Gemtuzumab ozogamicin plus midostaurin in combination with standard '7 + 3' induction therapy in newly diagnosed AML: Results from the SAL-MODULE phase I study.

We conducted a phase I trial in newly diagnosed acute myeloid leukaemia (AML) to investigate the combination of two novel targeted agents, gemtuzumab ozogamicin (GO) and midostaurin, with intensive chemotherapy in FLT3-mutated AML and CBF leukaemia. Three dose levels of midostaurin and one to three sequential doses of 3 mg/m2 GO in combination with '7 + 3' induction were evaluated. Based on safety findings in 12 patients, our results show that 3 mg/m2 GO on Days 1 + 4 and 100 mg midostaurin on Days 8-21 can be safely combined with IC in newly diagnosed AML.

Extramedullary infiltration in pediatric acute myeloid leukemia: Results from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) initiative.

BACKGROUND: The outcome of extramedullary infiltration (EMI) in pediatric acute myeloid leukemia (AML) is controversial, and little is known about the implications of stem cell transplantation (SCT) and gemtuzumab ozogamicin (GO) treatment on patients with EMI. METHODS: We retrieved the clinical data of 713 pediatric patients with AML from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset, and analyzed the clinical and prognostic characteristics of patients with EMI at diagnosis and relapse. RESULTS: A total of 123 patients were identified to have EMI at diagnosis and 64 presented with EMI at relapse. The presence of EMI was associated with age ≤2 years, M5 morphology, abnormal karyotype, and KMT2A rearrangements. Hyperleukocytosis and complex karyotype were more prevalent in patients with EMI at relapse. Additionally, patients with EMI at diagnosis had a reduced incidence of FLT3 ITD-/NPM1+, whereas those with EMI at relapse displayed a lower frequency of FLT3 ITD+. Patients with EMI at diagnosis exhibited a lower complete remission (CR) rate at the end of Induction Course 1 and higher relapse incidence. Importantly, EMI at diagnosis independently predicted both shorter event-free survival (EFS) and overall survival (OS). Regarding relapse patients, the occurrence of EMI at relapse showed no impact on OS. However, relapse patients with myeloid sarcoma (MS)/no central nervous system (CNS) exhibited poorer OS compared to those with CNS/no MS. Furthermore, regarding patients with EMI at diagnosis, SCT failed to improve the survival, whereas GO treatment potentially enhanced OS. CONCLUSION: EMI at diagnosis is an independent adverse prognostic risk factor for pediatric AML, and GO treatment potentially improves survival for patients with EMI at diagnosis.

A DNA Damage Response Related Signature to Predict Prognosis in Patients with Acute Myeloid Leukemia.

The prognosis of acute myeloid leukemia (AML) is disappointing in most subtypes and varies widely. DNA damage response (DDR) is associated with prognosis and immunotherapy in multiple cancers. Here, we identify a signature of eight DDR-related genes associated with overall survival, which stratifies AML patients into high- and low-risk groups. Patients in low-risk group were more likely to respond to sorafenib. The signature could be an independent prognostic predictor for patients treated with ADE and ADE plus gemtuzumab ozogamicin. Therefore, this DDR prognostic signature might be applied to prognostic stratification and treatment selection in AML patients, which warrants further studies.

Impact of gemtuzumab ozogamicin consolidation on hematopoietic stem cells (HSCs) mobilization in AML: analysis of 20 patients.

