ABSTRACT:CPX-351, a novel liposomal formulation of cytarabine and daunorubicin, represents the standard of care in fit patients with acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) and therapy-related AML (t-AML). Considering its better safety profile than conventional intensive chemotherapy, we investigated its cost-to-benefit ratio, in terms of overall survival and of mortality, in a large multicentric series of AML-MRC and t-AML receiving CPX-351 outside clinical trials between 2019 and 2022. Patients were classified as fit or unfit for intensive chemotherapy through a comprehensive evaluation of age, comorbidities, and performance status by adopting Italian Society of Hematology/Italian Society of Experimental Hematology/Gruppo Italiano per il Trapianto di Midollo Osseo (SIE/SIES/GITMO) criteria. Disease risk was defined according to the European LeukemiaNet 2017 classification. Before treatment start, 328 of 403 (81.4%) patients were classified as fit and 75 of 403 (18.6%) as unfit. Three hundred and ninety-six had a full genetic/cytogenetic profile, with 17 (4%) being categorized as favorable risk, 162 (41%) intermediate risk, and 217 (55%) adverse risk according to European LeukemiaNet 2017. After induction, 230 of 403 (57.1%) patients achieved complete remission, with no differences between fit (57.3%) and unfit (56%) patients. However, the 2 groups significantly differed in terms of survival (median overall survival, 18 months vs 8 months for fit and unfit patients, respectively) and of 28- and 100-day mortality (4.6% vs 10.7% at 28 days and 14.3% vs 32% at 100 days for fit and unfit patients, respectively). In conclusion, the SIE/SIES/GITMO criteria distinguished patient subgroups with different short- and long-term outcomes after treatment with CPX-351. The update or design of dedicated fitness criteria could represent a future and valid strategy to optimize the use of this specific treatment.

Objectives:To compare the efficacy of pre-emptive antifungal therapy (PAT) and empirical antifungal therapy (EAT) in patients with febrile neutropenic acute leukaemia (AL) with/without anti-mold prophylaxis. Methods:We included 92 patients with AL and neutropenia with fever unresponsive to empiric antibiotics, stratified by posaconazole prophylaxis to receive EAT (n = 40) or PAT (n = 52). In the PAT group, a standardized diagnostic workup for the detection of invasive fungal infection (IFI) was performed. The study endpoints were antifungal therapy initiation, IFI documentation, safety, and cost. Results:Posaconazole prophylaxis was equally distributed among the patients (overall 55.4%). Antifungal therapy was started in 58% of the patients in the PAT group versus 100% in the EAT group (P < 0.01; 95% CI: 0.42 [0.28-0.55]). In the EAT and PAT groups, overall proven/probable IFI rates were 2% and 17%, respectively (P = 0.02; 95%CI: -0.14 [-0.26 to -0.03]) and 4% and 10% in patients with posaconazole prophylaxis, respectively (P = 0.3; 95% CI: -0.06 [-0.20-0.07]). At hospital discharge, mortality was 19% in the EAT and 5% in the PAT groups (P = 0.02; 95% CI: -0.14 [-0.26 to -0.03]), unrelated to the use of posaconazole prophylaxis, and no IFI-related death was observed. The mean costs per patient were €7681 and €3344 in the EAT and PAT groups, respectively (P = 0.003; 95% CI: €4337 [€1814-6860]). Adverse reactions to antifungals were similar between the groups. Conclusions:In patients with persistently febrile neutropenic AL, PAT was safe and effective and reduced the use and costs of antifungals, irrespective of anti-mold prophylaxis, compared with empirical treatment.

