Chimeric antigen receptor (CAR) T-cell therapies are driving ever faster forward, with impressive response rates – including a high level of complete responses – in treatment of patients with lymphomas and multiple myeloma as shown by clinical trial results to be presented at the annual meeting of the American Society of Hematology.
Investigators will be presenting data on the first two CAR T constructs to receive Food and Drug Administration approval, each directed against CD19.
ZUMA-1 for non-Hodgkin lymphoma
Long-term follow-up results with the use of axicabtagene ciloleucel (Yescarta; axi-cel) in patients with refractory aggressive non-Hodgkin lymphoma will be presented by Sattva S. Neelapu, MD, of the University of Texas MD Anderson Cancer Center in Houston, on behalf of colleagues in the ZUMA-1 trial (Abstract 578).
At the 2017 European Hematology Association Congress in Madrid, ZUMA-1 investigators reported that axi-cel, an autologous anti-CD19 CAR-T product, was associated with an 82% objective response rate (ORR), including 54% complete responses, in patients with refractory diffuse large B cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma, or transformed follicular lymphoma. The 54% complete response rate was nearly sevenfold higher than that reported for historical controls, according to coinvestigator Yi Lin, MD, PhD, of the Mayo Clinic, Rochester, Minn.
The treatment was generally safe, with 13% of patients experiencing grade 3 or greater cytokine release syndrome (CRS), and 28% having grade 3 or greater neurologic events. The events were generally reversible, and the rates of each declined over time. The use of tocilizumab or steroids to control adverse events did not have a negative effect on responses.
This CAR T-cell construct received FDA approval in October 2017.
At ASH 2017, Dr. Neelapu will present 1-year follow-up data from the trial which will include both data on responses and toxicity, “but also some very interesting information on mechanisms of resistance, whether patients’ tumor cells become CD19 negative, or checkpoint, like PD-L1, positive,” said Kenneth Anderson, MD, of the Dana-Farber Cancer Institute in Boston, who discussed noteworthy abstracts in a media briefing prior to the meeting.
JULIET for DLBCL
Data on the use of another anti-CD19 CAR construct, tisagenlecleucel (Kymriah) in adults with relapsed or refractory DLBCL will be presented by Stephen J. Schuster, MD, of the University of Pennsylvania, Philadelphia, on behalf of investigators in the JULIET trial.
At the 2017 European Hematology Association Congress, coinvestigator Gilles Salles, MD, PhD, of the University of Lyon, France, reported an interim analysis from the trial, showing that the CAR T construct was associated with a 59% ORR, consisting of 43% complete responses and 16% partial responses in patients with relapsed or refractory DLBCL. The analysis “confirms the high response rates and durable responses observed in the previous single-center trial,” Dr. Salles said.
Dr. Schuster will present the primary analysis of the global phase 2 pivotal trial at ASH 2017 (Abstract 577), looking at patients who received the product from the U.S. manufacturing site.
As of the data cutoff in March 2017, the best ORR among 81 patients with at least 3 months of follow-up, or earlier discontinuation, was 53.1% with 39.5% complete responses and 13.6% partial responses. For 46 patients evaluable at 6 months, the complete response rate was 30% and partial response rate was 7%.
The response rates were consistent across subgroups, including patients who had previously undergone autologous stem cell transplant and those with double-hit lymphoma (i.e, with mutation in MYC and BCL2 or BCL6).
The responses also appeared to be durable, with the median duration not reached. The 6-month probability of being relapse free was 73.5%. Similarly, median overall survival was not reached; the 6-month probability of overall survival was 64.5%, according to the published abstract.
Adverse events included CRS in 58% of infused patients, with 15% grade 3 and 8% grade 4 in severity. CRS was managed according to protocol with tocilizumab and/or corticosteroids. There were no deaths associated with either the CRS or neurologic toxicities.
“This is a multicenter trial: 27 centers, 10 countries, 4 continents, so it sort of demonstrates to all of us that this technology can be done in an international scope,” Dr. Anderson said.
Anti-BCMA for multiple myeloma
CAR T-cells are relative newcomers in the treatment of multiple myeloma, but James N. Kochenderfer, MD, of the National Cancer Institute, Bethesda, Md., will be presenting updated results from a multicenter study of bb2121, a CAR T-cell construct directed against B-cell maturation antigen (BCMA).
BCMA was first described in myeloma in 2004 as a mechanism for the growth and survival of malignant plasma cells. As previously reported, a different anti-BCMA T-cell product induced clinical remissions in 33 of 35 patients with relapsed/refractory multiple myeloma who were treated in an early clinical trial.
With the construct being investigated by Dr. Kochenderfer and colleagues, 21 patients (median 58 years old) with a median of 5 years since a diagnosis of multiple myeloma were infused with bb2121. One-month data on clinical response was available for 18 patients at the time of data cutoff in May 2017 (Abstract 740).
In this heavily pretreated population, the ORR was 89% overall, and was 100% for patients treated with doses of 150 x 106 CAR+ T cells or higher. At this dose range or higher no patients had disease progression at up to 54 weeks after infusion. Of the four patients evaluable for minimal residual disease (MRD), all were MRD negative.
As of the data cut-off there were no dose-limiting toxicities and no treatment-related grade 3 or higher neurotoxicities. CRS was primarily grade 1 or 2 and was reported in 15 of 21 patients. Two patients had grade 3 CRS that resolved in 24 hours, and four patients received tocilizumab (one with steroids) for CRS management.
There was one on-study death, from cardiopulmonary arrest more than 4 months after bb2121 infusion in a patient with an extensive cardiac history. The death was judged to be unrelated to CAR T-cell therapy.
Dr. Kochenderfer will present data and analysis on an additional 5 months of follow-up.
“This abstract demonstrates that again, in patients, this time with myeloma with literally no other option, you can achieve very impressive response,” Dr. Anderson said.
The ZUMA-1 study is funded by Kite Pharma. Dr. Neelapu reported research funding from BMS, Poseida, Merck, Kite Pharma, and Cellectis. He reported consultancy and membership on the board of directors or advisory committees for Merck, Kite Pharma, and Celgene.
The JULIET study is funded by Novartis. Dr. Schuster reported consultancy and research funding from Novartis Pharmaceuticals, Celgene, Genentech, Bristol-Myers Squibb, Janssen R&D, and Gilead. He reported consultancy with Seattle Genetics and Nordic Nanovector, and research funding from Merck.
The multicenter study of bb2121 is sponsored by bluebird bio and Celgene. Dr. Kochenderfer reported research funding from bluebird bio and Kite Pharma. He reported having multiple patents in the CAR field.
Abstract 578 Long-Term Follow-up ZUMA-1: A Pivotal Trial of Axicabtagene Ciloleucel (Axi-Cel; KTE-C19) in Patients with Refractory Aggressive Non-Hodgkin Lymphoma (NHL) will be presented in session 626, Monday, Dec. 11, 2017, at 7:15 a.m.
Abstract 577 Primary Analysis of Juliet: A Global, Pivotal, Phase 2 Trial of CTL019 in Adult Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma will be presented in session 626, Monday, Dec. 11, 2017 at 7:00 a.m. Abstract 740 Durable Clinical Responses in Heavily Pretreated Patients with Relapsed/Refractory Multiple Myeloma: Updated Results from a Multicenter Study of bb2121 Anti-BCMA CAR T Cell Therapy will be presented in session 653, Monday, Dec. 11, 2017 at 3:00 p.m.