Bradshaw, Danielle

Background Brexucabtagene autoleucel (brexu-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR-T) cell therapy that recently received U.S. FDA approval as the first CAR-T cell therapy for adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL). Social determinants of health (SDoH) are shown to significantly influence outcomes in B-ALL. However, how SDoH relate to and affect outcomes in patients with B-ALL receiving CAR-T therapy has not been well established. We studied the impact of SDoH on outcomes of adults with B-ALL receiving brexu-cel as part of the Real-world Outcomes Collaborative of CAR-T in Adult ALL (ROCCA). Methods This retrospective multicenter analysis spanning 25 U.S centers included adults (≥18 years) with r/r B-ALL treated with commercial brexu-cel between 2021-2023. Progression-free survival (PFS) and overall survival (OS) were calculated from the day of brexu-cel infusion and were not censored for hematopoietic cell transplant (HCT) or maintenance. Univariate and multivariate Cox proportional hazards models were used to evaluate the association of age, sex, pre-apheresis disease burden, and SDoH (referral source, insurance, distance from home to CAR-T site, marital status, and the social deprivation index) with progression-free survival (PFS) and overall survival (OS). The social deprivation index (SDI), a composite measure (including income, education, employment, housing, household characteristics, and transportation) used to quantify socio-economic variation in health outcomes, with higher SDI indicating greater social disadvantage, was estimated at the zip code level. (Butler et al., 2013) Results Of the 152 patients who received brexu-cel (Table 1), 57% were male. 51% identified as non-Hispanic White, with the remainder identifying as Hispanic (34%), Asian/Pacific Islander (7%), Black (6%), American Indian/Alaskan Native (1%), or mixed race (1%). A majority (46%) were referred for brexu-cel from private/community-based practices and 62% lived within 50 miles of the CAR-T center (36% lived >50 miles and 2% were unknown). Health insurance coverage included primarily public (49%) and private (42%); no patients were uninsured. High SDI (76-100% percentile) was present in 26%, while 14% had a low SDI (0-25 th percentile). In unadjusted analyses, there was no difference in PFS or OS between patients with high versus low SDI; closer distance to the CAR-T site (<50 miles versus >50 miles)) was associated with worse OS (HR 1.96; 95% CI 1.00, 3.84; p=0.05). Multivariate analysis (Table 2) revealed that male sex was associated with inferior PFS (HR 1.98; 95% CI 1.02, 3.85; p=0.04) and OS (HR 2.52; 95% CI 1.09, 5.84; p=0.03). There was no difference in PFS (HR 0.95, 95% CI 0.48-1.88, p=0.88) or OS (HR 0.80; 95% CI 0.33,1.92; p=0.62) when comparing Hispanic and non-Hispanic White patients. Additionally, there was no difference in PFS or OS based on any SDoH, including insurance type, marital status, referral source, caregiver type, and distance to transplant center. Conclusions In patients receiving brexu-cel, survival outcomes appear independent of SDoH. Contrary to previous reports suggesting inferior outcomes for Hispanic patients with B-ALL after receiving traditional systemic therapies, we observed comparable outcomes to non-Hispanic patients treated with brexu-cel. Distance from the CAR-T site and referrals from the community did not affect outcomes. Additionally, those with higher SDI had similar outcomes to those with a lower SDI, although this analysis was limited by sample size and the selection bias that exists in being referred for brexu-cel in the first place. The relatively lower logistical burden of CAR-T compared to allogeneic stem cell transplant or non-fixed duration systemic therapies may have mitigated the impact of SDoH on outcomes. These real-world data suggest that continuing to improve access to and treatment with brexu-cel may improve overall outcomes for disadvantaged populations with r/r B-ALL.

