Ibrutinib and R-GemOx in patients with relapsed or refractory diffuse large B-cell lymphoma of non-GCB type: Phase II clinical trial of the Spanish GELTAMO group.

ABSTRACT

PURPOSE: This phase II clinical trial evaluated the combination of Ibrutinib with rituximab, gemcitabine and oxaliplatin (R-GemOx) in patients with non-germinal centre B-cell-like (non-GCB) diffuse large B-cell lymphoma (DLBCL). PATIENTS AND METHODS: The IBDCL trial (NCT02692248) included patients with histological diagnosis of non-GCB DLBCL with relapsed or refractory disease and non-candidates for stem cell transplantation. Patients received an induction treatment consisting of 6 or 8 cycles of R-GemOx at standard doses every 2 weeks, in combination with ibrutinib (560 mg daily), followed by a maintenance treatment with ibrutinib for a maximum of 2 years. The primary objective was to evaluate the overall response rate (ORR) after 4 cycles. RESULTS: Sixty-four patients were included, 72% of them refractory to the last regimen. The ORR and CR rate after the 4th cycle were 53% (95% confidence interval [CI], 41-65) and 34% (95% CI, 24-46), respectively. Twenty-four (37%) patients started maintenance and 7 (11%) completed the planned 2 years. After a median follow-up of 29.7 months (range 0.4-48.6), the estimated 2-year PFS and OS were 18% (95% CI, 8 - 28) and 26% (95% CI, 14 - 37), respectively. The most common grade ≥3 treatment-related adverse events (TRAEs) were thrombocytopenia (44%), neutropenia (30%) and anemia (14%). Grade ≥3 infectious and cardiovascular TRAEs were reported in 6 (9%) and 1 (2%) patient, respectively. CONCLUSIONS: Ibrutinib in combination with R-GemOx, followed by ibrutinib maintenance, demonstrated encouraging antitumor activity with durable responses and a manageable toxicity in patients with non-GCB DLBCL.