Search

BACKGROUND Many older adults with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) have a relapse despite having a measurable residual disease (MRD)-negative complete remission with combination chemotherapy. The addition of blinatumomab, a bispecific T-cell engager molecule that is approved for the treatment of relapsed, refractory, and MRD-positive BCP-ALL, may have efficacy in patients with MRD-negative remission. METHODS In a phase 3 trial, we randomly assigned patients 30 to 70 years of age with BCRcABLl-negative BCP-ALL (with :: indicating fusion) who had MRD-negative remission (defined as <0.01°/o leukemic cells in bone marrow as assessed on flow cytometry) after induction and intensification chemotherapy to receive four cycles of blinatumomab in addition to four cycles of consolidation chemotherapy or to receive four cycles of consolidation chemotherapy alone. The primary end point was overall survival, and relapse-free survival was a secondary end point. RESULTS The data and safety monitoring committee reviewed the results from the third efficacy interim analysis and recommended that they be reported. Complete remission with or without full count recovery was observed in 395 of 488 enrolled patients (81°/o). Of the 224 patients with MRD-negative status, 112 were assigned to each group. The characteristics of the patients were balanced between the groups. At a median follow-up of 43 months, an advantage was observed in the blinatumomab group as compared with the chemotherapy-only group with regard to overall survival (at 3 years: 85°/o vs. 68%; hazard ratio for death, 0.41; 95% confidence interval [CI], 0.23 to 0.73; P=0.002), and the 3-year relapse-free survival was 80% with blinatumomab and 64% with chemotherapy alone (hazard ratio for relapse or death, 0.53; 95% CI, 0.32 to 0.87). A higher incidence of neuropsychiatrie events was reported in the blinatumomab group than in the chemotherapy-only group. CONCLUSIONS The addition of blinatumomab to consolidation chemotherapy in adult patients in MRD-negative remission from BCP-ALL significantly improved overall survival. [ABSTRACT FROM AUTHOR]