Introduction: Autologous stem cell transplantation (ASCT) is regaining interest as a consolidation strategy for acute myeloid leukemia (AML) patients with favorable/intermediate risk and measurable residual disease (MRD) negativity. In fit older adults, its role remains debated due to concerns regarding toxicity and stem cell collection. Aim: To evaluate the long-term outcomes of ASCT in AML patients aged ≥60 years in first complete remission (CR1). Methods: We retrospectively analyzed 43 non-M3 AML patients (median age 64, range 60-72) who underwent ASCT in CR1 across five centers (2000-2024). Risk was stratified by ELN 2017. Primary endpoints were overall survival (OS) and disease-free survival (DFS). Results: The cohort included 22 favorable-risk and 21 intermediate-risk patients. Most (88%) achieved CR1 after one induction course. Median neutrophil and platelet engraftment occurred at 13 and 15 days, respectively. Grade III/IV infections were observed in 28% of patients; transplant-related mortality was low at 4%. At a median follow-up of 77 months, 5-year OS and DFS were 51% (95% CI: 37-70%) and 47% (95% CI: 34-65%), respectively. OS was significantly superior in favorable- versus intermediate-risk patients (68% vs. 35%, p = 0.027), with a similar trend for DFS (57% vs. 35%, p = 0.07). The number of consolidation cycles did not impact survival outcomes. Conclusions: This multicenter study confirms that ASCT is a feasible and effective consolidation strategy for selected fit AML patients aged ≥60. The low mortality and encouraging survival, particularly in favorable-risk subgroups, support ASCT as a valid alternative to prolonged chemotherapy or maintenance.

Background: Prognosis of intermediate and high-risk acute myeloid leukemia (AML) remains poor, with a 2-year estimated overall survival of about 30-40% in the young population. AML1718 trial combined venetoclax with fludarabine, idarubicine, and cytarabine (V-FLAI) with the specific aim of improving cure rate of these AML patients. Primary end-point analysis of the AML1718 trial demonstrated remarkable efficacy in term of probability of complete remission (CR) and mesurable residual disease negativity (MRD), 79% and 64%, respectively. Hereby, we present the mature data with overall survival and disease free survival analysis of the study. Methods: The GIMEMA AML1718 phase 1/2 multicenter trial (NCT03455504) enrolled patients from Feb 2019 to Feb 2023 and investigated safety and efficacy of V-FLAI as a first-line treatment for newly diagnosed adult patients with ELN 2017 intermediate- or high-risk AML. The study followed a modified two-stage Simon's design; safety of the combination of venetoclax 400 or 600 mg and FLAI was established in a safety run-in (6+6 patients); the two different dosages of venetoclax were randomly compared in part 1, with no significant difference (22+23 patients). Part 2 consisted in a confirmatory cohort of 67 patients treated at the lower effective dosage, as predefined (V-FLAI 400 mg). A second inductin was possible for patients without complete remission (CR/Cri/CRh). In patients responding to single induction, cytarabine-based consolidation were administered based on center guidelines. VEN administration was discontinued until recovery for patients achieving remission by day 21 and during consolidation courses; predefined dose adjustments were planned for patients receiving posaconazole. Allogeneic hematopoietic stem cell transplant (HSCT) was indicated as soon as possible. In part 2, a centralized MRD assessment was performed. Baseline characterization of patients with 91-genes panel is ongoing, and will eventually be presented at the meeting. Results: Mature follow-up data are available for all the 124 consecutive patients who received V-FLAI in the study. As previously reported, the median age was 55 years (ranging from 18 to 66), with 70 patients (56%) being male. The vast majority of the patients were of European ancestry. All the patient had baseline ECOG performance status <2. At baseline, 67 patients (54%) were locally classified as intermediate risk and 57 patients (46%) as high-risk, mostly basing on cytogenetic analysis, NPM1 and FLT3 status; the classification will be updated basing on centralized genetic analysis. FLT3 mutation was positive in 19 patients (15.3%), NPM1 mutation in 3 patients (2.4%), while 17 patients (14%) had a seconday AML. In our set, 95 patients received V-FLAI 400 mg and 29 patients V-FLAI 600 mg. After induction, 74 patients (59.6%) proceded to consolidation and 71 received HSCT (57.2%, of which 63, 93% in 1st CR). With a median follow-up of 22 months (IQR 11 - 31) , 1- and 2- years overall survival were 61% (95% CI 53-71) and 48% (95% CI 38-59) while 1- and 2- years disease free survival were 60% (95% CI 50-72) and 46% (95% CI 35%-60%), respectively. After 2 years, death and relapse probability lowered, and shape of the curves seems to suggest a plateau. Central MRD proven predictive value on disease free survival, results will be detailed presented in a separate abstract. As far as safety is of concern, we confirmed the low-incidence of treatment-related mortality, with 5 deaths recorded during induction (4.0%, no difference according VEN dose), a safety profile comparable with other intensive inductions regiments and no instances of graft failure or higher-than-expected incidence of graft-versus-host disease. No severe late effect of the combination was reported up to now. Conclusions: V-FLAI efficacy translated in long term survival for most of the treated patients. No unexpected long term toxicity or transplant-related toxicity emerged. Predicted 2 years survival seems to favor the adoption of this combination over other alternatives in the non-low-risk, fit population; a randomized trial comparison with the standard of care is warranted.

