Stem Cell Transplantation In CR1 Research Articles

Leukemic Stem Cells (LSCs) As Peri-Transplant MRD Assessment in AML Patients Undergoing Allogeneic Stem Cell Transplantation in CR

Background: Several studies have shown that the leukemic stem cells (LSCs: CD34 +CD38 -CD45RA +/Combi-6 +) play a crucial role in the development of relapses in AML patients (pts). LSCs are less sensitive to conventional therapy; moreover, their phenotypical characteristics may allow immune evasion promoting relapses after allo-SCT. Although ELN guidelines recommend including LSCs into MRD assessment, this approach has not yet been studied extensively in the allogeneic setting. Here we suggested that peri-transplant LSCs detection may provide additional prognostic information to conventional (c)MRD in AML pts allografted in CR. Methods: 90 pts (male, n=46; median, 60.5 years, 19-76) with AML in CR and available pre-transplant cMRD data (multicolor flow cytometry, “different from normal” approach, according to ELN guidelines), who received allografts (matched, n=73; mismatched, n=17) during 2019-2022 years at the Department of Stem Cell Transplantation at University Medical Centre Hamburg were included. LSCs were assessed according to Zeijlemaker et al. 2019 before and after transplant at days +30 and +100. Both methods (cMRD and LSCs detection) were investigated solely and combined for their prognostic impact. Results: Majority of pts had de novo AML (76%), adverse ELN risk (48%), received matched grafts (related, n=73, 81%; unrelated, n=17, 19%) and MAC regimen (n=55, 61%). ATG was used for GvHD prophylaxis in 70 pts (78%). There were 47 cMRD neg (52%) and 43 cMRD pos (48%) pts. LSCs were detected in 39 (56%) pts with a median proportion of 0.01% (0.005-0.37%) of WBC. There was no correlation between LSCs proportion and cMRD status. The cMRD pos pts were more frequently LSCs pos (67% vs 33%), and cMRD neg were more frequently LSCs neg (33% vs 67%, p=0.002). Before allo-SCT, 34 pts (38%) were cMRD neg/LSCs neg, 26 pts (29%) experienced cMRD pos/LSCs pos, 17 pts (19%) had cMRD neg/LSCs pos and 13 pts (14%) had cMRD pos/LSCs neg. The conformity between both assays was 67%. During a median follow up of 10 months (1-29) there were 17 mortalities, 13 relapses and 11 NRM events. The 1-year OS and LFS were significantly better in LSCs neg than in LSCs pos pts: 91% (77-97%) vs 73% (55-86%, p=0.012) and 88% (72-96%) vs 52% (35-68%, p=0.001), respectively. This was due to a higher relapse rate in LSCs pos group: 33% (18-52%) vs 4% (1-20%, p=0.002). The median time to relapse was 180 days (40-395). The difference in NRM was not significant. The area under the ROC curve for relapses was 0.74 (0.61-0.88, p=0.006). Regarding the combined used of LSCs/cMRD, the best 1-year OS (p=0.038) and LFS (p=0.002) were observed for the double negative group: 94% (77-99%) and 88% (65-97%); followed by cMRD pos/LSCs neg: 86% (59-96%) and 86% (61-97%); cMRD neg/LSCs pos: 77% (43-94%) and 71% (39-90%); and the double positive group: 63% (43-79%) and 42% (25-61%)., respectively ( Figure 1). This was due to in the differing relapse rate that was highest in cMRD neg/LSCs pos group: 47% (17-79%), followed by double positive: 29% (14-50%), double negative: 7% (1-32%), and cMRD pos/LSCs neg group: 0% (p=0.02). Post-transplant cMRD/LSCs data on days +30 and +100 were available in 70 consecutive pts. The post-transplant conversion rates (positive > negative) for LSCs, cMRD and cMRD/LSCs were 49%, 61%, and 63%, respectively. The majority of pts converted at day +30. We observed a higher conversion rate to LSC neg status after MAC vs RIC (12/16, 75% vs 5/11, 45%, p=0.12). Of nine pts who were MRD pos at day +30, six were LSC neg and three were LSC pos. One MRD pos/LSC neg pts died due to NRM while remaining five pts survived without relapse. All three MRD pos/LSC pos pts developed relapses with two mortalities. Conclusion: Peri-transplant detection of LSCs has a strong predictive value for early post-transplant relapses in AML pts. This approach can improve pre-transplant risk assessment for cMRD pos patients by defining a population with better survival and low relapses (cMRD pos/LSCs neg) and one with worse survival and more relapses (cMRD pos/LSCs pos). The post-transplant clearance of residual disease is associated with better survival regardless of the flow strategy being used (cMRD, LSCs, or both). Pts with persisting cMRD early after allo-SCT may be subdivided into different risk groups according to their LSCs status. Figure 1. Leukemia-free survival according to pre-transplant cMRD/LSCs status in 90 AML patients.

Dose Reduced Chemotherapy in Sequence with Blinatumomab for Newly Diagnosed Older Patients with Ph/BCR::ABL Negative B-Precursor Adult Lymphoblastic Leukemia (ALL): Preliminary Results of the GMALL Bold Trial

