Pharmacokinetics of oral posaconazole in neutropenic patients receiving chemotherapy for acute myelogenous leukemia or myelodysplastic syndrome

STUDY OBJECTIVE: To analyze the pharmacokinetics of posaconazole administered as prophylaxis for invasive fungal infection (IFI) in neutropenic patients receiving chemotherapy for acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS). DESIGN: Pharmacokinetic subanalysis of a phase III, prospective, randomized, multicenter, evaluator-blinded trial comparing posaconazole with standard azoles (fluconazole and itraconazole). PATIENTS: One hundred ninety-four patients with AML or MDS who received posaconazole oral suspension 200 mg 3 times/day with meals or a nutritional supplement for a minimum of 7 days to achieve steady state and for a maximum of 12 weeks. INTERVENTION: For the first 20 patients, blood samples were collected before the first dose on day 8 and at 2, 4, 6, and 24 hours after that first dose; for all other patients, blood samples were collected at 1 and 3 hours after the first dose on day 8 and during the first episode of evaluation for a possible IFI. MEASUREMENTS AND MAIN RESULTS: The effects of the following covariates on average (Cav) and maximum (Cmax) posaconazole plasma concentrations at steady state were explored: age, sex, and race-ethnicity; proven or probable IFI; baseline body weight and body surface area; and baseline (on or before day 7) increases in liver enzyme levels, mucositis, neutropenia, diarrhea, vomiting, or use of an H2-receptor antagonist or proton pump inhibitor. Diarrhea, proton pump inhibitor use, gamma-glutamyl transferase level of 2 or more times the upper limit of normal, and race-ethnicity reduced Cav. Although statistically significant, these results were not considered clinically significant and did not necessitate posaconazole dosage adjustments. Mean Cav and Cmax values did not appear different in the six patients with IFIs (three with proven IFIs, three with probable IFIs) compared with the entire sample of 194 patients; however, a definitive conclusion cannot be made due to the small sample size of patients with IFI. No factor found to affect posaconazole concentrations predominated in patients with IFIs. CONCLUSION: Oral posaconazole 200 mg 3 times/day provided plasma concentrations adequate for preventing IFIs. No dosage adjustments are recommended based on any covariate tested.     

泊沙康唑与伊曲康唑预防骨髓增生异常综合征/急性髓系白血病患者侵袭性真菌病的成本-效果分析

目的：开展泊沙康唑对比伊曲康唑用于预防骨髓增生异常综合征/急性髓系白血病患者发生侵袭性真菌病的成本-效果分析,为临床合理用药、药品费用不合理增长及医保药品目录的遴选提供决策依据。方法：基于医疗卫生体系角度,构建决策树模型及Markov模型,比较泊沙康唑和伊曲康唑用于预防侵袭性真菌病的短期和长期的经济性;短期健康产出为侵袭性真菌病的发生率,长期健康产出为患者所获得的生命年和质量调整生命年,成本数据来源于2019年中国真实医疗环境价格及文献研究。进行敏感性分析以验证基础分析结果的稳健性。结果：与伊曲康唑相比,泊沙康唑在短期模拟的100 d成本更高（10 992元vs. 8 038元）,但预防效果更好（侵袭性真菌病发生率4.6%vs. 11.1%）。在长期的患者全生命周期模拟中获得的生命年和质量调整生命年更多（2.949 LYs vs. 2.719 LYs,2.096 QALYs vs. 1.932 QALYs）,其增量成本-效果比为18 030元/QALY,远低于2019年中国社会意愿支付阈值（212 676元/QALY）。敏感性分析结果与基础分析结果一致。结论：在中国,泊沙康唑相比伊曲康唑用于预防骨髓增生异常综合征/急性髓系白血病患者发生侵袭性真菌病的经济性更好。     

