Faculty Bibliography

Acute myeloid leukemia (AML) is a common hematologic malignancy that is considered to be a disease of aging, and traditionally has been treated with induction chemotherapy, followed by consolidation chemotherapy and/or allogenic hematopoietic stem cell transplantation. More recently, with the use of next-generation sequencing and access to molecular information, targeted molecular approaches to the treatment of AML have been adopted. Molecular targeting is gaining prominence, as AML mostly afflicts the elderly population, who often cannot tolerate traditional chemotherapy. Understanding molecular changes at the gene level is also important for accurate disease classification, risk stratification, and prognosis, allowing for more personalized medicine. Some mutations are well studied and have an established gene-specific therapy, including FLT3 and IDH1/2, while others are being investigated in clinical trials. However, data on most known mutations in AML are still minimal and therapeutic studies are in pre-clinical stages, highlighting the importance of further research and elucidation of the pathophysiology involving these genes. In this review, we aim to highlight the key molecular alterations and chromosomal changes that characterize AML, with a focus on pathophysiology, presently available treatment approaches, and future therapeutic options.

BACKGROUND Acute myeloid leukemia is characterized by dysregulated proliferation and maturation arrest of myeloid precursors, precipitating a spectrum of complications. Among these, leukemia cutis refers specifically to ectopic deposition and proliferation of malignant myeloid cells within the skin. This infiltration pathogenesis remains unclear. Although there are numerous reports of leukemia cutis in the setting of acute myeloid leukemia or primary acute myeloid leukemia, there are no specific reports of leukemia cutis in the setting of relapsed acute myeloid leukemia. CASE REPORT A 59-year-old woman, with a history of remission from poor-risk acute myeloid leukemia, previously treated with chemotherapy and allogenic bone marrow transplant, presented with shortness of breath, lethargy, anemia, thrombocytopenia, and subcutaneous nodules on lower extremities. Leukemia cutis was diagnosed, in the setting of relapsed acute myeloid leukemia. After unsuccessful salvage chemotherapy and being deemed unsuitable for further treatment, she pursued palliative care and died a month later. CONCLUSIONS Our case highlights a lack of reporting or making a distinction of those patients with relapsed acute myeloid leukemia and leukemia cutis. Consequently, it can be deduced that patients who simultaneously have relapsed acute myeloid leukemia and leukemia cutis are expected to fare worse in terms of clinical outcomes than those with primary acute myeloid leukemia and leukemia cutis. Relapsed acute myeloid leukemia patients with leukemia cutis should be classified as a distinct group, warranting further research into aggressive therapeutic targets and survival rates, while emphasizing the need for more vigilant follow-up and lower biopsy thresholds for cutaneous lesions in patients with treated hematologic malignancies.

Blinatumomab is a BiTE® (bispecific T-cell engager) molecule that redirects CD3⁺ T-cells to engage and lyse CD19⁺ target cells. Here we demonstrate that subcutaneous (SC) blinatumomab can provide high efficacy and greater convenience of administration. In the expansion phase of a multi-institutional phase 1b trial (ClinicalTrials.gov, NCT04521231), heavily pretreated adults with relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL) received SC blinatumomab at two doses: (1) 250 μg once daily (QD) for week 1 and 500 μg three times weekly (TIW) thereafter (250 μg/500 μg) or (2) 500 μg QD for week 1 and 1000 μg TIW thereafter (500 μg/1000 μg). The primary endpoint was complete remission/complete remission with partial hematologic recovery (CR/CRh) within two cycles. At the data cutoff of September 15, 2023, 29 patients were treated: 14 at the 250 μg/500 μg dose and 13 at 500 μg/1000 μg dose. Data from two ineligible patients were excluded. At the end of two cycles, 12 of 14 patients (85.7%) from the 250 μg/500 μg dose achieved CR/CRh of which nine patients (75.0%) were negative for measurable residual disease (MRD; <10^-4 leukemic blasts). At the 500 μg/1000 μg dose, 12 of 13 patients (92.3%) achieved CR/CRh; all 12 patients (100.0%) were MRD-negative. No treatment-related grade 4 cytokine release syndrome (CRS) or neurologic events (NEs) were reported. SC injections were well tolerated and all treatment-related grade 3 CRS and NEs responded to standard-of-care management, interruption, or discontinuation. Treatment with SC blinatumomab resulted in high efficacy, with high MRD-negativity rates and acceptable safety profile in heavily pretreated adults with R/R B-ALL.

