Hyper-CVAD versus dose-adjusted EPOCH as initial treatment for adults with acute lymphoblastic leukemia

OBJECTIVES

We recently performed a single-arm phase II trial of DA-EPOCH in adults with acute lymphoblastic leukemia (ALL). We sought to compare these results to those with standard Hyper-CVAD.

METHODS

We created a retrospective matched cohort of patients who received Hyper-CVAD (n = 69) at our center and otherwise met eligibility criteria for the DA-EPOCH trial (n = 53).

RESULTS

Our outcomes support the use of Hyper-CVAD over DA-EPOCH in Ph- disease for both overall survival (OS; HR 0.18, p = .004) and event-free survival (EFS; HR 0.51, p = .06). In contrast, outcomes were similar in Ph+ disease (OS HR 0.97, p = .96; EFS HR 0.65, p = .21). Rates of morphologic remission and measurable residual-disease negativity were similar between the regimens. Hyper-CVAD was associated with significantly more febrile neutropenia (OR 1.9, p = .03) and a greater incidence of Grade 4 or 5 adverse events (20% vs. 6%). Average transfusions per cycle of both red blood cells (p < .001) and platelets (p < .001) were five-fold higher with Hyper-CVAD.

CONCLUSIONS

Our findings support continued use of Hyper-CVAD for Ph- ALL but suggest that DA-EPOCH may be a reasonable alternative for Ph+ ALL. These data also highlight a potential role for DA-EPOCH in resource-limited settings or when more intense therapy is not feasible.

Phase 1/2 study of sorafenib added to cladribine, high-dose cytarabine, G-CSF, and mitoxantrone in untreated AML

The multikinase inhibitor sorafenib improves event-free survival (EFS) when used with 7 + 3 in adults with newly-diagnosed acute myeloid leukemia (AML), irrespective of the FLT3-mutation status. Here, we evaluated adding sorafenib to cladribine, high-dose cytarabine, granulocyte colony-stimulating factor, and mitoxantrone (CLAG-M) in a phase 1/2 trial of 81 adults aged ≤60 years with newly diagnosed AML. Forty-six patients were treated in phase 1 with escalating doses of sorafenib and mitoxantrone. No maximum tolerated dose was reached, and a regimen including mitoxantrone 18 mg/m2 per day and sorafenib 400 mg twice daily was declared the recommended phase 2 dose (RP2D). Among 41 patients treated at RP2D, a measurable residual disease-negative complete remission (MRD- CR) rate of 83% was obtained. Four-week mortality was 2%. One-year overall survival (OS) and EFS were 80% and 76%, without differences in MRD- CR rates, OS, or EFS between patients with or without FLT3-mutated disease. Comparing outcomes using CLAG-M/sorafenib with those of a matched cohort of 76 patients treated with CLAG-M alone, multivariable-adjusted survival estimates were improved for 41 patients receiving CLAG-M/sorafenib at RP2D (OS: hazard ratio,0.24 [95% confidence interval, 0.07-0.82]; P = .023; EFS: hazard ratio, 0.16 [95% confidence interval, 0.05-0.53]; P = .003). Benefit was limited to patients with intermediate-risk disease (univariate analysis: P = .01 for OS; P = .02 for EFS). These data suggest that CLAG-M/sorafenib is safe and improves OS and EFS relative to CLAG-M alone, with benefits primarily in patients with intermediate-risk disease. The trial was registered at www.clinicaltrials.gov as #NCT02728050.

Phase II study of dose-adjusted EPOCH as initial therapy for adults with high-risk acute lymphoblastic leukemia

Treatments for adults with newly-diagnosed acute lymphoblastic leukemia (ALL) may be prohibitively toxic and/or resource-intense. To address this, we performed a phase II study of dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-EPOCH). Imatinib or dasatinib was added for Ph + disease; rituximab was added when CD20+. Fifty-three patients were evaluable: 28 with Ph + disease, and 25 with Ph-. All patients had ≥1 high-risk clinical feature. Measurable residual disease-negativity by multiparameter flow cytometry within 4 cycles was achieved in 71% in patients with Ph + ALL and 64% in Ph - ALL. Median overall survival (OS) was 49 months, with a 2-year OS of 71%. Median relapse-free survival (RFS) in the 47 patients that attained morphologic remission was 24 months, with a 2-year RFS of 57%. Early mortality was 2%. In summary, DA-EPOCH yields deep and durable remissions in adults with ALL comparable to some resource-intense strategies but with a low rate of treatment-related death.

Poor post-induction outcomes in patients with acute myeloid leukemia previously treated with hypomethylating agents

Patients with acute myeloid leukemia (AML) who have failed hypomethylating agents (HMA) have a poor prognosis. We examined whether high intensity induction chemotherapy could abrogate negative outcomes in 270 patients with AML or other high-grade myeloid neoplasms. Prior HMA therapy was significantly associated with a lower overall survival (OS) as compared to a reference group of patients with secondary disease without prior HMA therapy (median 7.2 vs 13.1 months). In patients with prior HMA therapy, high intensity induction was associated with a non-significant trend toward longer OS (median 8.2 vs 4.8 months) and decreased rates of treatment failure (39% vs 64%). These results redemonstrate poor outcomes in patients with prior HMA and suggest possible benefit of high intensity induction that should be evaluated in future studies.

Phase 1/2 Trial of CLAG-M with Dose-Escalated Mitoxantrone in Combination with Fractionated-Dose Gemtuzumab Ozogamicin for Newly Diagnosed Acute Myeloid Leukemia and Other High-Grade Myeloid Neoplasms

Simple Summary

Several studies have demonstrated that gemtuzumab ozogamicin (GO) improves outcomes with intensive chemotherapy in some adults with acute myeloid leukemia (AML), but it has remained unclear which dosing schedule of GO is best. Here, we conducted a phase 1/2 study in 66 adults with newly diagnosed AML or other high-grade myeloid neoplasm, and found that a fractionated dosing schedule of GO (GO3) can be safely combined with cladribine, high-dose cytarabine, G-CSF, and dose-escalated mitoxantrone (CLAG-M). Fifty-two out of sixty (87%) patients treated with CLAG-M/GO3 achieved a complete remission (CR)/CR with incomplete hematologic recovery (CRi), 45/52 (87%) without flow cytometric measurable residual disease. Six- and twelve-month event-free survival were 73% and 58%; among favorable-risk patients, these estimates were 100% and 95%. Compared to 186 medically matched adults treated with CLAG-M alone, CLAG-M/GO3 was associated with better survival in patients with favorable-risk disease. These data indicate that CLAG-M/GO3 is safe and more efficacious than CLAG-M alone in favorable-risk AML/high-grade myeloid neoplasm.

