SAN DIEGO – A single infusion of tisagenlecleucel (Kymriah) continues to demonstrate high efficacy a year and a half after pediatric and young adult patients with relapsed or refractory acute lymphoblastic leukemia (ALL) were enrolled in the pivotal ELIANA trial, , reported at a press conference at the annual meeting of the American Society of Hematology.
Of patients in complete remission after receiving the chimeric antigen receptor (CAR) T-cell therapy, 66% were still in remission at 18 months of follow-up and median survival has yet to be reached.
“We think the efficacy is sustained and excellent,” said Dr. Grupp, of the University of Pennsylvania, Philadelphia. “These are durable complete responses even without further therapy. We haven’t reached median duration of response or overall survival, and we can manage toxicity, so I think this is clearly an opportunity for us to treat our patients both in America and across the world.”
The results of ELIANA were the basis for the approval of tisagenlecleucel (Kymriah) for relapsed/refractory B-cell ALL in the United States, and for subsequent approvals by health authorities in the European Union, Switzerland, and Canada.
The international, single-arm, open-label, phase 2included 97 patients aged 3-24 years with relapsed or refractory B-cell ALL, most of whom had previously undergone a hematopoietic stem cell transplant. Of those patients, 79 patients went on to receive a single infusion of the CAR T-cell therapy.
The rate of overall remission, defined as the rate of complete remission or complete remission with incomplete blood count recovery, was 82% (65 patients). Among those patients, 66% were still in remission at 18 months, while overall survival was “excellent” at 70%, Dr. Grupp said, and the median overall survival was not reached.
Adverse events prevalence remained relatively unchanged since the previous analyses, according to Dr. Grupp, who added that appropriately trained personnel were able to effectively manage those adverse events across study sites. Cytokine release syndrome (CRS) occurred in 77% of patients. All cases were reversible; 39% received tocilizumab for treatment of CRS with or without other anticytokine therapies; 48% required ICU-level care for CRS, with a median ICU stay of 7 days.
The other most common grade 3/4 nonhematologic adverse events were neutropenia with a body temperature exceeding 38.3° C (62% within 8 weeks of infusion), hypoxia (20%), and hypotension (20%). Grade 3 neurologic effects occurred in 13% of patients, and none had cerebral edema. Based on laboratory results, 43% had grade 3/4 thrombocytopenia and 54% had neutropenia not resolved by day 28; most of these events resolved to grade 2 or less by 3 months.
There were 25 postinfusion deaths, with 2 occurring within 30 days (1 because of disease progression, 1 because of cerebral hemorrhage). Of the 23 deaths after 30 days (range, 53-859 days), 18 were caused by disease progression. The other deaths were caused by encephalitis, systemic mycosis, vasoocclusive hepatobiliary disorder related to allogeneic SCT, bacterial lung infection, and an unknown reason after study withdrawal.
Follow-up is ongoing in the ELIANA study, which is supported by Novartis, the maker of Kymriah.
Dr. Grupp reported research funding from Novartis, consultancy with Novartis, Jazz Pharmaceuticals, and Adaptimmune Therapeutics, and patents or royalties with the University of Pennsylvania.
SOURCE: Grupp SA et al. ASH 2018, .