地西他滨治疗骨髓增生异常综合征和急性髓细胞白血病临床观察

目的探讨地西他滨治疗骨髓增生异常综合征（MDS）和急性髓细胞白血病（AML）的临床疗效和安全性。方法收集2011年1月至2013年7月接受地西他滨[15mg／（m2·d）,第1—5天,静脉滴注持续1h以上1单药或联合CAGf阿糖胞苷（Ara-C）、阿克拉霉素（Acla）、粒细胞集落刺激因子（G-CSF）]方案治疗的20例MDS和AML患者的临床资料,评价其疗效和不良反应。结果20例患者中完全缓解（CR）4例,部分缓解（PR）8例,稳定（SD）及进展（PD）8例,总有效率为60．0％（12／20）。其中12例AML患者中CR2例,PR5例,总有效率为58.3％（7／12）,8例MDS患者中CR2例,PR3例,总有效率为62．5％（5／8）。1例MDS．难治性贫血伴环状铁粒幼细胞患者和2例慢性粒一单核细胞性白血病患者输血依赖情况有所改善。14例患者出现Ⅲ－Ⅳ度骨髓受抑,发生率为70．O％（14／20）。总感染率为35．0％（7,20）,其中肺部感染率为20．0％（4／20）,患者经积极抗感染、刺激造血及输血等支持治疗后感染控制。1例患者出现化疗相关死亡。20例患者均未出现严重肝功能损害及出血。结论地西他滨单药或联合CAG方案治疗MDS和AML有一定疗效,可廷缓疾病进展;患者对化疗不良反应均能耐受．且化疗相关病死率低。     

Vorinostat in acute myeloid leukemia and myelodysplastic syndromes

Introduction: The results of conventional treatment for acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) remain poor and innovative strategies are warranted. With this aim, epigenetic modulation became a promising approach over the last years. Vorinostat is an epigenetic targeted drug belonging to the histone deacetylase (HDAC) inhibitors family. It is the second-generation HDAC inhibitor that has been more extensively studied in AML and MDS.

Areas covered: In this review, we will present the rationale for its use in AML and MDS, describe the drug pharmacologic properties and review the current data available from clinical trials. The data presented here will allow the reader to overview the common mechanisms of action of this class of compounds in AML and MDS, as well as to better understand the biological specificities of vorinostat, and its current and future clinical development in the field.

Expert opinion: Vorinostat has shown an acceptable toxicity profile with mainly gastrointestinal and constitutional side effects. Efficacy as a single agent is limited in that group of patients, but promising results are currently observed with combinations of vorinostat and either conventional chemotherapy or investigational agents, including demethylating agents.     

Vorinostat in acute myeloid leukemia and myelodysplastic syndromes

INTRODUCTION: the results of conventional treatment for acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) remain poor and innovative strategies are warranted. With this aim, epigenetic modulation became a promising approach over the last years. Vorinostat is an epigenetic targeted drug belonging to the histone deacetylase (HDAC) inhibitors family. It is the second-generation HDAC inhibitor that has been more extensively studied in AML and MDS. AREAS COVERED: in this review, we will present the rationale for its use in AML and MDS, describe the drug pharmacologic properties and review the current data available from clinical trials. The data presented here will allow the reader to overview the common mechanisms of action of this class of compounds in AML and MDS, as well as to better understand the biological specificities of vorinostat, and its current and future clinical development in the field. EXPERT OPINION: vorinostat has shown an acceptable toxicity profile with mainly gastrointestinal and constitutional side effects. Efficacy as a single agent is limited in that group of patients, but promising results are currently observed with combinations of vorinostat and either conventional chemotherapy or investigational agents, including demethylating agents.     

Sequential arabinosylcytosin with or without fludarabine in paracmastic patients with acute myeloid leukemia

The purpose of this study is to assess how fludarabine (Fa) influences arabinosylcytosin's (Ara-C) mode of action. Plasma, cerebrospinal and urine samples were withdrawn from two study groups at specific time points and analyzed by HPLC. Group A was treated with Ara-C only whereas Group B was treated with Fa+Ara-C. The two study groups are all undergoing complete remission (CR). The Ara-C dose for Group A was 3g/m2 x 2, and the AUC(0-4) was 5.131 +/- 0.936. The Ara-C dose for Group B was 2g/m2 x 2, and the AUC(0-4) was 12.245 +/- 3.863. The AUC(0-4) for Group B is more than twice the AUC(0-4) for Group A, and these results indicate that Fa conduces a synergistic increase in the concentration and AUC of Ara-C in plasma and in cerebrospinal fluid. The pharmacokinetics between the different dose treatments was statistically different (P = 0.016). The differences in the ratios of C(Ara-u) to C(Ara-C), and in the Tmax between Groups A and B could indicate whether or not Ara-C combined with Fa. Although Group B demonstrates a higher AUC(0-4) with lower doses of Ara-C (2 g/m2 x 2), the adverse drug reaction (ADR) and bone inhibition were not more pronounced in Group B compared to Group A. These results are based on a limited number of case studies, hence, additional studies are necessary to support and prove this hypothesis.     