Abstract

Gemtuzumab ozogamicin (GO) improves outcomes when added to intensive AML chemotherapy. A meta-analysis suggested the greatest benefit when combining fractionated doses of GO (GO3) with 7 + 3. To test whether GO3 can be safely used with high intensity chemotherapy, we conducted a phase 1/2 study of cladribine, high-dose cytarabine, G-CSF, and dose-escalated mitoxantrone (CLAG-M) in adults with newly diagnosed AML or other high-grade myeloid neoplasm (NCT03531918). Sixty-six patients with a median age of 65 (range: 19–80) years were enrolled. Cohorts of six and twelve patients were treated in phase 1 with one dose of GO or three doses of GO (GO3) at 3 mg/m² per dose. Since a maximum-tolerated dose was not reached, the recommended phase 2 dose (RP2D) was declared to be GO3. At RP2D, 52/60 (87%) patients achieved a complete remission (CR)/CR with incomplete hematologic recovery (CRi), 45/52 (87%) without flow cytometric measurable residual disease (MRD). Eight-week mortality was 0%. Six- and twelve-month event-free survival (EFS) were 73% and 58%; among favorable-risk patients, these estimates were 100% and 95%. Compared to 186 medically matched adults treated with CLAG-M alone, CLAG-M/GO3 was associated with better survival in patients with favorable-risk disease (EFS: p = 0.007; OS: p = 0.030). These data indicate that CLAG-M/GO3 is safe and leads to superior outcomes than CLAG-M alone in favorable-risk AML/high-grade myeloid neoplasm.

A Novel GAB2::BRAF Fusion in Cutaneous Non-Langerhans Cell Histiocytosis with Systemic Involvement

Several mutations and gene fusions involved in the mitogen-activated protein kinase (MAPK) pathway have been reported in histiocytic neoplasms including Langerhans cell histiocytosis (LCH) and non-Langerhans cell histiocytosis (NLCH). We identified a GAB2::BRAF fusion in a cutaneous lesion from a 22-year-old woman who presented with central diabetes insipidus and red/brown papules on her face, oral mucosa, axilla, and groin. Skin biopsies showed a CD68+, S100-, and CD1a- histiocytic proliferation consistent with NLCH, best clinically classified as xanthoma disseminatum. Next-generation sequencing identified a GAB2::BRAF fusion involving exon 2 of GAB and exon 10 of BRAF. This case implicates a novel fusion in the MAPK signaling pathway, not previously reported in histiocytic neoplasms, as a possible driver of NLCH. Our findings underscore the utility of performing molecular studies on skin biopsies with NLCH to help identify potential targets for therapy. This article is protected by copyright. All rights reserved.

Targeting an alternate Wilms' tumor antigen 1 peptide bypasses immunoproteasome dependency

Designing effective antileukemic immunotherapy will require understanding mechanisms underlying tumor control or resistance. Here, we report a mechanism of escape from immunologic targeting in an acute myeloid leukemia (AML) patient, who relapsed 1 year after immunotherapy with engineered T cells expressing a human leukocyte antigen A*02 (HLA-A2)-restricted T cell receptor (TCR) specific for a Wilms' tumor antigen 1 epitope, WT1_126-134 (T_TCR-C4). Resistance occurred despite persistence of functional therapeutic T cells and continuous expression of WT1 and HLA-A2 by the patient's AML cells. Analysis of the recurrent AML revealed expression of the standard proteasome, but limited expression of the immunoproteasome, specifically the beta subunit 1i (β1i), which is required for presentation of WT1_126-134. An analysis of a second patient treated with T_TCR-C4 demonstrated specific loss of AML cells coexpressing β1i and WT1. To determine whether the WT1 protein continued to be processed and presented in the absence of immunoproteasome processing, we identified and tested a TCR targeting an alternative, HLA-A2-restricted WT1_37-45 epitope that was generated by immunoproteasome-deficient cells, including WT1-expressing solid tumor lines. T cells expressing this TCR (T_TCR37-45) killed the first patients' relapsed AML resistant to WT1_126-134 targeting, as well as other primary AML, in vitro. T_TCR37-45 controlled solid tumor lines lacking immunoproteasome subunits both in vitro and in an NSG mouse model. As proteasome composition can vary in AML, defining and preferentially targeting these proteasome-independent epitopes may maximize therapeutic efficacy and potentially circumvent AML immune evasion by proteasome-related immunoediting.

Histiocytic Neoplasms, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

Histiocytic neoplasms are rare hematologic disorders accounting for less than 1% of cancers of the soft tissue and lymph nodes. Clinical presentation and prognosis of these disorders can be highly variable, leading to challenges for diagnosis and optimal management of these patients. Treatment often consists of systemic therapy, and recent studies support use of targeted therapies for patients with these disorders. Observation ("watch and wait") may be sufficient for select patients with mild disease. These NCCN Guidelines for Histiocytic Neoplasms include recommendations for diagnosis and treatment of adults with the most common histiocytic disorders: Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai-Dorfman disease.

Comparative analysis of infectious complications with outpatient vs. inpatient care for adults with high-risk myeloid neoplasm receiving intensive induction chemotherapy

We recently reported an early hospital discharge (EHD) care strategy following intensive acute myeloid leukemia (AML)-like chemotherapy is safe. To evaluate its impact on infectious outcomes, we compared all adults treated from 8/1/2014 to 7/31/2018 discharging within 72 h of completing chemotherapy (EHD) with hospitalized patients (controls) across 354 induction and 259 post-remission cycles. While overall outcomes were similar, gram-positive bacteremias were more common in EHD patients than control (p<.001), although they received fewer days of IV antimicrobials (p< .001). Notably, cumulative infection risks in EHD patients were similar after induction and post-remission therapy. In multivariable analysis, only EHD status was independently associated with risk for gram-positive bacteremia (p= .01), whereas the only independent risk factor for fungal infection was fluconazole (vs. posaconazole) use (p< .001). The observation of increased rates of gram-positive bacteremias with EHD identifies improvements in catheter management as one area to further increase the safety of this care approach.