Older patients (pts) with newly diagnosed ALL are ineligible for unmodified pediatric-based therapies. Although results are improved with age-adapted, dose-reduced regimens including MRD-based treatment modification, there is much space for further improvement.Therefore, the GMALL study group developed a trial to evaluate Blinatumomab, a CD19 directed bi-specific T-cell engager, in sequence with chemotherapy in this patient population with high medical need (NCT 03480438). Importantly, Blinatumomab replaced three cycles of standard consolidation chemotherapy.Pts aged 56 - 76 years (yrs) with CD19-positive, Ph-neg B-precursor ALL wereeligible. The primary endpoint was complete hematologic remission (CR) afterinduction (1 cycle chemo, 1 cycle Blinatumomab) and the key secondary endpoint was molecular response (table 1). The efficacy population included pts treated with dose reduced and shortened induction I (IP1) and Blinatumomab 1 or early death (ED). Induction was followed by 3 further Blinatumomab cycles alternating with age adapted consolidation cycles (HDMTX/ASP, HDAC, reinduction and maintenance) according to GMALL protocols for older pts (Gökbuget et al, ASH 2021). The median age was 66 (56-76) yrs. 21% had pro-B-ALL and 79% c/preB subtype. 40% had comorbidities according to the Charlson Score; most frequent were diabetes (13%) myocardial infarction (10%) or vascular diseases (10%). 50 pts were evaluable for IP1: 76% achieved CR/CRu and 2 pts (4%) died due to infections. 33% (N=11) had a molecular response and 18% MolCR (table 1). 47 pts were evaluable for the primary endpoint after Blinatumomab 1: CR/CRu was observed in 85%; 2 experienced ED (4%; those mentioned above; no additional ED). 88% of the CR pts had a molecular response (82% MolCR). The median follow-up is 757 (61-1584) days. Overall Survival (OS) after 1 and 3 yrs was 80% and 67% for the efficacy population (figure 1). The resp results for the total population were 82% and 65%. The 3y OS was 69% for c/pre-B-ALL and 58% for pro-B-ALL (p>.05). 3y OS was 81% for pts aged 55-65 yrs and 53% for those older than 65 yrs (p=.025). Only three pts received an allogeneic stem cell transplantation in CR1. 6 pts relapsed, 2 pt developed a secondary malignancy (Colon Ca, MDS) and 3 pts died in CR (1 HLH, 1 arterial disease, 1 Covid19). EFS was 60% at 3 yrs. We compared the results with those of the current GMALL standard therapy for older pts with B-precursor ALL (N=186) (Gökbuget et al, ASH 2022). Patient characteristics were similar. CR rates after induction were 85% vs 78% for BOLD vs standard (p>.05). Molecular CR rates in pts with hematologic CR were 82% vs 55% (p=.006). OS at 3 yrs was 67% and 49% (p=0.08) and Remission Duration (RD) was 83% vs 58% (p=0.055). Overall tolerability and efficacy of the regimen was very promising with a high hematologic and molecular response rate; mortality in induction and consolidation was low. In comparison with the current standard therapy the MRD response rates were significantly better. OS and RD was superior despite the omission of several chemotherapy cycles in contrast to other trials with unmodified chemotherapy but additional cycles of Blinatumomab. An ongoing randomized trial (NCT04994717) compares an even more dose reduced combination of Blina and chemotherapy with standard of care. This is an independent academic trial initiated by the GMALL Study Group which received free supply of Blinatumomab and financial support by Amgen.

Superior outcomes after allogeneic stem cell transplantation (SCT) among patients (Pts) ≥ 60 years (yrs) treated with cladribine (CLAD), low dose cytarabine (LDAC) plus venetoclax (Ven) for newly diagnosed acute myeloid leukemia (AML).

7047 Background: CLAD/LDAC/VEN alternating with AZA-VEN has shown promising outcomes in older pts with AML ( Kadia, JCO Nov 2022). Improved disease control and preserved performance status achieved with CLAD/LDAC/VEN treatment, may translate into superior post-SCT outcomes. Methods: We compared outcomes of pts ≥ 60 yrs of age treated on the phase II study of CLAD-LDAC-VEN who underwent SCT in 1st remission (CR1) to a retrospective cohort of pts ≥ 60 yrs treated with hypomethylating agent (HMA)-VEN based or intensive (INT) therapy who underwent SCT in CR1 between 2013-2022. Relapse free survival (RFS) was from response to relapse/death & overall survival (OS) from start of therapy to death. Results: 35 pts treated with CLAD-LDAC-VEN were compared to 42 pts treated with INT & 40 pts with HMA-VEN therapy for remission induction prior to SCT at our center (Table). The median age of pts in the low-intensity arms were similar (68 yrs), but lower on the INT arm (62 yrs). More pts post INT therapy received a myeloablative conditioning (MAC). At a median follow up of 17+ months (m) for CLAD-LDAC-VEN arm, 59 m for INT arm, and 30 m for HMA arm, the median RFS (NR vs. 50 m vs. 20 m respectively, p <0.01) and OS (NR vs. 58 m vs. 32 m respectively, p < 0.01) was superior for the CLAD-LDAC-VEN arm. 3-yr cumulative incidence of relapse & NRM (as competing events) were both significantly lower with CLAD-LDAC-VEN (4% and 7%) compared to INT (17% and 23%) or HMA-VEN (41% and 27%) therapy. Conclusions: Older pts with AML proceeding to SCT after CLAD-LDAC-VEN therapy had significantly improved survival, characterized by significantly lower rates of NRM and relapse compared to HMA-VEN or INT therapies. Larger studies and longer follow up is needed to confirm its benefit. [Table: see text]

Characteristics and clinical outcomes of patients with acute myeloid leukemia with inv(3)(q21q26.2) or t(3;3)(q21;q26.2).

Acute myeloid leukemia (AML) with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) has a very poor prognosis. Determinants of clinical outcomes and optimal treatment remain uncertain. We retrospectively reviewed 108 cases of AML with inv(3)/t(3;3) and evaluated clinicopathological characteristics and clinical outcomes: 53 newly diagnosed (ND) AML and 55 relapsed/refractory (R/R) AML. Median age was 55 years. White blood cell (WBC) count ≥20x109/L and platelet count ≥140x109/L was observed in 25% and 32% of ND patients, respectively. Anomalies involving chromosome 7 were identified in 56% of patients. The most frequently mutated genes were SF3B1, PTPN11, NRAS, KRAS and ASXL1. In ND patients, the composite complete remission (CRc) rate was 46% overall; 46% with high-intensity treatments and 47% with lowintensity treatments. The 30-day mortality was 14% and 0%, with high- and low-intensity treatment, respectively. In R/R patients, the CRc rate was 14%. Venetoclax based-regimens were associated with a CRc rate of 33%. The 3-year overall survival (OS) was 8.8% and 7.1% in ND and R/R patients, respectively. The 3-year cumulative incidence of relapse was 81.7% overall. Older age, high WBC, high peripheral blast count, secondary AML and KRAS, ASXL1, DNMT3A mutations were associated with worse OS in univariable analyses. The 5-year OS rates were 44% and 6% with or without hematopoietic stem cell transplantation in CR1, respectively. AML with inv(3)/t(3;3) is associated with low CR rates, very high risk of relapse and dismal long-term survival. Intensive chemotherapy and hy pomethylating agents provide similar rates of remission and patients achieving CR benefit from hematopoietic stem cell transplantation in first CR.

