Acute Myeloid Leukemia In 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.

Hairy Cell Leukemia Following Acute Myeloid Leukemia, Concomitant or Secondary?

A 62-year-old man diagnosed with acute myeloid leukemia (AML) showed limited responses to two courses of azacitidine (AZA)+Venetoclax (VEN) therapy. Twenty days after being transferred to our hospital, flow cytometry with broad antigen coverage and mutation analysis confirmed the presence of a second malignancy, hairy cell leukemia (HCL). Following haploidentical combined umbilical cord blood transplantation, the patient achieved complete remission (CR) for both AML and HCL. This CR has been maintained for the past 14 months. Patients with dual hematologic malignancies may not respond well to conventional therapy regimens. Early initiation of hematopoietic stem cell transplantation is beneficial for improving prognosis and extending overall survival.

Treatment of acute myeloid leukemia with active pulmonary tuberculosis with venetoclax‑based anti‑acute myeloid leukemia regimen combined with an intensive and then individualized anti‑tuberculosis regimen: A report of two cases.

Patients with concurrent acute myeloid leukemia (AML) and active pulmonary tuberculosis (TB) exhibit certain characteristics; cough, phlegm, fever, hemoptysis, weight loss and dyspnea are common symptoms of both diseases. These patients often cannot tolerate traditional intensive chemotherapy regimens, and finding the optimal timing in the treatment of both AML and active pulmonary TB is complex. Neglecting timely treatment can lead to serious complications and even fatal outcomes. The present paper reports two cases of patients with AML who were diagnosed with active pulmonary TB. The patients received intensive anti-TB treatment with isoniazid, rifampicin, pyrazinamide and ethambutol for 10-15 days. After three consecutive negative sputum smears, the patients in cases 1 and 2 were treated with a venetoclax, homoharringtonine and cytarabine regimen; and a venetoclax and azacitidine regimen for anti-AML therapy, respectively, as well as individualized anti-TB regimens of isoniazid, pyrazinamide, ethambutol and quinolone. Subsequently, both patients achieved complete remission of AML and their active TB was well controlled.

Spontaneous remission of acute myeloid leukemia with NPM1 mutation during pregnancy:a case report

Spontaneous remission of acute myeloid leukemia with NPM1 mutation during pregnancy:a case report

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.

Real-world (RW) antiemetic use and its association with duration of oral azacitidine (Oral-AZA) maintenance in patients (pts) with acute myeloid leukemia (AML) in the United States (US).

e23259 Background : Oral-AZA was approved in the US in Sep 2020 for maintenance treatment of transplant-ineligible pts with AML in remission following intensive chemotherapy. Approval was based on the QUAZAR trial (NCT01757535), which showed that Oral-AZA was associated with longer survival outcomes than placebo in this pt population. Both the prescribing information and clinical guidelines recommend antiemetic prophylaxis with Oral-AZA for at least the first 2 cycles to prevent the most common adverse events, nausea and vomiting. However, the extent to which antiemetics are being used with Oral-AZA in the real world is not yet well understood. This study aimed to examine the use of antiemetics among pts with AML receiving Oral-AZA in RW clinical practice and to determine whether this has any association with duration of therapy (DoT). Methods : This was a retrospective, observational study using Flatiron Health electronic health record data from Jan 2014 to Apr 2023. Eligible pts were ≥18 years and had a diagnosis of AML and ≥1 order for Oral-AZA on or after Sep 1, 2020. The index date was date of Oral-AZA initiation. Pts were followed until death, loss to follow-up, or the end of the study. Pt characteristics were assessed on the index date; antiemetic use was assessed at index and over the follow-up period. For each pt, each 28-day cycle of Oral-AZA was denoted as “covered” or “not covered” by antiemetics according to whether the pt had ≥14 days of antiemetics available during the cycle. Total DoT was measured for Oral-AZA using cumulative incidence curves and compared between pts with their first 2 cycles covered and those without. Results: 189 pts with AML were included. Mean age was 66 years, 52% were female, 56% had evidence of prior cytarabine use, and 10% had a prior stem cell transplant. 152 pts had ≥2 cycles of Oral-AZA. Overall, less than half of pts (48%) had a claim for an antiemetic on the index date. 16% never initiated an antiemetic between index and the end of follow-up; in the remaining 84%, the mean time from the index date to antiemetic initiation was 57 days and 29% had a time to antiemetic initiation of > 56 days. Only 9% (14/152) of pts had both their first 2 Oral-AZA cycles covered by antiemetics. Overall, pts had a median of 5 Oral-AZA cycles. Pts with antiemetic coverage of their first 2 cycles had a median of 8.5 Oral-AZA cycles versus 6 in those without. The median DoT was longer for pts with antiemetic coverage of cycles 1 and 2 than those without (258 days vs 154 days). Conclusions: These findings suggest that antiemetics are not currently widely utilized with Oral-AZA in RW US clinical practice. This may reduce DoT and could potentially impact the likelihood of observing RW efficacy outcomes like those in the QUAZAR trial. Further studies are required to examine the association between guideline-recommended antiemetic use and clinical outcomes.

