The Changing Landscape of Treatment in Acute Myeloid Leukemia

Bridging the gap: understanding contemporary autopsies in acute leukemia by comparing ante-mortem and post-mortem profiles

This study investigates acute myeloid leukemia/lymphoblastic leukemia (AML/ALL) through a 14-year analysis (2009-2022) of 46 autopsied cases (age >12 years). B-ALL was the dominant subtype (34.8%). Liver and spleen were the common sites of active leukemia (63% cases). Symptoms like dyspnea and altered sensorium associated significantly with heart (p = .031) and brain leukostasis (p = .006). Measurable residual disease (MRD) negativity correlated with disease-free status outside the bone marrow, while MRD-positive cases displayed leukemic infiltrates. Infections were identified in 23 autopsied cases, notably linked to post-induction and post-transplant fatalities. Surprisingly, 18 of these 23 cases had unexpected infections mainly fungal (13 cases) with Aspergillus species as the most common. Diagnostic discrepancies were identified in 48% of cases. Malignant infiltration (46%) and infections (25%) were the leading causes of death. This research sheds light on leukemia in extra-medullary tissues, uncovers novel clinical-pathological associations, and highlights overlooked therapy side effects, offering insights for future case management.

Ubiquitin-specific protease 7 inhibitors reveal a differentiated mechanism of p53-driven anti-cancer activity

The USP7 deubiquitinase regulates proteins involved in the cell cycle, DNA repair, and epigenetics and has been implicated in cancer progression. USP7 inhibition has been pursued for the development of anti-cancer therapies. Here, we describe the discovery of potent and specific USP7 inhibitors exemplified by FX1-5303. FX1-5303 was used as a chemical probe to study the USP7-mediated regulation of p53 signaling in cells. It demonstrates mechanistic differences compared to MDM2 antagonists, a related class of anti-tumor agents that act along the same pathway. FX1-5303 synergizes with the clinically approved BCL2 inhibitor venetoclax in acute myeloid leukemia (AML) cell lines and ex vivo patient samples and leads to strong tumor growth inhibition in in vivo mouse xenograft models of multiple myeloma and AML. This work introduces new USP7 inhibitors, differentiates their mechanism of action from MDM2 inhibition, and identifies specific opportunities for their use in the treatment of AML.

Venetoclax with Hypomethylating Agents in Newly Diagnosed Acute Myeloid Leukemia: A Systematic Review and Meta-Analysis of Survival Data from Real-World Studies

In recent years, the association of venetoclax (VEN) with hypomethylating agents (HMAs) significantly improved the outcome of patients with newly diagnosed acute myeloid leukemia (AML) who were unfit for intensive chemotherapy and became the standard of care after the publication of the pivotal RCT VIALE-A. However, it is still not clear to what extent the results observed in the VIALE-A apply to a real-world setting. For this reason, we carried out a systematic review and meta-analysis of real-world studies on newly diagnosed patients with AML, ineligible for intensive induction chemotherapy, receiving first-line VEN+HMA. We then compared their results in term of survival with those from the VIALE-A. Kaplan-Meier curves were extracted from all included studies and individual survival data was reconstructed. We then estimated a pooled survival curve and compared it with the results of the VIALE-A using the log-rank test. We also conducted a secondary analysis including only studies considering VEN plus azacytidine (AZA) as treatment, as this was the schedule originally used in the VIALE-A. Nineteen real-world studies met the inclusion criteria and were included in the systematic review. Most of them reported a worse survival than the VIALE-A. The pooled survival curve was similar to that reported in the VIALE-A during the first three months of treatment but diverged thereafter (p-value = 0.0001). The pooled median survival among the real-world studies was 9.37 months (95%CI 8.81-10.5), substantially lower than that reported in the VIALE-A (14.7 months; 95%CI 11.9-18.7). Results slightly increased when the analysis was restricted to the studies using VEN+AZA as treatment (median survival: 11.5 months; 95%CI 10.2-14.8). Survival of newly diagnosed AML patients treated with VEN+HMAs in a real-world setting seems to be lower than previously reported in the VIALE-A, while the effect of VEN+AZA is more in line with expected results. Future studies are needed to evaluate whether this apparent discrepancy is due to the different characteristics of enrolled patients or to a non-optimal adherence to therapy, and whether alternative regimens can provide better results in terms of safety and effectiveness.

Outcomes with chimeric antigen receptor t-cell therapy in relapsed or refractory acute myeloid leukemia: a systematic review and meta-analysis

Background

We conducted a systematic review and meta-analysis to evaluate outcomes following chimeric antigen receptor T cell (CAR-T) therapy in relapsed/refractory acute myeloid leukemia (RR-AML).

Methods

We performed a literature search on PubMed, Cochrane Library, and Clinicaltrials.gov. After screening 677 manuscripts, 13 studies were included. Data was extracted following PRISMA guidelines. Pooled analysis was done using the meta-package by Schwarzer et al. Proportions with 95% confidence intervals (CI) were computed.

