At a median follow-up of 13.4 months (range, 5.2-21.7), cilta-cel produced an overall response rate (ORR) of 100% (95% CI, 82.4%-100%) in 19 patients; 90% of patients achieved a complete response (CR) or better and 95% had a very good partial response (VGPR) or better. The CAR T-cell therapy resulted in a partial response rate of 5%, and a stringent CR of 63%.

Levels of IL-6 and IFN-γ increased following infusion of cilta-cel, peaking at days 7 through 14 and returning to baseline levels within 2 to 3 months. Notably, the incidence of cytokine release syndrome (CRS) was associated with a higher peak of IL-6 and IFN-γ.

CRS was reported in 84% of patients; 1 patient had grade 3/4 CRS. The median time to onset of CRS was 8 days (range, 5-11), and the median duration was 3.5 days (range, 1-7). Additionally, 63% of patients received tocilizumab (Actemra) and 21% were given corticosteroids for CRS. This toxicity was resolved in all patients.

Neurotoxicity was reported in 26% of patients, and it had resolved in 3 of 5 patients. One patient experienced grade 1 immune effector cell–associated neurotoxicity syndrome, with a time to onset of 11 days and a duration of 4 days. Another patient experienced grade 3 movement and neurocognitive treatment-emergent adverse effects (MNTs)/parkinsonism that occurred at day 38. Notably, this patient had at least 2 risk factors for MNTs/parkinsonism, and they showed improvement at the time of data cutoff and achieved a CR.

Regarding other safety data, hematologic adverse effects (AEs) of any grade included neutropenia (95%), anemia (58%), thrombocytopenia (58%), lymphopenia (32%), and leukopenia (26%).

Grade 3 or 4 hematologic AEs included neutropenia (90%), anemia (47%), thrombocytopenia (26%), lymphopenia (32%), and leukopenia (26%). Notably, the rate of grade 3/4 cytopenias that did to not improve to grade 2 or less by day 60 was 16% for thrombocytopenia, 11% for lymphopenia, and 11% for neutropenia.

One death occurred on the study, due to progressive disease on day 158. For the 1 patient treated in an outpatient setting, the safety profile of cilta-cel was found to be manageable.

Ciltacabtagene Autoleucel (cilta-cel)