Older/unfit adults with AML have worse outcomes and fewer treatment options than their younger/fit counterparts. In vitro studies have found a synergistic effect of hypomethylating agents (HMA) with venetoclax (VEN) on AML cells and since the phase 3 VIALE-A trial demonstrated a survival benefit, HMA + VEN has become the standard of care in the frontline setting for older/unfit adults with AML. Unfortunately, the standard 28-day cycle of VEN is associated with a high degree of myelosuppression leading to treatment delays and dose modifications. Many small retrospective studies have successfully shown comparable outcomes to VIALE-A with reduced dose/duration of VEN. Furthermore, low dose metronomic dosing of HMA + VEN has shown clinical benefit while minimizing myelotoxicity. Future trials are vital to understand the appropriate dose of VEN in combination with HMA, to evaluate HMA + VEN compared to intensive therapy for younger/fit patients, and to explore its utility in the relapsed/refractory setting., Competing Interests: Declaration of competing interest Hannah Levavi receives consulting fees from Sobi. Keith Pratz receives research funding from AbbVie, Agios, Daiichi Sankyo, Millennium; advisory board member for AbbVie, Astellas, AstraZeneca, Boston Biomedical, Bristol Myers Squibb, Celgene, Novartis, Roche, Jazz Pharmaceuticals, and Servier. Douglas Tremblay receives contracted research funding paid to his institution from Sobi, Sumitomo, Cogent Biosciences and Gilead and consulting fees from Sobi, Novartis, AbbVie, Pharmaessentia, Sierra Oncology, GSK and Cogent Biosciences. All other authors have no conflicts of interest to disclose., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: During the COVID-19 pandemic, SARS-CoV-2 monoclonal antibodies for preexposure prophylaxis (SMA-PrEP) offered patients who were immunocompromised another option for protection. However, SMA-PrEP posed administrative, operational, and ethical challenges for health care facilities, resulting in few patients receiving them. Although the first SMA-PrEP medication, tixagevimab and cilgavimab, had its authorization revoked due to compromised in vitro efficacy, new SMA-PrEP medications are currently completing clinical trials. This article provides an operational framework for administrative organization, patient identification and prioritization, equitable medication allocation, medication ordering and administration, and patient tracking., Methods: A retrospective cohort study evaluating our hospital's SMA-PrEP administration strategy was performed. Multivariable logistic regression was used to examine factors associated with receipt of SMA-PrEP., Results: Despite the barriers in administering this medication and the scarcity of resources, our hospital was able to administer at least 1 dose of SMA-PrEP to 1359 of 5902 (23.0%) eligible patients. Even with the steps taken to promote equitable allocation, multivariable logistic regression demonstrated that there were still differences by race, ethnicity, and socioeconomic status. As compared with patients who identified as Black, patients who identified as White (odds ratio [OR], 1.85; 95% CI, 1.46-2.33), Asian (OR, 1.59; 95% CI, 1.03-2.46), and Hispanic (OR, 1.53; 95% CI, 1.02-2.44) were more likely to receive SMA-PrEP. When compared with patients with low socioeconomic status, patients with high socioeconomic status (OR, 1.37; 95% CI, 1.05-1.78) were more likely to be allocated SMA-PrEP., Conclusions: Despite efforts to mitigate health care disparities, differences by race/ethnicity and socioeconomic status still arose in patients receiving SMA-PrEP., Competing Interests: Potential conflicts of interest. D. A. J. has received personal fees for advisory board participation and/or consulting from Biogen, BMS, Cycle Pharma, Horizon, Merck/EMD Serono, Novartis, Roche/Genentech, TG Therapeutics, and Sanofi-Genzyme and grant support to the University of Pennsylvania from Biogen Idec, Roche/Genentech, Merck/EMD Serono, and Novartis. All other authors report no potential conflicts., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Chronic myeloid leukemia (CML) is defined by the presence of Philadelphia chromosome resulting from a reciprocal translocation between chromosomes 9 and 22 [t9;22] that gives rise to a BCR::ABL1 fusion gene. CML occurs in 3 different phases (chronic, accelerated, and blast phase) and is usually diagnosed in the chronic phase in developed countries. Tyrosine kinase inhibitor (TKI) therapy is a highly effective treatment option for patients with chronic phase-CML. The primary goal of TKI therapy in patients with chronic phase-CML is to prevent disease progression to accelerated phase-CML or blast phase-CML. Discontinuation of TKI therapy with careful monitoring is feasible in selected patients. This manuscript discusses the recommendations outlined in the NCCN Guidelines for the diagnosis and management of patients with chronic phase-CML.

Objectives: This network meta-analysis (NMA) assessed the efficacy of venetoclax (VEN) + azacitidine (AZA) and VEN + low-dose cytarabine (LDAC) compared with AZA, LDAC, and decitabine monotherapies and best supportive care (BSC) in adults with untreated acute myeloid leukemia ineligible for intensive chemotherapy., Methods: A systematic literature review and feasibility assessment was conducted to select phase III randomized controlled trials for inclusion in the NMA. Complete remission + complete remission with incomplete blood count recovery and overall survival (OS) were compared using a Bayesian fixed-effects NMA. Treatments were ranked using surface under the cumulative ranking curves (SUCRAs) with higher values indicating a higher likelihood of being effective., Results: A total of 1140 patients across 5 trials were included. VEN + LDAC (SUCRA 91.4%) and VEN + AZA (87.5%) were the highest ranked treatments for complete remission + complete remission with incomplete blood count recovery. VEN + LDAC was associated significantly higher response rates versus AZA (odds ratio 5.64), LDAC (6.39), and BSC (23.28). VEN + AZA was also associated significantly higher response rates than AZA (5.06), LDAC (5.74), and BSC (20.68). In terms of OS, VEN + AZA (SUCRA: 95.2%) and VEN + LDAC (75.9%) were the highest ranked treatments. VEN + AZA was associated with significant improvements in OS compared with AZA (hazard ratio 0.66), LDAC (0.57), and BSC (0.37), and VEN + LDAC was associated with significant improvements in OS compared with LDAC (0.70) and BSC (0.46)., Conclusions: VEN + AZA and VEN + LDAC demonstrated improved efficacy compared with alternative therapies among treatment-naive patients with acute myeloid leukemia ineligible for intensive chemotherapy., Competing Interests: Author Disclosures Drs Li, Suh, and Lachaine reported receiving personal fees from AbbVie Inc during the conduct of the study. Drs Schuh and Pratz reported receiving grants and personal fees from AbbVie Inc during the conduct of the study. Drs Betts and Song reported receiving other from AbbVie Inc during the conduct of the study. Ms Dua reported receiving personal fees from AbbVie Inc during the conduct of the study. Dr Bui reported receiving personal fees and other from AbbVie Inc during the conduct of the study. No other disclosures were reported., (Copyright © 2023 International Society for Pharmacoeconomics and Outcomes Research, Inc. Published by Elsevier Inc. All rights reserved.)