Survival of patients with newly diagnosed high-grade myeloid neoplasms who do not meet standard trial eligibility

Few patients with cancer, including those with acute myeloid leukemia and high-grade myeloid neoplasms, participate in clinical trials. Broadening standard eligibility criteria may increase clinical trial participation. In this retrospective single-center analysis, we identified 442 consecutive newly diagnosed patients from 2014 to 2016. Patients were considered “eligible” if they had a performance status 0-2, normal renal and hepatic function, no recent solid tumor, left ventricular ejection fraction (EF) ≥50%, and no history of congestive heart failure (CHF) or myocardial infarction (MI); “ineligible” patients failed to meet one or more of these criteria. We included 372 patients who received chemotherapy. Ineligible patients represented 40% of the population and had a 1.79-fold greater risk of death (95% Confidence Interval [CI]: 1.37-2.33) than eligible patients. Very few patients had cardiac comorbidities, including 2% with low EF, 4% with prior CHF, and 5% with prior MI. In multivariable analysis, ineligibility was associated with decreased survival (Hazard ratio [HR] 1.44; 95% CI: 1.07-1.93). Allogeneic transplantation, performed in 150 patients (40%), was associated with improved survival (HR 0.66, 95% CI: 0.48-0.91). Therefore, standard eligibility characteristics identify a patient population with improved survival. Further treatment options are needed for patients considered ineligible for clinical trials.

Financial Implications of Early Hospital Discharge After AML-Like Induction Chemotherapy: A 4-Year Retrospective Analysis

BACKGROUND

Early hospital discharge (EHD) after intensive acute myeloid leukemia (AML) induction chemotherapy has become routine at the University of Washington/Seattle Cancer Care Alliance over the past several years. We assessed the financial implications of EHD over the first 4 years after its broad adoption for patients with AML and other high-grade myeloid neoplasms undergoing AML-like induction chemotherapy.

PATIENTS AND METHODS

We retrospectively compared charges between 189 patients with EHD who received all postinduction inpatient/outpatient care within our care system between August 2014 and July 2018 and 139 medically matched control patients who remained hospitalized for logistical reasons. Charges from the day of initial discharge (patients with EHD) or end of chemotherapy (control patients) until blood count recovery, additional chemotherapy or care transition, hospital discharge (for control patients only), an elapse of 42 days, or death were extracted from financial databases and separated into categories: facility/provider, emergency department, transfusions, laboratory, imaging, pharmacy, and miscellaneous.

RESULTS

Combined charges averaged $4,157/day (range, $905-$13,119/day) for patients with EHD versus $9,248/day (range, $4,363-$48,522/day) for control patients (P<.001). The EHD cohort had lower mean facility/provider, transfusion, laboratory, and pharmacy charges but not imaging or miscellaneous charges. During readmissions, there was no statistically significant difference in daily inpatient charges between the EHD and control cohorts. After multivariable adjustment, average charges were $3,837/day lower for patients with EHD (P<.001).

CONCLUSIONS

Together with previous data from our center showing that EHD is safe and associated with reduced healthcare resource utilization, this study further supports this care approach for AML and other high-grade myeloid neoplasms if infrastructure is available to enable close outpatient follow-up.

Managing Cancer Care During the COVID-19 Pandemic: Agility and Collaboration Toward a Common Goal

The first confirmed case of coronavirus disease 2019 (COVID-19) in the United States was reported on January 20, 2020, in Snohomish County, Washington. At the epicenter of COVID-19 in the United States, the Seattle Cancer Care Alliance, Fred Hutchinson Cancer Research Center, and University of Washington are at the forefront of delivering care to patients with cancer during this public health crisis. This Special Feature highlights the unique circumstances and challenges of cancer treatment amidst this global pandemic, and the importance of organizational structure, preparation, agility, and a shared vision for continuing to provide cancer treatment to patients in the face of uncertainty and rapid change.

Does intensity of induction chemotherapy affect the impact of measurable residual disease (MRD) on prognosis in acute myeloid leukemia (AML)?

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Background: Absence of MRD in first complete remission (CR1) of AML decreases the probability of subsequent relapse both in patients given more (e.g. “7+3” or FLAG) or less (e.g. azacitidine) intense induction. Although high-intensity induction seems to increase the chance of CR without MRD, it is unknown whether induction intensity affects outcomes beyond eradication of MRD. Methods: We retrospectively studied adults with newly diagnosed AML or MDS with 10-20% blasts who received induction at the University of Washington from 2008 through 2015. Induction was classified as high or low intensity, CR defined by standard criteria, and marrow MRD by presence of blasts on multiparameter flow cytometry within 1-2 weeks of CR. Post-remission therapy in 10 patients included allogeneic hematopoietic cell transplant (HCT). Multivariate regression analysis examined the independent effects of age, initial cytogenetics (favorable, intermediate, adverse), performance status, de novo vs secondary AML, induction intensity, and MRD on post-CR outcomes. Results: 217 patients received high- and 38 low-intensity induction. 75% of the former vs. 42% of the latter achieved CR without MRD. Although high-intensity therapy was associated with longer overall survival (OS), this difference disappeared after accounting for the above covariates (HR 0.94, 95% CI 0.58 – 1.52, P = 0.8) and OS was poor regardless of chemotherapy intensity if MRD was present. Multivariate analysis found no interaction between the presence or absence of MRD and induction intensity (HR 0.95, 95% CI 0.4 – 2.29, P = 0.9). Conclusions: Receiving high-intensity induction chemotherapy does not appear to confer a separate advantage in long-term outcomes once CR without MRD is achieved, at least in patients mostly not receiving HCT. We are currently including more such patients who received HCT. Our results suggest that any effect of high-intensity induction largely reflects its association with a higher probability of achieving an MRD-negative CR.

