Interim Analysis of Prospective Clinical Trial of Outpatient Administration of Axicabtagene Ciloleucel in High-Grade B Cell Lymphoma

Introduction Pivotal trials of Axicabtagene Ciloleucel (axi-cel) were conducted in the inpatient setting because of the high rate of severe Cytokine Release Syndrome (CRS) and Immune effector Cell-Associated Neurotoxicity Syndrome (ICANS). Objectives We devised a single-center non-randomized prospective trial (NCT05108805) to evaluate the feasibility and safety of outpatient administration of axi-cel. Here we report outcomes of 15 consecutively treated patients (pts) out to 20 planned enrollment. Method Eligible pts with R/R DLBCL per axi-cel package label and met ZUMA 1 inclusion/exclusion criteria and ECOG 0-2 were included in the study. They were fitted with wearable devices to measure temp, BP, Pox and heart rate for continuous remote monitoring. Pts were seen in-person once daily and had remote video telehealth evaluation at 16:00 and 22:00 daily through day 14. Fever up to 102F without other symptoms was managed in clinic. Pts with higher grade CRS or any ICANS were admitted. The primary endpoint of the study was to explore the safety and feasibility of outpatient Axi-cel. Results Fifteen patients were enrolled and evaluable as of 9/21/2023. The median pt age was 69 (range: 54-79) yrs and stage III-IV disease in 14 (93%) pts. The median number of therapies was 2 (range: 1-4). No pt had prior autologous transplant. The median follow-up was 161 (range: 30-580) days. Prophylactic dexamethasone 10 mg/day, days 0-2 was given to 13 (87%) pts after axi-cel label update in Jan, 2022. All pts remained outpatient for at least 72 hours after axi-cel administration, and one (7%) pt remained outpatient through day 30. The median time from day 0 to hospitalization was 4 (range 3-6) days and the median hospital stay was 5 (range 0-11) days. The reason for first hospitalization was CRS in all pts. Overall CRS was reported in 14 (93%) pts (grade 1= 9, grade 2= 5), 5 (33%) pts had grade 1 ICANS, and 2 (13%) pts had grade 3 ICANS, both of duration < 2 days. No pt had grade ≥3 CRS or grade ≥4 ICANS. One patient briefly transferred to the ICU for 6 days on day 24 due to COPD exacerbation unrelated to axi-cel. By day 30, 10 (67%) pts achieved CR and rest with stable disease. There were 2 (13%) pts with PD/refractory disease at the last follow-up with one death from relapsed disease. There were no treatment-related deaths. Median PFS or OS was not reached by the last follow up. Six-month estimated OS was 86% (95% CI: 0.60-1.0). Our results were favorable compared to ZUMA 1 which reported grade ≥ 3 CRS and ICANS in 13% and 28% of pts, respectively. Conclusion Interim results of this prospective single-center study showed that axi-cel can be safely administered outpatient with prophylactic steroids and remote monitoring with wearable devices without compromising the efficacy of CAR T therapy. Longer additional pt follow-up data will be presented at the meeting.