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.

Peripheral blood stem cell versus bone marrow graft for patients ≥60 years undergoing reduced intensity conditioning haploidentical transplantation for acute myeloid leukemia in complete remission: An analysis of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

In the context of T-cell replete haploidentical stem cell transplantation (Haplo-SCT) using post-transplantation cyclophosphamide (PT-Cy), it is still unknown whether peripheral blood (PB) or bone marrow (BM) is the best graft source. While PB is associated with a higher incidence of graft-versus-host disease (GVHD), it may induce a stronger graft-versus-leukemia effect compared to BM, notably in acute myeloid leukemia (AML). From the EBMT registry database, we compared T-cell replete PB (n = 595) versus BM (n = 209) grafts in a large cohort of 804 patients over the age of 60 years who underwent Haplo-SCT with PT-Cy for an AML in first or second complete remission. The risk of acute GVHD was significantly higher in the PB group (Grade II-IV: HR = 1.67, 95% CI [1.10-2.54], p = 0.01; Grade III-IV: HR = 2.29, 95% CI [1.16-4.54], p = 0.02). No significant difference was observed in chronic GVHD or non-relapse mortality. In the PB group, the risk of relapse was significantly lower in the PB group (HR = 0.65, 95% CI [0.45-0.94], p = 0.02) and leukemia-free survival was significantly better (HR = 0.76, 95% CI [0.59-0.99], p = 0.04), with a trend toward better overall survival (HR = 0.78, 95% CI [0.60-1.01], p = 0.06). We conclude that in the specific context of Haplo-SCT with PT-Cy, PB grafts represent a valid option to decrease the risk of relapse and improve outcome of older AML patients who usually do not benefit from conditioning intensification.

Higher TIGIT+ γδ TCM cells may predict poor prognosis in younger adult patients with non-acute promyelocytic AML.