Gemtuzumab ozogamicin (GO), is an anti-CD33 monoclonal antibody, approved for AML CD33 + , those patients with low and intermediate-risk who obtain a complete response may also be candidated for consolidation with autologous stem cell transplantation (ASCT). However, there are scant data on the mobilization of hemopoietic stem cells (HSC) after fractionated GO. We retrospectively studied data from five Italian centers and identified 20 patients (median age 54 years, range 29-69, 15 female, 15 NPM1mutated) that attempted HSC mobilization after fractionated doses of GO + "7 + 3" regimen and 1-2 cycles of consolidation (GO + HDAC + daunorubicin). After chemotherapy and standard G-CSF, 11/20 patients (55%) reached the threshold of 20 CD34 + /µL, and HSC were successfully harvested, while 9 patients (45%) failed. The median day of apheresis was Day + 26 from the start of chemotherapy (range 22-39 days). In good mobilizer patients, the median circulating CD34 + cells were 35.9 cells/µL and the median CD34 + harvested were 4.65 × 106/kg of patients' body weight. With a median follow-up of 12.7 months, at 24 months from the first diagnosis, 93.3% of all 20 patients were alive and the median overall survival was 25 months. The 2-year RFS rate from the timepoint of the first CR was 72.6%, while the median RFS was not reached. However, only five patients underwent ASCT and achieved full engraftment.In conclusion, in our cohort of patients, the addition of GO reduced HSC mobilization and harvesting, which was reached in about 55% of patients. Nevertheless, further studies are warranted to evaluate the effects of fractionated doses of GO on HSC mobilization and ASCT outcomes.

Evaluation of the efficacy of ursodiol for prevention of hepatotoxicity in patients receiving gemtuzumab ozogamicin and inotuzumab ozogamicin.

Gemtuzumab ozogamicin (GO) and inotuzumab ozogamicin (InO) are indicated for newly diagnosed or relapsed/refractory CD33-positive acute myeloid leukemia and relapsed/refractory B-cell precursor acute lymphoblastic leukemia respectively. Patients undergoing therapy with these agents are at increased risk for hepatotoxicity. Forty-nine patients received either GO or InO with concomitant ursodiol (n=14) or no ursodiol (n=35) for hepatotoxicity prophylaxis. Hepatotoxicity occurred in 2 (14%) patients in the ursodiol group compared to 15 (43%) patients in the no ursodiol group (p=0.10). Median days (17 versus 11; p=0.66) and doses (4 versus 2; p=0.28) to development of hepatotoxicity were higher in the ursodiol versus no ursodiol group. After adjusting for concomitant hepatotoxic medications and prior chemotherapy, ursodiol did not significantly reduce the incidence of hepatotoxicity. Ursodiol prophylaxis was associated with a similar incidence of hepatotoxicity compared to no ursodiol, but may delay the time to occurrence.

Cost-effectiveness analysis of gemtuzumab ozogamicin for the treatment of de novo CD33-positive Acute Myeloid Leukaemia (AML) in Italy.

BACKGROUND: Based on the results from the ALFA-0701 study, gemtuzumab ozogamicin (GO) has been approved by the European Medicine Agency and by the Italian Drug Agency for the first line treatment of de novo acute-myeloid leukemia (AML). In this analysis, we assessed the cost-effectiveness of GO in combination with daunorubicin and cytarabine (DA), vs DA alone, adopting the perspective of the Italian National Health Service. METHODS: For this analysis, a cohort state transition model was developed. The model was designed to capture health states and events that occur throughout the entire disease course and that impact costs and outcomes. The ALFA-0701 study was the main source of clinical data for this analysis. In the model, patients had the same baseline characteristics and experienced the same clinical improvements as in the ALFA-0701 study. Economic data (resource consumption and unit costs) were adapted to reflect expenditure for the Italian National Health Service. Utilities per health state and disutilities due to adverse events were based on the literature and on the general population for those functionally cured. A lifetime horizon was adopted, with both costs and outcome being discounted of 3.0%, annually. Deterministic and probabilistic sensitivity analyses were conducted to assess the robustness of results. RESULTS: In the base case (lifetime horizon; primary source of data: study ALFA-0701; perspective: Italian National Health Service; discount rate on costs and outcomes: 3.0%), GO + DA was more effective DA both in terms of life-year (LY) survival (6.42 LY vs 5.75 LY, respectively) and quality-of-life adjusted survival (4.69 QALY vs 4.19 QALY, respectively). The overall costs were almost similar in the two groups (slightly lower with GO + DA than with DA; €162,424 and €162,708, respectively). The use of GO increased the costs of drug therapy but saved costs of relapse and costs associated with transplantation (HSCT). CONCLUSIONS: If results of the ALFA-0701 study are applied to the Italian healthcare environment, then gemtuzumab ozogamicin, in combination with daunorubicin and cytarabine, would clinical outcomes and reduce lifetime costs, compared with daunorubicin and cytarabine alone for the first line treatment of de novo AML. TRIAL REGISTRATION: Not applicable.

