Ibrutinib improves the efficacy of anti‐CD19‐CAR T‐cell therapy in patients with refractory non‐Hodgkin lymphoma

The efficacy and side effects of the second‐time humanized CD19 chimeric antigen receptor (CD19‐CAR) T‐cell therapy after unsuccessful first‐time anti‐CD19‐CAR T‐cell therapy and subsequent ibrutinib salvage treatment were observed in patients with refractory B‐cell lymphoma. In our study, 3 patients with refractory mantle cell lymphoma (MCL) and 4 patients with refractory follicular lymphoma (FL) reached stable disease (SD), partial remission (PR), or progression of disease (PD) after first‐time humanized anti‐CD19‐CAR T‐cell therapy. They received ibrutinib as a salvage treatment and kept an SD in the following 7‐16 mo, but their disease progressed again during ibrutinib salvage treatment. All 7 patients received a second‐time humanized anti‐CD19‐CAR T‐cell therapy, which was the same as their first‐time anti‐CD19‐CAR T‐cell therapy. In total, 3 MCL patients and 3 FL patients reached complete response (CR) with the second‐time anti‐CD19‐CAR T‐cell therapy combined with ibrutinib, whereas 1 FL patient reached PR. There were no differences in the transduction efficiency and proliferation between the 2 instances of anti‐CD19‐CAR T‐cell therapy. However, the second‐time anti‐CD19‐CAR T‐cell therapy led to higher peaks of anti‐CD19‐CAR T cells and anti‐CD19‐CAR gene copies, but also to higher grades of cytokine release syndrome (CRS) and more serious hematological toxicity. The successful outcome of the second‐time anti‐CD19‐CAR T‐cell therapy might suggest that the previous ibrutinib treatment improved the activities of anti‐CD19‐CAR T cells.