Effect of Linezolid on Hematologic Recovery in Newly Diagnosed Acute Myeloid Leukemia Patients Following Induction Chemotherapy.

OBJECTIVE: Assess the effects of linezolid on hematologic outcomes in newly diagnosed patients with acute myeloid leukemia (AML) following induction chemotherapy. DESIGN: Single-center, retrospective, observational, cohort study. SETTING: Large, tertiary care academic medical center. PATIENTS: A total of 225 patients ≥ 18 years admitted between December 2010 and 2013 with newly diagnosed AML were assessed for inclusion. Patients were identified through the use of ICD-9 codes and chemotherapy ordered via the computerized physician order entry system. Sixty-eight patients met inclusion criteria and were grouped into two arms based on antimicrobial treatment: LZD group (linezolid plus gram-negative antimicrobial, n=21) or control group (vancomycin or daptomycin plus gram-negative antimicrobial, n=47). INTERVENTIONS: The LZD group received linezolid ≥ 72 hours. The control group received vancomycin or daptomycin ≥ 72 hours. If patients switched extended gram-positive therapy, they were included in the LZD group as long as they had received ≥ 72 hours of linezolid. MEASUREMENTS/RESULTS: The primary end point of time to neutrophil recovery was not statistically different (28 days for LZD group vs 26 days for control group; p=0.675). The preplanned subgroup analysis of patients who received ≥ 14 days of linezolid demonstrated statistically similar median times to neutrophil recovery (29 days for LZD group vs 26 days for control group; p=0.487). Total duration of extended gram-positive antimicrobial therapy was significantly longer in the LZD group (27 days vs 16 days; p<0.001). Secondary end points not found to be statistically significant included platelet count at time of neutrophil recovery, duration of neutropenia, and length of hospital stay. CONCLUSIONS: There were no significant differences in hematologic outcomes in newly diagnosed AML patients who received linezolid for extended gram-positive antimicrobial coverage following induction chemotherapy. This study provides new insight with a primary focus on the effects of hematologic outcomes when using linezolid in a well-defined acute leukemia population. Further study is warranted with larger populations to assess the potential adverse effects linezolid may have in patients with acute leukemia.

A phase 1/2 study of chemosensitization with the CXCR4 antagonist plerixafor in relapsed or refractory acute myeloid leukemia.

The interaction of acute myeloid leukemia (AML) blasts with the leukemic microenvironment is postulated to be an important mediator of resistance to chemotherapy and disease relapse. We hypothesized that inhibition of the CXCR4/CXCL12 axis by the small molecule inhibitor, plerixafor, would disrupt the interaction of leukemic blasts with the environment and increase the sensitivity of AML blasts to chemotherapy. In this phase 1/2 study, 52 patients with relapsed or refractory AML were treated with plerixafor in combination with mitoxantrone, etoposide, and cytarabine. In phase 1, plerixafor was escalated to a maximum of 0.24 mg/kg/d without any dose-limiting toxicities. In phase 2, 46 patients were treated with plerixafor 0.24 mg/kg/d in combination with chemotherapy with an overall complete remission and complete remission with incomplete blood count recovery rate (CR + CRi) of 46%. Correlative studies demonstrated a 2-fold mobilization in leukemic blasts into the peripheral circulation. No evidence of symptomatic hyperleukocytosis or delayed count recovery was observed with the addition of plerixafor. We conclude that the addition of plerixafor to cytotoxic chemotherapy is feasible in AML, and results in encouraging rates of remission with correlative studies demonstrating in vivo evidence of disruption of the CXCR4/CXCL12 axis.

Use of cytomegalovirus intravenous immune globulin for the adjunctive treatment of cytomegalovirus in hematopoietic stem cell transplant recipients.