γδ T cells recognize and exert cytotoxicity against tumor cells. They are also considered potential immune cells for immunotherapy. Our previous study revealed that the altered expression of immune checkpoint T-cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT) on γδ T cells may result in immunosuppression and is possibly associated with a poor overall survival in acute myeloid leukemia (AML). However, whether γδ T-cell memory subsets are predominantly involved and whether they have a relationship with clinical outcomes in patients with AML under the age of 65 remain unclear. In this study, we developed a multicolor flow cytometry-based assay to monitor the frequency and distribution of γδ T-cell subsets, including central memory γδ T cells (TCM γδ), effector memory γδ T cells (TEM γδ), and TEM expressing CD45RA (TEMRA γδ), in peripheral blood from 30 young (≤65 years old) patients with newly diagnosed non-acute promyelocytic leukemia (also known as M3) AML (AMLy-DN), 14 young patients with AML in complete remission (AMLy-CR), and 30 healthy individuals (HIs). Compared with HIs, patients with AMLy-DN exhibited a significantly higher differentiation of γδ T cells, which was characterized by decreased TCM γδ cells and increased TEMRA γδ cells. A generally higher TIGIT expression was observed in γδ T cells and relative subsets in patients with AMLy-DN, which was partially recovered in patients with AMLy-CR. Furthermore, 17 paired bone marrow from patients with AMLy-DN contained higher percentages of γδ and TIGIT+ γδ T cells and a lower percentage of TCM γδ T cells. Multivariate logistic regression analyses revealed the association of high percentage of TIGIT+ TCM γδ T cells with an increased risk of poor induction chemotherapy response. In this study, we investigated the distribution of γδ T cells and their memory subsets in patients with non-M3 AML and suggested TIGIT+ TCM γδ T cells as potential predictive markers of induction chemotherapy response.

Abstract SY45-02: Engineering strategies based on receptors derived from gdT cells

Abstract SY45-02: Engineering strategies based on receptors derived from gdT cells

Transient Spontaneous Remission of Acute Myeloid Leukemia with Mutated RUNX1: A Rare Report.

Transient Spontaneous Remission of Acute Myeloid Leukemia with Mutated RUNX1: A Rare Report.

High Expression of ENO1 and Low Levels of Circulating Anti-ENO1 Autoantibodies in Patients with Myelodysplastic Neoplasms and Acute Myeloid Leukaemia.

In solid tumours, high expression of the glycolytic enzyme, α-enolase (ENO1), predicts for poor patient overall survival (OS), and circulating autoantibodies to ENO1 correlate positively with diagnosis and negatively with advanced disease. Although ENO1 is one of the most highly expressed genes in acute myeloid leukaemia (AML), its potential role as a biomarker in AML or its precursor, myelodysplastic neoplasms (MDS), has not been investigated. A meta-analysis of nine AML online datasets (n = 1419 patients) revealed that high ENO1 expression predicts for poor OS (HR = 1.22, 95% CI: 1.10-1.34, p < 0.001). Additionally, when compared to AML in remission (n = 5), ENO1 protein detected by immunohistochemistry was significantly higher at diagnosis in bone marrow from both AML (n = 5, p < 0.01) and MDS patients (n = 12, p < 0.05), and did not correlate with percentage of blasts (r = 0.28, p = 0.21). AML patients (n = 34) had lower circulating levels of ENO1 autoantibodies detected by ELISA compared to 26 MDS and 18 controls (p = 0.003). However, there was no difference in OS between AML patients with high vs. low levels of anti-ENO1 autoantibodies (p = 0.77). BM immunostaining for ENO1 and patient monitoring of anti-ENO1 autoantibody levels may be useful biomarkers for MDS and AML.

Matched unrelated donor transplantation versus haploidentical transplantation with post-transplant cyclophosphamide in children with acute myeloid leukemia: a PDWP-EBMT study.