The Use of Gemtuzumab Ozogamicin as Salvage Therapy in Patients with Acute Myeloid Leukemia: A Monocentric Real-World Experience.

Background and Objectives: Relapsed or refractory acute myeloid leukemia (r/r AML) is a disease with a poor prognosis. Limited treatment options are available in r/r AML. Here, we administered gemtuzumab ozogamicin (GO) as salvage therapy in twenty-four patients with r/r AML. The aim of the study was to determine the role of GO in r/r AML in real life. Material and Methods: This retrospective observational study recruited 24 adult patients with diagnosed r/r AML from 2018 to 2022. Twenty-four patients with r/r AML were treated with GO. GO treatment was used as monotherapy in 23 patients and in combination with cytarabine in 1 patient. At the time of diagnosis, the risk status of all patients was determined as favorable, intermediate, or adverse according to the 2017 ELN AML guidelines. Results: The median follow-up was 44.3 (13-144) months. Fifteen (62.5%) of the twenty-four patients were in the intermediate-risk cytogenetics group and nine (37.5%) were in the favorable cytogenetics group. The most common adverse events included nausea/vomiting in 79.17% (n = 19) of patients, headache in 62.50% (n = 15), elevated LFTs in 37.50% (n = 9), febrile neutropenia in 25% (n = 6), and bleeding in 25% (n = 6). The most common cause of death was infection. The most common causes of mortality were septic shock, accounting for 33.3% (n = 8) of deaths, and opportunistic lung infection, accounting for 12.5% (n = 3) of deaths. Acute infusion-related toxicities associated with GO were usually transient and, in most cases, responded to the standard of care treatment. After treatment with GO, 16.6% (n = 4) of patients achieved MLFS and 37.5% (n = 9) achieved CR. The overall response rate was 54.1%. The median overall survival time of the patients was 44 months (37.8-50.2 months). Disease-free survival was 22 months (0-48.6 months). The 5-year survival rate was 33%. Conclusions: A low dose of GO improved the overall survival and disease-free survival in r/r AML patients. GO treatment had a positive safety profile in terms of toxicity.

CD33-directed immunotherapy with third-generation chimeric antigen receptor T cells and gemtuzumab ozogamicin in intact and CD33-edited acute myeloid leukemia and hematopoietic stem and progenitor cells.

Immunotherapies, such as chimeric antigen receptor (CAR) modified T cells and antibody-drug conjugates (ADCs), have revolutionized the treatment of cancer, especially of lymphoid malignancies. The application of targeted immunotherapy to patients with acute myeloid leukemia (AML) has been limited in particular by the lack of a tumor-specific target antigen. Gemtuzumab ozogamicin (GO), an ADC targeting CD33, is the only approved immunotherapeutic agent in AML. In our study, we introduce a CD33-directed third-generation CAR T-cell product (3G.CAR33-T) for the treatment of patients with AML. 3G.CAR33-T cells could be expanded up to the end-of-culture, that is, 17 days after transduction, and displayed significant cytokine secretion and robust cytotoxic activity when incubated with CD33-positive cells including cell lines, drug-resistant cells, primary blasts as well as normal hematopoietic stem and progenitor cells (HSPCs). When compared to second-generation CAR33-T cells, 3G.CAR33-T cells exhibited higher viability, increased proliferation and stronger cytotoxicity. Also, GO exerted strong antileukemia activity against CD33-positive AML cells. Upon genomic deletion of CD33 in HSPCs, 3G.CAR33-T cells and GO preferentially killed wildtype leukemia cells, while sparing CD33-deficient HSPCs. Our data provide evidence for the applicability of CD33-targeted immunotherapies in AML and its potential implementation in CD33 genome-edited stem cell transplantation approaches.