Hypodiploidy has unfavorable impact on survival in pediatric acute myeloid leukemia: an I-BFM Study Group collaboration.

Hypodiploidy, defined as modal numbers (MNs) 45 or lower, has not been independently investigated in pediatric acute myeloid leukemia (AML) but is a well-described high-risk factor in pediatric acute lymphoblastic leukemia. We aimed to characterize and study the prognostic impact of hypodiploidy in pediatric AML. In this retrospective cohort study, we included children below 18 years of age with de novo AML and a hypodiploid karyotype diagnosed from 2000 to 2015 in 14 childhood AML groups from the International Berlin-Frankfurt-Münster (I-BFM) framework. Exclusion criteria comprised constitutional hypodiploidy, monosomy 7, composite karyotype, and t(8;21) with concurring sex chromosome loss. Hypodiploidy occurred in 81 patients (1.3%) with MNs, 45 (n= 66); 44 (n=10) and 43 (n= 5). The most frequently lost chromosomes were chromosome 9 and sex chromosomes. Five-year event-free survival (EFS) and overall survival (OS) were 34% and 52%, respectively, for the hypodiploid cohort. Children with MN≤44 (n= 15) had inferior EFS (21%) and OS (33%) compared with children with MN= 45 (n= 66; EFS, 37%; OS, 56%). Adjusted hazard ratios (HRs) were 4.9 (P= .001) and 6.1 (P= .003). Monosomal karyotype or monosomy 9 had particular poor OS (43% and 15%, respectively). Allogeneic stem cell transplantation (SCT) in first complete remission (CR1) (n= 18) did not mitigate the unfavorable outcome of hypodiploidy (adjusted HR for OS was 1.5; P= .42). We identified pediatric hypodiploid AML as a rare subgroup with an inferior prognosis even in the patients treated with SCT in CR1.

CNS Relapse in T-Cell Lymphoma Index: A Risk Score to Predict Central Nervous System Relapse in Patients with T-Cell Lymphomas

Background: Central nervous system (CNS) relapse (CNSr) in patients with aggressive non-Hodgkin lymphoma is uncommon but carries a high morbidity and mortality. Data in T- and NK-cell lymphomas (TCL) are sparse, though the few small case series describing CNSr in TCL report an incidence up to 9% with median overall survival (mOS) less than 3 months (mo). We previously reported a large (n=75) case series of CNSr in TCL (Abstract #1382, ASH 2021). Herein, we developed a prediction score for CNSr in newly diagnosed patients with TCL. Methods: We retrospectively collected clinicopathologic and treatment data from 19 US academic centers from patients diagnosed with TCL between 1/1/09-1/1/19 who experienced CNSr (CNSr cohort). We combined these data with that from patients diagnosed with TCL without CNSr from a single institution (Penn cohort) to create a training set (T-set) enriched for patients with CNSr. Patients with leukemic or cutaneous TCL subtypes were excluded. We applied a LASSO Cox proportional hazards model to the T-set to create a predictive score for factors associated with CNSr and validated this score in an independent population-based validation set (V-set) from the Swedish Lymphoma Registry, which was not enriched for CNSr. Results: We evaluated data from 91 and 135 patients in the CNSr and Penn cohorts, respectively, which were combined to form the T-set and compared them to the V-set (n=745). Median age in the T-set was lower than in the V-set (60 vs 67; p<0.001). The most common TCL subtypes in the T-set and V-set were peripheral TCL, not otherwise specified (PTCL, NOS; 23% vs 34%, respectively; p=0.002), TCL with T-follicular helper phenotype (23% vs 14%, respectively; p=0.001), and ALK-negative anaplastic large cell lymphoma (18% vs 15%, respectively; p=0.352). CNS prophylaxis, defined as intrathecal therapy or high-dose methotrexate, was more common in the V-set than in the T-set (15% vs 9%, respectively; p=0.012). Rates of stem cell transplantation (SCT) as consolidation in first remission (CR1) did not differ significantly between the T-set and V-set (p=0.140). The median follow-up time was 37.6 mo in the T-set and 95.9 mo in the V-set. The median progression free survival (mPFS) and mOS after diagnosis were 9.8 mo and 33.2 mo in the T-set, respectively, and 8.5 mo and 17.9 mo in the V set, respectively. Within the T-set, mPFS and mOS were shorter for patients in the CNSr cohort vs the Penn cohort (6.0 mo vs 37.1 mo [p<0.001] and 17.3 mo vs 78.1 mo [p<0.001], respectively). In univariate analysis of the CNSr-enriched T-set, CNS prophylaxis, SCT in CR1, or frontline etoposide did not significantly decrease the risk of CNSr. Using several clinicopathologic characteristics, we fitted a LASSO Cox proportional hazards model to the T-set, which selected histology, LDH, stage, B-symptoms, and ≥2 sites of extranodal involvement (ENI) for a weighted risk score of CNSr (Fig. 1A). Variables most strongly associated with CNSr were PTCL, NOS (HR 2.64), enteropathy-associated TCL (HR 2.92), and ≥2 sites of ENI (HR 2.66). We stratified the T-set into tertiles based on weighted scores (x), which was low-risk if x≤0.14, intermediate-risk if 0.14<x ≤1.11, or high-risk if x>1.11. Cumulative incidence of CNSr in each respective group was 19.6%, 55.1%, and 83.7%. When the same cutoffs were applied to weighted scores in the V-set, we confirmed separation into distinct low-, intermediate-, and high-risk groups with cumulative incidences of CNSr of 1.9%, 4.9%, and 7.3%, respectively (Fig. 1B). As the V-set population was not enriched for CNSr, the relative incidence is expectedly lower compared to the T-set. Compared to the low-risk group in the V-set, risk of CNSr was significantly increased in the high-risk group (HR 5.72, p=0.002) and increased with a trend toward significance in the intermediate-risk group (HR 3.35, p=0.057). Conclusions: In a cohort of patients with TCL enriched for CNSr, we were able to characterize several risk factors associated with CNSr and developed a predictive CNSr in T-cell lymphoma Index (CITI) that could stratify patients into 3 distinct risk groups. PTCL, NOS, EATL, and ≥2 sites of ENI had the highest impact on risk of CNSr. The CITI score was validated in an independent population-based cohort. Although CNSr was uncommon even in high-risk patients (7.3%), our data will inform clinical decision making and may allow for identification of patients with TCL at high-risk of CNSr in future studies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Real-World Outcomes and Adverse Events of Elderly Patients with Ph-Negative Acute Lymphoblastic Leukemia Treated with a Pediatric-Inspired Protocol

