B-cell non-Hodgkin's lymphomas are the most common hematological malignancies, which despite improvements in chemo-immunotherapy, carry a uniformly poor prognosis in the relapsed/refractory setting. CD19 is an antigen expressed on the surface of most malignancies arising from the B cells, and adoptive transfer of anti-CD19 chimeric antigen receptor (CAR)-expressing T cells has been shown to be effective in treating these B-cell malignancies. Axicabtagene ciloleucel (axi-cel, KTE-C19) is an autologous anti-CD19 CAR T-cell therapy which has shown high overall response rates and a manageable safety profile in patients with relapsed or refractory B-cell malignancies who lack effective and curative treatment options. Axi-cel is currently approved by the U.S. Food and Drug Administration (FDA) for the treatment of adult patients with relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy including diffuse large B-cell lymphoma (DLBCL), primary mediastinal large B-cell lymphoma, high-grade B-cell lymphoma and DLBCL arising from follicular lymphoma, and is also being evaluated in other B-cell malignancies in ongoing clinical trials. In this review we will discuss the mechanism of action of axi-cel, clinical trials leading to its FDA approval, ongoing clinical trials and its potential adverse effects, and will speculate on the future directions of axi-cel and CAR T-cell therapy in general.