Single-dose (4.5 mg/m2 ) gemtuzumab ozogamicin in combination with fludarabine, cytarabine and anthracycline as reinduction therapy in relapsed or refractory paediatric acute myeloid leukaemia.

Despite major therapeutic improvements, children with relapsed/refractory Acute Myeloid Leukaemia still have poor outcomes and overall survival does not exceed 40%. New treatments are required to improve their outcome; Gemtuzumab ozogamicin (GO), an anti-CD33 immunoconjugate antibody, is a potent cytotoxic agent whose efficacy has been demonstrated mainly in adults. The main objective of this retrospective multicentre study was to assess the outcome of children treated, between February 2008 and August 2019, with GO at a single 4.5 mg/m2 dose, in combination with Fludarabine, Cytarabine and antssshracyclines, in context of a first relapse (n = 26) or refractory disease (n = 3). The remission rate was 83% (24/29 children) and 20 children (69%) were allografted. With a median follow-up of 1.2 years (range: 0.1-8), the overall survival was 49% (CI95% = 33; 72). Most common adverse event was febrile neutropenia with microbiological identification in 55% of cases. Veno-occlusive disease occurred in 6 patients (21%), of which 5 subvened after bone marrow transplantation, and resolved within 2-32 days (median 10.5 days). Administration of GO in combination with FLA-anthracyclines chemotherapy appears to be a good reinduction regimen for relapsed or refractory AML with a good safety profile. These results warrant larger prospective study.

A phase III clinical trial evaluating efficacy and safety of minimal residual disease-based risk stratification for children with acute myeloid leukemia, incorporating a randomized study of gemtuzumab ozogamicin in combination with post-induction chemotherapy for non-low-risk patients (JPLSG-AML-20).

The purpose of this study is to establish a treatment with appropriate intensity for children (<16 years old at diagnosis) with de novo acute myeloid leukemia (excluding acute promyelocytic leukemia and myeloid leukemia associated with Down syndrome) according to a risk stratification based on recurrent leukemic cytogenetic abnormalities and flow-cytometric minimal residual disease at end of initial induction chemotherapy and to validate the safety and efficacy of gemtuzumab ozogamicin (GO)-combined post-induction chemotherapy for the non-low-risk (non-LR) patients. The primary endpoint of this phase III study is three-year disease-free survival rate, which will be compared between the GO and non-GO arms of the non-LR (intermediate-risk and high-risk [HR]) patients. All HR patients will be allocated to allogeneic hematopoietic stem cell transplantation in first remission. This trial has been registered at the Japan Registry of Clinical Trials (jRCTs041210015).

Next-generation sequencing in two cases of de novo acute basophilic leukaemia.

Acute basophilic leukaemia (ABL) is a rare subtype of acute myeloid leukaemia (AML); therefore, few data are available about its biology. Herein, we analysed two ABL patients using flow cytometry and next-generation sequencing (NGS). Two cell populations were detected by flow cytometry in both patients. In Case no. 1, blasts (CD34+ , CD203c- , CD117+ , CD123dim+ ) and basophils (CD34- , CD203c+ , CD117± , CD123+ ) were identified, both of which were found by NGS to harbour the 17p deletion and have loss of heterozygosity of TP53. In Case no. 2, blasts (CD33+ , CD34+ , CD123- ) and basophils (CD33+ , CD34+ , CD123+ ) were identified. NGS detected NPM1 mutations in either blasts or basophils, and TET2 in both. These data suggest an overlap of the mutational landscape of ABL and AML, including TP53 and TET2 mutations. Moreover, additional mutations or epigenetic factors may contribute for the differentiation into basophilic blasts.