Background TP53-mutated (m) acute myeloid leukemia (AML) is an adverse risk disease, which continues to have dismal outcome in the contemporary era of novel therapies. Venetoclax (VEN) in combination with hypomethylating agents (HMA; azacitidine or decitabine) have shown to improve complete remission (CR) rates compared to HMA alone, however no significant differences in overall survival (OS) have been observed. Methods We conducted a retrospective study through the COMMAND consortium (a collaboration of acute leukemia experts from 10 US academic institutions) to analyze the impact on survival outcomes of HMA plus (+) VEN compared to HMA-based therapies in adult (≥18 years) pts with TP53m AML. The AML Database of 381 pts with TP53m AML diagnosed between 2012-2022 was queried and 154 (40%) (HMA [n=50] and HMA +VEN [n=104]) pts were identified eligible for this analysis. Continuous variables were summarized as median (range) while categorical variables were reported as frequency (percentage). The Kaplan-Meier method was used to estimate OS, defined as time from diagnosis to death or last follow-up. Logistic regression models were used to determine the univariate and multivariate of OS. Multivariable models included all significant univariate predictors. All tests were two-sided with a p value <0.05 considered statistically significant. Results Baseline characteristics and responses The median age (years [yrs]) was 74 (range [R], 38-87) and 71 (R,29-88) yrs in the HMAand HMA + VEN groups (gps) (p= 0.23), respectively ( Table 1). Thirty-four (68%) and 57 (55%) patients (pts) were ≥ 70 yrs in the HMA and HMA + VEN gps, respectively (p= 0.16). Twenty-six percent vs 31% ( p=0.57), 86% vs 90% ( p=0.58) and 68% vs 73% ( p=0.56) of pts had secondary AML, had complex cytogenetics (CG), and had multi-hit TP53m in the HMA and HMA + VEN gps, respectively. The proportion of pts with most frequently occurring (> 5%) myeloid co-mutations ( RUNX1, ASXL1, TET2, DNMT3A, RAS, PTPN11 and JAK2) were not significantly (NS) different between the HMA and HMA + VEN gps, as shown in Table 1. The early treatment related mortality in first 30 days of induction was higher in the HMA+VEN gp (25%) when compared with the HMA gp (6%), p=0.004. The complete remission rates (CR/CRi) were higher in the HMA + VEN gp compared to the HMA gp (35% vs 18%, p=0.05). Similarly, the proportion of pts receiving allogeneic stem cell transplant (allo-HCT) after induction was higher in the HMA + VEN gp when compared with the HMA gp (13% vs 4%; p=0.14). Duration of response and overall survival The median follow up was 9.8 months (mo) (R, 1-56) and 5.80 mo (R, 1-30.4) in the HMA and HMA + VEN gps, respectively ( p=0.12). The median duration of response (DOR) was higher in the HMA +VEN gp (15.6 mo) when compared with the HMA gp (7.93 mo), but NS ( p=0.26). The median OS was NS different when comparing the HMA and HMA + VEN gps (9.23 vs 7.3 mo, p=0.80 [ Figure 1]). Multivariable analysis for duration of response and overall survival We did multivariable analysis (MVA) for DOR and OS using baseline variables ( Table 1) that showed significance/trend towards significance in univariate analysis ( p<0.1). Allo-HCT (HR; 0.11, 95% CI: 0.02-0.52, p=0.005) retained significance for better DOR, whereas age ≥ 70 yrs (HR; 1.7, 95% CI: 0.63-4.65, p=0.28) and complex CG (HR; 3.05, 95% CI: 0.79-11.73, p=0.10) did not retain significance in MVA. In MVA for OS, achievement of CR/CRi (HR; 0.35, 95% CI; 0.20-0.59, p=<0.001) and allo-HCT after induction (HR; 0.06, 95% CI; 0.09-0.46, p=0.007) retained favorable significance for OS, whereas complex CG (HR; 2.36, 95% CI: 1.11-4.99, p=0.02) retained significance for shorter OS. PTPN11m (HR; 1.57, 95%CI: 0.75-3.28, p=0.23) and TET2m (HR; 1.02, 95% CI: 0.56-1.87, p= 0.92) did not retain significance in MVA. Conclusion In this multi-center real-world study, while HMA+VEN led to improvement in CR rates and a higher proportion of pts were bridged to allo-HCT, it did not associate with an improvement in OS when compared with HMA monotherapy. More effective treatment strategies are warranted to improve outcome of pts with TP53m AML.