Abstract: The standard induction treatment for acute myeloid leukemia (AML) has limited efficacy for patients with non–low-risk AML. We conducted a multicenter study phase 1b/2, Gruppo Italiano Malattie EMatologiche dell'Adulto AML1718, to investigate the safety and efficacy of venetoclax (VEN) combined with fludarabine, cytarabine, and idarubicin (V-FLAI) as an induction therapy for patients with non–low-risk AML aged <65 years and at intermediate or high European LeukemiaNet risk. After a safety run-in, patients were randomly allocated to VEN 400 mg or VEN 600 mg cohorts. The primary objectives were safety and composite complete remission (bone marrow blasts of <5% with any recovery). We report a predefined interim analysis after 57 patients. Median exposure to VEN during induction was 22 days. Effectiveness and safety were similar between VEN 400 mg and VEN 600 mg cohorts. The 60-day mortality rate was 5.8%. Prolonged aplasia was observed in patients receiving high doses of cytarabine during consolidation. Composite CR was achieved in 84% of patients. With a median follow-up of 20.6 months, 1-year overall survival was 71%, 1-year disease-free survival was 66.2%, and 1-year cumulative incidence of relapse was 24%. V-FLAI is an effective induction therapy for young and fit patients. Fifty-five more patients will be enrolled in part 2; they will receive VEN 400 mg + FLAI as predefined and will be evaluated centrally for measurable residual disease. This trial was registered at www.clinicaltrials.gov as #NCT03455504.

OBJECTIVES:Azacitidine (AZA) combined with venetoclax (VEN) as an outpatient treatment of unfit patients with acute myeloid leukemia (AML) has been infrequently investigated. METHODS:We report on 65 elderly AML patients: 35 patients received AZA + VEN as first-line and 30 after progression on prior treatment with AZA (R/R group). Thirty-eight patients were treated as outpatients, while 27 were hospitalized. The overall survival (OS) and event-free survival (EFS) were calculated, and predictive factors were assessed using Cox regression models. RESULTS:Inpatients were slightly younger, with a median age of 72 versus 74 years in outpatients (p = 0.015). Median WBC was higher in inpatients (median 7.3 × 109/L vs. 2.9 × 109/L, p = 0.020). Median marrow blast count was 43% in inpatients versus 25.5% in outpatients (p = 0.042). Treatment setting emerged as a key predictive factor for infection development during Cycle 1 in both univariate (p = 0.016) and multivariate analysis (p = 0.043), in the overall cohort. Inpatients had a significantly higher infection rate (81.4%) versus outpatients (44.7%, p = 0.004). In R/R group, 1-year EFS was 68% for outpatients versus 38% for inpatients (p = 0.009). One-year OS was 77% in outpatients versus 38% in inpatients (p = 0.052). CONCLUSIONS:In most instances, outpatient administration of Cycle 1 of AZA + VEN should be preferred as a beneficial option.

This case-based review examines the spectrum of leukemic ocular involvement, focusing on its prognostic implications. A rare case of relapsed acute myeloid leukemia (AML) in a 63-year-old man is presented, featuring simultaneous orbital proptosis, adnexal involvement, choroidal and retinal infiltration, and hemorrhagic changes affecting both the anterior and posterior segments. This constellation of findings, affecting multiple ocular structures concurrently, highlights the eye’s potential role as a sanctuary site for leukemic cells and underscores the diagnostic challenge of distinguishing direct infiltration from treatment-related or secondary vascular damage. This case, integrated with a literature review, emphasizes that multifocal ocular signs may serve as early indicators of leukemic relapse and reinforce the need for close collaboration between ophthalmologists and hematologists in guiding patient management.