Poor outcomes in elderly patients with Acute Lymphoblastic Leukemia (ALL) result from the disease's adverse biology and poor tolerance to chemotherapy, leading to dose reductions, treatment delays, and high rates of early death and treatment-related mortality. Some reports indicate that pediatric-inspired chemotherapy protocols can be safely and efficiently used in older adults, resulting in improved median overall survival (mOS) ranging from 17 to 40 months. Despite such reports, front-line implementation of pediatric-inspired approaches to elderly patients with ALL remains a topic of discussion. Our goal is to estimate OS and define adverse events (AEs) in patients with ALL, aged > 60 years, and treated with a pediatric-inspired protocol. Methods All newly diagnosed patients aged > 60 years with Ph-negative ALL who received induction chemotherapy with a modified, asparaginase-intense, pediatric-inspired regimen between January 2002 and January 2022 were included. The treatment regimen consisted of induction, central nervous system prophylaxis, 7 cycles of intensification, and 24 cycles of maintenance. During these 20 years, we switched from native to pegylated E.coli asparaginase. Standard descriptive statistics were used to summarize patients’ demographics and outcomes of interest. 95% confidence intervals were provided where possible. Fisher's exact test was used to assess the impact of categorical covariates of interest on induction mortality. Using Fine-Gray methods, the Multivariable Cox proportional hazards regression model was used to determine the joint effect of potential factors for outcomes. P<0.05 was considered significant. Results A total of 76 patients were included. Patient and disease characteristics are presented in table 1. The median dose of Peg-asparaginase and L- asparaginase were 935 iu/m2 (477-1,111 iu/m2) and 5,944 iu/m2 (4,388-15,000 iu/m2) respectively. AEs rates found were severe pancreatitis 3.9%, thrombosis at any time during treatment 43.2%, hypofibrinogenemia <1g/L 30.6%, CTCAE grade IV transaminases, and total bilirubin 35.2%, and 17.3% respectively. The induction mortality rate was 12% (N=9) and the complete remission rate after induction (CR1) was achieved at 79% (n=60). Allogeneic hematopoietic stem cell transplantation in CR1 was carried out for 9.2% (N=7). The median follow-up among survivors was 49.7 months (range: 9-155) and the mOS was 35.1 months (95%CI: >19.3) (figure 1). OS rate at 1 and 4 years was 73.6% (95%CI: 62 - 82) and 42.2% (95%CI: 29.3 - 54.6) respectively, with a cumulative incidence of relapse from the date of diagnosis at 12 months of 12% (95% CI: 5.8 - 20). Leukemia-free survival rate at 4 years was 42.4% (95% IC 30 - 53). For the patients with early mortality, 5 patients had L-asparaginase, 3 patients had no asparaginase, and one Peg-asparaginase (11.11%). In contrast, in the no early mortality group, 46 (68.6%) patients received L-asparaginase, 2 (2.9%) patients had no asparaginase, and 19 (28.3%) patients received Peg-asparaginase (p=0.011). In univariate analysis, variables significantly associated with worse OS were: older age [<70 years old (n=46) median OS 70.8 months (95%CI >31.1) vs >70 years old (n=30)14.4 months (95%CI 9.2-54.2) (p=0.016)], higher WBC count [<11x10e9/L (n=54) median OS was 70 months (95%CI 27-NA), while in those with WBC >11x10e9/L (n=22) was 17.2 months (95%IC 6-31) (p= 0.004)], and no asparaginase given [OS at 12 months was: 85% (95%CI 60.4 -94.9) in patients treated with Peg-asparaginase; 72.4% (95%CI 57.9-82.6) in patients treated with L-asparaginase, and 40% (95%CI 5.2-75.3) in patients that did not receive asparaginase (p=0.0021). In multivariable analysis, younger age and lower WBC remained independent significant prognostic factors for increased OS [Patients <70 years old HR 2.67 (95% CI[1.38 - 5.17], p=0.0034) and patients with WBC <11x10e9/L HR 2.5 (95% CI [1.30- 4.82], p= 0.007)]. Conclusions The use of a pediatric-inspired chemotherapy protocol is shown to be effective and well tolerated in patients with Ph-negative ALL aged >60 years. Although AE rates were not negligible, outcomes were excellent and, early mortality improved over prior reports (Marc Poch Martell et al, BJH 2013, early mortality 20%). Further research will be needed to understand how the outcomes could be improved further using newer targeted treatments. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

PB1831: UTILITY OF FLT3 INHIBITORS IN PATIENTS WITH ACUTE MYELOID LEUKEMIA (AML) AND T(6;9)(P22;Q34)

