Background
Three-arm randomized open-label phase 3 superiority trial (European MCL Network, 165 centres), 4.5-year update. N=870 patients aged 18–65 with untreated stage II–IV mantle cell lymphoma suitable for ASCT, randomized 1:1:1 to test whether adding ibrutinib to immunochemotherapy plus ASCT improves outcomes and whether ASCT remains necessary when ibrutinib is added.
Interventions and follow up
Arm A (control): R-CHOP alternating with R-DHAP/R-DHAOx ×6 cycles, then ASCT (n=288).
Arm A+I: Same induction with oral ibrutinib 560 mg daily on days 1–19 of R-CHOP cycles, then ASCT, then 2 years ibrutinib maintenance (n=292).
Arm I: Same ibrutinib-containing induction without ASCT, then 2 years ibrutinib maintenance (n=290).
Primary endpoint: Failure-free survival (three pairwise one-sided log-rank comparisons).
mFollow up: 54.9 months (95% CI 54.4–56.0).
Arm A+I: Same induction with oral ibrutinib 560 mg daily on days 1–19 of R-CHOP cycles, then ASCT, then 2 years ibrutinib maintenance (n=292).
Arm I: Same ibrutinib-containing induction without ASCT, then 2 years ibrutinib maintenance (n=290).
Primary endpoint: Failure-free survival (three pairwise one-sided log-rank comparisons).
mFollow up: 54.9 months (95% CI 54.4–56.0).
Results
4-yr failure-free survival, A+I vs I: 82% (95% CI 78–87) vs 81% (76–86); HR 0.86 (one-sided 98.33% CI 0.00–1.27); P=.21 — A+I not superior to I.
4-yr failure-free survival, A+I vs A: 82% vs 70% (65–76); HR 0.63 (98.33% CI 0.00–0.89); P=.0026 — A+I superior to A.
4-yr failure-free survival, I vs A: 81% vs 70%; A not superior to I (P=.99).
4-yr OS, A+I vs A: 88% (84–92) vs 81% (76–85); HR 0.59 (95% CI 0.38–0.92); P=.0036.
4-yr OS, I vs A: 90% (87–94) vs 81%; HR 0.57 (0.36–0.90); P=.0019.
4-yr failure-free survival, A+I vs A: 82% vs 70% (65–76); HR 0.63 (98.33% CI 0.00–0.89); P=.0026 — A+I superior to A.
4-yr failure-free survival, I vs A: 81% vs 70%; A not superior to I (P=.99).
4-yr OS, A+I vs A: 88% (84–92) vs 81% (76–85); HR 0.59 (95% CI 0.38–0.92); P=.0036.
4-yr OS, I vs A: 90% (87–94) vs 81%; HR 0.57 (0.36–0.90); P=.0019.
Adverse events
Hematologic (grade 3–5, maintenance/follow-up): A+I 54% (127/234) vs I 28% (74/269) vs A 23% (56/240).
Infections (grade 3–5): A+I 34% (80/234) vs I 26% (71/269) vs A 15% (37/240).
Fatal infections (maintenance/follow-up): A+I 4 patients (2%) vs I 5 patients (2%); toxicity clearly higher with ASCT plus ibrutinib than ibrutinib alone.
Infections (grade 3–5): A+I 34% (80/234) vs I 26% (71/269) vs A 15% (37/240).
Fatal infections (maintenance/follow-up): A+I 4 patients (2%) vs I 5 patients (2%); toxicity clearly higher with ASCT plus ibrutinib than ibrutinib alone.
Conclusions
After 4.5 years, adding ASCT to an ibrutinib-containing first-line regimen did not improve failure-free survival and increased toxicity, while both ibrutinib-containing arms improved failure-free and overall survival versus the ASCT-only control. Ibrutinib plus R-CHOP/R-DHAP induction followed by 2 years of ibrutinib maintenance — without ASCT — should be a new standard for younger fit MCL patients.
Key Limitations
Open-label design. Follow-up of 4.5 years still relatively short for a disease where late relapses are common. Enrolled before second-generation BTK inhibitors (acalabrutinib, zanubrutinib) and alternatives (pirtobrutinib, BCL2 combinations, CAR-T) were widely available, so the optimal BTK-based induction backbone may evolve.
Clinical Context
Together with SHINE (Wang ML et al, NEJM 2022; PMID 35657079 — ibrutinib added to BR in older patients) and the 2024 primary TRIANGLE analysis, this update supports BTK-inhibitor incorporation into front-line MCL therapy and shows ASCT can be omitted in younger transplant-eligible patients receiving ibrutinib-containing induction plus maintenance, shifting ESMO and European MCL Network guidance away from routine consolidative ASCT.