Acute Myeloid Leukemia In First Complete Remission Research Articles

Measurable residual mutated IDH1 before allogeneic transplant for acute myeloid leukemia.

Measurable residual disease (MRD) in adults with acute myeloid leukemia (AML) in complete remission is an important prognostic marker, but detection methodology requires optimization. Persistence of mutated NPM1 or FLT3-ITD in the blood of adult patients with AML in first complete remission (CR1) prior to allogeneic hematopoietic cell transplant (alloHCT) associates with increased relapse and death after transplant. The prognostic implications of persistence of other common AML-associated mutations, such as IDH1, at this treatment landmark however remain incompletely defined. We performed testing for residual IDH1 variants (IDH1m) in pre-transplant CR1 blood of 148 adult patients undergoing alloHCT for IDH1-mutated AML at a CIBMTR reporting site between 2013 and 2019. No statistically significant post-transplant differences were observed between those testing IDH1m positive (n = 53, 36%) and negative pre-transplant (overall survival (OS): p = 0.4; relapse: p = 0.5). For patients with IDH1 mutated AML co-mutated with NPM1 and/or FLT3-ITD, only detection of persistent mutated NPM1 and/or FLT3-ITD was associated with significantly higher rates of relapse (p = 0.01). These data, from the largest study to date, do not support the detection of IDH1 mutation in CR1 blood prior to alloHCT as evidence of AML MRD for increased post-transplant relapse risk.

Higher survival following transplantation with a mismatched unrelated donor with posttransplant cyclophosphamide-based graft-versus-host disease prophylaxis than with double unit umbilical cord blood in patients with acute myeloid leukemia in first complete remission: A study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

The best donor option for acute myeloid leukemia (AML) patients lacking an HLA-matched donor has remained intensively debated. We herein report the results of a large retrospective registry study comparing hematopoietic cell transplantation (HCT) outcomes between double-unit umbilical cord blood transplantation (dCBT, n = 209) versus 9/10 HLA-matched unrelated donor (UD) with posttransplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis (UD 9/10, n = 270) in patients with AML in first complete remission (CR1). Inclusion criteria consisted of adult patient, AML in CR1 at transplantation, either peripheral blood stem cells (PBSC) from UD 9/10 with PTCy as GVHD prophylaxis or dCBT without PTCy, transplantation between 2013 and 2021, and no in vivo T-cell depletion. The 180-day cumulative incidence of grade II-IV acute GVHD was 29% in UD 9/10 versus 44% in dCBT recipients (p = .001). After adjustment for covariates, dCBT recipients had a higher non-relapse mortality (HR = 2.35, 95% CI: 1.23-4.48; p = .01), comparable relapse incidence (HR = 1.12, 95% CI: 0.67-1.86; p = .66), lower leukemia-free survival (HR = 1.5, 95% CI: 1.01-2.23; p = .047), and lower overall survival (HR = 1.66, 95% CI: 1.08-2.55; p = .02) compared with patients receiving UD 9/10 HCT. In summary, our results suggest that transplantation outcomes are better with UD 9/10 with PTCy-based GVHD prophylaxis than with dCBT for AML patients in CR1. These data might support the use of UD 9/10 with PTCy-based GVHD prophylaxis over dCBT in AML patients lacking an HLA-matched donor.

Older MRD vs. younger MUD in patients older than 50 years with AML in remission using post-transplant cyclophosphamide.

An increasing number of older patients with acute myeloid leukemia (AML) are offered an allogeneic hematopoietic stem cell transplantation (allo-HSCT). Normally, older patients have older matched related donors (MRD). Matched unrelated donors (MUD) are an important alternative, but it remains unclear whether a younger MUD is associated with better outcomes, especially in the context of post-transplant cyclophosphamide (PTCy). We compared outcomes of patients older than 50 years with AML in first complete remission (CR1) and receiving a first HSCT from a 10/10 MUD aged younger than 40 years to those receiving a graft from a MRD aged older than 50 years, using PTCy and with well-known transplant conditioning intensity (TCI) score. A total of 345 consecutive patients were included and classified according to TCI score as low, intermediate, or high. On multivariable analysis in the TCI-intermediate/high group, MUD was associated with better graft-versus-host disease-free, relapse-free survival, lower non-relapse mortality and lower relapse incidence. For patients receiving a TCI-low regimen, outcomes are independent on the type of donor. In patients with AML in CR1, older than 50 years and receiving a TCI-intermediate/high conditioning regimen using PTCy, a MUD younger than 40 years is preferable over a MRD older than 50 years.

High-dose cytarabine plus gemtuzumab ozogamicin as consolidation therapy in patients with favorable- or intermediate-risk acute myeloid leukemia.

Previous prospective randomized trials have investigated the efficacy of gemtuzumab ozogamicin in the frontline treatment of acute myeloid leukemia (AML). We evaluated the efficacy of high-dose cytarabine with GO as consolidation therapy in 20 patients with favorable- or intermediate-risk AML in first complete remission. They included six patients with wild-type nucleophosmin (NPM1) core binding factor (CBF), ten with NPM1-mutated non-CBF, and four with wild-type NPM1 non-CBF. The median follow-up for the entire cohort was 62.0months. The three-year overall survival (OS) and relapse-free survival (RFS) rates were 72.2% and 77.8%, respectively. OS and RFS were significantly higher for NPM1-mutated non-CBF AML than for wild-type NPM1 non-CBF AML (p = 0.001). We also examined the CD33 single-nucleotide polymorphism (SNP) rs12459419, which has been reported to influence the therapeutic efficacy of GO and CD33 expression. The CD33 expression ratio was higher in CD33 SNP C/C than in C/T (83.1% vs. 49.8%, p = 0.035), but 3-year OS and RFS did not differ significantly. These results suggest that consolidation therapy with high-dose cytarabine plus GO is highly effective in transplant-ineligible elderly patients and may be a reasonable treatment, especially for NPM1-mutated AML.

Tacrolimus versus cyclosporine a combined with post-transplantation cyclophosphamide for AML In first complete remission: a study from the acute leukemia working party (EBMT)

Choice of calcineurin inhibitor may impact the outcome of patients undergoing T-cell replete hematopoietic cell transplantation (HCT) with post-transplant cyclophosphamide (PT-Cy) and mycophenolate mofetil (MMF) for prophylaxis of graft-versus-host disease (GVHD). We retrospectively analyzed 2427 patients with acute myeloid leukemia (AML) in first remission transplanted from a haploidentical (n = 1844) or unrelated donor (UD, n = 583) using cyclosporine A (CSA, 63%) or tacrolimus (TAC, 37%) and PT-Cy/MMF. In univariate analysis, CSA and TAC groups did not differ in 2-year leukemia-free or overall survival, cumulative incidence (CI) of relapse or non-relapse mortality. CI of severe grade III-IV acute GVHD was lower with TAC (6.6% vs. 9.1%, p = 0.02), without difference in grade II-IV acute GVHD or grade III-IV acute GVHD/severe chronic GVHD, relapse-free survival (GRFS). In multivariate analysis, TAC was associated with a lower risk of severe grade III-IV acute GVHD solely with haploidentical donors (HR 0.64 [95% CI, 0.42–0.98], p = 0.04), but not UD (HR 0.49 [95% CI, 0.2–1.21], p = 0.12). There was no significant difference for chronic GVHD. In conclusion, PT-Cy/MMF-based GVHD prophylaxis resulted in favorable OS and GRFS, irrespective of the CNI added. In haploidentical HCT, TAC seemed to prevent severe acute GVHD more effectively than CSA without impact on other outcome parameters.