Introduction: Brexucabtagene autoleucel (brexu-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for adults with relapsed or refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL). Blinatumomab is a CD19-directed bispecific T-cell engager that is also approved for r/r B-ALL, and often used as early salvage therapy. Data in the pediatric/AYA population suggest that patients who did not respond to blinatumomab may have inferior outcomes to CD19-directed CAR-T products compared to those who have achieved a response to blinatumomab or were blinatumomab-naïve (Myers et al. J Clin Oncol 2022). In this study, we evaluate the response to blinatumomab and subsequent response to brexu-cel in adults with r/r B-ALL. Methods: Retrospective data were collected from 25 centers across the U.S. as part of the real-world outcomes collaborative study of CAR-T in B-ALL (ROCCA). Consecutive patients treated with brexu-cel from 2021 to 2023 were categorized by blinatumomab exposure status. Those exposed were separated into “blinatumomab responders” (B-R), defined as patients achieving a CR/CRi in response to any number of cycles of blinatumomab, and “non-responders” (B-NR). Each cohort was compared for outcomes of interest. The primary outcome was CR/CRi rate at day 28 following brexu-cel administration. Secondary outcomes were duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Survival outcomes were calculated from day of brexu-cel infusion and were not censored for allogeneic hematopoietic cell transplantation or maintenance therapy. All living patients were censored at data cutoff on June 30, 2023. Survival comparisons were made by log rank test. Results: Among 152 patients who received brexu-cel, the median follow-up time was 8.4 months. Eighty-eight (57%) of 152 r/r B-ALL brexu-cel recipients had received blinatumomab prior to apheresis. The median number of pre-apheresis blinatumomab cycles was 2 (range 1-12). The baseline characteristics of B-R, B-NR, and blinatumomab-naïve (B-NV) patients were similar, including pre-apheresis disease burden and receipt of maintenance therapy following brexu-cel infusion (Table 1). Seventy percent (N= 62) of the blinatumomab-exposed patients were B-R, while 30% (N=26) were B-NR. Rates of CR/CRi at day 28 following brexu-cel infusion were similar between B-R, B-NR, and B-NV patients (79% vs 84% vs 78%, respectively). Most of these remissions were negative for measurable residual disease (MRD), with similar MRD negativity rates in the three groups (table 2). 1-year DOR and PFS were significantly higher in the B-NV group compared to B-R or B-NR (77% vs 49% vs 50%, p<.0001; 60% vs 37% vs 30%, p<.0001). B-NV and B-R had better 1-year survival compared to B-NR (71% vs 65% vs 32%, p<.0001). There were more CD19-negative relapses following brexu-cel in B-NR (29%) and B-R (18%) compared to B-NV patients (8%), although this was not statistically significant. Conclusions: Brexu-cel induced deep responses in a majority of adults with r/r B-ALL, irrespective of prior exposure or response to blinatumomab. Similar to data published by the pediatric CAR-T cell groups, our data draw speculation that adult patients who did not respond to blinatumomab experience shorter overall survival following brexu-cel compared to those who responded to or did not receive blinatumomab. This should be confirmed in a larger, prospective clinical trial. Because this analysis could not account for patients who achieved durable remission after blinatumomab, these differences may not reflect superiority of sequencing brexu-cel before blinatumomab. The higher number of CD19-negative relapses in the blinatumomab-exposed cohort add to the interest in pursuing strategies to address antigen escape following CAR-T cell therapy directed against a previously targeted antigen.