Results

We analyzed 57 patients from 10 clinical trials and 3 case reports. The pooled complete and overall response rates were 49.5% (95% CI 0.18-0.81, I² =65%) and 65.2% (95% CI 0.36-0.91, I² =57%). The pooled incidence of cytokine release syndrome, immune-effector cell associated neurotoxicity syndrome, and graft-versus-host disease was estimated as 54.4% (95% CI 0.17-0.90, I² =77%), 3.9% (95% CI 0.00-0.19, I² =22%), and 1.6% (95%CI 0.00-0.21, I² =33%), respectively.

Conclusion

CAR-T therapy has demonstrated modest efficacy in RR-AML. Major challenges include heterogeneous disease biology, lack of a unique targetable antigen, and immune exhaustion.

A scoring system for AML patients aged 70 years or older, eligible for intensive chemotherapy: a study based on a large European data set using the DATAML, SAL, and PETHEMA registries

In a context of therapeutic revolution in older adults with AML, it is becoming increasingly important to select patients for the various treatment options by taking account of short-term efficacy and toxicity as well as long-term survival. Here, the data from three European registries for 1,199 AML patients aged 70 years or older treated with intensive chemotherapy were used to develop a prognostic scoring system. The median follow-up was 50.8 months. In the training set of 636 patients, age, performance status, secondary AML, leukocytosis, and cytogenetics, as well as NPM1 mutations (without FLT3-ITD), were all significantly associated with overall survival, albeit not to the same degree. These factors were used to develop a score that predicts long-term overall survival. Three risk-groups were identified: a lower, intermediate and higher-risk score with predicted 5-year overall survival (OS) probabilities of ≥12% (n = 283, 51%; median OS = 18 months), 3-12% (n = 226, 41%; median OS = 9 months) and <3% (n = 47, 8%; median OS = 3 months), respectively. This scoring system was also significantly associated with complete remission, early death and relapse-free survival; performed similarly in the external validation cohort (n = 563) and showed a lower false-positive rate than previously published scores. The European Scoring System ≥70, easy for routine calculation, predicts long-term survival in older AML patients considered for intensive chemotherapy.

Emvododstat, a Potent Dihydroorotate Dehydrogenase Inhibitor, Is Effective in Preclinical Models of Acute Myeloid Leukemia

Blocking the pyrimidine nucleotide de novo synthesis pathway by inhibiting dihydroorotate dehydrogenase (DHODH) results in the cell cycle arrest and/or differentiation of rapidly proliferating cells including activated lymphocytes, cancer cells, or virally infected cells. Emvododstat (PTC299) is an orally bioavailable small molecule that inhibits DHODH. We evaluated the potential for emvododstat to inhibit the progression of acute myeloid leukemia (AML) using several in vitro and in vivo models of the disease. Broad potent activity was demonstrated against multiple AML cell lines, AML blasts cultured ex vivo from patient blood samples, and AML tumor models including patient-derived xenograft models. Emvododstat induced differentiation, cytotoxicity, or both in primary AML patient blasts cultured ex vivo with 8 of 10 samples showing sensitivity. AML cells with diverse driver mutations were sensitive, suggesting the potential of emvododstat for broad therapeutic application. AML cell lines that are not sensitive to emvododstat are likely to be more reliant on the salvage pathway than on de novo synthesis of pyrimidine nucleotides. Pharmacokinetic experiments in rhesus monkeys demonstrated that emvododstat levels rose rapidly after oral administration, peaking about 2 hours post-dosing. This was associated with an increase in the levels of dihydroorotate (DHO), the substrate for DHODH, within 2 hours of dosing indicating that DHODH inhibition is rapid. DHO levels declined as drug levels declined, consistent with the reversibility of DHODH inhibition by emvododstat. These preclinical findings provide a rationale for clinical evaluation of emvododstat in an ongoing Phase 1 study of patients with relapsed/refractory acute leukemias.

Long-term trends in the clinical outcomes of patients with acute myeloid leukemia: a population-based real-world data analysis using the Osaka Cancer Registry

We evaluated the survival patterns for acute myeloid leukemia (AML) patients registered in the Osaka Cancer Registry from 1975 to 2017. During this period, 9706 patients were diagnosed with AML, with a median age of 60 years (range, 0-100). Patients were grouped by age (≤ 20, 21-40, 41-60, 61-70, and ≥ 71) and the year of their diagnosis (1975-1989, 1990-2001, 2002-2010, and 2011-2017). The overall survival (OS) rates of patients of ≤ 60 years of age improved significantly from the period 1975-1989 up to 1990-2001. However, there was a stagnation from 2002-2010 to 2011-2017. In terms of non-acute promyelocytic leukemia patients of > 60 years of age, the improvement of OS was limited during a very long period. In conclusion, the clinical outcome of patients with AML dramatically improved from 1975 to 2001. However, our dataset revealed stagnation in the improvement since 2002. Novel treatment options are needed to further improve the survival of elderly patients.