Safety outcomes in adult patients with AML who achieved their first complete remission with GO prior to HSCT.

e18504 Background: Gemtuzumab ozogamicin (GO) is approved in the US for the treatment of newly diagnosed and relapsed/refractory (R/R) CD33-positive acute myeloid leukemia (AML) in adults and pediatric patients of 1 month and older and 2 years and older, respectively. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative therapy for most adult patients with AML in first complete remission (CR1). Clinical studies have linked GO with hepatotoxicity and hepatic veno-occlusive disease (VOD); the risk of these events may be further elevated in patients receiving HSCT. This study aimed to characterize the toxicity after HSCT in adult patients with AML who were treated with GO prior to HSCT. These analyses look at outcomes in patients who were in CR1 at the time of HSCT. Methods: This non-interventional post-authorization safety study used de-identified healthcare data from the Center for International Blood and Marrow Transplant Research (CIBMTR) database. Data were collected from adult patients in the US with newly diagnosed AML treated with GO prior to proceeding with HSCT. Data collection began on 01 September 2017, data cutoff was 04 July 2023. Results: We present data of 84 patients receiving HSCT for AML in CR1 from 19 centers with a median follow-up of 23.9 months (range, 3.0-49.7). Median age was 54.2 y (range, 18.7-74.5); 55% male. Total cumulative GO dose was 1-3 mg/m2 in 15 (18%), 4-6 mg/m2 in 15 (18%), 7-9 mg/m2 in 28 (33%) and ≥10 mg/m2 in 8 (12%) patients. Measurable residual disease (MRD) was undetectable in 50% (n=42) of patients after GO and 51% (n=43) of patients at the time of HSCT. Most patients (58%; n=49) received myeloablative conditioning and 57% (n=48) received HLA matched unrelated donor HSCT. Non-fatal VOD was reported in 6 (7%) patients, most cases were mild (n=5; 83%). Cumulative incidences of transplant-related mortality (TRM) were: 6 months, 7% (95% CI, 3-14); 2 years, 15% (95% CI, 7-25). The 2-year relapse rate was 26% (95% CI, 16-36%). Kaplan-Meier probabilities of leukemia-free survival (LFS) outcomes at 1 and 2 years were, 68% (95% CI, 57-78) and 59% (95% CI, 47-71), respectively. There were 22 deaths during the study, 10 (46%) from relapse of AML, no VOD-related deaths were observed. Conclusions: The use of GO prior to allogeneic HSCT appears to be safe with low rates of posttransplant VOD observed in patients with AML in CR1. TRM and survival outcomes are similar to historically reported rates. Clinical trial information: B1767034.

Comparison of fludarabine/melphalan (FluMel) with fludarabine/melphalan/BCNU or thiotepa (FBM/FTM) in patients with AML in first complete remission undergoing allogeneic hematopoietic stem cell transplantation - a registry study on behalf of the EBMT Acute Leukemia Working Party.

Conditioning protocols for patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) are being developed continuously to improve their anti-leukemic efficacy and reduce their toxicity. In this study, we compared the conditioning protocol of fludarabine with melphalan 140 mg/m2 (FluMel) with conditioning protocols based on this same backbone but with an additional alkylating agent i.e., either fludarabine/BCNU (also known as carmustine)/melphalan (FBM), or fludarabine/thiotepa/melphalan (FTM) 110 mg/m2. We included 1272 adult patients (FluMel, n = 1002; FBM/FTM, n = 270) with acute myeloid leukemia (AML) with intermediate/poor cytogenetic risk in first complete remission (CR) from the registry of the EBMT Acute Leukemia Working Party. Despite patients in the FBM/FTM group were older (64.1 years vs. 59.8 years, p < 0.001) and had a worse Karnofsky performance score (KPS < 90, 33% vs. 24%, p = 0.003), they showed a better overall survival (OS) (2 y OS: 68.3% vs. 58.1%, p = 0.02) and less non-relapse mortality (NRM) (2 y NRM: 15.8% vs. 22.2%, p = 0.009) compared to patients treated with FluMel. No significant differences were observed in relapse incidence (RI) (2 y RI: 24.9% vs. 23.7%, p = 0.62). In conclusion, the addition of a second alkylating agent (BCNU/carmustine or thiotepa) to FluMel as FBM/FTM conditioning, improves OS in AML patients in first CR with intermediate/poor risk cytogenetics after allo-HCT.

Association between Molecular Profile and Outcome after Intensive Chemotherapy in Patients > 60 Years with Adverse Cytogenetic Risk and/or Secondary Acute Myeloid Leukemia - a Filo Study