Background: Core-binding factor acute myeloid leukemia (CBF-AML) is characterized by the presence of inv(16)/t(16;16) or t(8;21), and is classified as favorable risk by the 2022 European LeukemiaNet (ELN) guidelines. High remission rates are observed in the setting of cytarabine- or anthracycline-based induction regimens. However, for the subset of patients (pts) who relapse, outcomes after relapse were poor in prior single-center analysis with median survival of less than 1.5 years (Khan et al. Clin Leuk Lymph Myeloma 2017). There remains a need to better understand outcomes of pts who experience relapse after initial complete remission (CR), particularly after diverse intensive chemotherapy (IC) induction regimens, where variable practices show differential induction outcomes. We set out to investigate the outcomes of pts with CBF-AML in first relapse or with disease refractory to initial therapy, across 5 institutions that are part of the Consortium on Myeloid Malignancies and Neoplastic Diseases (COMMAND). Methods: Retrospective chart review was done to identify pts who were treated with intensive IC with inv(16)/t(16;16) or t(8;21) identified on cytogenetics, from January 2010 through April 2023, with disease in first relapse after initial CR or refractory to primary induction. Pts were treated across 5 geographically-diverse, academic institutions. Pt clinical characteristics, cytogenetics, molecular testing via next-generation sequencing (NGS), treatment, relapse, and overall survival (OS) data were collected. OS since time of disease relapse was analyzed using Kaplan-Meier analysis. Results: Fifty-four consecutive pts with relapsed/refractory (R/R) CBF-AML were identified, 24 (44%) with inv(16) and 30 (56%) with t(8;21). Median age of pts at initial diagnosis was 50 years (yrs) (range 20-80yrs), with 61% male pts. Molecular testing and/or NGS was available at initial diagnosis for 41 pts (76%); 12 (22%) pts had adverse-risk ELN cytogenetics or mutations when excluding CBF status, and 8/41 (20%) pts harbored KIT mutations. Other baseline pt characteristics are listed in Table 1. All pts underwent induction with IC; 14 (26%) pts received intensive induction with gemtuzumab ogozamicin (GO), 3 (6%) received intensive induction with a KIT inhibitor (dasatinib or midostaurin), and the remaining 37 (68%) received IC induction without a targeted agent. Forty-one (76%) pts achieved a CR to induction therapy. Measurable residual disease (MRD) testing by polymerase chain reaction (PCR) and/or fluorescence in situ hybridization (FISH) for CBF protein was available in 30 (56%) pts, with 16/21 (76%) achieving MRD-negativity by PCR and 20/26 (77%) by FISH. Forty-six pts underwent consolidation with a median of 4 cycles of chemotherapy (IQR 3-4), with 9 (17%) pts receiving GO with consolidation and 4 (7%) receiving a KIT inhibitor with consolidation. Median time to relapse was 10.1 months (IQR 8.0-13.6 months), and median OS after relapse was 9.2 months (IQR 4.4-22.1 months) for the whole cohort. Second line treatment data was available for 44 pts, with 29 (66%) receiving intensive 2nd line therapy vs 15 (34%) receiving lower intensity 2nd line therapy; 14 (32%) pts received venetoclax as part of their 2nd line therapy. There was no significant difference in 2-yr OS after relapse for those who received IC (50%, 95% CI: 34-72%) vs lower intensity therapy (24%, 95% CI: 8-72%) ( p=0.28) (Figure 1A). Twenty-eight (52%) pts who received 2nd line therapy for R/R disease proceeded to allogeneic stem cell transplantation (alloSCT), with a 2-yr OS of 57% (95%CI: 40-80%) for this group after time of relapse, compared to 15% (95% CI: 5-42%) for those who did not achieve CR after 2ndline therapy and/or proceed to transplant ( p<0.01) (Figure 1B). Conclusions: In this multi-center retrospective study of pts with R/R CBF-AML, we describe patterns of relapse after intensive induction chemotherapy, and do not observe a statistically difference in outcomes based on intensity of 2nd line therapy among pts with available treatment information. Median OS in the entire cohort was 9.2 months from diagnosis of R/R disease. Pts who proceeded to alloSCT after receiving 2nd line therapy had significantly improved long-term outcomes compared to those who did not proceed to alloSCT, highlighting the need for better therapies in the 2nd line and beyond to improve longer term outcomes for pts with CBF-AML.