Description and prognostic significance of the kinetics of minimal residual disease status in adults with acute lymphoblastic leukemia treated with HyperCVAD

HyperCVAD is a commonly-used regimen for adults with newly-diagnosed acute lymphoblastic leukemia (ALL). However, relatively little is known about the application of minimal residual disease (MRD) detection with this treatment. To address this, we studied 142 adults with ALL treated with hyperCVAD over a 10-year period who had MRD assessed by either multi-parameter flow cytometry or (for patients with Philadelphia chromosome positive ALL) reverse transcriptase polymerase chain reaction for the BCR-ABL1 translocation. In a multivariate analysis, patients who achieved MRD negativity (MRD^Neg ) at any point had significantly better overall survival (OS; hazard ratio [HR] 0.43; P = .01) and event-free survival (EFS; HR 0.27; P < .01). Of 121 patients with MRD assessed at various points within 90 days of starting hyperCVAD, 50% (n = 61) had achieved MRD^Neg . Among those that became MRD^Neg , the median time to MRD^Neg was 68 days. Time to MRD^Neg was significantly associated with EFS (P = .009), but not OS (P = .19), implying increasingly better EFS the earlier MRD^Neg is achieved. These data add to our understanding of MRD assessment during treatment with hyperCVAD, aide clinicians with predicting relapse risk, and provide additional historical data on which future clinical trials can be designed.

Mitoxantrone, etoposide and cytarabine following epigenetic priming with decitabine in adults with relapsed/refractory acute myeloid leukemia or other high-grade myeloid neoplasms: a phase 1/2 study

DNA methyltransferase inhibitors sensitize leukemia cells to chemotherapeutics. We therefore conducted a phase 1/2 study of mitoxantrone, etoposide, and cytarabine following “priming” with 5-10 days of decitabine (dec/MEC) in 52 adults (median age 55 [range: 19-72] years) with relapsed/refractory acute myeloid leukemia (AML) or other high-grade myeloid neoplasms. During dose escalation in cohorts of 6-12 patients, all dose levels were well-tolerated. As response rates appeared similar with 7 and 10-days of decitabine, a 7-day course was defined as the recommended phase 2 dose (RP2D). Among 46 patients treated at/above the RP2D, 10 (22%) achieved a complete remission (CR), 8 without measurable residual disease; five additional patients achieved CR with incomplete platelet recovery, for an overall response rate of 33%. Seven patients (15%) died within 28 days of treatment initiation. Infection/neutropenic fever, nausea, and mucositis were the most common adverse events. While the CR rate compared favorably to a matched historic control population (observed/expected CR ratio=1.77), CR rate and survival were similar to two contemporary salvage regimens used at our institution (G-CLAC and G-CLAM). Thus, while meeting the pre-specified efficacy goal, we found no evidence that dec/MEC is substantially better than other cytarabine-based regimens currently used for relapsed/refractory AML.

Resource Utilization and Safety of Outpatient Management Following Intensive Induction or Salvage Chemotherapy for Acute Myeloid Leukemia or Myelodysplastic Syndrome: A Nonrandomized Clinical Comparative Analysis

IMPORTANCE

Adults with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) typically remain hospitalized after induction or salvage chemotherapy until blood cell count recovery, with resulting prolonged inpatient stays being a primary driver of health care costs. Pilot studies suggest that outpatient management following chemotherapy might be safe and could reduce costs for these patients.

OBJECTIVE

To compare safety, resource utilization, infections, and costs between adults discharged early following AML or MDS induction or salvage chemotherapy and inpatient controls.

DESIGN

Nonrandomized, phase 2, single-center study conducted at the University of Washington Medical Center. Over a 43-month period (January 1, 2011, through July 31, 2014), 178 adults receiving intensive AML or MDS chemotherapy were enrolled. After completion of chemotherapy, 107 patients met predesignated medical and logistical criteria for early discharge, while 29 met medical criteria only and served as inpatient controls.

INTERVENTIONS

Early-discharge patients were released from the hospital at the completion of chemotherapy, and supportive care was provided in the outpatient setting until blood cell count recovery (median, 21 days; range, 2-45 days). Controls received inpatient supportive care (median, 16 days; range, 3-42 days).

MAIN OUTCOMES AND MEASURES

We analyzed differences in early mortality, resource utilization including intensive care unit (ICU) days, transfusions per study day, and use of intravenous (IV) antibiotics per study day), numbers of infections, and total and inpatient charges per study day among early-discharge patients vs controls.

RESULTS

Four of the 107 early-discharge patients and none of the 29 control patients died within 30 days of enrollment (P=.58). Nine early-discharge patients (8%) but no controls required ICU-level care (P=.20). No differences were noted in the median daily number of transfused red blood cell units (0.27 vs 0.29; P=.55) or number of transfused platelet units (0.26 vs 0.29; P=.31). Early-discharge patients had more positive blood cultures (37 [35%] vs 4 [14%]; P=.04) but required fewer IV antibiotic days per study day (0.48 vs 0.71; P=.01). Overall, daily charges among early-discharge patients were significantly lower than for inpatients (median, $3840 vs $5852; P<.001) despite increased charges per inpatient day when readmitted (median, $7405 vs $5852; P<.001).

CONCLUSIONS AND RELEVANCE

Early discharge following intensive AML or MDS chemotherapy can reduce costs and use of IV antibiotics, but attention should be paid to complications that may occur in the outpatient setting.