Patients undergoing haploidentical or mismatched unrelated donor (haplo/MMUD) allogeneic hematopoietic cell transplantation (alloHCT) receiving post-transplant cyclophosphamide (PTCy) are at high risk of cytomegalovirus (CMV) infection. Experience with letermovir (LET) in this population is limited. This single center retrospective cohort study compared CMV and transplant outcomes between LET and a historical control with high-dose valacyclovir (HDV) prophylaxis in adults undergoing haplo/MMUD alloHCT. Thirty-eight CMV seropositive patients were included, 19 in each arm. LET reduced the incidence of CMV infection (5% vs. 53%, RR 0.01, 95% CI 0.014-0.71, p  = .001) and need for CMV treatment by day +100 (5% vs. 37%, RR 0.14, 95% CI 0.18-0.99, p  = .017) compared to HDV. Median CMV event-free-survival was improved with LET (not reached vs. 80 days, HR 0.114, 95% CI 0.07-0.61, p  = .004). These data support the efficacy of LET in alternative donor transplants.

This analysis represents the longest-term follow-up for patients with acute myeloid leukemia (AML) treated with 400 mg of venetoclax plus azacitidine or decitabine. Adults with newly diagnosed AML ineligible for intensive chemotherapy were enrolled in an open-label, non-randomized, multicenter phase 1b trial of venetoclax with azacitidine (AZA; 75 mg/m 2 ; days 1-7) or decitabine (DEC; 20 mg/m 2 ; days 1-5). Endpoints included safety, response rates (complete remission [CR], CR with incomplete blood count recovery [CRi]), response duration and overall survival (OS). The median follow-up time was 29 and 40 months for patients treated with venetoclax plus AZA and DEC combinations, respectively. Key Grade ≥ 3 AEs (AZA and DEC) were febrile neutropenia (39% and 65%), anemia (30% and 26%), thrombocytopenia (25% and 23%), and neutropenia (20% and 10%). The CR/CRi rate was 71% for venetoclax plus AZA and 74% for venetoclax plus DEC. The median duration of CR/CRi was 21.9 months and 15.0 months, and the median OS was 16.4 months and 16.2 months, for venetoclax plus AZA and DEC, respectively. These results support venetoclax plus hypomethylating agents as highly effective frontline AML therapies for patients unfit for intensive chemotherapy., (© 2020 Wiley Periodicals LLC.)

Chronic myeloid leukemia (CML) is defined by the presence of Philadelphia chromosome (Ph) which results from a reciprocal translocation between chromosomes 9 and 22 [t(9;22] that gives rise to a BCR-ABL1 fusion gene. CML occurs in 3 different phases (chronic, accelerated, and blast phase) and is usually diagnosed in the chronic phase. Tyrosine kinase inhibitor therapy is a highly effective first-line treatment option for all patients with newly diagnosed chronic phase CML. This manuscript discusses the recommendations outlined in the NCCN Guidelines for the diagnosis and management of patients with chronic phase CML.

Pegaspargase (PEG) increases venous thromboembolism (VTE) in acute lymphoblastic leukemia (ALL) potentially due to depletion of anticoagulation factors, including antithrombin (AT). The benefit and cost of AT supplementation in adults is unclear. We aimed to characterize VTE incidence and risk factors following AT and determine the characteristics and costs of supplementation. Fifty-three adults received PEG and AT. VTE occurred in 21% (grade ≥3 8%). T cell ALL and patients receiving prednisone during induction were at highest risk. Repeat AT levels post supplementation were subtherapeutic forty-four percent of the time. A median of 18 days elapsed between PEG and two sequential therapeutic AT levels despite supplementation. Patients received a median of 2 AT doses per PEG dose at a median cost of $11,145. VTE remains common in adults despite AT supplementation. More aggressive AT supplementation may reduce VTE but warrant prospective evaluation given the significant cost.

