Real-world experience with chimeric antigen receptor (CAR) T-cell therapies for large B-cell lymphomas compares favorably with experience in commercial and trial settings and provides new insights for predicting outcomes, according to Paolo Corradini, MD.
The 12-month duration of response (DOR) and progression-free survival (PFS) rates in 152 real-world patients treated with tisagenlecleucel (tisa-cel; Kymriah) for an approved indication were 48.4% and 26.4%, respectively, data reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) and published in November 2020 in Blood Advances showed.
who relapsed or were refractory to at least two prior lines of therapy, Dr. Corradini said at the third European CAR T-cell Meeting, jointly sponsored by the European Society for Blood and Marrow Transplantation and the European Hematology Association.
A clinical update of the JULIET trial, as presented by Dr. Corradini and colleagues in a poster at the 2020 annual conference of the American Society of Hematology, showed a relapse-free probability of 60.4% at 24 and 30 months among 61 patients with an initial response.
The 12- and 36-month PFS rates as of February 2020, with median follow-up of 40.3 months, were 33% and 31%, respectively, and no new safety signals were identified, said Dr. Corradini, chair of hematology at the University of Milan.
Similarly, real-world data from the U.S. Lymphoma CAR T Consortium showing median PFS of 8.3 months at median follow-up of 12.9 months in 275 patients treated with axicabtagene ciloleucel (axi-cel; YESCARTA) were comparable with outcomes in the ZUMA-1 registrational trial, he noted.
An ongoing response was seen at 2 years in 39% of patients in ZUMA-1, and 3-year survival was 47%, according to an update reported at ASH 2019.
Of note, 43% of patients in the real-world study, which was published in the Journal of Clinical Oncology in September 2020, would not have met ZUMA-1 eligibility criteria because of comorbidities at the time of leukapheresis.
Predicting outcomes
The real-world data also demonstrated that performance status and lactate dehydrogenase (LDH) levels can predict outcomes: Patients with poor Eastern Cooperative Oncology Group performance status of 2-4 versus less than 2, and elevated LDH had shorter PFS and overall survival (OS) on both univariate and multivariate analysis, Dr. Corradini noted.
A subsequent multicenter study showed similar response rates of 70% and 68% in ZUMA-1-eligible and noneligible patients, but significantly improved DOR, PFS, and OS outcomes among the ZUMA-1-eligible patients.
The authors also looked for “clinical predictive factors or some easy clinical biomarkers to predict the outcomes in our patients receiving CAR T-cells,” and found that C-reactive protein levels of more than 30 mg at infusion were associated with poorer DOR, PFS, and OS, he said.
In 60 patients in another U.S. study of both tisa-cel- and axi-cel-treated patients at Memorial Sloan Kettering Cancer Center, 1-year event-free survival and OS were 40% and 69%, and Dr. Corradini’s experience with 55 patients at the University of Milan similarly showed 1-year PFS and OS of 40% and 70%, respectively.
“So all these studies support the notion that the results of CAR T-cells in real-world practice are durable for our patients, and are very similar to results obtained in the studies,” he said.
Other factors that have been shown to be associated with poor outcomes after CAR T-cell therapy include systemic bridging therapy, high metabolic tumor volume, and extranodal involvement; patients with these characteristics, along with those who have poor ECOG performance status or elevated LDH or CRP levels, do not comprise “a group to exclude from CAR T-cell therapy, but rather ... a group for whom there is an unmet need with our currently available treatments,” he said, adding: “So, it’s a group for which we have to do clinical trials and studies to improve the outcomes of our patient with large B-cell lymphomas.”
“These are all real-world data with commercially available products, he noted.