Dose-escalating Manner Research Articles

Targeting tumor metabolism with 2‐deoxyglucose in patients with castrate‐resistant prostate cancer and advanced malignancies

A profound difference between cancer and normal tissues is the preferential utilization of glycolysis by cancer cells. To translate this paradigm in the clinic, we completed a phase I study of 2-deoxyglucose (2DG), and assessed 2DG uptake with fluorodeoxyglucose (FDG) positron emission tomography (PET) and the autophagy substrate p62 as a marker of 2DG resistance. Patients received 2DG orally on days 1-14 of a 21-day cycle in cohorts of three in a dose-escalating manner. Correlative assessments included PET scans at baseline and day 2 and p62 protein in peripheral blood mononuclear cells as a potential marker of 2DG resistance. The dose of 45 mg/kg was defined as the recommended phase II dose, secondary to dose-limiting toxicity of grade 3 asymptomatic QTc prolongation at a dose of 60 mg/kg. PK evaluation of 2DG revealed linear pharmacokinetics with C(max) 45 microg/ml (277 microM), 73.7 microg/ml (449 microM), and 122 microg/ml (744 microM) in dose levels 30, 45, and 60 mg/kg, respectively. Five of eight patients assessed with FDG-PET scanning demonstrated decreased FDG uptake by day 2 of therapy, suggesting competition of 2DG with FDG. Five of six patients assessed for p62 had a decrease in p62 at 24 hr. These data support the safety of 2DG, defined 2DG PK, demonstrated the effect of 2DG on FDG-PET imaging, and demonstrated the feasibility of assessment of p62 as an autophagic resistance marker. These data support future studies of 2DG alone or in combination with approaches to abrogate autophagy.

Time-dependent effects of imatinib in human leukaemia cells: a kinetic NMR-profiling study

The goal of this study was to evaluate the time course of metabolic changes in leukaemia cells treated with the Bcr-Abl tyrosine kinase inhibitor imatinib. Human Bcr-Abl+ K562 cells were incubated with imatinib in a dose-escalating manner (starting at 0.1 μM with a weekly increase of 0.1 μM imatinib) for up to 5 weeks. Nuclear magnetic resonance spectroscopy and liquid-chromatography mass spectrometry were performed to assess a global metabolic profile, including glucose metabolism, energy state, lipid metabolism and drug uptake, after incubation with imatinib. Initially, imatinib treatment completely inhibited the activity of Bcr-Abl tyrosine kinase, followed by the inhibition of cell glycolytic activity and glucose uptake. This was accompanied by the increased mitochondrial activity and energy production. With escalating imatinib doses, the process of cell death rapidly progressed. Phosphocreatine and NAD+ concentrations began to decrease, and mitochondrial activity, as well as the glycolysis rate, was further reduced. Subsequently, the synthesis of lipids as necessary membrane precursors for apoptotic bodies was accelerated. The concentrations of the Kennedy pathway intermediates, phosphocholine and phosphatidylcholine, were reduced. After 4 weeks of exposure to imatinib, the secondary necrosis associated with decrease in the mitochondrial and glycolytic activity occurred and was followed by a shutdown of energy production and cell death. In conclusion, monitoring of metabolic changes in cells exposed to novel signal transduction modulators supplements molecular findings and provides further mechanistic insights into longitudinal changes of the mitochondrial and glycolytic pathways of oncogenesis.

Evaluation of interferon alpha‐2B and thalidomide in patients with disseminated malignant melanoma, phase 2, SWOG 0026

Southwest Oncology Group protocol 0026 evaluated interferon alpha-2b plus thalidomide in patients with disseminated melanoma. Endpoints were 6-month progression-free survival rate, response rate, and toxicity. Twenty-six patients with Stage IV melanoma, measurable or nonmeasurable disease, performance status of 0-2, and adequate renal and hepatic functions were registered. One prior systemic therapy for Stage IV disease was required. Interferon was administered subcutaneously (1 million U) twice daily; thalidomide was orally administered (200-400 mg) each evening in a dose-escalating manner. Response evaluations using Response Evaluation Criteria in Solid Tumors were performed every 8 weeks. After 2 sudden deaths and 1 grade 4 treatment-related pulmonary embolism, this study was temporarily closed. One patient with deep-vein thrombosis and 2 with grade 3 cardiac arrhythmias were reported. The relationship of these events to the treatment was worrisome but not definitive. Grade 3 treatment-related adverse events occurred in 14 of 26 patients. Because of concern for patient safety the study was permanently closed. No treatment responses were seen in the 22 evaluable patients. Estimated 6-month progression-free survival rate was 15% (95% confidence interval [CI], 2%-29%), estimated 6-month overall survival was 58% (95% CI, 39%-77%), and estimated response probability was 0 of 22 (95% CI, 0%-15%). This regimen demonstrated a lack of response and was associated with multiple severe toxicities. Further investigation of interferon alpha-2b and thalidomide in this dose and schedule is not warranted.