Background: Allogeneic blood or marrow transplantation (alloBMT) is a potentially life-saving treatment for individuals with HIV and haematological malignancies; challenges include identifying donors and maintaining antiretroviral therapy (ART). The objectives of our study were to investigate interventions to expand donor options and to prevent ART interruptions for patients with HIV in need of alloBMT., Methods: This single-arm, interventional trial took place at the Johns Hopkins Sidney Kimmel Comprehensive Cancer Center (Baltimore, MD, USA). Individuals with HIV who were at least 18 years of age and referred for alloBMT for a standard clinical indication were eligible. The only exclusion criterion was a history of documented resistance to enfuvirtide. We used post-transplant cyclophosphamide as graft-versus-host disease (GVHD) prophylaxis to expand donor options and an optimised ART strategy of avoiding pharmacoenhancers and adding subcutaneous enfuvirtide during post-transplant cyclophosphamide and during oral medication intolerance. Our primary outcome was the proportion of participants who maintained ART through day 60 after alloBMT. We measured the HIV latent reservoir using a quantitative viral outgrowth assay. This study is registered on ClinicalTrials.gov, NCT01836068., Findings: Between June 1, 2013, and August 27, 2015, nine patients who were referred for transplant provided consent. Two patients had relapsed malignancy before donor searches were initiated. Seven patients had suitable donors identified (two matched sibling, two matched unrelated, two haploidentical, and one single-antigen mismatched unrelated) and proceeded to alloBMT. All patients maintained ART through day 60 and required ART changes (median 1, range 1-3) in the first 90 days. One patient stopped ART and developed HIV rebound with grade 4 meningoencephalitis at day 146. Among six patients who underwent alloBMT and had longitudinal measurements available, the HIV latent reservoir was not detected post-alloBMT in four patients with more than 95% donor chimerism, consistent with a 2·06-2·54 log 10 reduction in the HIV latent reservoir. In the two patients with less than 95% donor chimerism, the HIV latent reservoir remained stable., Interpretation: By using post-transplant cyclophosphamide as GVHD prophylaxis, we successfully expanded alloBMT donor options for patients with HIV. Continuing ART with a regimen that includes enfuvirtide post-alloBMT was safe, but life-threatening viral rebound can occur with ART interruption., Funding: amfAR (the Foundation for AIDS Research), Johns Hopkins University Center for AIDS Research, and National Cancer Institute., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: Increasingly, acute promyelocytic leukemia (APL) is treated with a combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). This study characterizes bone marrow findings after ATRA/ATO therapy., Methods: Bone marrow biopsies from 16 patients treated with ATRA/ATO and seven patients treated with ATRA/chemotherapy (CTX) for APL were evaluated., Results: In ATRA/ATO cases, the marrow was likely to be hypercellular (79%) with a decreased myeloid:erythroid (M:E) ratio (88%), megaloblastoid maturation of erythroid precursors (100%), erythroid atypia (75%), and increased (88%) and atypical (75%) megakaryocytes. Significant myeloid atypia was only seen in extensive residual disease. The ATRA/CTX cases were less likely to be hypercellular (38%), have a M:E ratio of 1:1 or less (0%), exhibit significant erythroid atypia (0%), or have increased (0%) or atypical (38%) megakaryocytes., Conclusions: Bone marrow biopsies from patients treated with ATO have unusual but characteristic features. Despite variability in marrow findings, clinical outcomes were uniformly favorable., (© American Society for Clinical Pathology, 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Acute myeloid leukemia (AML) is the most common form of acute leukemia among adults and accounts for the largest number of annual deaths due to leukemias in the United States. Recent advances have resulted in an expansion of treatment options for AML, especially concerning targeted therapies and low-intensity regimens. This portion of the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for AML focuses on the management of AML and provides recommendations on the workup, diagnostic evaluation and treatment options for younger (age <60 years) and older (age ≥60 years) adult patients.