Background: Efficacy of FLT3 inhibitors in patients (pts) with AML and t(6;9)(p22;q34)/DEK-NUP214 is not well established. Aims: We compared overall survival (OS) and event-free survival (EFS) of AML pts with t(6;9) who received FLT3 inhibitor (FLT3-i) in frontline (FL) or salvage (SL) setting, regardless of their FLT3 mutation status. Methods: We retrospectively evaluated pts with AML or high-risk Myelodysplastic Syndrome (HR-MDS) who presented to our center between 1995-2021. Among 9936 pts, 55 pts (0.5%) had t(6;9) (48 AML, 7 HR-MDS). In FL setting, pts were divided according to their induction regimen with (n:5) or without FLT3-i (n:48). In SL setting, 35 pts who relapsed or were refractory to FL regimen were recategorized according to their SL regimen with (n:16) or without FLT3-i (n:17). Four pts were excluded from analysis due to incomplete data. Results: Among 47 pts with available molecular data, 35 (74%) was FLT3-ITD+, 5 (10.6%) with both ITD and TKD mutation. ITD allelic ratio (AR) was known for 28 (80%) pts (AR range: 0.01-0.95) with 11 (31%) pts having an AR ≥0.5. Age was well-balanced across all cohorts with median of 41 years (yr). Most pts had ECOG performance status of 0-1 (92%) on presentation. Pts with FLT3-ITD mutation were more likely (83%) to receive intensive chemotherapy (IC) compared to pts without (50%, p=0.02). Most pt in FL cohort with or without FLT3-i received IC (80% and 77%, respectively). There was no significant different in FLT3-ITD positivity between FL cohort with or without FLT3-i (p=0.3). Sorafenib was used in 62% of cases, followed by Quizartinib (24%). All pts in FL cohort with FLT3-i achieved CR/CRi with 60% MRD negative rate as compared to 52% in non-FLT3-I, and 60% of FLT3-i cohort had stem cell transplantation (SCT) in CR1 (vs. 21% of non-FLT3-i). Median number (No.) of therapy cycle was 1 to reach CR/CRi in all FL cohorts. Outcomes are shown in Figure 1. With median follow up of 47 months (mos), 2-yr OS and EFS were higher in FLT3-i than non-FLT3-i cohort (80% and 60% vs. 41% and 20%, respectively), although not statistically significant (p=0.2 for OS and 0.1 for EFS). Among pts with known mutation status, there were non-significant lower 2-yr OS and EFS in FLT3-ITD+ pts than wild-type FLT3 (FLT3-wt) pts (44% and 22% vs. 58% and 42%, respectively; p=0.4 for OS and 0.3 for EFS), regardless of whether FLT3-i was included in the induction regimen. CR/CRi rate was similar between FLT3-ITD+ (57%) and FLT3-wt pts (58%) but FLT3-wt pts was more likely to receive SCT in CR1 (42%) than FLT3-ITD+ pts (23%). In SL setting, 75% pts in FLT3-i cohort received low intensity therapy as compared to 12% pts in non-FLT3-i cohort (p<0.01) and 69% pts in SL cohort without FLT3-i were FLT3-ITD+ (p=0.03). Pts were heavily treated in both group (67% pts were in salvage 2+), but never received FLT3-i as part of their prior salvage regimen. No. of prior therapies and proportion of pts with prior SCT and FLT-i- containing induction regimen were similar across cohort. CR/CRi rate was higher in FLT3-i cohort (69%) than non-FLT3-i cohort (41%) after median No. of 1 therapy cycle with similar proportion of pts who went to SCT post salvage regimen. With median follow up of 47 mos, 2-yr OS and EFS were poor in both FLT3-i cohort and non-FLT3-i cohort (27% and 12% vs. 12.5% and 6%, respectively, p=0.3 for OS and 0.7 for EFS). Image:Summary/Conclusion:FLT3 mutation status does not impact survival in pts with t(6;9). Addition of FLT3-i to FL and SL regimen in subset of pts with FLT3-ITD mutation is beneficial and should be further evaluated.

Improved outcomes among newly diagnosed patients with FMS-like tyrosine kinase 3 internal tandem duplication mutated acute myeloid leukemia treated with contemporary therapy: Revisiting the European LeukemiaNet adverse risk classification.

Mutations in fms-like tyrosine kinase 3 (FLT3) gene are common genomic alterations in acute myeloid leukemia (AML). FLT3 internal tandem duplication mutations (FLT3-ITD) have consistently been shown to be adversely prognostic, particularly those with high allelic ratio (AR). Current AML treatment strategies, including high dose cytarabine, purine analogs, FLT3 inhibitors (FLT3i), and with or without allogeneic stem cell transplant (SCT) have been shown to improve the outcomes in patients with FLT3 mutations. We analyzed a consecutive cohort of newly diagnosed patients with AML treated at a large academic medical center from January 2012 to January 2020. A total of 1576 patients with a new diagnosis of AML were reviewed. Among these, 1438 (91%) had molecular testing for FLT3 mutations and 21% (304/1438) had an FLT3 mutation, including 17% with an FLT3-ITD mutation. We show that FLT3-ITD high AR with NPM1 wild-type have significantly improved survival compared with other European LeukemiaNet (ELN) adverse risk disease. In multivariable cox proportional hazards model of patients receiving intensive or low-intensity induction regimens, FLT3 mutations did not have prognostic significance. The use of allogeneic SCT in CR1 for patients with FLT3 mutations appears to improve survival, particularly in those with ELN adverse risk disease. Overall, this data highlights the changing prognostic impact of FLT3 mutations in a contemporary era with appropriate use of induction therapy combined with targeted agents and allogenic SCT.

Impact of Central Nervous System Involvement in Adult Patients with Acute Lymphoblastic Leukemia Treated in a Pediatrics-Inspired Protocol - a Graall Study