Idarubicin, cytarabine, and pravastatin as induction therapy for untreated acute myeloid leukemia and high-risk myelodysplastic syndrome

Previous studies suggest that idarubicin/cytarabine(ara-C)/pravastatin (IAP) is an active salvage regimen for patients with AML. We therefore investigated this regimen in patients with newly-diagnosed AML or MDS (≥10% blasts). Patients were eligible if the anticipated treatment-related mortality (TRM) was <10%. Patients received pravastatin (1,280 mg/day po; days 1-8), cytarabine (1.5 g/m(2) /day; days 4-7), and idarubicin (12 mg/m(2) /day, days 4-6). Up to 3 cycles of consolidation with a shortened course was permitted. The primary endpoints were "good CR" rate (CR on day 35 without minimal residual disease) and TRM in the first 28 days. The study was to stop if after each cohort of 5 patients (a) the Bayesian posterior probability was < 5% that the true "good CR rate" was ≥ 70% or (b) the posterior probability was >25% that the TRM rate was ≥5%. Twenty-four patients were included. Conventional CR was achieved in 15 (63%) patients but only 12 (50%) achieved "good CR". 4 of 12 (33%) patients with "good CR" relapsed at median of 16 weeks (10.5-19). Five (21%) patients had refractory disease. Survival probability at 1 year was 72% (48.7-64). Two (8.3%) patients died within 28 days from multiorgan failure. The most common grade 3-4 adverse effects were febrile neutropenia (75%) and diarrhea (25%). Based on the stopping rules accrual ceased after entry of these 24 patients. IAP did not meet the predefined efficacy criteria for success. Therefore, we would not recommend this regimen for phase three testing in this patient subset.

Development of a hematology/oncology ICD-10 documentation job aid

Conversion to the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) was mandated for October 1, 2014, but was delayed by one year. ICD-10 accommodates newly developed diagnoses and procedures and is expected to help measure quality of care. When implemented, it will impact oncology practices because of conversion costs, loss of productivity, and billing problems. Clinical documentation must meet the specificity required by ICD-10 codes or risk denial of payments, which are projected to dramatically increase. In preparation for the now delayed conversion, the ICD-10 transition team at the Seattle Cancer Care Alliance (SCCA) examined the ICD-10 codes for primary hematology/oncology diagnoses and comorbidities of cancer and therapy seen at our institution to identify the need for and feasibility of developing a printable job aid to guide clinical documentation. We found that the variable complexity of ICD-10 codes in hematology/oncology frequently requires nonintuitive specificity likely to be overlooked without prompting. We were able to develop a succinct and facile documentation aid usable in both electronic and printed forms that includes all hematology/oncology diagnoses and the comorbidities most frequently seen in our multidisciplinary institution. This document is organized in a notebook format for easy review and will be continuously improved with feedback from practitioners. It is available for free download from the SCCA Web site.

G-CSF priming, clofarabine, and high dose cytarabine (GCLAC) for upfront treatment of acute myeloid leukemia, advanced myelodysplastic syndrome or advanced myeloproliferative neoplasm

Prior study of the combination of clofarabine and high dose cytarabine with granulocyte colony-stimulating factor (G-CSF) priming (GCLAC) in relapsed or refractory acute myeloid leukemia resulted in a 46% rate of complete remission despite unfavorable risk cytogenetics. A multivariate analysis demonstrated that the remission rate and survival with GCLAC were superior to FLAG (fludarabine, cytarabine, G-CSF) in the relapsed setting. We therefore initiated a study of the GCLAC regimen in the upfront setting in a multicenter trial. The objectives were to evaluate the rates of complete remission (CR), overall and relapse-free survival (OS and RFS), and toxicity of GCLAC. Clofarabine was administered at 30 mg m(-2) day(-1) × 5 and cytarabine at 2 g m(-2) day(-1) × 5 after G-CSF priming in 50 newly-diagnosed patients ages 18-64 with AML or advanced myelodysplastic syndrome (MDS) or advanced myeloproliferative neoplasm (MPN). Responses were assessed in the different cytogenetic risk groups and in patients with antecedent hematologic disorder. The overall CR rate was 76% (95% confidence interval [CI] 64-88%) and the CR + CRp (CR with incomplete platelet count recovery) was 82% (95% CI 71-93%). The CR rate was 100% for patients with favorable, 84% for those with intermediate, and 62% for those with unfavorable risk cytogenetics. For patients with an antecedent hematologic disorder (AHD), the CR rate was 65%, compared to 85% for those without an AHD. The 60 day mortality was 2%. Thus, front line GCLAC is a well-tolerated, effective induction regimen for AML and advanced myelodysplastic or myeloproliferative disorders.

Outpatient bendamustine and idarubicin for upfront therapy of elderly acute myeloid leukaemia/myelodysplastic syndrome: a phase I/II study using an innovative statistical design

Combinations of agents may improve outcomes among elderly acute myeloid leukaemia (AML) and high-risk myelodysplastic syndrome (MDS) patients. We performed an adaptive phase I/II trial for newly-diagnosed AML or high-risk MDS patients aged ≥50 years using a Bayesian approach to determine whether 1 of 3 doses of bendamustine (45, 60, 75 mg/m(2) days 1-3), together with idarubicin (12 mg/m(2) days 1-2), might provide a complete response (CR) rate ≥40% with <30% grade 3-4 non-haematological toxicity. We treated 39 patients (34 AML; five MDS with >10% marrow blasts; median age 73 years). None of the three bendamustine doses in combination with idarubicin met the required CR and toxicity rates; the 75 mg/m(2) dose because of excess toxicity (two of three patients) and the 60 mg/m(2) dose because of low efficacy (CR rate 10/33), although no grade 3-4 non-haematological toxicity was seen at this dose. Median survival was 7·2 months. All patients began treatment as outpatients but hospitalization was required in 90% (35/39). Although we did not find a dose of bendamustine combined with idarubicin that would provide a CR rate of >40% with acceptable toxicity, bendamustine may have activity in AML/MDS patients, suggesting its addition to other regimens may be warranted.

Are new oral anticoagulants ready for use in patients with cancer?

Patients with cancer have long been an important and enigmatic part of basic science and clinical research in thromboembolic disease. The reciprocal deleterious effects on outcomes of a cancer diagnosis on patients with thrombosis and a thrombotic event on patients with cancer have been observed and documented for more than a century. Patients with cancer continue to be one of the more difficult populations to manage using the available unfractionated and low-molecular-weight heparins and the oral vitamin K antagonists. High rates of failure and bleeding complications have made researchers and practitioners alike seek newer more effective anticoagulation agents. The novel oral direct thrombin and activated factor Xa inhibitors have been shown in large clinical trials to be safe and efficacious in many prophylaxis and treatment settings. However, practitioners who treat patients with cancer should be cautious using these agents until more studies are specifically performed in this thrombophilic patient population.