Background: Recognizing the prognostic importance of genetic characteristics rather than clinical history, secondary acute myeloid leukemia (AML), i.e., arising from prior cytotoxic therapy and/or an antecedent hematologic disorder (AHD), is now considered a diagnostic qualifier rather than a separate disease entity (Döhner, Blood 2022). To assess the relationship between clinical history and/or adverse cytogenetics and outcome, we report herein the molecular profile of AML patients &amp;gt;60 years with secondary AML and/or adverse cytogenetics included in a multicentric prospective trial. Methods: Fit patients &amp;gt;60 years with secondary AML and/or adverse cytogenetics according to the European LeukemiaNet, included in the Rev-5-Aza trial (NCT01301820), received induction therapy with lomustine 200 mg/m 2 day 1, idarubicin 8 mg/m 2 days 1-5, and cytarabine 100 mg/m 2 days 1-7. Patients in complete remission (CR) after one induction cycle received consolidation therapy with 12 cycles of alternating azacitidine 75 mg/m 2 days 1-7 and lenalidomide 10 mg days 1-21 every 28 days (Hunault-Berger M, Blood Cancer J 2017). Mutational profile was determined by targeted sequencing of complete coding regions, including splice sites, of 77 genes recurrently mutated in myeloid malignancies using custom SureSelect QXT capture system (Agilent, Santa Clara, CA, USA) on NextSeq500 platform (Illumina, San Diego, CA, USA). As a validation cohort, we determined the molecular profile of 73 patients with adverse cytogenetic risk and/or secondary AML in first CR after the same induction therapy but who received standard chemotherapy consolidation with 6 cycles of idarubicin 8 mg/m 2 day 1 and cytarabine 50 mg/m 2/12 hours days 1-5. Results: Between March 2011 and February 2013, 117 fit patients &amp;gt;60 years included in the Rev-5-Aza trial received induction therapy with 56% reaching first CR and four patients undergoing allogeneic hematopoietic cell transplantation. The molecular profile could be established in 97 of these patients (83%; median age 70 years, interquartile range (IQR): 65-73; therapy-related AML, 32%; AHD, 46%; adverse cytogenetic risk, 70%). Secondary-type mutations were the most frequently observed (49%; ASXL1, 12%; BCOR, 16%; EZH2, 2%; RUNX1, 18%; SF3B1, 8%; SRSF2, 14%; STAG2, 10%; U2AF1, 8%; and ZRSR2, 0%) followed by TP53 mutations (44% of patients). Patients with TP53 mutations were more likely to have adverse risk cytogenetics (95%) in comparison to patients with secondary-type mutations (64%). No clinical or biological characteristic was associated with the achievement of CR (secondary-type mutations, 51%, TP53 mutation, 49%). Clinical history was not associated with overall survival (OS) as patients with therapy-related AML had the same outcome as other patients (hazard ratio [HR]=1.04, P=0.9) and patients with AHD had a more favorable outcome (HR=0.57, P=0.02). On the other hand, adverse cytogenetics was associated with decreased OS (HR=3.32, P&amp;lt;0.001). Whereas TP53 mutations were associated with decreased OS (HR=3.71, P&amp;lt;0.001), secondary-type mutations were not (HR=0.64, P=0.049; Figure A). After multivariable analysis, both complex karyotype (CK; HR=0.006, P=0.006) and TP53 mutations (HR=2.12, P=0.03) were independently associated with OS. Considering both CK and TP53 mutations identified three groups of patients with differential OS (median 1.57 vs. 0.91 vs. 0.45 years, P&amp;lt;0.001; Figure B). Similar results were observed in the validation cohort. Patients in first CR from both cohorts were then compared to identify molecular subgroups for which a lenalidomide/azacitidine consolidation was associated with improved OS in comparison to standard chemotherapy. No molecular subgroup had increased OS with lenalimomide/azaciditine consolidation while standard chemotherapy was associated with improved outcomes in patients with adverse risk cytogenetics. Conclusion: Together, these data suggest that the clinical history contains limited prognostic value compared to genetics, supporting the most recent approach to use cytogenetic and molecular data to assess disease risk. In this patient population, complex karyotype and TP53 mutations, rather than secondary-type mutations, were associated with outcome. Figure. (A) Overall survival according to secondary-type and TP53 mutations status. (B) Overall survival according to complex karyotype (CK) and T P53 mutation status.

Decitabine/Cedazuridine (ASTX727) Combined with a Molecularly-Targeted Agent (Venetoclax, Gilteritinib, Ivosidenib, or Enasidenib) As Personalized Maintenance Therapy in Acute Myeloid Leukemia: First Results from a Phase 1b Study

Background: Disease relapse is the major cause of treatment failure and death in acute myeloid leukemia (AML). Currently, oral azacitidine (CC-486) is the only drug approved in the maintenance setting in patients with AML who are unable to complete standard therapy. The ECOG ACRIN E2906 trial suggested an overall survival (OS) benefit with 3-day IV decitabine maintenance. Decitabine/cedazuridine (ASTX727) is an oral formulation of decitabine that achieves systemic exposures as seen with IV decitabine. Multiple small-molecule agents are now available targeting key leukemic drivers (BCL-2, FLT3, and IDH1/IDH2 inhibitors). We developed a multi-arm phase 1b study (NCT05010772) to evaluate an oral maintenance regimen composed of an ASTX727 backbone combined with a molecularly-targeted agent (venetoclax, gilteritinib, ivosidenib, or enasidenib). Methods: Patients ≥ 18 years with AML in first complete remission (CR) or CR with incomplete blood count recovery (CRi) not currently eligible for stem cell transplantation (SCT) and unable/unwilling to complete standard therapy were eligible. Patients having received either intensive induction (at least 2 cycles of therapy based on intermediate to high dose cytarabine) or low-intensity induction (at least 3 cycles based on low-dose cytarabine or a hypomethylating agent) were permitted. Other inclusion criteria were ECOG ≤ 3, adequate hepatic/renal function, absolute neutrophil count &amp;gt; 0.5 x 10 9/L, and platelets &amp;gt; 50 x 10 9/L. Patients were enrolled in one of five arms per physician choice based on molecular profile. Arm A consisted of ASTX727 35/100 mg PO on D1-3. All other arms combined this ASTX727 backbone with either venetoclax 400 mg (adjusted for azoles) PO on D1-5 (arm B), gilteritinib 120 mg PO on D1-28 (arm C), enasidenib 100 mg PO on D1-28 (arm D), or ivosidenib 500 mg PO on D1-28 (arm E). Treatment was administered in 4-week cycles, up to 24 cycles. Each arm initially consisted of a safety lead-in cohort with predetermined dose reductions for dose-limiting toxicity (DLT) per a 3+3 dose de-escalation design. Prophylactic antibiotics, antifungals, and antivirals were encouraged. The primary objective was safety and tolerability. Secondary objectives included relapse-free survival (RFS) and OS. Patients becoming eligible for SCT were taken off study and censored at the time of SCT for time-to-event endpoints. Results: 23 patients, with a median age of 68 years (range 33-83), have been enrolled (3 on arm A, 19 on arm B, and 1 on arm C). 12 (52%) were enrolled following intensive induction and 11 (48%) after low-intensity induction. 16 (70%) had prior venetoclax. Best response at enrollment was CR in 22 (96%) patients and CRi in 1 (4%). 6/22 (27%) patients with available testing were measurable residual disease (MRD)-positive. 2 (9%) patients had antecedent myelodysplastic/myeloproliferative neoplasms and 1 (4%) had therapy-related AML. ELN 2022 risk was favorable in 10 (43%), intermediate in 3 (13%), and adverse in 10 (43%) patients. The most common grade 3/4 adverse events were neutropenia (96%), thrombocytopenia (74%), anemia (39%), lung infection (22%), hypertension (17%), and neutropenic fever (17%). Cycle 2 dose reductions due to myelosuppression occurred in 5/23 (22%) patients. No DLTs were observed. No deaths occurred on protocol. Two patients died in remission from SCT-related complications after going off maintenance. The current median follow-up time is 5.3 months (m). The median number of cycles given is 3 (1-15). Three relapses have occurred to date (1 in arm A, 2 in arm B). The median RFS for the full cohort is not reached (NR, 1-year 71%). The median OS for the full cohort (figure 1A) is NR (1-year 100%). The median RFS for arms A, B, and C are NR (1-year 67%), NR (1-year 84%), and NR, respectively (figure 1B). The median RFS is 14.5 m (1-year 50%) for patients who received intensive induction and NR (1-year 75%) for those who received low-intensity induction. The median RFS for patients who were MRD-negative and MRD-positive at enrollment were NR (6-month 93%) and NR (6-month 75%), respectively (p=0.50). Of the 6 MRD-positive patients, 2 (33%) cleared their MRD while on maintenance (both patients in arm B). Conclusions: A fully oral, targeted maintenance regimen is feasible in AML. Early results show encouraging RFS and OS. Further enrollment and follow-up are required to better assess the safety and efficacy of these regimens.