Among the cancer types that commonly affect men of reproductive age there are leukemias. In literature, little is known about the correlation between semen quality and acute leukemia. It could be assumed that the disease may evoke a systemic response mediated by cytokines secreted by tumor cells, which may have an impact on semen parameters. Significant advances in survival rates due to new therapeutic strategies have focused attention on fatherhood and fertility preservation. The aim of this study was to evaluate semen quality of patients with acute leukemia before chemotherapy. We also evaluated semen parameters after therapy in a subgroup of patients and we collected fertility information. Finally, we collected information about the feasibility of the semen cryopreservation and evaluated any shifts in the approach to fertility preservation in these patients. A retrospective study was conducted, and it included the collection of data related to: semen analysis, information related to paternity desire and childbearing, number of cryopreservations performed over the years and the feasibility of the procedure. The median semen characteristics of these patients were above the 25° percentile, before cancer treatment. After therapies, an increase of the percentage of azoospermic at one year of follow-up can be observed. Four patients succeeded in achieving fatherhood through at least one cycle of assisted reproductive technology. These results allow us to recommend increased awareness among onco-hematologists about cryopreservation of semen for acute leukemia patients to ensure that they can become parents in the future and face the treatment course with greater confidence.

"Helping professions" are characterized have intense involvement between operator and user. Working in such circumstances can lead to a typical emotional stress called "burnout". The aim of this study was to evaluate the perceived 46 state of physical and mental health, and verify the existence of burnout among health care workers of Hematology unit in a Teaching Hospital. Anonymous questionnaires were administered to healthcare professionals (physicians, nurses, health care workers). It includes socio demographic variables, the Maslach Burnout Inventory (MBI) and SF12 also. The MBI captures three dimensions of burnout: emotional exhaustion (EE), depersonalization (DP), and personal accomplishment (RP); whereas the SF12 defines two quality of life scores:Mental Score (MCS) and Physical Score (PCS).Of 120 operators 70 individuals responded to the study.The questionnaire shows that the burnout levels were high in the followed part of the sample: 40% have high level of EE; 24% of DP; 15% of RP. The correlation analysis between SF12 and MBI undelines followed significance: r = -0.576 with p<0.001 between EE and MCS; r = 0.557 with p<0.001 between EE and DP.The three multivariate analysis refer that: the EE is associated indirectly to PCS and MCS with p<0.05; the DP is directly and significantly (p<0.05) associated to MCS, "years of work" and to female gender. The RP dimension no underlines significant associations with variables studied.The findings were consistent with the type of work and assisted patients (chronic patient, often with poor prognosis and low expectations in terms of care and survival) that contribute to stressful situations. Personal fulfillment, instead, seems to be quite high in this contest. The relatively small sample couldn't represent the world of health care workers in hematological units, but there is no doubt that a systematic assessment of burnout, to investigate the causes of burnout are main elements to identify the potential solutions to address the phenomenon. Additional investigations of the MBI dimensions using biggest samples would be useful to confirm the results in order to generate burnout reduction measures by institutional and national policies.

CPX-351 has been approved for patients with therapy-related acute myeloid leukemia (tAML) or AML with myelodysplasia-related changes (MRC-AML). No extensive data are available on measurable residual disease (MRD) and long-term clinical outcome using CPX351 in AML in real life. We retrospectively collected data from 168 patients in 36 centers in France and Italy who had received 1 or 2 cycles of induction with CPX-351. All patients were aged >18 years and had newly diagnosed, untreated t-AML or MRC-AML. With a median follow-up of 3 years, the median overall survival (OS) was 13.3 months. The median OS was 20.4 months vs 12.9 months for patients with MRD below or above 10(-3), respectively (P = .006). In a multivariate analysis, only MRD >10(-3) was associated with a poorer OS toward a better median OS in patients who underwent hematopoietic stem cell transplantation with MRD <10(-3) (not reached vs 26.0 months; P = .06). Achievement of MRD negativity contributed to the improvement of OS in the overall population and, maybe, in patients receiving transplant. These data provide the rationale for the 2 ongoing studies evaluating CPX-351 vs 7+3 in non-MRC-AML and non-t-AML using MRD as the primary end clinical trial.