Introduction: Brexucabtagene autoleucel (brexu-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy approved for adults with relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL). Bridging therapy, defined as anti-leukemia therapy given between apheresis and lymphodepleting chemotherapy, was permitted on the pivotal ZUMA-3 trial. The optimal bridging therapy is unknown in this setting. Here we report patient and disease characteristics in those receiving bridging therapies prior to brexu-cel and the impact of bridging on clinical outcomes in a large multicenter cohort. Methods and Results: ROCCA includes 25 US institutions contributing retrospective data from 152 B-ALL patients treated with standard of care brexu-cel between 2021-2023. Ninety-nine patients (65%) received bridging therapy, while 53 patients (35%) received no bridging therapy. Bridging therapy consisted of cytotoxic chemotherapy ( n=65, 66%), immunotherapy ( n=26, 26%; 23 inotuzumab, 3 blinatumomab), tyrosine kinase inhibitors (TKI) ( n=20, 20%; 16 ponatinib), steroids only ( n=10, 10%), and intrathecal chemotherapy ( n=22, 22%). The median age of the cohort was 46 (IQR 32-61). Patients were heavily pre-treated with a median of 4 prior lines of therapy. The median days from apheresis to infusion was 33 (IQR 26-42). 119 patients had known pre-apheresis blast counts; the bridging group had higher pre-apheresis blast burden, with 21 of 76 patients (28%) having ≥ 50% blasts compared to only 5 of 43 patients (12%) in the no bridging group ( p=0.02). In addition, more patients who received bridging had pre-apheresis extramedullary disease (32% vs. 15%, p=0.02). All other baseline characteristics were similar between the two groups (Table 1). Fifty-four (54%) patients had response assessment after bridging therapy and prior to brexu-cel infusion. In patients who received inotuzumab for pre-apheresis active disease, defined as ≥ 5% blasts, 6 of 13 (46%) who had post-bridging assessment achieved a complete response (CR; 5 measurable residual disease (MRD)+, 1 MRD-), with a mean proportional reduction in blast burden of 46% from baseline. In contrast, after chemotherapy bridging, only 2 of 16 patients (13%) with pre-apheresis active disease had a CR. Patients receiving chemotherapy bridging had a mean proportional increase in blast burden of 4.4%. In recipients of TKI bridging, 2 of 4 patients (50%) with pre-apheresis active disease had a CR. Compared to no bridging, patients in the bridging group had similar rates of grade 3 or 4 CRS (9% bridging vs. 8% no bridging, p=0.73) and grade 3 or 4 ICANS (34% vs. 26%, p=0.32). In univariate analysis, there was no statistically significant difference in day 28 response with 63 patients (72%) achieving MRD- complete response in the bridging group as compared to 36 patients (78%) in the no bridging group ( p=0.60). Non-relapse mortality was similar between the two groups (17% bridging vs. 9% no bridging, p=0.20). Overall survival (OS) and progression-free survival (PFS) were superior in the no bridging group: 1-year OS 74.7% vs 56.8% (log-rank p=0.04), and 1-year PFS 57.3% vs 41.7% (log-rank p=0.04). In a multivariate analysis stratified by bridging and pre-apheresis disease burden, patients with pre-apheresis blasts ≥ 5% and bridging had worse survival than ≥ 5% blasts and no bridging: 1-year OS 45.3% vs. 87.5% and 1-year PFS 27.7% vs. 64.3% (Figure 1). However, patients with < 5% blasts had similar survival regardless of bridging. Conclusions: In our real-world analysis, adults with R/R B-ALL receiving bridging therapy had a higher disease burden at baseline. Despite greater baseline disease, there were no significant differences in toxicity and day 28 response in those receiving bridging therapy vs. not. While survival was inferior in patients with pre-apheresis active disease who received bridging, this may be confounded by the degree of tumor burden. In patients with < 5% blasts pre-apheresis, bridging did not impact survival. Furthermore, inotuzumab bridging demonstrated the most significant disease debulking. However, the comparisons in this study are limited by the variability in practice for post-bridging disease reassessment and the small proportion of patients with active disease who did not receive bridging. A more uniform approach to peri-CAR disease assessment would enable more robust study of optimal bridging strategies.