Older patients with acute myeloid leukemia (AML) respond poorly to standard induction therapy. B-cell lymphoma 2 (BCL-2) overexpression is implicated in survival of AML cells and treatment resistance. We report safety and efficacy of venetoclax with decitabine or azacitidine from a large, multicenter, phase 1b dose-escalation and expansion study. Patients (N = 145) were at least 65 years old with treatment-naive AML and were ineligible for intensive chemotherapy. During dose escalation, oral venetoclax was administered at 400, 800, or 1200 mg daily in combination with either decitabine (20 mg/m 2 , days 1-5, intravenously [IV]) or azacitidine (75 mg/m 2 , days 1-7, IV or subcutaneously). In the expansion, 400 or 800 mg venetoclax with either hypomethylating agent (HMA) was given. Median age was 74 years, with poor-risk cytogenetics in 49% of patients. Common adverse events (>30%) included nausea, diarrhea, constipation, febrile neutropenia, fatigue, hypokalemia, decreased appetite, and decreased white blood cell count. No tumor lysis syndrome was observed. With a median time on study of 8.9 months, 67% of patients (all doses) achieved complete remission (CR) + CR with incomplete count recovery (CRi), with a CR + CRi rate of 73% in the venetoclax 400 mg + HMA cohort. Patients with poor-risk cytogenetics and those at least 75 years old had CR + CRi rates of 60% and 65%, respectively. The median duration of CR + CRi (all patients) was 11.3 months, and median overall survival (mOS) was 17.5 months; mOS has not been reached for the 400-mg venetoclax cohort. The novel combination of venetoclax with decitabine or azacitidine was effective and well tolerated in elderly patients with AML (This trial was registered at www.clinicaltrials.gov as #NCT02203773)., (© 2019 by The American Society of Hematology.)

Timed sequential therapy (TST) aims to improve outcomes in acute myelogenous leukemia (AML) by harnessing drug-induced cell cycle kinetics of AML, where a second drug is timed to coincide with peak leukemia proliferation induced by the first drugs. We analyzed outcomes in 301 newly diagnosed AML patients treated from 2004-2013 with cytarabine, anthracycline, and etoposide TST induction. Median age was 52 (range 20-74) and complete remission rate 68%. With median follow-up 5.8 years, 5-year DFS and overall survival (OS) were 37% (95% CI 31-45%) and 32% (95% CI 27-38%), respectively. In multivariate analysis, older age, unfavorable cytogenetics, and WBC≥50×10 9 /L resulted in worse OS. Among patients not undergoing blood and marrow transplant, a propensity score analysis, which reduces imbalance in baseline characteristics, showed consolidation with TST compared with 1 or more cycles high-dose cytarabine trended toward lower DFS and post-remission survival with hazard ratio (HR) 1.9 (95% CI 0.9-4.0), and 1.6 (95% CI 0.7-3.6), respectively. Our results demonstrate the efficacy and feasibility of TST induction for newly diagnosed patients with AML, with results comparable to that seen in clinical trials with other TST therapies and 7+3., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Aims: Veliparib is a potent inhibitor of poly(ADP-ribose) polymerase (PARP) enzyme. The objectives of the analysis were to evaluate the effect of baseline covariates and co-administration of topotecan plus carboplatin (T + C) on pharmacokinetics of veliparib in patients with refractory acute leukaemia, and compare veliparib concentration in various biological matrices., Methods: A population pharmacokinetic model was developed and effect of age, body size indices, sex, creatinine clearance (CrCL) and co-administration of T + C on the pharmacokinetics of veliparib were evaluated. The final model was qualified using bootstrap and quantitative predictive check. Linear regression was conducted to correlate concentrations of veliparib in various biological matrices., Results: A two compartment model with first-order absorption with T lag described veliparib pharmacokinetics. The apparent clearance (CL/F) and volume (V c /F) were 16.5 l h -1 and 122.7 l, respectively. The concomitant administration of T + C was not found to affect veliparib CL/F. CrCL and lean body mass (LBM) were significant covariates on CL/F and Vc/F, respectively. While a strong positive relationship was observed between veliparib concentrations in plasma and bone marrow supernatant, no correlation was observed between plasma and peripheral blood or bone marrow blasts., Conclusions: Consistent with veliparib's physiochemical properties and its elimination mechanism, LBM and CrCL were found to affect pharmacokinetics of veliparib while concomitant administration of T + C did not affect veliparib's CL/F. Plasma concentrations were found to be a reasonable surrogate for veliparib concentrations in peripheral blood and bone marrow supernatant but not blasts. The current model will be utilized to conduct exposure-response analysis to support dosing recommendations., (© 2017 The British Pharmacological Society.)