Azacitidine Plus Venetoclax Maintenance in Acute Myeloid Leukemia Produces Sustained Remissions with Low Toxicity: Results of a Phase 2 Study

Background: Most patients diagnosed with acute myeloid leukemia (AML) achieve remission following induction therapy. However, disease relapse remains a major clinical concern. The QUAZAR AML-001 study demonstrated improved overall and relapse-free survival with oral azacitidine (CC-486) maintenance. We designed a phase 2 study (NCT04062266) to evaluate low doses of azacitidine plus venetoclax as maintenance therapy following both intensive and low-intensity induction in AML. We present updated results of this study with close to 2 years of median follow-up. Methods: Patients ≥ 18 years of age with non-APL AML in first complete remission (CR) or CR with incomplete count recovery (CRi) not immediately eligible for allogeneic stem cell transplantation (SCT) were eligible. Cohort 1 enrolled patients who had received at least 2 cycles of intensive therapy (defined as containing intermediate to high-dose cytarabine). Cohort 2 enrolled patients who had received at least 3 cycles of low-intensity therapy (defined as hypomethylating agent or low-dose cytarabine-based). Patients with positive measurable residual disease (MRD) by flow cytometry were eligible in CR1 or beyond. Other inclusion requirements were ECOG ≤ 3, adequate hepatic/renal function, and adequate bone marrow reserve (defined as absolute neutrophil count &amp;gt; 0.5 x 10 9/L and platelets &amp;gt; 30 x 10 9/L). Treatment consisted of azacitidine 50 mg/m 2 SQ/IV on D1-5 and venetoclax 400 mg PO (adjusted for concomitant CYP3A inhibitors) on D1-14 in 28-day cycles, up to 24 cycles. Venetoclax duration could be reduced to D1-7 per physician discretion to mitigate myelosuppression and dose modifications during subsequent cycles were allowed. Antibacterial, antifungal, and antiviral prophylaxis were recommended in all patients. The primary objective was relapse-free survival (RFS, defined as time from enrollment to progression or death). Secondary objectives included overall survival (OS), safety/toxicity, and MRD clearance. Patients subsequently becoming eligible for SCT were taken off study and censored for analyses at the time of SCT. Results: 35 patients have been enrolled (25 in cohort 1 and 10 in cohort 2). The median age was 47 years in cohort 1 and 71 years in cohort 2. The baseline characteristics are shown in table 1. The median number of cycles given was 9 (range 1-24). 22/35 (63%) patients had 7 days of venetoclax during cycle 1. Median follow-up is currently 20.9 months (m). For the full cohort, the median RFS was not reached (NR; 2-year 60%) and the median OS was NR (2-year 75%). In cohort 1, the median RFS and OS were NR (2-year 71%) and NR (2-year 77%), respectively. In cohort 2, the median RFS and OS were 23.5 m (2-year 34%) and NR (2-year 67%), respectively. When stratified by ELN 2017, patients who were favorable (n=16), intermediate (n=11), and adverse (n=8) had a median RFS of NR (2-year 85%), NR (2-year 64%), and 4.0 m (2-year 0%), respectively. Corresponding median OS were NR (2-year 91%), NR (2-year 76%), and 14.9 m (2-year 27%), respectively. 4/8 (50%) of the ELN adverse patients had complex cytogenetics and/or TP53 mutations. Patients who were MRD-positive at enrollment (n=7, 3 with prior venetoclax exposure) had significantly shorter RFS compared to those who were MRD-negative (median 4.0 m versus NR, p&amp;lt;0.01). Only 2/7 (29%) MRD-positive patients converted to MRD-negative while on maintenance. As mutations in NPM1, IDH1, or IDH2 may sensitize AML to venetoclax, we analyzed RFS based on the presence or absence of these mutations (figure 1). Patients with sensitizing mutations had a trend towards longer RFS (median RFS NR versus 23.5 m, 2-year RFS 79% vs 36%, p=0.08). The most common grade 3/4 adverse events were infections (26%), neutropenia (17%), thrombocytopenia (17%), hypotension (6%), and neutropenic fever (6%). 4 (11%) patients required cycle 2 venetoclax dose reductions. 8 (23%) of patients went off protocol to receive SCT. All observed deaths (n=8) occurred following AML relapse (n=7) or SCT-related complications (n=1). Conclusions: Lower dose azacitidine plus venetoclax is a feasible and safe maintenance strategy in AML. This approach yields encouraging results in MRD-negative patients with non-adverse ELN risk (favorable or intermediate risk). A genetic-guided strategy may help select patients who benefit the most from this combination (i.e. those with NPM1, IDH1, or IDH2 mutations).

Persistence of FLT3-TKD in Blood Prior to Allogeneic Transplant Is Associated with Increased Relapse and Death in Adults with AML in First Remission

Introduction: Next-generation sequencing (NGS) represents a promising modality for measurable residual disease (MRD) testing in patients with acute myeloid leukemia (AML), but systematic efforts are required to define the appropriate targets, test characteristics, and clinical implications. We recently reported that detection of persistent NPM1 or FLT3 internal tandem duplication (ITD) mutations in adults with AML in first complete remission (CR1) prior to allogeneic hematopoietic cell transplantation (alloHCT) is associated with increased relapse and death compared with those testing negative (JAMA 2023, PMID: 36881031). FLT3 tyrosine kinase domain (TKD) variants are present in 7-10% of adult patients with AML but the utility of this target for AML MRD testing in CR1 prior to alloHCT was previously unknown. Methods: Patients aged 18 or older who underwent alloHCT for AML in CR1 between 2013 and 2019 reported to have a FLT3-TKD variant at diagnosis and a pre-conditioning remission blood sample available in the CIBMTR biorepository were eligible for this study. Single-amplicon NGS (SA-NGS) library generation utilizing UMI-tagged primers targeting the D835 and I836 codons of FLT3 was performed on 400ng genomic DNA sequenced with unique dual indices, with error-corrected variant calling. Primary outcomes were overall survival (OS) and cumulative incidence of relapse (CIR). Secondary outcomes were relapse-free survival (RFS) and non-relapse mortality (NRM), with NRM being considered as a competing risk. Results: A total of351 patients met inclusion criteria for this study, and 342 (97.4%) had sufficient DNA for SA-NGS and were analyzed for clinical outcomes. Of these patients, 81 (23.7%) experienced relapse at a median of 5 months post-alloHCT. Using the current ELN-recommended variant allele fraction (VAF) threshold of 0.1% for NGS-based AML MRD, 14 patients (4.1%) tested positive. Patients with FLT3-TKD MRD VAF≥0.1% experienced higher rates of relapse (73.8% vs. 20.5%, p &amp;lt; 0.0001) and decreased OS (11.4% vs. 66.8%, p &amp;lt; 0.001) compared to VAF&amp;lt;0.1%. The highly sensitive SA-NGS method allowed for exploration to determine if a deeper VAF threshold of 0.01% (previously validated for NPM1 and FLT3-ITD in the Pre-MEASURE study) was prognostic for FLT3-TKD as an MRD target. This led to an additional 20 patients being reclassified as positive (n = 34 with VAF above 0.01%, =9.9%). However, there was no significant difference in CIR (33.6% vs. 19.7%, p = 0.089) or OS (65.2% vs. 66.9%, p = 0.267) between patients with 0.01%≤VAF&amp;lt;0.1% and VAF&amp;lt;0.01% ( Figure). Out of 28 SA-NGS positive calls, 6 could not be validated by orthogonal digital droplet PCR testing, and interestingly, none of those 6 patients experienced relapse. Site-reported pre-transplant remission multiparametric flow cytometry (MFC) was available for 335 patients (98%). Results of MFC were not associated with differences in CIR (HR 1.2, 95% CI 0.52 - 2.76, p = 0.67) or OS (HR 0.78, 95% CI 0.34 - 1.77, p = 0.551).In multivariable analysis, FLT3-TKD NGS-MRD VAF≥0.1% remained prognostic for CIR (HR 6.1, 95% CI 3.1 - 12.0, p &amp;lt; 0.001) and OS (HR 3.2, 95% CI 1.7 - 5.9, p &amp;lt; 0.001). Conclusions: Detectable persistence of FLT3-TKD variants in blood from AML patients in first remission prior to first alloHCT is rare, but at a VAF level of 0.1% was strongly associated with increased relapse and death after transplant compared to those testing negative. In contrast to FLT3-ITD NGS-MRD, no evidence was found to support lowering the NGS-MRD VAF threshold from 0.1% to 0.01% for FLT3-TKD. Alternative methodology may further improve NGS-MRD test performance. Site-reported MFC prior to alloHCT did not stratify for post-transplant relapse or survival. Optimal NGS-MRD testing for patients with AML will likely require a multi-target approach and testing for persistence of FLT3-TKD MRD is shown here to represent an important component of this strategy.

