A phase II study of ibrutinib in combination with rituximab-cyclophosphamide-doxorubicin hydrochloride-vincristine sulfate-prednisone therapy in Epstein-Barr virus-positive, diffuse large B cell lymphoma (54179060LYM2003: IVORY study): results of the final analysis

Abstract

Epstein-Barr virus (EBV) positivity in diffuse large B cell lymphoma (DLBCL) provokes a critical oncogenic mechanism to activate intracellular signaling by LMP1. LMP1 specifically mimics the role of BTK-dependent B cell receptor. Therefore, a trial considering RCHOP therapy along with ibrutinib (I-RCHOP) in combination was conducted among patients with EBV-positive DLBCL. This study was an open-label, single-arm, prospective multicenter phase II clinical trial. Patients received 560 mg of ibrutinib with RCHOP every 3 weeks until 6 cycles were completed or progression or unacceptable toxicity was observed. The primary endpoint was objective response, while secondary endpoints included toxicity, progression-free survival, and overall survival. A matched case-control analysis was completed to compare the efficacy and toxicity of I-RCHOP and RCHOP, respectively, in EBV-positive DLBCL patients. From September 2016 to August 2019, 24 patients proven to have EBV-positive DLBCL in the tissue were enrolled and received I-RCHOP. Their median age was 58 years (range, 28-84 years). The objective overall response was 66.7%, including 16 patients who achieved complete response after 6 cycles. Patients aged younger than 65 years presented a superior OR (87.5%) as compared with those older than 65 years (25.0%; p = 0.01). In a matched case-control study, I-RCHOP therapy provoked a more favorable complete response rate (87.3%) than did RCHOP (68.8%) in those younger than 65 years. Treatment-related mortality was linked most frequently with I-RCHOP therapy (four patients presented with unusual infection without Gr3/4 neutropenia) in the older age group (age >= 65 years). In conclusion, in this phase II trial for EBV-positive DLBCL, I-RCHOP was effective but did not show a significant improvement in response and survival in comparison with RCHOP. Also, I-RCHOP promoted serious toxicity and treatment-related death in older patients.