In children with acute myeloid leukemia (AML) who lack a human leukocyte antigen (HLA) identical sibling, the donor can be replaced with an HLA-matched unrelated donor (MUD) or a haploidentical donor (haplo). We compared outcomes of patients <18 years with AML in first and second complete remission (CR1 and CR2) undergoing a hematopoietic stem cell transplantation (HCT) either with a MUD with anti-thymocyte globulin (ATG) (N=420) or a haplo HCT with post-transplant cyclophosphamide (PT-CY) (N=96) after a myeloablative conditioning regimen (MAC) between 2011 and 2021, reported to the European Society for Blood and Marrow Transplantation. A matched pair analysis was performed to adjust for differences among groups. The final analysis was performed on 253 MUD and 95 haplo-HCT. In the matched cohort, median age at HCT was 11.2 and 10 years and median year of HCT was 2017 and 2018, in MUD and haplo-HCT recipients, respectively. The risk of grade III-IV acute graft-versus-host disease (aGVHD) was significantly higher in the haplo group (hazard ratio [HR]=2.33, 95% confidence interval [CI]: 1.18-4.58; P=0.01). No significant differences were found in 2 years overall survival (OS; 78.4% vs. 71.5%; HR=1.39, 95% CI: 0.84-2.31; P=0.19), leukemia-free survival (LFS; 72.7% vs. 69.5%; HR=1.22, 95% CI: 0.76-1.95; P=0.41), CI of relapse (RI; 19.3% vs. 19.5%; HR=1.14, 95% CI: 0.62-2.08; P=0.68) non-relapse-mortality (NRM; 8% vs. 11%; HR=1.39, 95% CI: 0.66-2.93; P=0.39) and graft-versus-host free relapse-free survival (GRFS; 60.7% vs. 54.5%, HR=1.38, 95% CI: 0.95-2.02; P=0.09) after MUD and haplo-HCT respectively. Our study suggests that haplo-HCT with PT-CY is a suitable option to transplant children with AML lacking a matched related donor.

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.

Multiple Hepatic Microabscesses Caused by Magnusiomyces Clavatus in a Patient with Acute Myeloid Leukemia: A Case Report

Abstract Introduction/Objective Invasive fungal infections can result in significant complications for acute myeloid leukemia (AML) patients undergoing induction chemotherapy. While Candida and Aspergillus are the most common fungal pathogens, Magnusiomyces clavatus (Geotrichum clavatum) is a rare fungal pathogen that has been reported to cause invasive infection in immunocompromised patients. Here, we report a case of fungemia and hepatic microabscess with Magnusiomyces clavatus in an 18-year-old female with AML. Methods/Case Report An 18-year-old female with AML in remission after induction chemotherapy presented with fevers. Further work-up revealed fungemia on her blood culture. While awaiting culture speciation, numerous hepatic lesions were identified on the abdominal CT scan, which were biopsied. The liver biopsy showed aggregates of fungi with septate hyphae on silver-stained sections. The initial morphologic differential diagnosis included Aspergillus and Mucormycosis. Her blood cultures ultimately revealed fungemia with Magnusiomyces clavatus (Geotrichum clavatum), a yeast that is rising in prevalence, particularly among neutropenic and leukemic patients. The morphology of fungi detected in the liver biopsy resembled Magnusiomyces clavatus and a subsequent PCR testing confirmed that the fungi present was Magnusiomyces clavatus. She was started on voriconazole and liposomal amphotericin B. She became afebrile with no growth on blood cultures for several days and was discharged to outpatient follow-up. Results (if a Case Study enter NA) N/A Conclusion This case highlights the clinical significance of Magnusiomyces clavatus in immunocompromised patients, particularly those with AML, and emphasizes the importance of considering rare fungal pathogens in such patients who present with fever. Treatment with voriconazole and liposomal amphotericin B can be helpful in relieving symptoms.

Comparing Older Matched Related to Younger Matched Unrelated Donors in Acute Myeloid Leukemia in Remission Using Post-Transplant Cyclophosphamide

