free survival (3-year rate = 75.7% vs 35%, HR = 0.285, P < .001) as well as time to next treatment (3-year rate = 86.8% vs 33.6%, HR = 0.114, P < .001).
Moreover, the level of rituximab exposure during the initial three months of treatment was found to have a significant impact on patient outcomes. High rituximab exposure during this period was associated with extended progression-free survival (HR = 0.428, P = .0010), increased complete response rate (odds ratio = 7.449, P = .016), and prolonged time to next treatment (HR = 0.333, P = .0004).
Conclusion: Subcutaneous rituximab administration, exemplified by Rituxan Hycela, offers substantial advantages over intravenous rituximab. The study’s results indicate that achieving a complete response at month 12 is strongly associated with prolonged progression-free survival and time to next treatment. Additionally, the level of rituximab exposure during the first three months may influence the patient outcomes. These findings support the use of subcutaneous rituximab as one of the preferred treatment option if possible, emphasizing the importance of early and adequate rituximab exposure for maximizing therapeutic benefits in this type of lymphoid malignancies.