STUDY OBJECTIVE: To describe the characteristics and clinical outcomes of hematopoietic stem cell transplant (HSCT) recipients who received adjunctive cytomegalovirus intravenous immune globulin (CMV-IVIG) for probable or proven CMV disease. DESIGN: Retrospective cohort study. SETTING: Large, university-affiliated, tertiary-care medical center. PATIENTS: Thirty-five adult HSCT recipients who received at least one dose of CMV-IVIG for adjunctive treatment of probable or proven CMV disease between January 1, 1999, and December 31, 2007. MEASUREMENTS AND MAIN RESULTS: All-cause mortality at hospital discharge was the primary outcome. All patients received an allogeneic HSCT. Twenty-six patients (74%) had pneumonitis, nine (26%) had enteritis, and 29 (83%) had CMV viremia. All patients received concomitant antiviral therapy; 31 (89%) received ganciclovir, and 14 (40%) received foscarnet. All-cause mortality at hospital discharge was 49% (17 patients). Patient characteristics associated with mortality included requiring intubation for CMV pneumonia (11 [79%] of 14 nonsurvivors vs 3 (25%) of 12 survivors, p=0.016) and earlier disease onset after HSCT (median 48 days for nonsurvivors vs 106 days for survivors, p<0.001). In the multivariate analysis, only requiring intubation for CMV pneumonia remained a significant risk factor for increased mortality. A low rate of adverse events was attributed to CMV-IVIG, with mild hypertension (two patients [6%]) and erythema and chills (one patient [3%]) being the most common. CONCLUSION: The mortality rate in our study population was similar to previous reports in the literature and may be somewhat lower than rates reported with antiviral monotherapy. Our analysis suggests that factors associated with mortality include the need for intubation and, possibly, earlier onset of CMV disease after HSCT. Treatment with CMV-IVIG appears to be well tolerated in HSCT recipients. These findings support further trials of CMV-IVIG efficacy in this setting.

Salvage therapy for acute myeloid leukemia with fludarabine, cytarabine, and idarubicin with or without gemtuzumab ozogamicin and with concurrent or sequential G-CSF.

The current salvage therapies for relapsed/refractory acute myeloid leukemia (AML) are unsatisfactory. Over the past 7 years, we have used two salvage regimens: fludarabine, cytarabine, and idarubicin with (FLAG-IM) or without gemtuzumab ozogamicin (GO) (9 mg/m(2) on Day 8) (FLAG-I) in relapsed/refractory AML. Three-quarters of patients also received concurrent G-CSF. Seventy-one patients were treated, 23 with FLAG-I and 48 with FLAG-IM. The median duration of follow-up was 30.6 months. The treatment groups were well balanced with median ages of 48 years (range 18-70) and 47 years (range 20-68), unfavorable cytogenetics in 57% and 35%, prior allogeneic stem cell transplant in 43% and 42%, and CR1 duration <1 year in 60% and 67%, respectively, for FLAG-I and FLAG-IM. The complete remission (CR) rate in the FLAG-I group was 39% with an additional 13% achieving a CRp [overall response rate (ORR) 52%]; the CR rate in the FLAG-IM group was 29% with an additional 27% achieving a CRp (ORR 56%). The median duration of response (DOR; 16.8 vs. 8.3 months), event-free survival (EFS; 7.4 vs. 4.1 months), and overall survival (OS; 8.8 vs. 5.0 months) trended to favor FLAG-I over FLAG-IM. The patients who received G-CSF concurrent with chemotherapy had superior overall response rate (ORR; 62% vs. 29%, P = 0.026), median EFS (6.2 vs. 3.4 months, P = 0.010), and OS (8.8 vs. 3.9 months, P = 0.004) when compared with those who sequentially received G-CSF and chemotherapy, regardless of chemotherapy regimen. The addition of GO, at this dose and schedule, to FLAG-I failed to improve the outcomes in patients with relapsed/refractory AML. The patients who received G-CSF concurrently with chemotherapy had improved outcomes. Am. J. Hematol., 2009. (c) 2009 Wiley-Liss, Inc.

Cladribine in the treatment of acute myeloid leukemia: a single-institution experience.

BACKGROUND: Despite advances in novel therapeutics, supportive care, and postremission therapy, the outcome of high-risk and elderly patients as well as those with relapsed/refractory acute myeloid leukemia (AML) remains poor. There is likely still room for improvement through optimizing conventional chemotherapy. PATIENTS AND METHODS: Through a pharmacy database search we identified all patients with AML treated at Washington University with cladribine-based regimens. RESULTS: Twenty-four patients were identified that were treated with 2 cladribine-based regimens: CLAG (cladribine [5 mg/m2 days 1-5], cytarabine [2 g/m2 days 1-5] and granulocyte colony-stimulating factor [G-CSF; 300 microg subcutaneously (s.c.) days 0-5]) and CLAM (cladribine [5 mg/m2 days 1-5], cytarabine [2 g/m2 days 1-5], G-CSF [300 mg s.c. days 0-5] and mitoxantrone [10 mg/m2 days 1-3]). Complete responses were achieved in 53% of patients given induction chemotherapy and 44% of those given salvage chemotherapy. The regimens were well tolerated with minimal extramedullary toxicity. CONCLUSION: These data suggest that cladrabine-based regimens should be further explored in both the salvage and first-line setting and might offer an attractive backbone on which to add novel therapies.