Relapsed/refractory (r/r) acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) outcomes remain poor. A targeted cluster of differentiation (CD)33 × CD3 bispecific antibody, JNJ-67571244, was assessed to identify the maximum tolerated dose (MTD), recommended phase II dose (RP2D), safety and tolerability, and preliminary clinical activity in patients with r/rAML or r/rMDS. This first-in-human, open-label, phase I, dose-escalation/dose-expansion study included patients with r/rAML or r/rMDS who were ineligible for or had exhausted standard therapeutic options. JNJ-67571244 was administered intravenously or subcutaneously using step-up dosing until ≥1 discontinuation condition was met. Outcomes included safety/tolerability, preliminary clinical activity, and systemic pharmacokinetics and pharmacodynamics. The study was terminated after evaluating 10 dose-escalation cohorts (n = 68) and before starting dose-expansion. Overall, 11 (16.2%) patients experienced ≥1 dose-limiting toxicity; all experienced ≥1 treatment-emergent adverse event (TEAE; treatment related: 60 [88.2%]); and 64 (94.1%) experienced ≥1 TEAE of Grade ≥3 toxicity (treatment related: 28 [41.2%]). Although some patients had temporary disease burden reductions, no responses were seen. JNJ-67571244 administration increased multiple cytokines, which coincided with incidence of cytokine release syndrome, infusion-related reactions, and elevated liver function tests. A prolonged step-up strategy was tested to improve tolerability, though this approach did not prevent hepatotoxicity. T-cell activation following treatment suggested target engagement but did not correlate with clinical activity. Safely reaching the projected exposure level for JNJ-67571244 efficacy was not achieved, thus MTD and RP2D were not determined.

Reducing the incidence of graft-versus host disease (GvHD) following haploidentical hematopoietic stem cell transplantation (HSCT) is warranted. Post-transplant cyclophosphamide (PTCy) is the main agent used for GvHD prevention in this setting. It remains unknown if costimulation blockade can be safely combined with PTCy and enhance its efficacy. We performed a phase Ib-II clinical trial to examine the combination of PTCy, abatacept and a short course of tacrolimus (CAST) following peripheral blood haploidentical HSCT. The primary end-point was the incidence of acute GvHD grades II-IV at day +120. The study enrolled 46 patients with a median age of 60 years (range: 18 to 74). The cumulative incidence of acute GvHD grades II-IV and III-IV was 17.4% (95% CI, 9.2% to 32.9%) and 4.4% (95% CI, 1.1% to 17.1%). With a median follow-up of 15.3 months, the cumulative incidence of one-year treatment-related mortality is 4.4% (95% CI, 1.1% to 17.1%). The estimated one-year chronic GvHD moderate to severe rate, relapse rate, progression-free survival, overall survival, and GvHD- and relapse-free survival were 15.9% (95% CI, 8% to 31.7%), 11.7% (95% CI, 5% to 27.2%), 84.1% (95% CI, 73.8% to 95.7%), 85.9% (95% CI, 75.9% to 97.2%) and 66.1% (95% CI, 53.4% to 81.8%), respectively. Toxicities were similar to those expected in patients receiving haploidentical HSCT. This clinical trial showed that CAST regimen is safe and effective in reducing the rate of grades II-IV acute GvHD following haploidentical peripheral blood HSCT (NCT04503616 at https://clinicaltrials.gov/ct2/show/NCT04503616).

