Moore, Jozal

Abstract In a real-world analysis of brexucabtagene autoleucel recipients with relapsed/refractory B-cell acute lymphoblastic leukemia (N = 278), lack of response to prior blinatumomab correlates with significantly worse following chimeric antigen receptor T-cell therapy outcomes.

Abstract Chimeric antigen receptor (CAR) T-cell (CAR-T) treatment for B-cell acute lymphoblastic leukemia (ALL) induces high initial response rates, but most patients relapse. Low disease burden (often defined as <5% blasts in the bone marrow) is associated with better outcomes. CAR HEMATOTOX (HT) is a score using prelymphodepletion hematologic and inflammatory parameters to predict outcomes in lymphoma. Here, we assess its prognostic utility in a large multicenter adult B-cell ALL cohort. Patients who received brexucabtagene autoleucel across 33 centers in North America were included as part of the Real-World Outcomes Collaborative of CAR-T in Adult ALL (ROCCA) consortium. An independent cohort of 61 patients with ALL treated with an investigational CD19 CAR-T therapy at 1 center was also described. Among 199 ROCCA consortium patients, 43 (22%) patients with HTlow scores had lower rates of delayed neutrophil recovery than those with HThigh scores (26% vs 52%, P = .002) and fewer severe infections (2.5% vs 18.8%, P = .011). They also had higher response rates, overall survival (OS), and event-free survival (EFS), as well as lower nonrelapse mortality and cumulative incidence of relapse. The survival differences remained significant after multivariable adjustment for disease burden and other covariates. In the investigational cohort of 61 patients, patients with HTlow scores had improved OS and EFS, as well as higher peak CAR-T expansion. In summary, CAR HT score is a prognostic factor independent of disease burden in adult ALL. HTlow score is associated with superior outcomes after CD19 CAR-Ts and higher CAR-T expansion in a single-center cohort. These trials were registered at www.clinicaltrials.gov as #NCT01044069 and #NCT01860937.

Abstract The effect of prior inotuzumab ozogamicin (InO) treatment on brexucabtagene autoleucel (brexu-cel) outcomes remains unclear in adults with acute lymphoblastic leukemia (ALL). We conducted a retrospective multicenter analysis of 189 patients with relapsed/refractory ALL treated with brexu-cel. Over half of the patients received InO before brexu-cel (InO exposed). InO-exposed patients were more heavily pretreated (P = .02) and frequently had active marrow disease before apheresis (P = .03). Response rate and toxicity profile after brexu-cel were comparable for InO-exposed and InO-naïve patients; however, consolidation therapy after brexu-cel response was used at a higher rate in InO-naïve patients (P = .005). With a median follow-up of 11.4 months, InO-exposed patients had inferior progression-free survival (PFS; P = .013) and overall survival (OS; P = .006) in univariate analyses; however, prior InO exposure did not influence PFS (hazard ratio, 1.20; 95% confidence interval, 0.71-2.03) in multivariate models. Within InO-exposed patients, InO responders had superior PFS (P = .002) and OS (P < .0001) relative to InO-refractory patients. The timing of administering InO did not affect brexu-cel outcomes, with comparable PFS (P = .51) and OS (P = .86) for patients receiving InO as bridging therapy or before apheresis. In conclusion, although InO exposure was associated with inferior survival outcomes after brexu-cel in unadjusted analyses, these associations were no longer significant in multivariate analyses, suggesting it is unlikely that InO negatively affects brexu-cel efficacy. Our data instead imply that InO-exposed recipients of brexu-cel tend to be higher-risk patients with intrinsic adverse leukemia biology.