Not all patients with relapsed or refractory large B cell lymphoma (r/r LBCL) are candidates for high-dose chemotherapy or hematopoietic stem cell transplantation (HSCT), and options for second-line therapies for this population are limited, said Dr. Alison Sehgal of the University of Pittsburgh Medical Center in her presentation of the findings.
Lisocabtagene maraleucel (liso-cel) is a CD19-directed CAR T-cell product. In a previous phase 3 randomized trial (the TRANSFORM study), lisocabtagene showed superiority over salvage chemotherapy for LBCL patients who were fit candidates for stem cell transplant, but its use in older, frail patients who are not transplant candidates remains uncertain, wrote Dr. Sehgal and colleagues in their poster at the meeting.
In the study, the researchers identified 74 patients with r/r LBCL. Of these, 61 were treated with liso-cel. The patients ranged in age from 53 to 84 years, with a median age of 74 years, 61% were male, and 89% were white. Approximately half were refractory and half were relapsed.
For the therapy, patients underwent lymphodepletion with cyclophosphamide and fludarabine, followed 2-7 days later by an infusion of liso-cel at a target dose of 100 x 106 CAR+ T cells; all patients had at least 6 months of follow-up from their first response.
The primary endpoint of overall response rate occurred in 80% of the patients, and clinically meaningful complete response occurred in 54% over a median follow-up of 12.3 months.
“Clinically meaningful CRs were observed across all subgroups,” Dr. Sehgal said in her presentation.
The response lasted a median of 21.7 months, and the median follow-up for duration of response was 15.5 months. The median overall survival was not reached, but the median progression-free survival was 9.0 months, with a median follow-up period of 13.0 months.
Responses occurred across all prespecified subgroups, with no significant differences in either safety or efficacy based on hematopoietic cell transplantation–specific comorbidity index (HCT-CI) scores.
“Despite the advanced age and comorbidities of the population, the safety profile was consistent with previous reports,” and no new or increased safety signals appeared, Dr. Sehgal said.
The most common treatment-emergent adverse events of grade 3 or higher were neutropenia (48%), leukopenia (21%), thrombocytopenia (20%), and anemia (11%). Cytokine-release syndrome (CRS) occurred in 23 patients (38%); of these, 1 patient was grade 3 and none were grades 4 or 5.
Approximately one-third of the patients (31%) experienced neurological events during the study; three cases were grade 3, none were grades 4 or 5. Patients with CRS or NE were treated with tocilizumab (10%), corticosteroids (3%), or both (20%). Treatment-emergent adverse events of grade 3 or higher occurred in 79% of patients overall, including grade 5 events in two patients because of COVID-19.
The study findings were limited by the small sample size and lack of controls. However, the results support the potential use of liso-cel as a second-line therapy for r/r LBCL patients who are not candidates for HSCT, Dr. Sehgal concluded.