BACKGROUND AND METHODS:This real-world study evaluated the clinical effectiveness of gilteritinib in 205 patients with relapsed or refractory (R/R) FLT3-mutated acute myeloid leukemia (AML) enrolled in the Italian expanded access since January 2018. RESULTS:Of the 205 patients, 124 (60.5%) received gilteritinib as a bridging therapy to allogeneic stem cell transplantation (allo-SCT), achieving complete remission in 52.4% (n = 65). The median overall survival (OS) for the entire cohort was 11.0 months, with estimated OS rates of 46.8% at 1 year and 28.5% at 3 years. Sixty patients (48% of those bridged) underwent allo-SCT after a median of 3.7 months on gilteritinib, achieving posttransplant OS rates of 65.2% at 1 year and 56.1% at 3 years. The acquisition of FLT3 mutations at relapse and the presence of TP53 co-mutations were significantly associated with inferior outcomes. Among 46 patients (22.4%) who relapsed after allo-SCT, gilteritinib treatment yielded an overall response rate (ORR) of 54.3%, a median OS of 11.1 months, and 1- and 3-year OS rates of 49.5% and 15.5%, respectively. Additionally, 35 patients (17.1%) previously treated with nonintensive chemotherapy received gilteritinib until disease progression or intolerance, achieving an ORR of 11.4%, a median OS of 5.9 months, and a 1-year OS rate of 29.0%. CONCLUSIONS:These real-world data confirm that clinical outcomes achieved with gilteritinib in patients with R/R FLT3-mutated AML are consistent with those observed in pivotal clinical trials. Notably, approximately half of the transplant-eligible patients were successfully bridged to allo-SCT and demonstrated encouraging long-term survival.

Internal tandem duplications of FLT3 (FLT3-ITD) in acute myeloid leukemia (AML) are associated with poor outcomes. CD99 is frequently overexpressed in AML and emerged as potential diagnostic marker. Ninety consecutive newly diagnosed AML patients were retrospectively analyzed. Immunophenotypic profiles were correlated with molecular assessment. Patients were categorized into FLT3-ITDmut (28.9%) and FLT3wt (71.1%). CD99 was expressed in 100% of FLT3-ITDmut-AML compared to 48% in FLT3wt cases. FLT3-ITDmut-AML exhibited higher CD99 expression percentage. CD34 expression was lower in FLT3-ITDmut-AML, with a positivity rate of 31% versus 83% in FLT3wt cases. Multivariate analysis confirmed that CD99 positivity (OR 17.67; p = 0.010) and CD34 negativity (OR 10.00; p = 0.039) were independently associated with FLT3-ITDmut-AML. CD99 and CD34 displayed NPVs of 100% and 86.9%, respectively, with moderate PPVs (45.6% and 62.1%) for the diagnosis of FLT3-ITDmut-AML. CD99 is a highly reliable marker in FLT3-ITDmut-AML and its absence virtually excludes the presence of a FLT3-ITD mutation.

Central venous catheter-related infections are of particular importance in onco-hematological patients. Candida parapsilosis is generally reported as a mild pathogen, however it is able to effectively colonize intravascular devices and potentially give rise to sustained fungemias. Here we report a case of invasive, potentially lethal C. parapsilosis disseminated infection in a neutropenic patient affected by chronic myeloid leukemia with blast crisis. We underline the importance of removing the central venous catheter as potential source of infection as soon as possible during the course of candidemia, and not replacing it with other polyurethan intravascular devices, which pose a risk for the maintenance of the fungemia despite the administration of the best antifungal therapy available.

Background: The introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has radically improved the prognosis of acute promyelocytic leukemia (APL), with cure rates above 80%. While relapse occurs in less than 20% of cases, addressing this issue remains challenging. Identifying effective salvage therapies for relapsed APL is crucial to improve patient outcomes. Methods: A retrospective analysis was performed on a multicentric cohort of 67 APL patients in first relapse, treated in three Italian hematology centers from June 1981 to November 2021. The overall survival (OS) and cumulative incidence of relapse (CIR) were calculated, and predictive factors were assessed using Cox regression models. Results: Overall, 61 patients (91%) received ATO ± ATRA (40.3%), chemo-based regimens (40.3%), or ATRA ± Gemtuzumab ozogamicin (GO) (10.4%). Complete remission (CR) was achieved in 98.2% of patients (molecular CR, n = 71.4%). With a median follow-up time of 54.5 months, the 5-year OS was 73% in the ATO ± ATRA group, 44% in the chemo-based group, and 29% in the ATRA ± GO group (p = 0.035). The 5-year OS rate was also higher for transplant recipients vs. non-recipients within the chemo-based cohort (50% vs. 33%, p = 0.017), but not in the ATO-based cohort (p = 0.12). ATO-based salvage therapy resulted in better OS in both univariate (p = 0.025) and multivariate analyses (p = 0.026). The 2-year CIR was higher in patients without molecular CR vs. patients in molecular CR (66% vs. 24%, p = 0.034). Molecular CR was a significant predictor of second relapse in both univariate (p = 0.035) and multivariate analyses (p = 0.036). Conclusions: Our findings support the efficacy of ATO-based therapies in first relapse of APL and confirm the achievement of molecular remission as an independent outcome predictor in both first and second APL relapse.