AbstractBackgroundAlthough the clinical outcomes of patients with TP53‐mutated acute myeloid leukemia (AML) are dismal, subsets of patients eligible for curative‐intent therapies may fare better. Because racial disparities are known to affect outcome in hematologic malignancies, the authors sought to explore disparities among patients with TP53‐mutated AML.MethodsA multicenter, retrospective study was conducted in a cohort of 340 patients who had TP53‐mutated AML (275 non‐Hispanic White [NHW] and 65 non‐Hispanic Black [NHB]) to analyze differences in treatment and outcome among NHW and NHB patients.ResultsThe median patient age was comparable between NHW and NHB patients (p = .76). A higher proportion of NHB patients had therapy‐related AML (31% vs. 20%; p = .08) and had co‐mutations (74% vs. 61%; p = .06). A higher proportion of NHW patients received intensive chemotherapy compared with NHB patients (47% vs. 31%; p = .02). Conversely, a higher proportion of NHB patients received low‐intensity chemotherapy (9% vs. 5.5%; p = .02) or best supportive care (22% vs. 7%; p < .001). The complete response rate (including complete responses with or without complete count recovery) was 31% versus 24.5% (p = .39) in NHW and NHB patients, respectively. Only 5% of NHB patients received allogeneic stem cell transplantation compared with 15.5% of NHW patients (p = .02). The proportion of patients who were event‐free (18.5% vs. 8.5%; p = .49) or who remained alive (24.9% vs. 8.3%; p = .13) at 18 months was numerically higher in NHW versus NHB patients, respectively, but was not statistically significant.ConclusionsThe current study highlights disparities between NHW and NHB patients with TP53‐mutated AML. Efforts are warranted to eliminate treatment disparities in minority populations.

Abstract We conducted a multi-center study to analyze factors predicting survival among patients with TP53-mutated (m) AML receiving allogeneic hematopoietic stem cell transplant (allo-HSCT) in the recent era. Among 370 patients, 68 (18%) patients were bridge to allo-HSCT. The median age of the patients was 63 years (range, 33–75), 82% of patients had complex cytogenetics and 66% of patients had multi-hit TP53m. Forty three percent received myeloablative conditioning (MAC) and 57% received reduced intensity conditioning (RIC). The incidence of acute graft versus host disease (GVHD) was 37% and chronic GVHD was 44%. The median event-free survival (EFS) from the time of allo-HSCT was 12.4 months (95% CI: 6.24–18.55) and median overall survival (OS) was 24.5 months (95% CI: 21.80-27.25). In multivariate analysis utilizing variables that showed significance in univariate analysis, complete remission at day 100 post allo-HSCT retained significance for EFS (HR: 0.24, 95% CI: 0.10–0.57, p = 0.001) and OS (HR: 0.22, 95% CI: 0.10–0.50, p = < 0.001). Similarly, occurrence of chronic GVHD retained significance for EFS (HR: 0.21, 95% CI: 0.09–0.46, p = < 0.001) and OS (HR: 0.34, 95% CI: 0.15–0.75, p = 0.007). Our report suggests that allo-HSCT offers the best opportunity to improve long-term outcome among patients with TP53m AML.