Backgroud. Over the past 25 years, the landscape of allogeneic stem cell transplantation (allo-SCT) changed from being rarely performed in patients 50 years or older to accounting for a little less than half of the transplantations reported in USA and Europe. Older patients will on average have older matched related siblings (MRD) being considered as donors with issues such as comorbidities, risk of clonal haematopoiesis of indeterminate potential, and impaired immune and regenerative potential of stem cells. Although younger HLA-matched unrelated donors (MUD) are an important alternative in this context, it remains unclear whether the use of MUD is associated with better outcomes. This is especially true in the context of post-transplant cyclophosphamide (PTCy) as graft-versus-host disease (GvHD) prophylaxis. Methods. The aim of this study was to compare the graft-relapse-free survival (GRFS) for patients diagnosed with acute myeloid leukemia (AML) in first complete remission (CR1), aged 50y or more, and having received a first allo-SCT from a 10/10 MUD younger than 40y or a MRD older than 50y using PTCy for in-vivo T-cell depletion. All transplants were performed between 2015-2021 at the EBMT centres. Results. A total of 410 consecutive patients were included, 172pts receiving a MRD, 238pts transplanted from a MUD. All patients with detailed conditioning regimen dosages were classified according to the transplant conditioning intensity (TCI) score in low (1-2), intermediate (2.5-3.5), high (4-6). TCI-score was available for 345 patients and was as follows: low in 53pts (36.8%), intermediate in 79pts (54.9%) and high in 12pts (8.3%) for MRD, low in 91pts (45.3%), intermediate in 93pts (46.3%) and high in 17pts (8.5%) for MUD (p=0.26). Only patients with available TCI-score were analysed. In univariate analysis the 2-year GRFS was 58% (49.8-65.3%) for TCI intermediate-high and 43.1% [34.3-51.5] for TCI low (p=0.005). In TCI-score intermediate-high non-relapse mortality (NRM) wasn't higher compared to TCI-score low (12.7% [12.2-24] vs 13.7% [8.4-20.3], p=0.53) but relapse incidence (RI) was lower (17.7% [12.2-24] vs 33.2% [25.1-41.5], p=0.003). As a strong interaction between TCI-score and type of donor was found, we compared transplant outcomes between MRD and MUD separately for TCI-score low and TCI-score intermediate-high. In TCI-score low, 2-year GRFS was 44.4% [33.5-54.8] for MUD and 40.9% [26.4-54.9] for MRD (p=0.83) (Figure 1A). In multivariable analysis (MVA) type of donor was not a risk factors for neither GRFS (HR 0.98, CI: 0.57-1.69; p=0.95) nor for any other transplant outcome. In TCI-score intermediate-high, 2-year GRFS was 67.2% [55.8-76.2] for MUD and 46.1% [34.4-57.1] for MRD (p=0.001) (Figure 1B). In MVA MUD were associated to better GRFS (HR 0.41, CI: 0.24-0.7; p=0.001), lower NRM (HR 0.19, CI: 0.07-0.55; p=0.002) and lower RI (HR 0.32, CI: 0.14-0.73; p=0.007) without advantages in terms of neither aGvHD nor cGvHD. Conclusions. In patients with AML in CR1, aged 50y or more and receiving a conditioning regimen with TCI-score ≥ 2.5 in the PTCy setting, a MUD younger than 40y is associated to longer GRFS, lower NRM and lower RI compared to a MRD older than 50y. For patients receiving regimens with TCI-score low transplant outcomes are independent on the type of HLA-matched donor.

Clonal Dynamics of Gene Mutations during Oral Azacitidine Maintenance Therapy in Patients with Acute Myeloid Leukemia (AML): Outcomes from the QUAZAR AML-001 Trial