▪Background: The prognosis of central nervous system (CNS) involvement in adult patients with acute lymphoblastic leukemia (ALL) has been historically associated with a dismal outcome. Whereas the prognosis of adult patients with ALL has greatly improved since the advent of pediatrics-inspired regimens, the prognostic impact of CNS involvement has not been formerly reevaluated. We report herein the impact of CNS involvement in patients included in the pediatric-inspired prospective GRAALL-2005 study.Methods: All patients received a 5-drug induction therapy with native E. Coli-ASP intravenous injections. Patients in complete remission (CR) received two consolidation courses with alternating cycles including high dose cytarabine (2g/m2/12h on days 1 and 2), high dose methotrexate (3 g/m2 on day 1), and cyclophosphamide. All patients in persistent CR and with no indication for allogeneic stem cell transplantation (SCT) received late intensification, followed by one last consolidation course. Patients with initial CNS involvement, clinically and/or cytologically (cerebrospinal fluid), were recommended to receive an increased number of triple intrathecal therapy, CNS irradiation, and were eligible for allogeneic SCT in first CR. They received less Asp injections during induction therapy to avoid CNS adverse events. CNS irradiation included two lateral fields encompassing the skull, facial, the base of the skull, and the first two cervical vertebrae at a dose of 24 grays for those not receiving allogeneic SCT and 15 grays for those receiving allogeneic SCT.Results: Between 2006 and 2014, 784 adult patients with newly diagnosed Philadelphia-negative ALL were included with 55 (7%) having initial CNS involvement. These patients were more likely to be of T-phenotype (51 versus 32%, p=.004) and had more white blood cells at diagnosis (median 23 G/l versus 11 G/l, p=.02). Most patients (36 pts, 66%) were classified as CNS-3 (> 5 white blood cells/µl and a positive cytospin and/or clinical signs) whereas 5 patients (9%) were CNS-2 (< 5 white blood cells/µl and a positive cytospin), and 14 (25%) have data pending. Among patients with details regarding CNS involvement, 25/41 (61%) had clinical signs including trigeminal anesthesia (9 pts, 36%), facial paralysis (4 pts, 16%), extremities paresthesia (4 pts, 16%), visual signs (2 pts, 8%), meningeal syndrome (2 pts, 8%), and motor deficit (2 pts, 8%), and 4/18 (22%) had radiological signs. Induction death, CR1 rate, and negative minimal residual disease after induction were similar whether patients had CNS involvement or not (6 vs 6%, 89 vs 89%, 73 vs 62%, 26 vs 22%, respectively). Patients with CNS involvement had a worse outcome than those without with a median event-free survival (EFS) of 391 days (versus not reached for patients without CNS involvement, HR: 1.7, 95% CI: 1.2 - 2.5, p=.002) and a median overall survival (OS) of 608 days (versus not reached for patients without CNS involvement, HR: 1.8, 95% CI: 1.3 - 2.6, p=.001) (figure). Similar results were observed when patients who received allogeneic SCT in CR1 were censored at the time of graft. As recommended, patients with CNS involvement were more likely to receive allogeneic SCT than those without (53 versus 34%, p=.01), with a median time of 169 days. A 150-day landmark analysis, excluding 12 patients with an EFS event before 150 days, was performed to study the impact of allogeneic SCT on the outcome of patients with CNS involvement. Allogeneic SCT had no impact on either EFS (HR: .5, 95% CI: .2 - 1.2, p=.15) or OS (HR: .8, 95% CI: .3 - 1.8, p=.53).Conclusion: Despite improved outcome in young adult ALL patients with pediatrics-inspired protocols, CNS involvement remains a poor-risk feature. The historical use of allogeneic SCT does not improve outcome. Specific regimens should be developed for adult ALL patients with CNS involvement. [Display omitted] DisclosuresHuguet: Amgen: Other: Advisor; BMS: Other: Advisor; Celgene: Other: Advisor; Jazz Pharmaceuticals: Other: Advisor; Novartis: Other: Advisor; Pfizer: Other: Advisor. Barbieux: ASTRA-ZENECCA: Consultancy. Vey: Amgen: Honoraria; BMS: Honoraria; BIOKINESIS: Consultancy, Research Funding; NOVARTIS: Consultancy, Honoraria, Research Funding; SERVIER: Consultancy; JAZZ PHARMACEUTICALS: Honoraria; JANSSEN: Consultancy. Dombret: Amgen: Honoraria, Research Funding; Incyte: Honoraria, Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; Novartis: Research Funding; Pfizer: Honoraria, Research Funding; Servier: Research Funding; Abbvie: Honoraria; BMS-Celgene: Honoraria; Daiichi Sankyo: Honoraria. Boissel: Bristol-Myers Squibb: Honoraria, Research Funding; Servier: Consultancy, Honoraria; Incyte: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; JAZZ Pharma: Honoraria, Research Funding; CELGENE: Honoraria; SANOFI: Honoraria; PFIZER: Consultancy, Honoraria. Mathilde: ABBVIE: Consultancy; SERVIER: Consultancy.

Outcomes of Patients Treated with CPX-351 As First Line Therapy for AML Based on Their Antecedent History of Myeloid Malignancy

Outcomes of Patients Treated with CPX-351 As First Line Therapy for AML Based on Their Antecedent History of Myeloid Malignancy

Central Nervous System Involvement By Mantle Cell Lymphoma

Central Nervous System Involvement By Mantle Cell Lymphoma

Phase II Study of Cladribine, Idarubicin, Cytarabine (CLIA) Plus Gilteritinib in Patients with FLT3 Mutated Acute Myeloid Leukemia (AML)

Phase II Study of Cladribine, Idarubicin, Cytarabine (CLIA) Plus Gilteritinib in Patients with FLT3 Mutated Acute Myeloid Leukemia (AML)

First Results of the Risk-Adapted, MRD-Stratified GMALL Trial 08/2013 in 705 Adults with Newly Diagnosed Acute Lymphoblastic Leukemia/Lymphoma (ALL/LBL)

First Results of the Risk-Adapted, MRD-Stratified GMALL Trial 08/2013 in 705 Adults with Newly Diagnosed Acute Lymphoblastic Leukemia/Lymphoma (ALL/LBL)

The Prognostic Significance of Translocation (1;19) in Adult Patients (Pts) with B-Cell Acute Lymphoblastic Leukemia (ALL)

The Prognostic Significance of Translocation (1;19) in Adult Patients (Pts) with B-Cell Acute Lymphoblastic Leukemia (ALL)

A Phase II Trial of Sirolimus with Standard Induction Chemotherapy in Patients with De Novo Acute Myeloid Leukemia