SummaryAll‐trans‐retinoic acid (ATRA) and arsenic trioxide (ATO) represent the standard of care for low‐intermediate risk acute promyelocytic leukaemia (APL). Leucocytosis during induction with ATRA‐ATO represents a common complication with an incidence of up to 60%. To identify predictive factors for this complication, we studied a cohort of 65 low‐intermediate risk APL patients treated with ATRA‐ATO in three highly specialized Italian centres. Overall, 39/65 (60%) patients developed leucocytosis, with a peak in leucocyte count being most frequent in the second week from diagnosis. All cases were successfully managed with hydroxyurea. Predictive factors for leucocytosis in univariate analysis were lower platelet counts (odds ratio [OR] 0.98, 0.97–1.00, p = 0.018), lower fibrinogen levels (OR 0.36, 0.17–0.66, p = 0.003), higher bone marrow blast infiltration (OR 1.03, 1.01–1.07, p = 0.021) and CD117 expression by flow (OR 1.04, 1.01–1.08, p = 0.012). Multivariate analysis confirmed lower levels of fibrinogen at diagnosis as the strongest predictive factor for the development of leucocytosis (OR 0.36, 0.15–0.72, p = 0.009). Differentiation syndrome (DS) occurred only in patients developing leucocytosis showing a strict correlation with rising leucocytes counts (16/39 vs. 0/26, p < 0.001). In addition, other treatment‐related complications including QTc prolongation, cardiac events, liver, and haematological toxicities were significantly more frequent in patients experiencing leucocytosis (22/39 vs. 3/26, p < 0.001). In conclusion, APL patients undergoing ATRA‐ATO therapy with lower fibrinogen levels and platelet counts at diagnosis and with a massive bone marrow blast infiltrate should be carefully monitored for the development of leucocytosis during induction. DS and other treatment‐related complications seem to occur almost exclusively in patients developing leucocytosis, who should necessarily receive DS prophylaxis and more intensive monitoring and supportive therapy to prevent treatment complications.

We analyzed 140 patients with a median age of 51 years; 21% had WBC ≥ 100 × 109/L, and 52% had an NPM1 co-mutation. Until 2018, 101 patients received chemotherapy; thereafter, 39 received 3+7+midostaurin. The overall CR rate was 64%, higher in NPM1 mutant patients (73%). Univariate analysis showed that NPM1 mutation (p = 0.032) and WBC < 100 × 109/L (p = 0.013) positively influenced the response, with a trend for FLT3i administration (p = 0.052). Multivariate analysis confirmed WBC count as an independent prognostic factor (p = 0.017). In CR1, 41/90 patients underwent allogeneic and 18 autologous transplantation. The median EFS was 1.1 vs. 1.6 years in autografted and allografted patients, respectively (p = 0.9). The one-year non-relapse mortality was 0.00% for autologous and 28% for allogeneic transplants (p = 0.007); CIR at 1 and 3 years was higher in autologous transplants (39% vs. 15% and 57% vs. 21%, p = 0.004). The median survival was not reached in the FLT3i group. Overall, 69 patients received stem cell transplantation (18 autologous, 51 allogeneic). Post-transplant FLT3i was resumed in eight patients, all alive after a median of 65 months. Allogeneic transplantation is crucial in FLT3-mutated AML, but the next challenge will be to identify which patients can benefit from transplants in CR1 and in which to intensify post-transplant therapy.

