Chimeric antigen receptor T cells persist and induce sustained remissions in relapsed refractory chronic lymphocytic leukemia
David L Porter, Wei-Ting Hwang, Noelle V Frey, Simon F Lacey, Pamela A Shaw, Alison W Loren, Adam Bagg, Katherine T Marcucci, Angela Shen, Vanessa Gonzalez, David Ambrose, Stephan A Grupp, Anne Chew, Zhaohui Zheng, Michael C Milone, Bruce L Levine, Jan J Melenhorst, Carl H June, David L Porter, Wei-Ting Hwang, Noelle V Frey, Simon F Lacey, Pamela A Shaw, Alison W Loren, Adam Bagg, Katherine T Marcucci, Angela Shen, Vanessa Gonzalez, David Ambrose, Stephan A Grupp, Anne Chew, Zhaohui Zheng, Michael C Milone, Bruce L Levine, Jan J Melenhorst, Carl H June
Abstract
Patients with multiply relapsed or refractory chronic lymphocytic leukemia (CLL) have a poor prognosis. Chimeric antigen receptor (CAR)-modified T cells targeting CD19 have the potential to improve on the low complete response rates with conventional therapies by inducing sustained remissions in patients with refractory B cell malignancies. We previously reported preliminary results on three patients with refractory CLL. We report the mature results from our initial trial using CAR-modified T cells to treat 14 patients with relapsed and refractory CLL. Autologous T cells transduced with a CD19-directed CAR (CTL019) lentiviral vector were infused into patients with relapsed/refractory CLL at doses of 0.14 × 10(8) to 11 × 10(8) CTL019 cells (median, 1.6 × 10(8) cells). Patients were monitored for toxicity, response, expansion, and persistence of circulating CTL019 T cells. The overall response rate in these heavily pretreated CLL patients was 8 of 14 (57%), with 4 complete remissions (CR) and 4 partial remissions (PR). The in vivo expansion of the CAR T cells correlated with clinical responses, and the CAR T cells persisted and remained functional beyond 4 years in the first two patients achieving CR. No patient in CR has relapsed. All responding patients developed B cell aplasia and experienced cytokine release syndrome, coincident with T cell proliferation. Minimal residual disease was not detectable in patients who achieved CR, suggesting that disease eradication may be possible in some patients with advanced CLL.
Conflict of interest statement
Competing interests: Patents related to the technology described here have been issued in the United States (8,916,381; 8,911,993; 8,906,682; 8,975,071) and are licensed to Novartis.
Copyright © 2015, American Association for the Advancement of Science.
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Source: PubMed