Background: The initial treatment of FLT3 wild type acute myeloid leukemia (AML) has not significantly changed since induction therapy with Ara-C and anthracyclines was first developed. Preclinical data suggests constitutive activation of the AKT3/mammalian target of rapamycin (mTOR) pathway may play a role in pathogenesis of this disease in a subset of AML patients. Previous data from our group has shown that the presence of phosphorylated ribosomal S6 (pS6) in AML blasts as detected by flow cytometry may predict response to the combination of sirolimus and induction chemotherapy. Here we report the clinical and pharmacodynamics results of a phase II study of the combination of these drugs.Methods: Subjects had newly diagnosed AML based on WHO criteria. Subjects received oral sirolimus starting on day 1 (12 mg loading dose) then 4 mg daily on days 2-10 with idarubicin 12mg/m2 days 4-7 and cytarabine 100mg/m2 days 4-10. Clinical response was assessed at hematologic recovery or by day 42 using IWG for response. Samples for pharmacodynamic studies of blasts were drawn prior to treatment with sirolimus on day 1, and then again prior to dosing of idarubicin and cytarabine on day 4. Assessment of pS6 on gated blasts, a biomarker of mTORC1 activation, was assessed by flow cytometry using previously described methods.Results: 55 patients enrolled on this trial received sirolimus with an average age of 58 years. Toxicity was similar to published 7+3 data and prolonged aplasia without recovery was not observed. Twenty-nine patients (53%) had high risk cytogenetic or molecular mutations, 15 (27%) had intermediate risk disease, and 11 (20%) patients had lower risk disease. As a whole, 35 patients (64%) entered into CR or CRp, 1 had a PR, 17 (27%) were non-responders. Two (4%) patients (ages 64 and 71) died during induction. Thirteen (45%) patients with high risk disease had a CR or CRp, 14 (48%) were non-responders, and 2 died in induction. Of the 15 subjects with intermediate risk disease, 11 (79%) patients had a CR or CRp, 1 had a partial response, and 3 were non-responders. All low risk patients had a CR, and 9 of 11 are alive and in remission at the time of censoring of data with a median time on study of 674 days. One patient with low risk disease subsequently relapsed, went to stem cell transplant, and is currently in CR. Two patients with low risk disease refused to proceed with standard of care consolidation; of these, 1 is alive and in remission 946 days from study entry, and 1 died in relapse. Fifteen patients (27%) subsequently underwent allogeneic stem cell transplantation in CR, and 8 (53%) are still alive an average of 358 days after transplant.Thirty-seven of 55 patients had adequate samples for pharmacodynamic analysis. Surprisingly, all patients demonstrated activation of ribosomal S6 prior to therapy in contrast to 67% positivity seen in previous studies that focused on patients with relapsed AML. mTORC1 was inhibited greater than 40% in 28/37 (76%) of patients. Inhibition did not correlate with either overall survival or age of patients.Conclusions: Sirolimus and 7+3 is a well-tolerated regimen. mTORC1 appears to be activated in almost all patients at the time of diagnosis of AML as assessed by flow cytometric assessment of ribosomal S6. Inhibition of mTORC1 did not correlate with response, suggesting that AML cells may have redundant signaling pathways that regulate chemosensitivity when mTORC1 is inhibited. Given the large percentage of samples with mTORC1 activation in this upfront AML study, future research into dual mTORC inhibitors may prove valuable. DisclosuresCarroll:Astellas Pharmaceuticals: Research Funding; Incyte Pharmaceuticals: Research Funding. Porcu:Innate Pharma: Research Funding; Kura: Research Funding; Miragen: Research Funding; Kiowa: Research Funding; Galderma: Research Funding; Tetralogic: Research Funding; Cell Medica: Research Funding; Celgene: Research Funding. Perl:Arog Pharmaceuticals: Consultancy; Novartis: Other: Advisory Board; Pfizer: Other: Advisory Board; Seattle Genetics: Other: Advisory board; Asana Biosciences: Other: Scientific advisory board; Astellas: Consultancy; Daiichi Sankyo: Consultancy; Actinium Pharmaceuticals: Other: Scientific Advisory Board.

Flow Cytometric Minimal Residual Disease As Risk Stratification Tool in Younger Adults with NPM1 Wild Type Standard Risk Acute Myeloid Leukemia

Response to induction therapy is a powerful prognostic indicator in acute myeloid leukemia (AML). Measurable/minimal residual disease (MRD) assays are being increasingly incorporated into response assessment; however, their value as a surrogate for long-term outcome remains unclear because of assay limitations and the effect of post remission therapies. This is particularly the case for the molecularly heterogeneous NPM1 wild type standard risk patients for whom treatment decisions, including predicting the benefit of allogeneic stem cell transplantation (SCT), are particularly challenging. We investigated the effect on outcome of MRD status compared to other response criteria after each cycle of induction for NPM1 wild type (wt) standard risk patients and other risk groups in a cohort of younger AML patients.Patients and MethodsAs part of the UK NCRI AML17 trial (ISRCTN55675535) for patients with AML or high risk MDS up to the age of 60, prospective flow cytometric MRD (MFC-MRD) monitoring was performed after each course of induction. Any level of MRD detected was considered MRD+ (sensitivity thresholds: ~0.02% by tracking diagnostic leukemic aberrant phenotypes/LAIP, ~0.05-0.1% by “different-from normal” blast LAIP). Clinicians were not informed of MFC-MRD results. Following cycle 1 of induction with daunorubicin/ara-C based therapy, patients were allocated a risk group by a validated score (comprising cytogenetics, WBC, age, secondary disease, blast response to cycle 1 and mutation status). Standard risk patients including ITD wt/ NPM1 wt received a second daunorubicin/ara-C induction with some proceeding to SCT after 1 or 2 consolidation cycles (high dose ara-C).Results2450 non APML patients, median age 51, randomised 4/09 to 12/14, contributed data. For the total cohort, 5 year overall survival (OS) excluding early deaths was 52% for those achieving CR/CRi vs 31% for those not in CR (p<.001).Post cycle 1 (C1) responses were categorised as resistant disease (RD), partial remission (PR) and CR/CRi by clinicians, with CR/CRi subdivided by MFC-MRD assay into MRD+ and MRD-. RD vs PR vs MRD+ vs MRD- frequencies were 15% vs 14% vs 40% vs 31% for all patients with response data (n=1443), 5% vs 7% vs 45% vs 43% for good / standard risk (n=785), 10% vs 8% vs 47% vs 35% NPM1 wt standard risk (n=320).Post C1 response was prognostic for survival: OS for RD vs PR vs MRD+ vs MRD- were 25% vs 36% vs 43% vs 63% all patients; 33% vs 49% vs 51% vs 70% good/standard risk and 28% vs 38% vs 47% vs 59% NPM1 wt standard risk. (p<.0001 throughout). For NPM1 wt standard risk as well as good/standard risk patients adjusted analyses confirmed significant OS differences between C1 RD vs PR or MRD+ but not PR vs MRD+. Results were similar when censored at SCT.Post C1 best response was CRi for 39/446 MRD- vs 49/575 MRD+ overall (11/111 vs 8/149 for NPM1 wt standard risk). C1 CRi was associated with reduced OS overall (39% vs 53% CR, p=.002) and in MRD+ (19% vs 45% CR, p=.001) but not for MRD- patients. OS for NPM1 wt standard risk MRD+ was 25% CRi vs 43% CR (p=0.4). No significant difference was detected for 5 year cumulative incidence of relapse (CIR).The effect on outcomes of MRD status post cycle 2 (C2) for the 806 patients in CR/CRi with MFC-MRD data appeared greater (relapse HR 1.88(1.50- 2.36), p<0.001; OS HR 1.77(1.41-2.22) p<0.001)than C1 (relapse HR 1.70(1.40- 2.06), p<0.001; OS HR 1.50(1.23-1.84) p<0.001). MRD+ levels of ≥0.1% predicted highest CIR in NPM1 wt standard risk patients at C1 (CIR 71%) and C2 (CIR 89%) but any MRD+ at C2 reduced OS (32% vs 63% MRD-, p=0.003) and OS censored at any SCT (35% vs 88%). The effect of CR vs CRi was smaller post C2 although outcomes were still worst in CRi/MRD+ve patients.Of 204 NPM1 wt standard risk patients with C2 MRD data 83 had an allograft (44 in CR1: 29 MRD-, 15 MRD+). In Mantel-Byar analyses, although numbers were small, there was a suggestion that transplant could be considered in MRD +ve (HR 0.72 (0.31-1.69)) but not MRD -ve patients (HR 1.68 (0.75-3.85); p-value for interaction p=0.16).ConclusionMRD status by MFC refines response criteria at induction time-points to differentiate NPM1 wild type standard risk patients with poor outcome and helps define a group of patients who may benefit from SCT in CR1. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Outcomes in mantle cell lymphoma with central nervous system involvement.