Acute myeloid leukemia (AML) is the most common form of acute leukemia among adults and accounts for the largest number of annual deaths due to leukemias in the United States. This portion of the NCCN Guidelines for AML focuses on management and provides recommendations on the workup, diagnostic evaluation, and treatment options for younger (age <60 years) and older (age ≥60 years) adult patients., (Copyright © 2017 by the National Comprehensive Cancer Network.)

Background: Anthracyclines have activity against acute promyelocytic leukemia (APL) but can cause cardiac toxicity and secondary malignancy. The all-trans retinoic acid (ATRA)-arsenic trioxide (ATO) combination is an effective noncytotoxic approach for APL. However, its efficacy against high-risk APL (white blood cell count > 10,000/μL) has not been documented. Also, it requires ≥ 8 months to complete therapy., Patients and Methods: We report a retrospective analysis of 63 patients with APL given one cycle of ATO-based consolidation chemotherapy., Results: The 5-year overall survival, event-free survival, and leukemia-free survival was 93% (95% confidence interval [CI], 82%-97%), 89% (95% CI, 77%-95%), and 92% (95% CI, 80%-97%), respectively., Conclusion: These data have confirmed that an abbreviated ATO-based chemotherapy regimen is an effective consolidation therapy for APL, including high-risk APL, and can be completed within 4 months., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Treatment of relapse after related HLA-haploidentical T cell-replete bone marrow transplantation (haploBMT) with post-transplantation cyclophosphamide (PTCy) using haploidentical donor lymphocyte infusion (haploDLI) is not documented. All patients who received haploDLI after haploBMT with PTCy between June 2003 and October 2012 were identified and assessed for graft-versus-host disease (GVHD) and outcomes. Forty patients received 52 haploDLI doses. Sixteen patients had acute myeloid leukemia, 11 had lymphomas, and 34 had nonmyeloablative conditioning before haploBMT. The median time from haploBMT to relapse was 183 (range, 0 to 1399) days. The median age at haploDLI was 48 (range, 3 to 70) years. The first haploDLI doses were 1 × 10(5) CD3(+) cells/kg with subsequent escalation. The most commonly used first haploDLI dose was 1 × 10(6) CD3(+) cells/kg. The median follow-up after haploDLI was 7 (mean, 15.4; range, .5 to 96) months for the entire cohort, and 17.5 (mean, 28; range, 2.4 to 96) months for the responders. Acute GVHD developed in 10 patients (25%), 6 patients had grade 3 to 4, and 3 developed chronic GVHD. Twelve (30%) patients achieved a complete response (CR) with a median duration of 11.8 (mean, 22.5; range, .4 to 94) months. At last follow-up, 8 responders were alive in CR; 6 for over a year. HaploDLI for relapse after haploBMT is associated with acceptable toxicities and can result in durable responses., (Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

A hallmark of cancer is the disruption of differentiation within tumor cells. Internal tandem duplication mutations of the FLT3 kinase (FLT3/ITD) occur commonly in acute myeloid leukemia (AML) and are associated with poor survival, leading to efforts to develop FLT3 kinase inhibitors. However, FLT3 inhibitors have thus far met with limited success, inducing only a clearance of peripheral blasts with minimal BM responses. Quizartinib is a novel potent and selective FLT3 inhibitor currently being studied in clinical trials. In 13 of 14 FLT3/ITD AML patients with normal karyotype treated with quizartinib, we observed terminal myeloid differentiation of BM blasts in association with a clinical differentiation syndrome. The single patient whose blasts failed to differentiate had a preexisting C/EBPα mutation and another developed a C/EBPα mutation at disease progression, suggesting a mechanism of resistance to FLT3 inhibition. In vitro, in primary blasts cocultured with human BM stroma, FLT3 inhibition with quizartinib induced cell-cycle arrest and differentiation rather than apoptosis. The present study is the first description of terminal differentiation of cancer cells in patients treated with a tyrosine kinase inhibitor. These data highlight the importance of the differentiation block in the patho-genesis of AML.