Pemetrexed pharmacokinetics and pharmacodynamics in a phase I/II study of doublet chemotherapy with vinorelbine: implications for further optimisation of pemetrexed schedules

The purpose of this study was to investigate the utility of plasma pharmacokinetic and pharmacodynamic measures including plasma deoxynucleosides, homocysteine and methylmalonic acid concentrations in understanding the time course and extent of the inhibition of thymidylate synthase (TS) by pemetrexed in the context of a phase I/II combination study with vinorelbine. Eighteen patients received supplementation with folic acid and Vitamin B12 1 week before beginning treatment with pemetrexed and vinorelbine administered in a dose-escalating manner on a 21-day cycle. Heparinised blood samples were collected from consenting patients in the first cycle for pharmacokinetic analyses and in the first two cycles for determination of plasma thymidine, deoxyuridine, homocysteine and methylmalonic acid concentrations. These values were correlated with response and toxicity. Plasma deoxyuridine was used as a measure of TS inhibition, and concentrations of deoxyuridine were significantly elevated relative to baseline on days 1 (P<0.01), 2 (P<0.001) and 3 (P<0.05) after treatment at all pemetrexed dose levels (400–700 mg m−2). The magnitude of deoxyuridine elevation correlated with pemetrexed area under the plasma concentration–time curve (AUC) (r2=0.23, P<0.05). However, deoxyuridine concentrations returned to baseline between 8 and 15 days after treatment with pemetrexed, suggesting that inhibition of TS was not durable. Pemetrexed AUC correlated with the percentage decline (relative to baseline) in both platelets (r2=0.58, P<0.001) and leucocytes (r2=0.26, P<0.05) at day 8. Baseline homocysteine was also significantly correlated with these measures of haematological toxicity (r2=0.37, P<0.01 and r2=0.39, P<0.01, respectively). In addition, there was a significant reduction of plasma homocysteine on days 8 (P<0.005) and 15 (P<0.05) in cycle 1 compared to baseline values. The results suggest that the TS inhibitory effects of pemetrexed are short-lived and make the case for a more frequent schedule of administration such as every 2 weeks. The lack of protracted TS inhibition may be due to concomitant vitamin administration, and this may be the mechanism by which vitamins prevent life-threatening toxicity from pemetrexed. Baseline homocysteine concentration remains a predictive marker for haematological toxicity even following folate supplementation.

Mutational Pathways, Resistance Profile, and Side Effects of Cyanovirin Relative to Human Immunodeficiency Virus Type 1 Strains with N-Glycan Deletions in Their gp120 Envelopes

Limited data are available on the genotypic and phenotypic resistance profile of the alpha-(1-2)mannose oligomer-specific prokaryotic lectin cyanovirin (CV-N). Therefore, a more systematic investigation was carried out to obtain a better view of the interaction between CV-N and human immunodeficiency virus type 1 (HIV-1) gp120. When HIV-1-infected CEM cell cultures were exposed to CV-N in a dose-escalating manner, a total of eight different amino acid mutations exclusively located at N-glycosylation sites in the envelope surface gp120 were observed. Six of the eight mutations resulted in the deletion of high-mannose type N-glycans (i.e., at amino acid positions 230, 332, 339, 386, 392, and 448). Two mutations (i.e., at position 136 and 160) deleted a complex type N-glycan in the variable V1/V2 domain of gp120. The level of phenotypic resistance of the mutated virus strains against CV-N generally correlated with the number of glycan deletions in gp120, although deletion of the glycans at N-230, N-392, and N-448 generally afforded a more pronounced CV-N resistance than other N-glycan deletions. However, the extent of the decrease of antiviral activity of CV-N against the mutated virus strains was markedly less pronounced than observed for alpha(1-3)- and alpha(1-6)-mannose-specific plant lectins Hippeastrum hybrid agglutinin (HHA) and Galanthus nivalis agglutinin (GNA), which points to the existence of a higher genetic barrier for CV-N. This is in agreement with a more consistent suppression of a wider variety of HIV-1 clades by CV-N than by HHA and GNA. Whereas the antiviral and in vitro antiproliferative activity of CV-N can be efficiently reversed by mannan, the pronounced mitogenic activity of CV-N on peripheral blood mononuclear cells was unaffected by mannan, indicating that some of the observed side effects of CV-N are unrelated to its carbohydrate specificity/activity.