e19527 Background: While extra nodal involvement by MCL is relatively common, involvement of the central nervous system (CNS) is a rare ( &lt; 5% of cases) complication with limited treatment options. We report the outcomes of a large cohort of patients (pts) with CNS MCL. Methods: MCL pts with CNS involvement seen at Mayo Clinic between 1/1/1995-9/16/2020 were identified. CNS involvement was defined by histologically confirmed CNS MCL, CSF analysis demonstrating lymphoma cells, and/or neuroimaging findings compatible with CNS lymphoma. Medical records were reviewed for baseline characteristics, treatment, and outcome. Kaplan-Meier method was used for time to event analysis. Results: Out of 1,753 pts with MCL, 36 (2%) had CNS involvement by MCL. Median age at MCL diagnosis was 64 years (range 36-83) and 26 were male (72%). At MCL diagnosis, non-CNS extranodal involvement was seen in 30 pts, 24 with 1 site and 6 with ≥ 2 sites; 24 had bone marrow involvement. 11 (31%) pts had blastoid variant. Median Ki-67 was 40% (range 15-100%). MIPI score was available in 17 pts [low risk (n = 5, 29%), intermediate risk (n = 9, 53%), high risk (n = 3, 18%)]. The most common frontline regimen for MCL was R-CHOP and 14 (39%) pts underwent autologous stem cell transplant in CR1. The incidence of CNS involvement was overall similar over the study period. Median time from MCL diagnosis to CNS involvement was 25 months (m) (range 0-167). 4 (11%) pts presented with CNS involvement at initial diagnosis and 32 presented at relapse (12 isolated CNS relapse and 20 concurrent CNS and systemic relapse. Abnormal CSF was noted in 27 (87%) pts [consistent with MCL diagnosis (n = 26), atypical lymphocytes (n = 1)]. Abnormal CNS imaging was reported in 27 (75%) pts [leptomeningeal (n = 18), leptomeningeal and parenchymal (n = 5), parenchymal (n = 2), ocular (n = 2)]. First line CNS-directed therapy data was available in 33 (92%) pts. 12 (34%) received intrathecal (IT) therapy alone, 19 (54%) received systemic +/- IT therapy, 2 (6%) received radiation alone, and 2 (6%) pts received no treatment (hospice). The overall CNS response to therapy was CR in 13 (42%) pts, PR in 3 (10%), SD in 8 (26%), and PD in 7 (22%) pts. Three pts received BTK inhibitors [ibrutinib (n = 2) or acalabrutinib (n = 1)] as the first CNS-directed therapy. One patient achieved a CR with a response lasting 4 m, another patient achieved a PR with response lasting 10 m. CNS response data was not available in the remaining pts. Median follow up from CNS involvement was 72 m (95% CI: 41-NR). Median EFS for the 1st CNS-directed therapy was 3.7 m (95% CI: 1.6-6.1). At last follow up, 30 pts were deceased. The cause of death was CNS lymphoma in 10 (33%) pts and systemic lymphoma in 9 (30%) pts. Median OS from CNS involvement was 4.7 m (95% CI: 2.3-6.7). Conclusions: CNS involvement by MCL has dismal outcomes as evident by a median OS of approximately 5 m. BTK inhibitors may have a role in treatment of this rare complication, but further prospective investigation is needed.

Alternating versus concurrent schedules of imatinib and chemotherapy as front-line therapy for Philadelphia-positive acute lymphoblastic leukemia (Ph+ALL)

The best strategy for incorporating imatinib in front-line treatment of Ph+ acute lymphoblastic leukemia (ALL) has not been established. We enrolled 92 patients with newly diagnosed Ph+ ALL in a prospective, multicenter study to investigate sequentially 2 treatment schedules with imatinib administered concurrent to or alternating with a uniform induction and consolidation regimen. Coadministration of imatinib and induction cycle 2 (INDII) resulted in a complete remission (CR) rate of 95% and polymerase chain reaction (PCR) negativity for BCR-ABL in 52% of patients, compared with 19% in patients in the alternating treatment cohort (P = .01). Remarkably, patients with and without a CR after induction cycle 1 (INDI) had similar hematologic and molecular responses after concurrent imatinib and INDII. In the concurrent cohort, grades III and IV cytopenias and transient hepatotoxicity necessitated interruption of induction in 87% and 53% of patients, respectively; however, duration of induction was not prolonged when compared with patients receiving chemotherapy alone. No imatinib-related severe hematologic or nonhematologic toxicities were noted with the alternating schedule. In each cohort, 77% of patients underwent allogeneic stem cell transplantation (SCT) in first CR (CR1). Both schedules of imatinib have acceptable toxicity and facilitate SCT in CR1 in the majority of patients, but concurrent administration of imatinib and chemotherapy has greater antileukemic efficacy.

Integrating ELN Criteria and a ‘Knowledge Bank’ Approach to Guide Allogeneic Stem Cell Transplantation (SCT) Indication in Younger Adults with Acute Myeloid Leukemia (AML): An Acute Leukemia French Association Study

Integrating ELN Criteria and a ‘Knowledge Bank’ Approach to Guide Allogeneic Stem Cell Transplantation (SCT) Indication in Younger Adults with Acute Myeloid Leukemia (AML): An Acute Leukemia French Association Study