Gemtuzumab ozogamicin in combination with vorinostat and azacitidine in older patients with relapsed or refractory acute myeloid leukemia: a phase I/II study

Epigenetic therapeutics such as the histone deacetylase inhibitor, vorinostat, and the DNA methyltransferase I inhibitor, azacitidine, enhance gemtuzumab ozogamicin efficacy in vitro. We therefore investigated vorinostat/azacitidine/gemtuzumab ozogamicin in 52 adults aged 50 years or over with acute myeloid leukemia requiring therapy for first relapse (remission duration ≤ 12 months) or primary refractory disease in a phase I/II trial. Vorinostat and gemtuzumab ozogamicin were escalated step-wise during the phase I portion of the trial. Vorinostat (400 mg/day orally from Days 1-9), azacitidine (75 mg/m(2)/day intravenously or subcutaneously from Days 1-7), and gemtuzumab ozogamicin (3 mg/m(2)/day intravenously on Days 4 and 8) were identified as the maximum tolerated dose. Among the 43 patients treated at this dose, 10 achieved a complete remission and 8 achieved a complete remission with incomplete blood count recovery, for an overall response rate of 41.9% (exact 95% confidence interval (CI): 27.0-57.9%). Four of these 18 patients (2 with complete remission and 2 with complete remission with incomplete blood count recovery) had persistence of minimal residual disease by flow cytometry at the time of best response. Four patients died within 28 days of treatment initiation. Median overall survival for the 18 patients achieving complete remission/complete remission with incomplete blood count recovery was significantly longer than for those 21 patients who failed therapy but lived at least 29 days after treatment initiation (224.5 days (range 70-798) vs. 95 days (range 36-900); P=0.0023). These data indicate that vorinostat/azacitidine/gemtuzumab ozogamicin has activity in this difficult-to-treat acute myeloid leukemia patient subset. (ClinicalTrials.gov: identifier 00895934).

Clofarabine with high dose cytarabine and granulocyte colony-stimulating factor (G-CSF) priming for relapsed and refractory acute myeloid leukaemia

This phase I/II study was conducted to determine the maximum tolerated dose, toxicity, and efficacy of clofarabine in combination with high dose cytarabine and granulocyte colony-stimulating factor (G-CSF) priming (GCLAC), in the treatment of patients with relapsed or refractory acute myeloid leukaemia (AML). Dose escalation of clofarabine occurred without dose-limiting toxicity, so most patients were treated at the maximum dose, 25 mg/m(2) per day with cytarabine 2 g/m(2) per day, each for 5 d, and G-CSF 5 μg/kg, beginning the day before chemotherapy and continuing daily until neutrophil recovery. The complete remission (CR) rate among the 46 evaluable patients was 46% (95% confidence interval [CI] 31-61%) and the CR + CR but with a platelet count <100 × 10(9)/l rate was 61% (95% CI 45-75%). Multivariate analysis showed that responses to GCLAC were independent of age, cytogenetic risk category, and number of prior salvage regimens. GCLAC is highly active in relapsed and refractory AML and warrants prospective comparison to other regimens, as well as study in untreated patients.

Gene Targeting with Viral Vectors

Genetic manipulation of cells for scientific and therapeutic goals can be achieved by both gene-addition and gene-targeting methods. Gene targeting precisely alters a gene in its natural chromosome location, providing distinct advantages over gene-addition approaches. Classic gene-targeting delivery systems (microinjection, electroporation, or calcium phosphate transfection) have led to major scientific advances, but are too inefficient in their current state to be used for some applications, including gene therapy. This review describes the development of gene-targeting vectors based on three types of viruses (retrovirus, adenovirus, and adeno-associated virus) and discusses the design, possible mechanisms of action, and applications of gene-targeting vectors based on adeno-associated virus.

Chromosomal integration and homologous gene targeting by replication-incompetent vectors based on the autonomous parvovirus minute virus of mice

The molecular mechanisms responsible for random integration and gene targeting by recombinant adeno-associated virus (AAV) vectors are largely unknown, and whether vectors derived from autonomous parvoviruses transduce cells by similar pathways has not been investigated. In this report, we constructed vectors based on the autonomous parvovirus minute virus of mice (MVM) that were designed to introduce a neomycin resistance expression cassette (neo) into the X-linked human hypoxanthine phosphoribosyl transferase (HPRT) locus. High-titer, replication-incompetent MVM vector stocks were generated with a two-plasmid transfection system that preserved the wild-type characteristic of packaging only one DNA strand. Vectors with inserts in the forward or reverse orientations packaged noncoding or coding strands, respectively. In human HT-1080 cells, MVM vector random integration frequencies (neo(+) colonies) were comparable to those obtained with AAV vectors, and no difference was observed for noncoding and coding strands. HPRT gene-targeting frequencies (HPRT mutant colonies) were lower with MVM vectors, and the noncoding strand frequency was threefold greater than that of the coding strand. Random integration and gene-targeting events were confirmed by Southern blot analysis of G418- and 6-thioguanine (6TG)-resistant clones. In separate experiments, correction of an alkaline phosphatase (AP) gene by gene targeting was nine times more effective with a coding strand vector. The data suggest that single-stranded parvoviral vector genomes are substrates for gene targeting and possibly for random integration as well.