Phase I and pharmacological study of the novel aurora kinase inhibitor AZD1152

3008 Background: AZD1152 is a specific aurora kinase inhibitor, selective for Aurora B, currently undergoing Phase I evaluation in patients with advanced solid malignancies. AZD1152 induces p53 independent cellular multinucleation and polyploidy, resulting in apoptosis. It is rapidly converted to the active moiety (AZD1152-HQPA) in plasma. This is the first human study, aimed at determining the maximum tolerated dose, dose limiting toxicities (DLT), pharmacokinetic profile (PK), and to recommend a dose and schedule for further clinical evaluation. Methods: AZD1152 is being administered as a 2-hour IV infusion given weekly in a dose-escalating manner, utilizing an accelerated titration design in patients for whom no other therapy of proven benefit exists. Patients with WHO-PS of 0-2 and adequate bone marrow, liver and renal function were eligible. Results: To date, a total of 13 patients have been recruited: 10M/3F, median age 58 yrs (range 52–71). Patients had colon cancer (n = 3), melanoma (n = 2), or various other solid tumors. Doses were escalated from 100 mg to 200, 300 and 450 mg. DLT was CTC grade 4 neutropenia in 3 patients at 450 mg, signifying a non-tolerated dose on this schedule. Bone marrow recovery was generally noted by 2 wks post-dose. Problematic non-hematological toxicities have not been reported to date. Five patients have remained on therapy for &gt;12 wks (2 × 12+ wks, 16+ wks, 20+ wks and 28+ wks, respectively). AZD1152 is rapidly converted to AZD1152-HQPA with an apparent dose proportional increase in the systemic exposures of both. Population PK analysis of AZD1152-HQPA in the first eight patients revealed a linear three compartment model with clearance 22.4 ± 1.03 L/h. Interoccasion variability was low (CV 5.7%). Conclusions: To date, AZD1152 has been well tolerated when administered IV over 2 hours on a weekly schedule at doses up to 300 mg, however further patients are being enrolled to confirm. Neutropenia is the DLT at 450 mg and no other clinically significant toxicities have been reported. Both AZD1152 and AZD1152-HQPA appeared to have linear kinetics. Significant disease stabilization observed in this rapidly progressive disease setting supports continued clinical development. [Table: see text]

Pilot Clinical Trial of Adoptive Immunotherapy with Chimeric, Co-Stimulated Tumor-Infiltrating Lymphocytes after Allogeneic Hematopoietic Stem Cell Transplantation.

Treatment of refractory or recurrent malignancy with donor lymphocyte infusion (DLI) after allogeneic hematopoietic stem cell transplantation (alloHSCT) is often not curative, with graft-vs-tumor (GVT) effects frequently accompanied by graft-versus-host disease (GVHD), requiring immune suppression that compromises efficacy. After alloHSCT, chimeric T lymphocytes infiltrating residual tumor (chimeric TIL) may provide enhanced antigen specificity and maintain tumor-specific homing. Compared with DLI, they may have a better GVT effect with less GVHD. Based on the success of autologous TIL therapy for melanoma, we tested the hypothesis that enhanced GVT with limited GVHD could be achieved through administration of ex-vivo activated chimeric TIL after alloHSCT. Preclinical TIL production carried out on several tumor types from non-transplanted patients demonstrated effective T cell isolation, expansion and activation using anti-CD3/CD28 bead co-stimulation, yielding a 10- to 30-fold expansion of CD3+ cells. Clinical evaluation of chimeric TIL therapy was initiated with a 51 year-old woman for metastatic breast cancer whose disease progressed after a T cell-depleted reduced-intensity alloHSCT with delayed DLI from a 6/6 HLA-matched sibling donor and subsequent conventional therapy plus DLI. Two weeks after administration of unmanipulated DLI, two thoracic metastases were surgically removed. T cells were liberated from 9.4 cm of tumor using enzymatic digestion and mechanical dispersion, lymphocyte-enriched by density gradient separation, and expanded for 14 days through co-stimulation with anti-CD3/CD28-coated magnetic beads (3:1 bead-to-total nucleated cell ratio) and media containing IL-2 (100 or 1000 IU/mL). This process yielded 42.5 x 106 cells, 33% expressing CD3, and generated 14.7 x 109 chimeric TIL, 85% expressing CD3 (a 3.1-log T cell expansion). There was no tumor contamination of the T cell product by immunohistochemistry. Flow cytometry demonstrated that the CD4/CD8 T cell ratio increased from 1.3 to 1.9 after expansion. Three infusions of the chimeric TIL product were given in a dose-escalating manner (5, 25 and 100 x 106 CD3+ cells/kg). A fourth infusion was given in conjunction with low-dose IL-2 (6mu SQ per day x 3D). CT scan performed after each infusion monitored disease response, with progressive disease the indication for the next dose administration. No infusion-related or delayed toxicities were observed, except for rigors following IL-2 administration. The patient shows no evidence of GVHD, even after the highest dose of 108 allogeneic T cells. Evaluation of the remaining thoracic lesion demonstrated progressive disease after the first two chimeric TIL dose-levels, transient disease stability one month after the third dose-level, and stable disease one month after the fourth dose with IL-2. This is the first clinical report of the application of chimeric TIL and represents a novel approach for developing new forms of adoptive immunotherapy in the setting of alloHSCT.