Background: Acute myeloid leukemia (AML) is a genetically heterogeneous disease and despite some patients (pts) achieving remission with frontline intensive chemotherapy (IC), most eventually relapse. In the QUAZAR trial (NCT01757535), oral azacitidine (Oral-AZA) prolonged overall survival and relapse-free survival (RFS) vs placebo (PBO) in older pts with AML in remission post IC (Wei et al, N Engl J Med 2020). Here, we studied the molecular landscape and clonal dynamics of pts treated with Oral-AZA/PBO in the QUAZAR study. The mutational landscape for older patients with AML in remission after IC may be confounded by persistence of pre-leukemic (PL) or age-related clonal hematopoietic (CH) variants. The implications of these residual mutations on disease relapse and treatment (Tx) outcome are largely unknown. Aims: 1) characterize the mutational landscape from remission bone marrow at baseline (BL) prior to Oral-AZA maintenance (i.e., in remission post-IC); 2) determine the fate of variants over time and at relapse in the Oral-AZA vs PBO arms; 3) examine associations between mutational landscape and relapse risk between Tx arms. Methods: In QUAZAR, 472 pts (≥55 years) with AML with intermediate- or poor-risk cytogenetics in remission after IC (BL) were randomized 1:1 to Oral-AZA or PBO. Among pts who consented to biomarker analyses (n=310), targeted NGS (37 myeloid genes) was performed on bone marrow DNA at BL (Oral-AZA/PBO: n=165/145), cycle 6 (n=107/79) and relapse (n=83/77). Mean NGS coverage was 13K reads and median minimal detectable variant allele frequency (VAF) was 0.12% (range: 0.02-2.79). Clonal variants were categorized by the longitudinal association between VAF and blast percentage (slope of leukemic variants &amp;gt;0.1; PL/CHIP &amp;lt;0.1). RFS was computed from time of randomization to relapse (≥5% BM blasts) or death, estimated by Kaplan-Meier methods. Hazard ratios (HR) and 95% confidence intervals (CI) were obtained from Cox regression models. Nominal P values were derived from log-rank tests. Results: In the NGS cohort (n=310), median RFS (mRFS) for Oral-AZA vs PBO was 10.2 vs 4.7 months (mo), respectively. At BL, prior to maintenance Tx, 221 (71.3%) had detectable mutations, the most frequently occurring mutations (&amp;gt;5% of pts) were in DNMT3A (28.4%), TP53 (15.5%), IDH2 (12.3%), TET2 (11.9%), SRSF2 (11.0%), IDH1 (6.1%) and ASXL1 (5.5%). At BL, 110/310 (35.5%) pts had VAF &amp;gt;5%, potentially representing persistence of PL/CH variants in remission. Comparative analysis of all gene variants at BL and relapse revealed that some VAFs increased with blast frequency, while other variants remained largely static. Applying a variant classification algorithm, 97/258 pts had potential leukemic variants detected at BL. These involved DNMT3A (16.1%), SRSF2 (7.1%), TP53 (7.1%) and IDH2 (5.7%). PL/CH variants included DNMT3A (17.5%), TP53 (8%), IDH2 (5.7%) or TET2 (5.7%). TP53 was detected in 19.4% PL/CH variants (mean VAF 1.7%; range 0.2-13.4). Notably, when analyses were limited to potential leukemic variants at BL (&amp;lt;5% VAF), their presence was correlated with worse RFS (PBO: mRFS for 0, 1 or 2+ mutations was 6.1, 4.7 or 1.9 mo, respectively). The presence of ≥2 leukemic mutations was associated with shorter RFS only in PBO arm (mRFS vs &amp;lt;2 mutations: 1.9 vs 5.7 mo, P=0.02; Oral-AZA: 10.2 vs 10.2 mo). RFS favored Oral-AZA in pts with low mutational burden at BL (&amp;lt;2 mutations: mRFS 10.2 vs 5.7 mo [ P=0.003]; n=145 vs 122 [PBO]), and in a small subset of pts with higher mutational burden (≥2 mutations: mRFS 10.2 vs 1.9 mo [ P=0.008]; n=14 vs 13 [PBO]). Oral-AZA prolonged RFS vs PBO in pts across most mutational subtypes, when assessed for mutations that were deemed potentially leukemic (Figure). At relapse, the frequency of mutations, hotspots variants and co-mutations were comparable between Tx arms. Mutation-based pathway analysis indicated Ras pathway genes were enriched at relapse in PBO (28.6%) vs Oral-AZA arm (14.5%, P=0.03). Summary: In pts with AML in remission post IC, post-hoc analyses showed that Oral-AZA improved RFS vs PBO regardless of the mutational landscape at baseline. The spectrum of mutations at relapse was similar between Tx arms, suggesting that Oral-AZA maintenance prolongs remission without altering mutational heterogeneity.