Veno-occlusive disease risk in pediatric patients with acute myeloid leukemia treated with gemtuzumab ozogamicin before allogeneic hematopoietic cell transplantation.

BACKGROUND: Gemtuzumab ozogamicin (GO) administered before allogeneic hematopoietic cell transplantation (alloHCT) has been linked to an increased risk of hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS). PROCEDURE: This retrospective analysis examined VOD/SOS risk and clinical outcomes in pediatric patients with acute myeloid leukemia who received myeloablative alloHCT in 2008-2011 with (n = 148) and without (n = 348; controls) prior GO exposure and were reported to the Center for International Blood and Marrow Transplant Research. RESULTS: Cumulative incidences (95% confidence interval [CI]) of VOD/SOS and severe VOD/SOS, respectively, at 100 days were 16% (11-23%) and 8% (4-13%) for GO-exposed patients and 10% (7-13%) and 3% (2-5%) for controls. With a median follow-up of approximately 7 years, the 5-year adjusted overall survival probability (95% CI) after alloHCT was 51% (43-58%) and 55% (50-60%) for GO-exposed patients and controls, respectively; three (4%) and one (<1%) deaths were attributed to VOD/SOS. In multivariate analyses, GO exposure was observed to be associated with an increased risk of VOD/SOS at 100 days, but was not associated with overall survival, disease-free survival, relapse, or nonrelapse mortality. CONCLUSIONS: Results suggest that GO treatment prior to alloHCT in pediatric patients may increase the risk of VOD/SOS but not death.

3+7 Combined Chemotherapy for Acute Myeloid Leukemia: Is It Time to Say Goodbye?

PURPOSE OF REVIEW: With the recent approval of multiple new drugs for the treatment of acute myeloid leukemia (AML), the relevance of conventional treatment approaches, such as daunorubicin and cytarabine ("3+7") induction chemotherapy, has been challenged. We review the AML risk stratification, the efficacy of the newly approved drugs, and the role of "3+7". RECENT FINDINGS: Treatment of AML is becoming more niched with specific subtypes more appropriately treated with gemtuzumab, midostaurin, and CPX-351. Although lower intensity therapies can yield high response rates, they are less efficient at preventing relapses. The only curative potential for poor-risk AML is still an allogeneic stem cell transplant. The number of AML subtypes where 3+7 alone is an appropriate therapeutic option is shrinking. However, it remains the backbone for combination therapy with newer agents in patients suitable for intensive chemotherapy.

Post-Induction Treatment for Acute Myeloid Leukemia: Something Change?

PURPOSE OF REVIEW: Until recently, improvement in terms of survival for patients with acute myeloid leukemia (AML) was achieved mostly in younger patients with dose intensification of conventional chemotherapy and a broadening use of allogeneic hematopoietic cell transplantation (allo-HCT) whereas the results remained dismal and very stable in patients older than 60 years. The current review highlights the recent developments in standard intensive post-remission chemotherapy, evidence for the use of recently approved agents, and discusses the relevance of measurable residual disease (MRD) measurement in treatment adaptation. RECENT FINDINGS: Current approvals of midostaurin, venetoclax, gemtuzumab ozogamicin, VYXEOS, ivosidenib, enasidenib, glasdegib, and CC-486 have changed the structure, aim, and schedule of consolidation therapy, and new, well-tolerated agents are being evaluated as maintenance therapies. Furthermore, MRD assessment has been implemented to guide the duration and type of consolidation and maintenance therapy as well as indicate the optimal timing of allo-HCT. Novel therapies have changed the structure and perspective of post-remission therapy in AML for both young and elderly patients. In addition, MRD assessment could guide the type, duration, and intensity of consolidation and maintenance therapy.

Comparing cure rates for gemtuzumab ozogamicin plus standard chemotherapy vs standard chemotherapy alone in acute myeloid leukemia patients.