Etoposide pharmacokinetics in children treated for acute myeloid leukemia

We studied the pharmacokinetics of etoposide in 45 children treated for newly diagnosed acute myeloid leukemia. Etoposide, 100 mg/m body surface area/24 h, was administered by 96-h continuous intravenous infusion. Concomitantly, the children received cytarabine 200 mg/m/24 h by intravenous infusion and 6-thioguanine 100 mg/m twice daily orally. Median total body clearance in children 0.5-1.8 (n=4) and 2.3-17.7 years old (n=36) without Down's syndrome was 17.1 and 17.6 ml/min/m, respectively (P=0.96). Five children with Down's syndrome had a median clearance of 13.6 ml/min/m (P=0.067 compared with non-Down's syndrome children). Eighteen of the children received a second identical treatment course 3-4 weeks later; there was a significant correlation between individual clearance values (rho=0.56; P=0.017). We found no significant correlation between etoposide pharmacokinetics and the remission rate or the relapse rate. In conclusion, our findings indicate that special dose-calculation guidelines for infants above 3 months old are not substantiated by age-dependent pharmacokinetics of etoposide. Down's syndrome children might be candidates for dose reduction if our data are confirmed in larger numbers of patients. Low course-to-course variability indicates that pharmacokinetically guided dosing of etoposide might be clinically relevant, if larger studies can demonstrate that this approach decreases toxicity or increases response rates.     

Itraconazole vs. posaconazole for antifungal prophylaxis in patients with acute myeloid leukemia undergoing intensive chemotherapy: A retrospective study

ObjectiveThe objective of this study was to compare itraconazole with posaconazole for antifungal prophylaxis in acute myeloid leukemia (AML) patients undergoing intensive chemotherapy.MethodsAdult patients with AML received either itraconazole or posaconazole for antifungal prophylaxis while undergoing intensive chemotherapy. The primary endpoint was incidence of prophylaxis failure (change in antifungal agent due to suspected invasive fungal infection [IFI], drug intolerance, drug interaction, or adverse event).ResultsFrom February 2016 to January 2018, 90 patients were included in the itraconazole group and 45 patients in the posaconazole group. Prophylaxis failure occurred in 88% of itraconazole recipients compared with 33% of posaconazole recipients (P<0.001). The primary reason for prophylaxis failure with itraconazole was suspected IFI (58%) whereas for posaconazole, failure predominantly related to drug interaction (60%). An antifungal regimen was continued upon discharge in 47% of itraconazole recipients compared with 9% of posaconazole recipients (P<0.001). The use of breakthrough IFI diagnostic tests was not significantly different in the two groups. A larger proportion of drug concentrations were collected in the posaconazole group.ConclusionsIn AML patients undergoing intensive chemotherapy, posaconazole was associated with significantly lower rates of prophylaxis failure and less need for continued antifungal therapy on discharge compared with itraconazole.     

Erlotinib and gefitinib for the treatment of myelodysplastic syndrome and acute myeloid leukemia: a preclinical comparison

Erlotinib and gefitinib, two inhibitors of the epidermal growth factor receptor (EGFR), can stimulate apoptosis and differentiation of myeloid cell lines that lack EGFR, unveiling a novel, therapeutically exploitable off-target effect of tyrosine kinase inhibitors. Here, we performed a side-by-side comparison of erlotinib and gefitinib effects on a broad spectrum of malignant myeloid cell lines, as well as on primary myeloblasts freshly purified from the bone marrow of patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Both erlotinib and gefitinib induce apoptosis of a cell line (KG-1) that represents AML, and differentiation in another cell line (P39) derived from a patient with high-risk MDS. In this setting, erlotinib was more efficient than gefitinib. Erlotinib and gefitinib were equipotent in inducing apoptosis of primary CD34⁺ myeloblasts from MDS and AML patients, yet had no toxic effect on CD34⁺ progenitor cells from healthy donors. Although the response of individual MDS and AML patients in vitro was highly heterogeneous, the pro-apoptotic effects of erlotinib and gefitinib correlated significantly. These results suggest that erlotinib and gefitinib share a mechanistically related off-target effect that may be taken advantage of for the therapy of MDS and AML.     