Outcomes of 3- versus 5-day administration schedule of consolidation cytarabine in adults with acute myeloid leukemia (AML).

7014 Background: Consolidation therapy with intermediate to high-dose cytarabine is critical to prevent relapse in AML. Cytarabine is typically administered every 12 hours on days 1, 3, 5. Two large studies have examined a condensed 3-day administration schedule in patients &lt;60 years and demonstrated a shorter time to absolute neutrophil count (ANC) recovery without compromising long term outcomes. However, use of this regimen in patients ≥60 years has not been evaluated. Here we report our experience with the condensed administration schedule compared with the standard schedule in patients over and under 60 years. Methods: All patients with AML in first complete remission (CR) following intensive induction chemotherapy receiving consolidation at our institution between 1/1/2020 to 12/31/2021 were included in the study. Patients received cytarabine every 12 hours on days 1, 3, 5 (AC135) from 1/1/2020 – 12/31/2020 and cytarabine every 12 hours on days 1, 2, 3 (AC123) from 1/1/2021 – 12/31/2021. All patients received peg-filgrastim support. Data was collected to determine time to ANC recovery &gt;1,000/µL, hemoglobin (Hb) &gt;8g/dL, and platelets &gt;75,000/µL. Comparison of continuous variables between two groups was done using multiple t-tests. Results: Between 1/1/2020 - 12/31/2021, 91 patients received at least one cycle of consolidation with 212 individual encounters. 38 patients received all cycles with AC135, 45 received AC123, and 8 received at least one cycle each of AC123 and AC135. Median age of the AC123 cohort was 50.2 years (range 19-72 years) and 54.3 years for the AC135 cohort (range 22-72 years). For patients ≥60 years of age, 33% (71/213) of the encounters were in the AC123 cohort and the rest in AC135 cohort. Median dose of cytarabine was 5,100 mg/dose in AC123 and 4,600 mg /dose in AC135 (p=0.02). Median time to ANC recovery, hemoglobin, and platelets as well as hospital-related outcomes are described in the table. In patients ≥60 years, median time to ANC recovery was 16.5 vs. 18.6 days (p = 0.03) and platelet recovery was 17.4 vs. 19.7 (p = 0.0008) in AC123 vs AC135 respectively. No neurotoxicity events were noted. Complication rates were similar in both arms. Conclusions: Our study demonstrates that AC123, as compared to AC135, is safe and leads to earlier hematopoietic recovery in adults under and over 60 years. AC123 should be considered the preferred schedule of consolidation therapy administration. [Table: see text]

Impact of measurable residual disease on outcomes of unrelated donor haematopoietic cell transplantation with post-transplant cyclophosphamide in AML in first complete remission.

Pre-transplant measurable residual disease (MRD) predicts relapse and outcome of allogeneic haematopoietic cell transplantation (allo-HCT). The impact of MRD on the outcomes of post-transplant cyclophosphamide (PTCy)-based allo-HCT from a matched unrelated donor (UD) is unknown. This study assessed the impact of MRD in acute myeloid leukaemia (AML) in the first complete remission (CR1). A total of 272 patients (MRD negative [MRD-], n= 165; MRD positive [MRD+], n= 107) with a median follow-up of 19 (range: 16-24) months were studied. The incidence of grades II-IV and grades III-IV acute GVHD at day 180 was 25.2% and 25% (p= 0.99), and 10.6% and 6.8% (p= 0.29), respectively, and 2-year chronic GVHD was 35% and 30.4% (p= 0.96) in MRD+ and MRD- cohorts, respectively. In multivariate analysis, MRD+ status was associated with a higher incidence of relapse (RI) (hazard ratio [HR]=2.56, 95% CI: 1.39-4.72), lower leukaemia-free survival (LFS) (HR=2.04, 95% CI: 1.23-3.39), overall survival (OS) (HR=1.83, 95% CI: 1.04-3.25) and GVHD-free, relapse-free survival (GRFS) (HR=1.69, 95% CI: 1.10-2.58). MRD status did not have a significant impact on non-relapse mortality (NRM), or acute or chronic GVHD risk. Among patients with AML undergoing UD allo-HCT with PTCy, pre-transplant MRD+ status predicted a higher relapse rate, lower LFS, OS and GRFS.

An Analysis of the Worldwide Utilization of Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia

Acute myeloid leukemia (AML) has an aggressive course and a historically dismal prognosis. For many patients, hematopoietic stem cell transplantation (HSCT) represents the best option for cure, but access, utilization, and health inequities on a global scale remain poorly elucidated. We wanted to describe patterns of global HSCT use in AML for a better understanding of global access, practices, and unmet needs internationally. Estimates of AML incident cases in 2016 were obtained from the Global Burden of Disease 2019 study. HSCT activities were collected from 2009 to 2016 by the Worldwide Network for Blood and Marrow Transplantation through its member organizations. The primary endpoint was global and regional use (number of HSCT) and utilization of HSCT (number of HSCT/number of incident cases) for AML. Secondary outcomes included trends from 2009 to 2016 in donor type, stem cell source, and remission status at time of HSCT. Global AML incidence has steadily increased, from 102,000 (95% uncertainty interval: 90,200-108,000) in 2009 to 118,000 (104,000-126,000) in 2016 (16.2%). Over the same period, a 54.9% increase from 9659 to 14,965 HSCT/yr was observed globally, driven by an increase in allogeneic (64.9%) with a reduction in autologous (-34.9%) HSCT. Although the highest numbers of HSCT continue to be performed in high-resource regions, the largest increases were seen in resource-constrained regions (94.6% in Africa/East Mediterranean Region [AFR/EMR]; 34.7% in America-Nord Region [AMR-N]). HSCT utilization was skewed toward high-resource regions (in 2016: AMR-N 18.4%, Europe [EUR] 17.9%, South-East Asia/Western Pacific Region [SEAR/WPR] 11.7%, America-South Region [AMR-S] 4.5%, and AFR/EMR 2.8%). For patients <70 years of age, this difference in utilization was widened; AMR-N had the highest allogeneic utilization rate, increasing from 2009 to 2016 (30.6% to 39.9%) with continued low utilization observed in AFR/EMR (1.7% to 2.9%) and AMR-S (3.5% to 5.4%). Across all regions, total HSCT for AML in first complete remission (CR1) increased (from 44.1% to 59.0%). Patterns of donor stem cell source from related versus unrelated donors varied widely by geographic region. SEAR/WPR had a 130.2% increase in related donors from 2009 to 2016, and >95% HSCT donors in AFR/EMR were related; in comparison, AMR-N and EUR have a predilection for unrelated HSCT. Globally, the allogeneic HSCT stem cell source was predominantly peripheral blood (69.7% of total HSCT in 2009 increased to 78.6% in 2016). Autologous HSCT decreased in all regions from 2009 to 2016 except in SEAR/WPR (18.9%). HSCT remains a central curative treatment modality in AML. Allogeneic HSCT for AML is rising globally, but there are marked variations in regional utilization and practices, including types of graft source. Resource-constrained regions have the largest growth in HSCT use, but utilization rates remain low, with a predilection for familial-related donor sources and are typically offered in CR1. Further studies are necessary to elucidate the reasons, including economic factors, to understand and address these health inequalities and improve discrepancies in use of HSCT as a potentially curative treatment globally.

Specific Cytogenetic Abnormalities at Diagnosis Predict Survival after Hematopoietic Cell Transplant in Poor-Risk Pediatric Acute Myeloid Leukemia: A PDWP/EBMT Study

Introduction: Cytogenetic abnormalities are an important prognostic factor for predicting overall survival (OS) and relapse incidence (RI) in children with acute myeloid leukemia (AML). Although allogeneic hematopoietic cell transplant (HCT) is generally recommended for patients with AML in first complete remission (CR1) and poor-risk (PR) cytogenetics, whether these cytogenetic and molecular features retain their prognostic value after HCT is unknown. Additionally, PR AML is a heterogeneous category that includes several distinct cytogenetic abnormalities, some of which might have a worse prognosis than others. In this study, we evaluated whether the cytogenetic risk classification at diagnosis of AML was predictive of post-HCT outcomes in pediatric patients. Methods: All patients <18 years of age at the time of HCT reported to the European Society for Blood and Marrow Transplantation (EBMT) registry, who had received their first allogeneic HCT for AML in CR1 between 2005 and 2020, and who had their karyotype evaluation at diagnosis available were included in this analysis. Patients were subgrouped as (a) monosomy 7/del7q or monosomy 5/del5q, (b) 11q23 abnormality excluding t(9;11), (c) complex or monosomal karyotype, or (d) other. A complex karyotype was defined as one with three or more structural abnormalities, and a monosomal karyotype was defined as a monosomy with one or more structural abnormalities, excluding WHO-designated recurring translocations or inversions based on 2017 ELN recommendations. Other cytogenetic abnormality subgroup included t(6;9), t(3;5), t(9;22), t(8;16), inv(3) or t(3;3), t(16;21), abn(11p15), and del(12p) or abn(12p13). Cytogenetic subgroup, age at HCT, whether HCT was from a female donor to a male recipient, patient/donor CMV status, time from AML diagnosis to HCT, and year of HCT were included as predictors for OS, RI and non-relapse mortality (NRM) in the multivariate analysis. Results: We included 744 pediatric patients (42.2% female; median age at HCT: 8.6 years [range: 0.3-18 years]) from 139 participating centers in the study. Median follow-up after HCT was 4.4 years. Thirty-seven percent had an 11q23 abnormality, 24% had monosomy 7/del7q or monosomy 5/del5q, 24% had a complex or monosomal karyotype, and 15% met the criteria for other PR cytogenetic abnormalities. Only 7% had secondary AML. Pre-HCT minimal residual disease (MRD) data were available for 346 patients, 86% of whom were MRD negative at the time of HCT. Patients received grafts from a matched related donor (27%), a mismatched related donor (11%), an unrelated donor (46%), or a cord blood donor (16%). Of the total patients, 55% received bone marrow, 29% received peripheral blood-derived stem cells and the rest (16%) received cord blood as the stem cell source. Myeloablative conditioning was used in 97% of the patients. The OS and leukemia free survival for the entire cohort was 76% and 70% respectively at 2 years. In a multivariate model, 11q23 (hazard ratio [HR] = 0.59, P = 0.01) and other poor-risk cytogenetic abnormalities (HR = 0.49, P < 0.01) were associated with significantly better OS when compared with monosomy 7/del7q or monosomy 5/del5q. The "other PR cytogenetic abnormalities" category was also associated with a lower risk of disease relapse after HCT (HR = 0.4, P = 0.01). Receiving an HCT from an unrelated donor, as compared with a matched related donor, was associated with lower RI (HR = 0.58, P = 0.03). Additionally, older age at HCT (12-18 years) was associated with the highest risk of NRM (HR = 1.95, P = 0.02) and with worse OS (HR = 1.71, P < 0.01) than seen in younger patients (aged 4-12 years). Conclusion: PR cytogenetic abnormalities at diagnosis remain predictive of OS after HCT for AML in pediatric patients. Monosomy 7/del7q or monosomy 5/del5q confer a poor prognosis even after HCT, whereas 11q23 abnormality and other PR cytogenetic abnormalities predict a favorable outcome after HCT. Our data also suggest that an HCT from an unrelated donor may offer greater protection against relapse than an HCT from a matched related donor, but this requires further validation. Efforts for improving conditioning regimens and transplant techniques should focus on reducing NRM and reducing RI in this population. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Siremadlin Monotherapy and in Combination with Donor Lymphocyte Infusion for Patients with Acute Myeloid Leukemia Post Allogeneic Stem Cell Transplantation Who Are in Complete Remission but at High Risk for Relapse