Introduction. Measurable residual disease (MRD) negativity represents the primary endpoint in the management of adult Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) patients. MRD assays must be highly sensitive and specific. Droplet digital PCR (ddPCR) and next-generation sequencing (NGS) can overcome some limitations of standard methodologies. In order to evaluate the best marker for MRD monitoring, in this study we performed: i) MRD evaluation by BCR::ABL1 fusion transcript and immunoglobulin/T-cell receptor clonal gene rearrangements (IG/TR); ii) a comparison of the MRD concordance rate between the two markers; iii) a correlation with biologic features and clinical outcome. Methods. A total of 167 samples from111 adults enrolled in the ongoing phase III GIMEMA ALL2820 trial were collected. Samples derived from cases from both the experimental and the control arm, based respectively on ponatinib followed by blinatumomab and on a combination of imatinib and conventional chemotherapy. Established time points were day +70 (end of induction) and day +133 (after 2 cycles of blinatumomab or after 6 cycles of chemotherapy, respectively). At diagnosis, patients underwent a screening for the identification of the predominant IG/TR rearrangement by standard PCR and/or by NGS approach [LymphoTrack assay for IGH (FR1/2/3) and IGK] and the IKZF1plus signature by Multiplex Ligation-dependent Probe Amplification (MLPA). MRD monitoring was evaluated by RQ-PCR of BCR::ABL1 and, for translational research purposes, IG/TR monitoring was evaluated by ddPCR. The MRD concordance rate was evaluated comparing the results obtained between the 2 markers. Results. Overall, 97/111 (87.4%) cases were evaluable for IG/TR MRD monitoring. At day +70, the overall concordance rate between BCR::ABL1 and IG/TR was46.4%; 48/97 (49.5%) cases were BCR::ABL1pos; 20 were concordantly IG/TRpos (41.7%), 1 was IG/TRpositive not quantifiable and 27 were IG/TRneg; 34/97 (35%) cases were BCR::ABL1neg, 25 of which were concordantly IG/TRneg (73.5%), 5 were IG/TRpos and 4 were IG/TRpositive not quantifiable; finally, 15/97 (15.5%) cases were BCR::ABL1positive not quantifiable, 5 of which were IG/TRpos and 10 were IG/TRneg. The concordance rate was similar between IKZF1plus vs IKZF1 WT/IKZF1 loss (48.4% vs 44%), and p190 vs p210-p190/p210 (47% vs 42%) cases. At day +133, 70 patients were studied and the overall concordance rate was 41.4%: 28/70 (40%) cases were BCR::ABL1pos, 4 of which were concordantly IG/TRpos (14.3%), 2 were IG/TRpositive not quantifiable and 22 were IG/TRneg; 27/70 (38.6%) cases were BCR::ABL1neg, 25 of which were concordantly IG/TRneg (92.6%) and 2 were IG/TRpos; finally, 15/70 (21.4%) cases were BCR::ABL1positive not quantifiable and IG/TRneg. A lower concordance was observed in the IKZF1plus (24%) vs IKZF1 WT/IKZF1 loss (51%) and in the p210-p190/p210 (27.3%) compared to p190 (48%) cases.Five patients experienced a hematologic relapse. Dual monitoring was feasible in 4/5 cases (in 1 material was lacking) and, in addition to the evaluation at day +70 and +133, a retrospective backtracking was carried out at a previous time-point: 1 was concordantly BCR::ABL1pos (0.26 BCR::ABL1/ABL1 x 100) and IG/TRpos (4.0E-04), 1 was BCR::ABL1pos (7.12 BCR::ABL1/ABL1 x 100) and IG/TRneg, while the other 2 cases were both BCR::ABL1neg but IG/TRpos at 4.0E-05 and 2.0E-04, respectively, suggesting the presence at the onset of non Ph+ subclone. Conclusions. IG/TR MRD monitoring was feasible in 87.4% of Ph+ ALL cases indicating that a fraction of patients is not suitable for this strategy. Overall, the concordance rate between BCR::ABL1 and IG/TR is limited, in line with the literature. While some groups reported a higher predictive prognostic power of IG/TR monitoring, our findings do not confirm these data, also in view of the very low rate of relapses so far observed. Nevertheless, a double-hit strategy may be informative for MRD monitoring and possibly for the distinction between typical/lymphoid Ph+ ALL vs multilineage/CML-like Ph+ ALL.