骨髓增生异常综合征转变急性白血病的临床分析

目的：研究骨髓增生异常综合征（MDS）转变post MDS-AL临床表现及联合化疗成效。方法：运用WHO标准开展成效回顾。结果：62例患者中12例转为急性白血病（AL）,主要属于AML,中位转白期限12个月,联合化疗总体有效率为（OR）67%。结论：MDS高危向AL转化,post MDS-AL治疗难度极大,预后成效不佳。     

Effect of oral posaconazole on the pharmacokinetics of cyclosporine and tacrolimus

STUDY OBJECTIVE: To analyze the pharmacokinetic properties of the immunosuppressants cyclosporine and tacrolimus when either is coadministered with oral posaconazole. DESIGN: Two single-center, open-label pharmacokinetic studies of cyclosporine in a multiple-dose design and of tacrolimus in a one-sequence, crossover, single- and multiple-dose design. SETTING: One clinical investigative center in the United States and one in the United Kingdom. SUBJECTS: Four adult heart transplant recipients in the cyclosporine study and 36 healthy adult volunteers in the tacrolimus study. INTERVENTIONS: In the cyclosporine study, patients who took an established cyclosporine dose 3 times/day for 6 weeks or longer were given posaconazole 200 mg/day for 10 days. In the tacrolimus study, subjects received tacrolimus 0.05 mg/kg/day on days 1 and 14 and posaconazole 400 mg twice/day on days 7-14. MEASUREMENTS AND MAIN RESULTS: In the cyclosporine study, blood samples were collected on day 1 to determine cyclosporine pharmacokinetics and on day 10 to measure the pharmacokinetics of cyclosporine and posaconazole. Coadministration of posaconazole increased cyclosporine exposure and necessitated dosage reductions of 14-29% for cyclosporine in three subjects. In the tacrolimus study, blood samples were collected on days 12-14 to assess posaconazole pharmacokinetics and on days 1 and 14 for as long 72 hours after dosing to evaluate tacrolimus pharmacokinetics. Posaconazole increased the maximum blood concentration and the area under the concentration-time curve for tacrolimus by 121% and 358%, respectively, on day 14 compared with day 1 (both p=0.001). In both studies, posaconazole pharmacokinetics were unaffected. CONCLUSION: These findings suggest that the dosage of cyclosporine or tacrolimus should be reduced when posaconazole therapy is started and that plasma levels of the immunosuppressant should be monitored during and at the discontinuation of posaconazole therapy so that dosages are adjusted accordingly. This recommendation is consistent with current standard of care for patients receiving cyclosporine or tacrolimus with concomitant azole antifungal therapy.     

Guadecitabine (SGI-110): an investigational drug for the treatment of myelodysplastic syndrome and acute myeloid leukemia

ABSTRACT

Introduction: The incidence of acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) is increasing with the aging population. Prognosis and overall survival (OS) remain poor in elderly patients and in those not eligible for intensive treatment. Hypomethylating agents (HMAs) have played an important role in this group of patients but their efficacy is limited.

Areas covered: This article reviews the mechanism of action, pharmacology, safety profile and clinical efficacy of subcutaneous guadecitabine, a second-generation DNA methylation inhibitor in development for the treatment of AML and MDS.

Expert opinion: Although guadecitabine did not yield improved complete remission (CR) rates and OS compared to the control arm in patients with treatment-naïve AML who were ineligible for intensive chemotherapy, subgroup analysis in patients who received ≥4 cycles of therapy demonstrated superior outcomes in favor of guadecitabine. Given its stability, ease of administration, safety profile and prolonged exposure time, guadecitabine would be the more appropriate HMA, replacing azacitidine and decitabine, to be used combination treatment regimens in patients with myeloid malignancies.     

Suppression of farnesyltransferase activity in acute myeloid leukemia and myelodysplastic syndrome: current understanding and recommended use of tipifarnib

Importance of the field: Acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) incidence in the United States increases with age. Given the progressive ageing of the general population, incidence of these diseases is likely to continue to rise in the future. There is an acute need for therapeutic developments because of the poor prognosis of these diseases. Since the knowledge of molecular genetics in AML and MDS has expanded recently, targeted therapeutics should offer an exciting new frontier for advancement. Of all the targeted inhibitors developed, tipifarnib represents one of the few compounds with some activity as a single agent.

Areas covered in this review: Described in this review are the molecular targets of tipifarnib, safety and tolerability of the drug, chemistry, and clinical efficacy in AML.

What the reader will gain: The reader will gain a thorough understanding of tipifarnib as it relates to the current and future use of the drug in AML.

