Real-world outcomes of ibrutinib therapy in Korean patients with relapsed or refractory mantle cell lymphoma: a multicenter, retrospective analysis

Abstract

Abbreviations AE adverse event ASCT autologous stem cell transplantation CI confidence interval CR complete response MCL mantle cell lymphoma ORR overall response rate OS overall survival PFS progression-free survival PR partial response RR relapsed or refractory RT radiation therapy Dear Editor, Despite the introduction of novel front-line therapies including rituximab plus high-dose cytarabine followed by consolidative autologous stem cell transplantation (ASCT) and salvage therapy with bendamustine, lenalidomide or bortezomib, mantle cell lymphoma (MCL) is still considered incurable and most patients experience relapse or refractory (RR) disease. The median progression-free survival (PFS) from the front-line treatment was 24.0 months (95% confidence interval [CI]: 21.6-28.2 months), and the median duration of response was 26.7 months (95% CI: 22.5-31.1 months). Collectively, an overall response rate (ORR) of ∼65% and a median PFS of ∼12 months were observed. TABLE 1 Cross-trials comparison of prospective and retrospective studies dealing with RR MCL patients treated with ibrutinib (median (range) for age and prior lines of therapy; median [95% CI] for DoR, PFS, and OS) Trials Number of patients Age (year, [median, range]) Prior lines Prognostic indices ORR (%) DoR (months) PFS (months) OS (months) Discontinue therapy due to AEs (%) Pooled analysis of three prospective trials [ 4] 370 N/A 2 (1-9) 31.8% high-risk simplified MIPI 69.7 21.8 (17.2-26.4) 12.5 (9.8-16.6) 26.7 (22.5-38.4) 10.3 US retrospective trial [ 5] 97 63 (39-87) 2 (1-8) 27% high-risk MIPI 65 17 15 22 N/A Italian retrospective trial [ 6] 77 68.6 (38.5-83.7) 3 (1-10) N/A 36.4 36 12.9 16 16.9 French observational trial [ 7] 106 74 (49-88) 1 (39%); 2 (31%); ≥3 (30%); N/A 76.4 27.4 (17.3 – N/A) 23.7 (18.3-30.4) 29.9 (23.2-39.2) 9.3 US retrospective trial [ 8] 159 71 (48-90) 2 (1-3) N/A N/A N/A 19.6 (16.5 – 24.3) 25.8 (19.9 – not reached) 25.6 Current study 88 71 (42-92) 1 (1-6) 40.9% high-risk MIPI 64.8 26.7 (22.5-31.1) 20.8 (10.8-30.8) 2-year OS rate 79.5% 6.8 N/A, not available; CI, confidence interval Compared to previous studies [ 10], the post-ibrutinib OS was more favorable in the present study at 19.4 months (vs. 5.8 months).