CAR-T Cell Therapy for Acute Myeloid Leukemia: Preclinical Rationale, Current Clinical Progress, and Barriers to Success

Chimeric antigen receptor (CAR)-T cell therapy has shown impressive results in chemorefractory B cell malignancies, raising the possibilities of using this immunotherapeutic modality for other devastating hematologic malignancies, such as acute myeloid leukemia (AML). AML is an aggressive hematologic malignancy which, like B cell malignancies, poses several challenges for clinical translation of successful immunotherapy. The antigenic heterogeneity of AML results in a list of potential targets that CAR-T cells could be directed towards, each with advantages and disadvantages. In this review, we provide an up-to-date report of outcomes and adverse effects from published and presented clinical trials of CAR-T cell therapy for AML and provide the preclinical rationale underlying these studies and antigen selection. Comparison across trials is difficult, yet themes emerge with respect to appropriate antigen selection and association of adverse effects with outcomes. We highlight currently active clinical trials and the potential improvements and caveats with these novel approaches. Key hurdles to the successful introduction of CAR-T cell therapy for the treatment of AML include the effect of antigenic heterogeneity and trade-offs between therapy specificity and sensitivity; on-target off-tumor toxicities; the AML tumor microenvironment; and practical considerations for future trials that should be addressed to enable successful CAR-T cell therapy for AML.

Improved Survival of Leukemic Mice Treated with Sodium Caseinate in Combination with Daunorubicin without Toxicity

In recent years, low doses of chemotherapy have been resumed and explored for the treatment of acute myeloid leukemia. Thus, CPX-351, a dual-drug liposomal encapsulation of cytarabine and daunorubicin, was approved by the US Food and Drug Administration, to deliver a synergistic 5 : 1 molar drug ratio into leukemia cells to a greater extent than normal bone marrow cells and significantly enhance survival compared with conventional treatment in older and newly diagnosed AML patients, but overall survival rate remains low; therefore, the need for new therapeutic options continues. Sodium caseinate (SC), a salt of casein, the main milk protein, has cytotoxic effect in leukemia cell lines, but promotes proliferation of hematopoietic normal cells, while its administration in leukemic mice promotes survival for more than 40 days, but bone marrow surviving mice still harbour leukemic cells, but it is not known whether the combination with cytarabine or daunorubicin can improve survival without damaging normal hematopoietic cells. Here, it is shown that, in vitro, the combination of the IC₂₅ of SC-cytarabine or SC-daunorubicin synergizes in the elimination of leukemic cells, with evident induction of apoptosis, while the proliferation of mononuclear cells of bone marrow is not affected. In leukemic mice, the combined administration of SC-daunorubicin or SC-cytarabine promotes the highest survival rate at 40 days; in addition, no autoproliferating cells were detected in the bone marrow of survivors of more than 60 days, evidence of eradication of leukemic cells, but only the bone marrow of mice treated with the SC-daunorubicin combination proliferated in the presence of interleukin-3, which shows that this combination is not toxic to normal bone marrow cells, thus emerging as a possible antileukemic agent.

Impact of Conditioning Intensity and Genomics on Relapse After Allogeneic Transplantation for Patients With Myelodysplastic Syndrome

PURPOSE

Patients with myelodysplastic syndrome (MDS) are at risk of relapse after allogeneic hematopoietic cell transplantation. The utility of ultra-deep genomic testing to predict and the impact of conditioning intensity to prevent MDS relapse are unknown.

METHODS

Targeted error-corrected DNA sequencing was performed on preconditioning blood samples from patients with MDS (n = 48) from the Blood and Marrow Transplant Clinical Trials Network 0901 phase III randomized clinical trial, which compared outcomes by allogeneic hematopoietic cell transplantation conditioning intensity in adult patients with < 5% marrow myeloblasts and no leukemic myeloblasts in blood on morphological analysis at the time of pretransplant assessment. Clinical end points (53-month median follow-up) included transplant-related mortality (TRM), relapse, relapse-free survival (RFS), and overall survival (OS). Of the 48 patients examined, 14 experienced TRM, 23 are relapse-free, and 11 relapsed, of which 7 died.

RESULTS

Using a previously described set of 10 gene regions, 42% of patients (n = 20) had mutations detectable before random assignment to reduced intensity conditioning (RIC) or myeloablative conditioning (MAC). Testing positive was associated with increased rates of relapse (3-year relapse, 40% v 11%; P = .022) and decreased OS (3-year OS, 55% v 79%, P = .045). In those testing positive, relapse rates were higher (3-year relapse, 75% v 17%; P = .003) and RFS was lower (3-year RFS, 13% v 49%; P = .003) in RIC versus MAC arms. Testing additional genes, including those associated with MDS, did not improve prognostication.

CONCLUSION

This study provides evidence that targeted DNA sequencing in patients with MDS before transplant can identify those with highest post-transplant relapse rates. In those testing positive, random assignment to MAC lowered but did not eliminate relapse risk.