Aim: Assess the suitability of standard parametric, piecewise and mixture cure models (MCMs) for modeling long-term survival of acute myeloid leukemia patients achieving remission following treatment with gemtuzumab ozogamicin (GO) + standard chemotherapy (SC) or SC alone. MCMs can model survival data comprising of statistically cured (patients in long-term remission) and uncured patients. Materials & methods: Models were fit to patient-level data corresponding to individual treatment arms. Results: Visual inspection showed that MCMs fit the clinical data best. Survival modeling with MCMs showed that treatment with GO + SC versus SC alone results in higher statistical cure rates for event-free survival (rates: 26-35% vs 21-23%) and overall survival (rates: 48-52% vs 38-44%). Conclusion: MCMs are well suited to modeling long-term survival in acute myeloid leukemia patients. Clinical trial registration: NCT00927498 (ClinicalTrials.gov).

Lay abstract To assess the effectiveness of acute myeloid leukemia (AML) treatments, researchers use statistical models to estimate the survival rate of patients who receive a particular treatment. Some patients receiving certain AML treatments can achieve long-term remission and are often considered 'cured'. Standard statistical models cannot differentiate between cured and uncured patients and so tend to underestimate the survival rates of cured patients. Mixture cure models (MCMs) can account separately for the survival of cured versus uncured patients. We tested MCMs and standard statistical models using data from a clinical trial comparing gemtuzumab ozogamicin (GO) + standard chemotherapy against standard chemotherapy alone in AML patients. Of all the models tested, MCMs generated survival extrapolations over time that most closely resembled the data from the clinical trial. Through our analyses, we demonstrated that GO + standard chemotherapy can result in higher survival rates than standard chemotherapy alone.

Treatment options for older unfit patients with acute myeloid leukemia.

Older acute myeloid leukemia patients usually experience a bleak outcome, especially those in the unfit group. For this unfit category, intensive chemotherapy and allogeneic stem cell transplantation are usually accompanied by higher early mortality, which results from higher risk genetic profiles and worse psychological and physiological conditions. The significant improvement in genetic technology recently has driven the appearance of several mutation-targeted therapies, such as FLT3, Bcl-2, IDH and Hedgehog pathway inhibitors and an anti-CD33 antibody-drug conjugate, which have changed enormously the therapeutic landscape of acute myeloid leukemia. This review describes the treatment dilemma of the unfit group and discusses the objective clinical data of each targeted drug and mechanisms of resistance, with a focus on combination strategies with fewer toxicities and abrogation of drug resistance.

Targeted Therapeutic Approach Based on Understanding of Aberrant Molecular Pathways Leading to Leukemic Proliferation in Patients with Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is a heterogenous hematopoietic neoplasm with various genetic abnormalities in myeloid stem cells leading to differentiation arrest and accumulation of leukemic cells in bone marrow (BM). The multiple genetic alterations identified in leukemic cells at diagnosis are the mainstay of World Health Organization classification for AML and have important prognostic implications. Recently, understanding of heterogeneous and complicated molecular abnormalities of the disease could lead to the development of novel targeted therapeutic agents. In the past years, gemtuzumab ozogamicin, BCL-2 inhibitors (venetovlax), IDH 1/2 inhibitors (ivosidenib and enasidenib) FLT3 inhibitors (midostaurin, gilteritinib, and enasidenib), and hedgehog signaling pathway inhibitors (gladegib) have received US Food and Drug Administration (FDA) approval for the treatment of AML. Especially, AML patients with elderly age and/or significant comorbidities are not currently suitable for intensive chemotherapy. Thus, novel therapeutic planning including the abovementioned target therapies could lead to improve clinical outcomes in the patients. In the review, we will present various important and frequent molecular abnormalities of AML and introduce the targeted agents of AML that received FDA approval based on the previous studies.

Prior Gemtuzumab Ozogamicin Exposure in Adults with Acute Myeloid Leukemia Does Not Increase Hepatic Veno-Occlusive Disease Risk after Allogeneic Hematopoietic Cell Transplantation: A Center for International Blood and Marrow Transplant Research Analysis.

