P1134: outcomes for patients with mantle cell lymphoma post-cbtk inhibitor therapy in the united states and japan: a study of two real-world databases

Background: Patients with mantle cell lymphoma (MCL) have limited treatment options following covalent Bruton’s tyrosine kinase inhibitor (cBTKi) therapy, with no standard regimens defined. Aims: The aim of this study was to investigate real-world treatment patterns and the outcomes for patients with MCL following cBTKi treatment utilizing two separate datasets—one from the US and one from Japan. Methods: De-identified patient-level electronic medical record data from two real-world databases (ConcertAI in the US and Medical Data Vision in Japan) were utilized for this study. Eligible patients were ≥18 years old and were diagnosed with MCL between January 2011 and October 2020 in the US or between December 2010 and July 2020 in Japan. Data were available through 2020 to allow a minimum of 1 year of follow-up for all patients. Patients were required to have completed treatment with at least one cBTKi during the first through third lines of therapy. Time-to-event analyses utilized the Kaplan-Meier method. Results: 946 US patients (median age 72 years, male 75.1%) and 196 Japanese patients (median age 78 years, male 73.5%) met the eligibility criteria. 352 (37.2%) patients in the US and 103 (52.6%) in Japan received subsequent post-cBTKi therapy. The remaining 387 (40.9%) patients in the US and 93 (47.5%) patients in Japan did not receive further treatment. In the US, immediate post-cBTKi regimens included rituximab (with or without other chemotherapy agents, n=152, 43.2%) or additional cBTKi-based 146 (41.5%) or B-cell lymphoma 2 inhibitor–based (n=30, 8.5%) therapy. In Japan, immediate post-cBTKi regimens were nearly exclusively chemotherapy based (n=92, 89.3%), and only 11 (10.7%) patients were retreated with cBTKi-containing regimens. Median time from the end of cBTKi therapy to discontinuation of the immediate post-cBTKi therapy or death was 3.9 months (95% confidence interval [CI]: 3.3-4.6) in the US and 2.4 months (n=196, 95% CI: 1.7-3.0) in Japan. Among those who received post-cBTKi therapy, the duration of therapy was 2.6 months (95% CI: 2.1-3.3) in the US and 1.8 months (n=103, 95% CI: 1.1-2.3) in Japan. Median overall survival (OS) from discontinuation of cBTKi therapy was 10.3 months (95% CI: 8.0-13.0 in US patients and 7.1 months (n=196, 95% CI: 4.6-12.7) in Japanese patients. Summary/Conclusion: Patients with MCL previously treated with cBTKi experience very poor outcomes, as measured by their duration of subsequent therapy and OS. Data were generally consistent between the US and Japan. The development of new safe and effective therapies after cBTKi is needed to address the growing unmet medical need in this treatment setting.