Real-World Treatment Patterns for Waldenstrom Macroglobulinemia: Implications for Treatment Sequencing.

BACKGROUND: Due to the rarity of Waldenstrom macroglobulinemia (WM) and scarcity of direct comparative data, there remains uncertainty regarding the optimal therapeutic approach for treatment-naïve patients and subsequent treatment sequence. To bridge such knowledge gap and generate data on most appropriate treatment in relatively resource constraint setting, we conducted this study with 168 WM patients. METHODS: Due to the diversity of treatment regimens, patients were categorized into four groups: cytotoxic regimen, rituximab-based regimen, proteasome inhibitor (PI)/immunomodulatory drug (IMiD)-based regimen, and bruton tyrosine kinase inhibitor (BTKi). Treatment patterns and efficacy outcomes were analyzed. RESULTS: The overall response rate (ORR) between rituximab-based vs. PI/IMiD based regimens were similar (74.2% vs. 80.0%, P = 0.750), but rituximab-based regimens were associated with longer response (median progression free survival [PFS] 44.3 vs. 8.5 months, P < 0.001), while PI/IMiD based regimens were associated with faster response (median time to initial response 1.8 vs. 0.9 months, P = 0.040). Among rituximab-based regimens, bendamustine-rituximab was associated with better response (ORR, 83.3%) and significantly longer PFS compared to rituximab + cyclophosphamide-based regimen group (median PFS 61.3 months vs. 18.2 months, P < 0.001). Ultimately 56% underwent second line treatment. Prior treatment did not seem to affect subsequent BTKi efficacy. CONCLUSION: Our findings underscore the importance of optimizing treatment strategies and offer real-world data to support informed decision-making in settings with constrained resources.