Gemtuzumab ozogamicin (GO) therapy before allogeneic hematopoietic cell transplantation (alloHCT) has been historically associated with an increased risk of hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) in patients with acute myeloid leukemia (AML). The current analysis examined VOD/SOS risk and outcomes in a cohort of patients who in recent years were reported to the Center for International Blood and Marrow Transplant Research. Adults with AML who had GO exposure before myeloablative alloHCT were matched 1:4 by age and disease status at transplant to recipients without GO exposure (control subjects). One hundred thirty-seven patients with GO exposure and 548 matched control subjects who underwent alloHCT between 2008 and 2011 were included in this analysis. With a median ∼8-year follow-up of survivors, the 5-year overall survival probability was similar in the 2 cohorts: 38% and 38% in the GO-exposed versus control groups (P = .97). Incidence of VOD/SOS and severe VOD/SOS, respectively, at 100 days was 4% (95% confidence interval [CI], 1% to 7%) and 3% (95% CI, 1% to 6%) in GO-exposed patients and 3% (95% CI, 2% to 5%) and 1% (95% CI, 0% to 2%) in control subjects. Correspondingly, among patients who developed VOD/SOS, 1-year survival probability after VOD/SOS diagnosis was 33% (95% CI, 5% to 72%) and 27% (95% CI, 11% to 47%; P = .78). In multivariate analyses, GO exposure before alloHCT was not associated with an increased risk of VOD/SOS (odds ratio, 1.10; P = .85) or death (hazard ratio, 1.08; P = .57). Three deaths (3%) in the GO group and 3 deaths (<1%) in the control group were attributed to VOD/SOS. Our results suggest that GO treatment before myeloablative alloHCT in the recent era is not associated with an increased risk of post-transplant VOD/SOS or death.

Acute myeloid leukemia transformed to a targetable disease.

Acute myeloid leukemia (AML) is a heterogeneous neoplasm characterized by the monoclonal proliferation of immature progenitors. It is the most common acute leukemia in adults and its incidence increases with age. The standard traditional treatment in fit patients was the '3 + 7' regimen and cytarabine consolidation followed or not with allogeneic stem cell transplantation. Recently, several targeted therapies such as gemtuzumab ozogamicin targeting the CD33+ AML, midostaurin, gilteritinib and crenolanib inhibiting FLT3-positive AML and ivosidenib and enasidenib blocking IDH-mutated AML have been approved. These new drugs led to the change of the landscape of the treatment of AML and transforming this disease to a targetable one. We aimed in this paper to review the implications of each new target, the mechanisms of action of these new drugs and we discuss all the studies leading to the approval of these new drugs in their indications according to each target.

Biomarkers of Gemtuzumab Ozogamicin Response for Acute Myeloid Leukemia Treatment.

Gemtuzumab ozogamicin (GO, Mylotarg®) consists of a humanized CD33-targeted antibody-drug conjugated to a calicheamicin derivative. Growing evidence of GO efficacy in acute myeloid leukemia (AML), demonstrated by improved outcomes in CD33-positive AML patients across phase I to III clinical trials, led to the Food and Drug Administration (FDA) approval on 1 September 2017 in CD33-positive AML patients aged 2 years and older. Discrepancies in GO recipients outcome have raised significant efforts to characterize biomarkers predictive of GO response and have refined the subset of patients that may strongly benefit from GO. Among them, CD33 expression levels, favorable cytogenetics (t(8;21), inv(16)/t(16;16), t(15;17)) and molecular alterations, such as NPM1, FLT3-internal tandem duplications and other signaling mutations, represent well-known candidates. Additionally, in depth analyses including minimal residual disease monitoring, stemness expression (LSC17 score), mutations or single nucleotide polymorphisms in GO pathway genes (CD33, ABCB1) and molecular-derived scores, such as the recently set up CD33_PGx6_Score, represent promising markers to enhance GO response prediction and improve patient management.