A simple and rapid method with high performance liquid chromatography/tandem mass spectrometry is described for the quantitation of the kinase inhibitor sorafenib and its active metabolite sorafenib N-oxide in human plasma. A protein precipitation extraction procedure was applied to 50 μL of plasma. Chromatographic separation of the two analytes, and the internal standard [(2)H(3)(13)C]-sorafenib, was achieved on a C(18) analytical column and isocratic flow at 0.3 mL/min for 4 min. Mean within-run and between-run precision for all analytes were <6.9% and accuracy was <5.3%. Calibration curves were linear over the concentration range of 50-10,000 ng/mL for sorafenib and 10-2500 ng/mL for sorafenib N-oxide. This method allows a specific, sensitive, and reliable determination of the kinase inhibitor sorafenib and its active metabolite sorafenib N-oxide in human plasma in a single analytical run., (Copyright © 2010 Elsevier B.V. All rights reserved.)

PURPOSE To determine the efficacy and toxicity of the combination of sorafenib, cytarabine, and idarubicin in patients with acute myeloid leukemia (AML) younger than age 65 years. PATIENTS AND METHODS In the phase I part of the study, 10 patients with relapsed AML were treated with escalating doses of sorafenib with chemotherapy to establish the feasibility of the combination. We then treated 51 patients (median age, 53 years; range, 18 to 65 years) who had previously untreated AML with cytarabine at 1.5 g/m(2) by continuous intravenous (IV) infusion daily for 4 days (3 days if > 60 years of age), idarubicin at 12 mg/m(2) IV daily for 3 days, and sorafenib at 400 mg orally twice daily for 7 days. RESULTS Overall, 38 (75%) patients have achieved a complete remission (CR), including 14 (93%) of 15 patients with mutated FMS-like tyrosine kinase-3 (FLT3; the 15th patient had complete remission with incomplete platelet recovery [CRp]) and 24 (66%) of 36 patients with FLT3 wild-type (WT) disease (three additional FLT3-WT patients had CRp). FLT3-mutated patients were more likely to achieve a CR than FLT3-WT patients (P = .033). With a median follow-up of 54 weeks (range, 8 to 87 weeks), the probability of survival at 1 year is 74%. Among the FLT3-mutated patients, 10 have relapsed and five remain in CR with a median follow-up of 62 weeks (range, 10 to 76 weeks). Plasma inhibitory assay demonstrated an on-target effect on FLT3 kinase activity. CONCLUSION Sorafenib can be safely combined with chemotherapy, produces a high CR rate in FLT3-mutated patients, and inhibits FLT3 signaling.

FMS-Like-Tyrosine kinase-3 (FLT3) mutations are found in about 30% of cases of acute myeloid leukemia and confer an increased relapse rate and reduced overall survival. Targeting of this tyrosine kinase by direction inhibition is the focus of both preclinical and clinical research in AML. Several molecules in clinical development inhibit FLT3 with varying degrees of specificity. Preclinical models suggest that these compounds enhance the cytotoxicity of conventional chemotherapeutics against FLT3 mutant leukemia cells. The pharmacodynamic interactions between FLT3 inhibitors and chemotherapy appear to be sequence dependent. When the FLT3 inhibitor is used prior to chemotherapy, antagonism is displayed, while if FLT3 inhibition is instituted after to exposure to chemotherapy, synergistic cytotoxicity is seen. The combination of FLT3 inhibitors with chemotherapy is also complicated by potential pharmacokinetic obstacles, such as plasma protein binding and p-glycoprotein interactions. Ongoing and future studies are aimed at incorporating FLT3 inhibitors into conventional induction and consolidation therapy specifically for patients with FLT3 mutant AML.