Background: Relapse post allogeneic stem cell transplantation (SCT) remains the main cause of treatment failure (~40%) for patients (pts) with acute myeloid leukemia (AML). Many pts who ultimately relapse post SCT do so within the first year post transplant, and earlier relapse is associated with poorer survival. Therapeutics that prevent early relapse for these pts are urgently needed. Early cellular or pharmacologic intervention or maintenance strategies that enhance the graft-versus-leukemia (GvL) effect after SCT are of renewed interest as they have the potential to reduce relapse risk post SCT. Siremadlin (HDM201) is a novel investigational MDM2 inhibitor with single-agent, anti-AML activity. MDM2 inhibitors, including siremadlin, possess potent immunomodulatory effects in murine solid tumor and AML models. MDM2 inhibition has been shown to synergize with the allogeneic immune response, increase the vulnerability of AML cells to allogeneic donor T cells, and promote the cytotoxicity and longevity of allogeneic donor T cells in murine models. As such, the post-SCT setting is ideal for investigating the immunomodulatory effects of MDM2 inhibition on enhancing the GvL effect (Ho et al. Blood. 2022). Here we describe the design of a Phase Ib/II, open-label study of siremadlin as monotherapy and in combination with donor lymphocyte infusion (DLI) in pts with AML post SCT who are in complete remission (CR) but at high risk for relapse based on the presence of pre-SCT risk factors (NCT05447663). Study Design: The trial is not yet recruiting but aims to enroll ~38 adult pts with AML who underwent first SCT and are currently between Day 60-120 post SCT. Prior to a patient's SCT, they must have a risk factor that puts them at high risk for relapse, including AML in first CR with adverse risk genetics per 2017 European LeukemiaNet risk stratification, therapy-related AML, or secondary AML; or AML in second or greater CR. The SCT must be from an 8/8 human leukocyte antigen (HLA) matched related or unrelated donor at HLA-A, -B, -C, -DRB1 loci using unmanipulated/T-cell replete bone marrow or peripheral blood stem cells as a stem cell source. Post SCT, pts must have achieved CR or CR with incomplete hematologic recovery (CRi) with no evidence of hematologic relapse. Exclusion criteria include prior exposure to an MDM inhibitor, active graft-vs-host disease (GvHD), past history of grade ≥III acute GvHD (aGvHD) or moderate/severe chronic GvHD (cGVHD), recipient of SCT from a haploidentical family donor or cord blood transplant, and prior systemic AML-directed treatments given at any time after SCT (including DLI). This study contains 2 parts, Part 1 is a dose confirmation of siremadlin monotherapy and will enroll ~12 pts. Siremadlin will be tested at a maximum of 3 dose levels with a starting dose of 30 mg/d on Days 1-5 of a 28-day cycle, dose level +1 at 40 mg/d and dose level -1 at 20 mg/d. The safety and tolerability of these dose levels will be assessed to determine the siremadlin recommended dose (RD) for Part 2. Pts in Part 1 of the study will receive siremadlin monotherapy for the entire duration of the treatment and will not receive DLI. Subsequently, ~26 pts will be enrolled in Part 2 and proceed through a priming phase with siremadlin monotherapy at the RD, followed by a combination phase of siremadlin + DLI, and subsequently a maintenance phase with siremadlin monotherapy (Figure). Primary safety endpoints of the study are incidence of dose-limiting toxicities (DLTs) in Part 1 and time to DLT in Part 2. The primary efficacy endpoint is the proportion of pts in Part 2 who are alive and maintained CR/CRi without hematologic relapse ≥6 months after the start of study treatment. Secondary endpoints include number of pts in Part 1 who are alive and maintained CR/CRi without hematologic relapse ≥6 months after the start of study treatment at the RD for Part 2, time to first documented hematologic relapse or death, incidence of relapse at 1 year and 2 years post study treatment, safety, GvHD-free/relapse-free survival, incidence of and time to treatment-emergent grade ≥III aGvHD or moderate/severe cGvHD, and pharmacokinetics. Conclusions: This Phase Ib/II study investigates siremadlin monotherapy and siremadlin in combination with DLI in pts with AML in remission but at high risk of relapse post SCT. The study will evaluate the unique immunomodulatory potential of siremadlin to reduce risk of relapse in this population with high unmet need. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Abstract CT537: A phase 2, multicenter, randomized, double-blind trial of maintenance therapy with FLT3 inhibitor gilteritinib (ASP2215) in patients with FLT3/ITD AML (GOSSAMER study)

Abstract Background: Patients with acute myeloid leukemia (AML) in remission are at high risk of relapse, warranting remission-prolonging therapy. Gilteritinib is the first FMS-like tyrosine kinase 3 (FLT3) inhibitor approved as monotherapy in FLT3-mutated relapsed/refractory AML. The aim of the study was to compare relapse-free survival (RFS) in patients with FLT3/internal tandem duplication AML in first complete remission who received gilteritinib or placebo. Method: In this phase 2, double-blind trial, patients were randomized 2:1 to gilteritinib (120 mg) or placebo once daily for up to 2 years, beginning after completion of induction/consolidation (I/C) therapy. RFS, defined as time from randomization date until the date of documented relapse or death from any cause was assessed via independent review committee adjudication (primary efficacy endpoint). Overall survival (OS) was defined as the time from date of randomization until date of death from any cause. Survival and treatment-emergent adverse events (TEAEs) were assessed 30 days after treatment discontinuation, and every 3 months thereafter. Due to a slow accrual rate, this trial (NCT02927262) was changed from a planned phase 3 to phase 2 based on the reduction in sample size. Results: 124 patients were screened and 98 were randomized (gilteritinib 63, placebo 35) and are included in the full analysis set (FAS), of whom 32 (gilteritinib 20, placebo 12) completed 2 years of treatment. The safety analysis set (SAF) comprised 97 patients (gilteritinib 62, placebo 35) who had received ≥1 dose of study drug. In the FAS, relapse occurred in 31/63 (49.2%) gilteritinib- and 20/35 (57.1%) placebo-treated patients; 3/63 (4.8%) gilteritinib-treated patients died without relapse. RFS was not significantly improved with gilteritinib vs placebo (hazard ratio [HR] 0.738, 95% confidence interval [CI] 0.407-1.336; 1-sided stratified log-rank p-value 0.163). Median RFS was 24.02 months for gilteritinib and 15.84 months for placebo. OS in the FAS was not significantly different between treatments (gilteritinib 21/63, [33.3%], placebo 11/35 [31.4%]; HR 1.130, 95% CI 0.540-2.364; 1-sided stratified log-rank p-value 0.627). Median OS was not reached in either arm. TEAEs in the SAF occurred in 58/62 (93.5%) gilteritinib- and 33/35 (94.3%) placebo-treated patients including, respectively, 51/62 (82.3%) and 20/35 (57.1%) drug-related TEAEs and 10/62 (16.1%) and 3/35 (8.6%) serious drug-related TEAEs. The most common TEAEs were increased blood creatine phosphokinase (gilteritinib 18/62 [29.0%], placebo 1/35 [2.9%]) and thrombocytopenia (gilteritinib 12/62 [19.4%], placebo 4/35 [11.4%]). Conclusion: Gilteritinib showed improved RFS versus placebo, but the difference was not statistically significant. There were no new safety findings in the gilteritinib arm. Citation Format: Mark D. Minden, Jacob M. Rowe, Emmanuel Gyan, Kohmei Kubo, Nahla Hasabou, David Delgado, Wensheng He, Stanley C. Gill, Jason E. Hill, Ramon Tiu. A phase 2, multicenter, randomized, double-blind trial of maintenance therapy with FLT3 inhibitor gilteritinib (ASP2215) in patients with FLT3/ITD AML (GOSSAMER study) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT537.

Oral azacitidine plus venetoclax in patients with relapsed/refractory or newly diagnosed acute myeloid leukemia: The phase 1b OMNIVERSE trial.