Myeloid cell proliferation stimulated by Steel factor is pertussis toxin sensitive and enhanced by cholera toxin

Effects of G-protein toxins on Steel factor (SLF) and granulocyte-macrophage colony stimulating factor (GM-CSF) stimulated proliferation of human factor-dependent cell line, M07e, were evaluated. Pertussis toxin pretreatment suppressed GM-CSF- or Steel factor-induced proliferation by 54 +/- 8%; however, proliferation induced by the combination of GM-CSF plus Steel factor was suppressed to a much lesser extent (14 +/- 8%). Pretreatment of M07e cells with cholera toxin, suppressed GM-CSF- and GM-CSF plus Steel factor-stimulated proliferation by 57 +/- 6% and 79%, respectively, but increased the proliferative response to Steel factor alone by twofold. Similar effects of pertussis toxin and cholera toxin were observed on proliferation of normal myeloid progenitor cells from human umbilical cord blood. Pertussis toxin treatment of M07e cells for 4 h resulted in the ADP-ribosylation of 40-42 kDa protein band but did not significantly increase cyclic AMP levels. Cholera toxin pretreatment was associated with a 10-fold increase in intracellular cyclic AMP levels. These results implicate pertussis toxin sensitive pathways for both GM-CSF and Steel factor, but suggest that these pathways may not be required for synergistic proliferation stimulated by the combination. In addition, proliferation stimulated by GM-CSF, +/- Steel factor, is sensitive to cholera toxin pretreatment; whereas cholera toxin pretreatment enhanced proliferation stimulated by Steel factor, possibly via increased cyclic AMP. This suggests divergent signal transduction pathways for the two cytokines.

Ligand-dependent polyubiquitination of c-kit gene product: a possible mechanism of receptor down modulation in M07e cells

Quantities of proteins in cells are balanced by protein synthesis and degradation. Protein ubiquitination is an important adenosine-triphosphate dependent proteolytic pathway for "short-lived" proteins. We show that soluble steel-factor (SLF) stimulation at 37 degrees C rapidly induced polyubiquitination of c-kit protein in growth-factor-dependent human-myeloid cell line M07e, resulting in smeared, retarded migration of c-kit protein in sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the molecular weight region of 145 kD. Receptor ubiquitination was almost completely absent when cells were treated with SLF at 4 degrees C or at 37 degrees C in the presence of 0.2% sodium azide, or when the cells were pretreated with anti-c-kit monoclonal antibody or genistein, a tyrosine-kinase inhibitor. This suggested that c-kit ubiquitination was ligand dependent and appeared to require intrinsic tyrosine-kinase activation of the c-kit protein. Flow-cytometric analysis of c-kit expression on the cell surface of M07e cells showed down modulation of c-kit within 5 minutes after soluble-SLF treatment at 37 degrees C. However, rapid receptor down modulation was almost completely suppressed when cells were treated with SLF at 4 degrees C or at 37 degrees C in the presence of 0.2% sodium azide, conditions that concomitantly suppressed polyubiquitination of c-kit protein. In addition, these conditions almost completely suppressed radiolabeled SLF (125I-SLF) internalization after ligand-receptor interaction. Pulse-chase studies of 35S-methionine-labeled c-kit protein showed that SLF stimulation at 37 degrees C strikingly enhanced c-kit degradation (T1/2; approximately 20 minutes) compared with that in cells stimulated with SLF at 4 degrees C or at 37 degrees C with 0.2% sodium azide. However, in the presence of chloroquine, which blocks lysosomal degradation, this ligand-induced c-kit degradation at 37 degrees C was only suppressed in part. These data suggest that SLF-induced polyubiquitination of the c-kit receptor protein may play a role in regulation of c-kit-encoded protein-receptor expression in M07e cells.

Recombinant human interleukin-9 induces protein tyrosine phosphorylation and synergizes with steel factor to stimulate proliferation of the human factor-dependent cell line, M07e

Human interleukin-9 (IL-9) was originally identified and cloned based on its stimulatory effect on proliferation of human myeloid cell line, M07e. IL-9 synergized with Steel factor, the ligand for the c-kit product, to stimulate M07e cell proliferation. To investigate potential mechanisms for this, IL-9 was assessed for effects on protein tyrosine kinase activities in M07e cells by immunoblotting with anti-phosphotyrosine monoclonal antibody; results were compared with those of Steel factor alone and in combination with IL-9, and those of 12-0-tetradecanoyl phorbol-13-acetate (TPA). Recombinant human IL-9 (10 ng/mL) rapidly and transiently induced or enhanced at least four tyrosine phosphorylated protein bands with molecular weights of 105, 97, 85, and 81 Kd. This tyrosine phosphorylation pattern was different from that generated by recombinant murine Steel factor or TPA stimulation and the combination of IL-9 and Steel factor did not change the IL-9-induced pattern. IL-9-induced tyrosine phosphorylated bands were completely blocked by treatment of IL-9 with anti-IL-9 antibody under conditions that also neutralized the synergistic effect of IL-9 with Steel factor on M07e cell proliferation. Genistein, a tyrosine kinase inhibitor, blocked phosphorylation of IL-9 and Steel factor-induced bands. Unlike Steel factor or TPA, IL-9 did not appear to stimulate phosphorylation of 42-Kd mitogen-activated protein (MAP) kinase or Raf-1, or enhance MAP kinase activity. MAP kinase and Raf-1 are serine/threonine kinases that are phosphorylated and activated by many growth factors and by agonists for protein kinase C. While the combination of IL-9 plus SLF did not appear to induce phosphorylation of new bands not already seen with either IL-9 or SLF alone, or enhance the phosphorylation of those bands seen with either cytokine alone, the results suggest that IL-9 activates specific and unique signal transduction pathways.

The kit receptor and its ligand, steel factor, as regulators of hemopoiesis

Mouse strains carrying mutations at the Dominant White Spotting (W) locus or the Steel (Sl) locus are anemic and display defects in pigmentation and gametogenesis. In W mutants the anemia is due to a deficiency of hemopoietic stem cells and, in Sl mutants, to a deficiency of supporting stromal cells in the bone marrow. The W locus encodes the c-kit proto-oncogene product, a cell surface receptor with protein-tyrosine kinase activity, and the Sl locus encodes its ligand, a hemopoietic cytokine known variously as Steel factor (SLF), mast cell growth factor, stem cell factor, and Kit ligand. SLF can synergize with a number of other cytokines to stimulate growth of hemopoietic progenitors in vitro and stimulates blood cell production in vivo in animals. Here we review the biological activities of SLF, with particular emphasis on its effects on hemopoietic stem and progenitor cells. We also discuss present knowledge of the molecules involved in SLF-triggered signal transduction, and speculate on potential therapeutic applications for SLF in human disease.