Take home message: The future of tipifarnib, along with other molecularly-targeted drugs, lies in achieving a better understanding of leukemia biology and harnessing the activity of this agent using predictive biomarkers for improved patient selection.     

Doxorubicin pharmacokinetics is correlated to the effect of induction therapy in children with acute myeloid leukemia

We studied the pharmacokinetics of doxorubicin in 41 children treated for newly diagnosed acute myeloid leukemia. Doxorubicin, 75 mg/m2 body surface area, was administered by constant i.v. infusion over 8 h. Four children with Down's syndrome (DS), 1.2-2.3 years old, had a median total body clearance of 523 ml/min/m2. The median clearance in non-DS children, 0.6-1.8 years old (n = 4) and 2.5-17.7 years old (n = 33), was 446 and 538 ml/min/m2, respectively. Patients who went into complete remission (CR) after induction therapy had a significantly higher median plasma concentration of doxorubicin than those who did not, 249 compared with 180 ng/ml, respectively (P = 0.036; analysis restricted to non-DS patients). Doxorubicin plasma concentration was an independent factor for CR, both in univariate (P = 0.031) and multivariate analysis including sex, age and white blood cell count at diagnosis (P = 0.021). Patients who reached CR had a significantly lower doxorubicin clearance than those who did not, 513 and 657 ml/min/m2, respectively (P = 0.017). In conclusion, doxorubicin plasma concentration and total body clearance during up-front treatment were correlated to the effect of induction therapy. Prospective studies should be performed to confirm the concentration-effect relationship and explore the possibility of therapeutic monitoring.     

The efficacy of sapacitabine in treating patients with acute myeloid leukemia

ABSTRACT

Introduction: Acute myeloid leukemia (AML) remains a poor prognosis hematological malignancy. The introduction of aggressive chemotherapy with allogeneic stem cell transplantation has resulted in improved clinical outcomes in younger patients. However, the treatment results in unfit elderly AML population remain disappointing. New strategies should be introduced to improve the prognosis in this group of patients.

Areas covered: This review presents and discusses the mechanism of action, safety and efficacy of sapacitabine in AML patients.

Expert opinion: Sapacitabine, a novel nucleoside analog, seemed to be a promising new agent for AML treatment. Its oral bioavailability and tolerable toxicity profile allow the drug to be used in an outpatient setting, especially in elderly unfit patients. Sapacitabine is known to have antileukemic activity in randomized clinical trials. In AML patients, sapacitabine monotherapy offered no advantage over low-intensity cytarabine treatment, and the combination of sapacitabine with decitabine was not significantly more effective than decitabine alone. However, the oral administration of sapacitabine allows it to be used in AML maintenance therapy.     

Vatalanib population pharmacokinetics in patients with myelodysplastic syndrome: CALGB 10105 (Alliance)

AimsVatalanib is an oral anti-angiogenesis agent that inhibits vascular endothelial growth factor receptor tyrosine kinases, which in patients showed auto induction of metabolism and variability in pharmacokinetic (PK) disposition. The objective was to characterize the population PK and time-dependent change in vatalanib clearance and assess exposure–toxicity relationship in patients with myelodysplastic syndrome (MDS).MethodsThis was an open-label phase II study of vatalanib in MDS patients receiving 750–1250 mg once daily in 28-day cycles. Serial blood samples were obtained and plasma vatalanib concentrations measured by HPLC. Population PK analysis was performed using nonmem 7.2 with FO estimation since FOCE failed. The final model was evaluated using goodness-of-fit plots, bootstrap analysis, and visual predictive check.ResultsPharmacokinetic data were complete for 137 patients (86 M, 51 F), of median age 70 years (range 20–91). A one-compartment model with lagged first-order absorption and time-dependent change in oral clearance was fitted to the vatalanib plasma concentration versus time data. The population means for pre-induction and post-induction oral clearance were 24.1 l h^–1 (range: 9.6–45.5) and 54.9 l h^–1 (range: 39.8–75.6), respectively. The apparent oral clearance increased 2.3-fold, (range: 1.7–4.1-fold) from first dose to steady state. Our data did not identify a significant relationship of the predefined covariates with vatalanib pharmacokinetics, although power to detect such a relationship was limited.ConclusionsVatalanib pharmacokinetics were highly variable and the extent of auto induction was not determined to correlate with any of the pre-defined covariates.