TPS7068 Background: For patients (pts) with acute myeloid leukemia (AML) who cannot undergo intensive chemotherapy (IC), lower-intensity treatment (Tx) regimens, including low-dose cytarabine (LDAC) and hypomethylating agents (HMAs; azacitidine [AZA], decitabine), are generally well tolerated but are associated with lower response rates than IC [Vey 2020]. Similarly, the BCL2 inhibitor, venetoclax (VEN), has shown antileukemic activity, although only modest clinical benefit as monotherapy [Konopleva 2016]. VEN + AZA shows synergistic activity in preclinical models, enhancing leukemic cell apoptosis in vitro and anti-tumor activity in vivo [Jin 2020]. In IC-ineligible pts with ND AML, VEN + injectable AZA significantly increased complete remission (CR)/CR with incomplete hematologic recovery (CRi) rates ( P &lt; 0.001) and prolonged overall survival (OS; P &lt; 0.001) vs AZA only [DiNardo 2020]. VEN, in combination with an HMA or LDAC, is approved in the US for Tx of pts with ND AML ≥ 75 years (y) of age or who cannot undergo IC due to comorbidities. Oral-AZA (CC-486) is approved for Tx of pts with newly diagnosed (ND) AML in first CR or CRi after IC who cannot receive curative therapy (eg, HSCT). In the phase 3 QUAZAR AML-001 trial, maintenance Tx with Oral-AZA 300 mg QD for 14 days (d)/28-d Tx cycle improved OS and relapse-free survival vs placebo in older pts in CR/CRi after IC [Wei 2020]. Incorporation of AZA into DNA is S-phase-restricted; thus, extending AZA exposure over a longer duration by using an oral formulation increases the opportunity for cycling tumor cells to incorporate the drug to sustain therapeutic activity [Laille 2015]. Additionally, an all-oral combination regimen allows for outpatient administration to optimize pt convenience and reduce resource utilization. Methods: OMNIVERSE (NCT04887857) is an open-label, multicenter, 2-part phase 1b trial. The main goals are to evaluate safety and establish the maximum tolerated dose of Oral-AZA + VEN in pts ≥ 18 y of age with relapsed/refractory AML who are ineligible for further IC ( part 1), and subsequently, in pts with ND AML ≥ 75 y of age, or pts 18–74 y of age with comorbidities that prevent use of IC or HSCT ( part 2). Key eligibility criteria include ECOG performance status of 0–2 (ECOG 3 is allowed for pts 18–74 y of age with comorbidities) and unfavorable-risk cytogenetics for pts with ND AML. The Oral-AZA starting dose is 300 mg QD × 14 d/28-d cycle, which can be de-escalated to 200 mg QD × 14 d depending on dose-limiting toxicities; oral VEN 400 mg QD is taken continuously (or 21 d/cycle for dose level −2). A modified toxicity probability interval-2 design is used to evaluate dose levels. Sample size depends on the dose levels utilized (≤ 18 pts/part). Enrollment began in 2021. The trial is ongoing at clinical sites in the United States and Australia. Clinical trial information: NCT04887857.

Age is no barrier for adults undergoing HCT for AML in CR1: contemporary CIBMTR analysis.

Acute Myeloid Leukemia (AML) has a median age at diagnosis of 67 years. The most common curative therapy remains an allogeneic hematopoietic stem cell transplantation (HCT), yet it is complicated by treatment-related mortality (TRM) and ongoing morbidity including graft versus host disease (GVHD) that may impact survival, particularly in older patients. We examined the outcomes and predictors of success in 1,321 patients aged 60 years and older receiving a HCT for AML in first complete remission (CR1) from 2007–2017 and reported to the CIBMTR. Outcomes were compared in three age cohorts (60–64; 65–69; 70+). With median follow-up of nearly 3 years, patients aged 60–64 had modestly, though significantly better OS, DFS and lower TRM than those either 65–69 or 70+; cohorts with similar outcomes. Three-year OS for the 3 cohorts was 49.4%, 42.3%, and 44.7% respectively (p=0.026). TRM was higher with increasing age, cord blood as graft source and HCT-CI score of ≥ 3. Conditioning intensity was not a significant predictor of OS in the 60–69 cohort with 3-year OS of 46% for RIC and 49% for MAC (p=0.38); MAC was rarely used over age 70. There was no difference in the relapse rate, incidence of Grade III/IV acute GVHD, or moderate-severe chronic GVHD across the age cohorts. After adjusting for other predictors, age had a small effect on OS and TRM. High-risk features including poor cytogenetics and measurable residual disease (MRD) prior to HCT were each significantly associated with relapse and accounted for most of the adverse impact on OS and DFS. Age did not influence the incidence of either acute or chronic GVHD; while graft type and associated GVHD prophylaxis were most important. These data suggest that age alone is not a barrier to successful HCT for AML in CR1 and should not exclude patients from HCT. Efforts should focus on minimizing residual disease and better donor selection.

Measurable residual disease, FLT3-ITD mutation, and disease status have independent prognostic influence on outcome of allogeneic stem cell transplantation in NPM1-mutated acute myeloid leukemia.

Nucleophosmin‐1 (NPM1) mutations in acute myeloid leukemia (AML) confer a survival advantage in the absence of FLT3‐internal tandem duplication (FLT3‐ITD). Here, we investigated the main predictors of outcome after allogeneic hematopoietic stem cell transplantation (allo‐HCT). We identified 1572 adult (age ≥ 18 year) patients with NPM1‐mutated AML in first complete remission (CR1:78%) or second complete remission (CR2:22%) who were transplanted from matched sibling donors (30.8%) or unrelated donors (57.4%) between 2007 and 2019 at EBMT participating centers. Median follow‐up for survivors was 23.7 months. FLT3‐ITD was present in 69.3% of patients and 39.2% had detectable minimal/measurable residual disease (MRD) at transplant. In multivariate analysis, relapse incidence (RI) and leukemia‐free survival (LFS) were negatively affected by concomitant FLT3‐ITD mutation (HR 1.66 p = 0.0001, and HR 1.53, p < 0.0001, respectively), MRD positivity at transplant (HR 2.18, p < 10−5 and HR 1.71, p < 10−5, respectively), and transplant in CR2 (HR 1.36, p = 0.026, and HR 1.26, p = 0.033, respectively), but positively affected by Karnofsky score ≥90 (HR 0.74, p = 0.012, and HR 0.7, p = 0.0002, respectively). Overall survival (OS) was also negatively influenced by concomitant FLT3‐ITD (HR 1.6, p = 0.0001), MRD positivity at transplant (HR 1.61, p < 10−5), and older age (HR 1.22 per 10 years, p < 0.0001), but positively affected by matched sibling donor (unrelated donor: HR 1.35, p = 0.012; haploidentical donor: HR 1.45, p = 0.037) and Karnofsky score ≥90 (HR 0.73, p = 0.004). These results highlight the independent and significant role of FLT3‐ITD, MRD status, and disease status on posttransplant outcomes in patients with NPM1‐mutated AML allowing physicians to identify patients at risk of relapse who may benefit from posttransplant prophylactic interventions.