Comparative analysis of signaling pathways between mast cell growth factor (c-kit ligand) and granulocyte-macrophage colony-stimulating factor in a human factor-dependent myeloid cell line involves phosphorylation of Raf-1, GTPase-activating protein and mitogen-activated protein kinase

Mast cell growth factor (MGF, the ligand for c-kit receptor) can stimulate proliferation of factor dependent myeloid cell line, M07e, and MGF synergizes with granulocyte-macrophage colony-stimulating factor (GM-CSF) or IL-3 in this effect. The effect of MGF on protein tyrosine kinase activity in M07e cells was investigated by immunoblotting with anti-phosphotyrosine mAb and this was compared with effects of GM-CSF. MGF stimulation rapidly induced or enhanced at least 12 tyrosine phosphorylated bands. Major bands had molecular weights of 145, 120, 110, 98, 62, 55 and 42 kD. P145, the most prominent phosphorylated protein, was identified as c-kit product using anti-c-kit-mAb (YB5.B8), suggesting ligand-dependent receptor autophosphorylation. Five of six tyrosine phosphorylated bands induced or enhanced by GM-CSF stimulation comigrated with those tyrosine phosphorylated by MGF (138, 120, 76, 55 and 42 kD). P42 was identified, at least in part, as mitogen-activated protein (MAP) kinase. MGF induced tyrosine phosphorylation of a complex of GTPase-activating protein (GAP, 120 kD) and GAP associated proteins (p62/p190) as detected by anti-GAP Ab immunoprecipitation followed by immunoblotting with anti-phosphotyrosine mAb. GM-CSF also stimulated slightly but consistently tyrosine phosphorylation of GAP and p190 but not p62. Both MGF and GM-CSF enhanced Raf-1 phosphorylation and increased Raf-1 associated kinase activity in vitro. Phosphoamino acid analysis revealed Raf-1 phosphorylation by these two growth factors occurred almost exclusively on serine residues. No tyrosine phosphorylation of Raf-1 protein was detected. These data suggest shared and unshared components of signaling pathways of both factors, which may be involved in cell proliferation.

Mast cell growth factor (c-kit ligand) enhances cytokine stimulation of proliferation of the human factor-dependent cell line, M07e

Murine mast cell growth factor (muMGF), a c-kit ligand, has additive to greater-than-additive effects on in vitro colony formation of murine and human myeloid progenitor cells stimulated with erythropoietin, granulocyte-macrophage colony-stimulating factor (GM-CSF), and/or interleukin (IL)-3. To confirm direct-acting effects on responding cells, MGF was assessed alone and in combination with other cytokines for effects on the proliferation of the human factor-dependent cell line, M07e. Proliferation was assayed in liquid culture by [3H]thymidine uptake and in semisolid medium by colony formation. Purified recombinant (r) muMGF (25-50 ng/ml) by itself had proliferative activity but less than r human (hu) GM-CSF. In combination with rhuGM-CSF (250 U/ml) or IL-3 (500 U/ml), rmuMGF (25 ng/ml) enhanced [3H]thymidine uptake two- to sevenfold greater than the sum of the effects of each factor alone. Similar enhancement was seen in the number and size of colonies formed. When MGF was used in combination with rhuIL-4 (500-1000 U/ml), rhuIL-6 (5 ng/ml), rhuIL-9 (5-10 U/ml), or rhu interferon gamma (IFN-gamma; 250-500 U/ml) (factors that alone stimulate little proliferation), [3H]thymidine uptake and colony formation were respectively increased 2- to 11- and 3- to 55-fold over the sum of each of the effects of the factors alone. Exposure of 5 x 10(5) cells/ml to 50 ng/ml MGF for 24 h, a time during which synergism is noted with MGF plus either GM-CSF or IL-3, did not change GM-CSF or IL-3 receptor binding affinity or the number of binding sites. Exposure of cells to MGF for 48 h did not alter subsequent GM-CSF- or IL-3-stimulated proliferation. The results suggest that M07e cells will be useful as a model for the analysis of intracellular biochemical mechanisms of the direct-acting proliferative and synergistic effects of MGF.

CD45 cell surface antigens are linked to stimulation of early human myeloid progenitor cells by interleukin 3 (IL-3), granulocyte/macrophage colony-stimulating factor (GM-CSF), a GM-CSF/IL-3 fusion protein, and mast cell growth factor (a c-kit ligand)

CD45 antigens are protein tyrosine phosphatases. A possible link was evaluated between expression of CD45 antigens on human myeloid progenitor cells (MPC) (colony-forming unit-granulocyte/macrophage [CFU-GM], burst-forming unit-erythroid [BFU-E], and colony-forming unit-granulocyte/erythroid/macrophage/megakaryocyte [CFU-GEMM]) and regulation of MPC by colony-stimulating factors (CSF) (interleukin 3 [IL-3], GM-CSF, G-CSF, M-CSF, and erythropoietin [Epo]), a GM-CSF/IL-3 fusion protein, and mast cell growth factor (MGF; a c-kit ligand). Treatment of cells with antisense oligodeoxynucleotides (oligos) to exons 1 and 2, but not 4, 5, or 6, of the CD45 gene, or with monoclonal anti-CD45, significantly decreased CFU-GM colony formation stimulated with GM-CSF, IL-3, fusion protein, and GM-CSF + MGF, but not with G-CSF or M-CSF. It also decreased GM-CSF, IL-3, fusion protein, and MGF-enhanced Epo-dependent BFU-E and CFU-GEMM colony formation, but had little or no effect on BFU-E or CFU-GEMM colony formation stimulated by Epo alone. Similar results were obtained with unseparated or purified (greater than or equal to one of two cells being a MPC) bone marrow cells. Sorted populations of CD343+ HLA-DR+ marrow cells composed of 90% MPC were used to demonstrate capping of CD45 after crosslinking protocols. Also, a decreased percent of CD45+ cells and CD45 antigen density was noted after treatment of column-separated CD34+ cells with antisense oligos to exon 1 of the CD45 gene. These results demonstrate that CD45 cell surface antigens are linked to stimulation of early human MPC by IL-3, GM-CSF, a GM-CSF/IL-3 fusion protein, and MGF.