Assessment of an alternative meropenem dosing strategy compared with imipenem-cilastatin or traditional meropenem dosing after cefepime failure or intolerance in adults with neutropenic fever.

STUDY OBJECTIVE: To compare clinical outcomes of patients receiving an alternative dosage of meropenem with those of patients receiving imipenem-cilastatin or the traditional dosage of meropenem after failure of or intolerance to cefepime for treatment of febrile neutropenia. DESIGN: Retrospective, single-center cohort study. SETTING: 1250-bed urban academic medical center. PATIENTS: One hundred twenty-seven adults with neutropenic fever who received either imipenem-cilastatin or meropenem; imipenem-cilastatin was the preferred carbapenem until September 1, 2006, after which meropenem became the formulary carbapenem. MEASUREMENTS AND MAIN RESULTS: Of the 127 patients, 40 received imipenem-cilastatin 500 mg every 6 hours between September 1, 2005, and August 31, 2006; 87 patients received meropenem between September 1, 2006, and August 31, 2007: 29 received a traditional dosage of meropenem 1 g every 8 hours, and 58 received an alternative dosage of meropenem 500 mg every 6 hours. Primary outcomes of time to defervescence (median 3 vs 2 vs 3 days), need for additional antibiotics (20% vs 17% vs 14%), and time to receipt of additional antibiotics (median 5 vs 2 vs 1 days) were not significantly different among the imipenem-cilastatin, traditionally dosed meropenem, and alternatively dosed meropenem groups, respectively. In addition, significant differences in secondary outcomes, which were treatment duration (median 10 vs 8 vs 8 days), seizure rate (0% vs 0% vs 0%), in-hospital mortality (5% vs 7% vs 7%), and 30-day mortality (13% vs 7% vs 14%), were not identified among the three groups, respectively. CONCLUSION: The alternative meropenem dosage of 500 mg every 6 hours yielded similar patient outcomes, including time to defervescence, need for additional antibiotics, duration of therapy, and mortality, when compared with the traditional meropenem dosage and imipenem-cilastatin in adults with febrile neutropenia. In addition, no adverse effects on clinical outcomes were observed with the alternative dosage of meropenem.

Treatment of acute promyelocytic leukemia during pregnancy.

Management of the pregnant patient with acute promyelocytic leukemia (APL) is a challenge. Immediate treatment of APL is critical, as it is an oncologic emergency, with a high risk of morbidity and mortality associated with disseminated intravascular coagulation. However, administration of chemotherapy and differentiating agents in pregnancy is controversial because of potential teratogenic effects. In addition, complications associated with APL, including retinoic acid syndrome, add to the complexity of management. To better understand how to manage this complex patient care situation, we searched the PubMed database (January 1972-May 2008) for English-language articles about maternal and fetal outcomes resulting from APL treatment during pregnancy. A total of 42 cases from 35 articles were identified: 12 first-trimester, 21 second-trimester, and 9 third-trimester cases. The most commonly administered agents were all-trans-retinoic acid (ATRA), anthracyclines, and antimetabolites. Complete remission was reported in 35 (83%) of 42 patients. Administration of ATRA or chemotherapy in the first trimester was associated with an increased risk of fetal malformations and spontaneous abortion, whereas administration in the second and third trimesters was associated with relatively favorable fetal outcomes. The overall treatment of the pregnant patient with APL should include a discussion about pregnancy termination, especially if APL is diagnosed in the first trimester. If the pregnancy is to continue, then the appropriate chemotherapy regimen needs to be determined. Frequent fetal monitoring, along with aggressive management of potential APL-related complications, is necessary to allow for optimal maternal and fetal outcomes.