BACKGROUND:Acute myeloid leukemia (AML) is a disease of the hematopoietic system that remains a therapeutic challenge despite advances in our understanding of the underlying cancer biology in the past decade. It is also an affliction of the elderly that predominantly affects patients above 60 years of age. Standard therapy involves intensive chemotherapy that is often difficult to tolerate in older populations. Fortunately, recent developments in molecular targeting have shown promising results in treating leukemia, paving the way for novel treatment strategies that are easier to tolerate. SUMMARY/CONCLUSIONS:Venetoclax, a BCL-2 inhibitor, when combined with a hypomethylating agent, has proven to be a highly effective and well-tolerated drug, and established itself as a new standard for treating AML in patients who are unfit for standard intensive therapy. Other targeted therapies include clinically proven and FDA approved agents, such as IDH1/2 inhibitors, FLT3 inhibitors, and Gemtuzumab, as well as newer and more experimental drugs such as magrolimab, PI-kinase inhibitors, and T-cell engaging therapy. Some of the novel agents such as magrolimab and menin inhibitors are particularly promising, providing therapeutic options to a wider population of patients than ever before. Determining who will benefit from intense or novel low intense therapy remains a challenge and it requires careful assessment of individual patient's fitness and disease characteristics. KEY MESSAGES/CONCLUSIONS:This article reviews past and current treatment strategies that harness various mechanisms of leukemia-targeting agents and introduces novel therapies on the horizon aimed at exploring therapeutic options for elderly and unfit patient population. It also provides a strategy to select the best available therapy for elderly patients with both newly diagnosed and relapsed/refractory AML.

We present the case of a 56-year-old female with a diagnosis of acute T-cell lymphoblastic leukemia who received myeloablative conditioning for bone marrow transplant with total body irradiation (TBI) using volumetric modulated arc therapy (VMAT) to the upper body and anterior-posterior/posterior-anterior (AP/PA) open fields to the lower body followed by hematopoietic stem cell transplant. Her clinical course was complicated by high-grade pulmonary toxic effects 55 days after treatment that resulted in death. We discuss the case, planning considerations by radiation oncologists and radiation physicists, and the multidisciplinary medical management of this patient.

CONTEXT/BACKGROUND:Asparaginase remains an important component in many adult regimens for acute lymphoblastic leukemia (ALL). In pediatric patients (<21 years), calaspargase pegol (Cal-PEG) provides sustained asparagine depletion as compared to pegaspargase, with similar rates of complete remission (CR), minimal residual disease (MRD), event-free survival (EFS), and overall survival (OS), with a similar safety profile. OBJECTIVE:To confirm the recommended dose of Cal-PEG in adults (age ≥22 years) and to establish safety and PK/PD analysis. DESIGN/METHODS:. A minimum of 4 (initial cohort) and ~8 patients will be enrolled per group. The study will be conducted in ≤25 investigational centers in the US. Part 2 will comprise expansion cohorts after verifying safety and PK/PD analysis. PATIENTS/METHODS:Newly diagnosed patients with Philadelphia-negative B- or T-cell ALL ≥22 years with ECOG performance status 0-2, no known history of pancreatitis, coagulopathy, CNS thrombosis, or severe hepatic impairment. Approximately 114-122 patients are expected to be enrolled in the study, including 16-32 patients in Part 1. INTERVENTIONS/METHODS:. A total of 6 Cal-PEG doses will be administered during the treatment period as part of a multiagent chemotherapy regimen based on CALGB 10403, with an end-of-treatment visit 1 year after the induction dose, and an additional 2 years of survival follow-up. MAIN OUTCOME MEASURES/METHODS:The primary endpoints in part 1 are the safety of Cal-PEG, the incidence of pre-defined unacceptable toxicities within 30 days after the induction dose and achieving plasma asparaginase activity ≥0.1 U/mL 21 days after the consolidation day 43 dose. Secondary endpoints include immunogenicity, CR, end-of-induction and consolidation MRD, 1-, 2- and 3-year EFS, disease-free survival, and OS.

BACKGROUND:Large granular lymphocytic leukemia is a rare lymphocytic neoplasm that can pose a treatment challenge in patients with severe neutropenia in whom conventional therapies fail. We report one of the first cases in which allogeneic stem cell therapy was used as treatment for large granular lymphocytic leukemia. We report and discuss the case of a 42-year-old white Caucasian female who, despite multiple therapies including methotrexate, cyclophosphamide, prednisone, cyclosporine, and pentostatin, continued to show severe neutropenia and recurrent infections. The patient was treated successfully and cured by allogeneic stem cell transplant without any major complications. CONCLUSIONS:The significant importance of this case report is the introduction of a new treatment algorithm for challenging cases of T-cell large granular lymphocytic leukemia in which standard care fails. We hope that this case report will raise awareness of the potential benefits of allogeneic stem cell transplant in the treatment of aggressive forms of T-cell large granular lymphocytic leukemia.