Pharmacokinetics of Gatifloxacin in Infants and Children

Gatifloxacin is an 8-methoxy fluoroquinolone effective against a broad spectrum of pathogens common in pediatric infections. The safety and pharmacokinetics of a single dose of gatifloxacin were studied in pediatric patients from 6 months to 16 years of age. Seventy-six pediatric patients (average age, 6.7 +/- 5.0 years) were administered a single oral dose of gatifloxacin suspension (5, 10, or 15 mg/kg of body weight; 600-mg maximum) in a dose-escalating manner. Subjects were stratified by age into 4 groups. An additional 12 children, greater than 6 years of age, received gatifloxacin as the tablet formulation at a dose of approximately 10 mg/kg. Gatifloxacin's apparent clearance and half-life were 5.5 +/- 2.1 ml/min/kg and 5.1 +/- 1.4 h. The maximum concentration of drug in plasma and area under the concentration-time curve (AUC) increased in a manner approximately proportional to the dose. At the 10-mg/kg dose, the bioavailability was similar between the suspension and tablet formulation. The apparent oral clearance of gatifloxacin, normalized for body weight, exhibited a small but statistically significant decrease with increasing age. In all subjects receiving gatifloxacin at 10 mg/kg, the AUC exceeded 20 microg . h/ml (estimated free AUC/MIC ratio of > or =34 for MIC of < or =0.5 microg/ml). These data suggest that gatifloxacin at a dose of 10 mg/kg every 24 h will achieve therapeutic concentrations in plasma in infants and children.

Levocetirizine better protects than desloratadine in a nasal provocation with allergen

BackgroundDirect comparisons of antihistamines are rare but very much needed. Newly available antihistamine preparations, levocetirizine, the R-enantiomer of racemate cetirizine, and desloratadine, an active metabolite of loratadine, have been recently released for allergic rhinitis. ObjectiveWe sought to compare levocetirizine and desloratadine in a nasal provocation test (NPT) with grass pollen. MethodsTwenty-four volunteers with grass pollen allergy and a history of rhinitis were enrolled in a double-blind, placebo-controlled, crossover study. Three NPTs were performed in a dose-escalating manner during the out-of-season period 4 hours after a single dose of levocetirizine (5 mg), desloratadine (5 mg), or placebo. ResultsDifferences in the mean allergen dose level (primary end point) necessary to reach the NPT threshold indicated improved protection provided by levocetirizine compared with that provided by desloratadine (P=.02). Sneezing and rhinorrhea were better inhibited by levocetirizine than desloratadine. Nasal congestion, as assessed by using objective methods, was not limited by either active substances or placebo. In nasal lavage fluid, IL-5, IL-8, eotaxin, and eosinophil cationic protein levels increased at 24 hours, without differences between the groups. In contrast, levocetirizine, but not desloratadine, significantly limited albumin extravasation into nasal lavage fluid in the early-phase response. ConclusionsThis study demonstrates a better overall protection of a single dose of levocetirizine compared with desloratadine in an NPT with grass pollen allergen. In contrast to late-phase inflammatory markers, which were unaffected, extravascular leakage of the early-phase marker albumin was significantly limited by levocetirizine.

Pharmacokinetics and tolerability of intravenous infusion of adenosine (SUNY4001) in healthy volunteers.

To examine the tolerability and disposition of i.v. adenosine (SUNY4001) in healthy male Japanese volunteers. SUNY4001 was infused i.v. for 6 min at 0 (placebo), 60, 100, 120 and 140 microg kg-1 min-1 in a dose-escalating manner in 30 healthy subjects. Adenosine and its metabolites were determined in the plasma and urine. Only plasma hypoxanthine was increased from 3 min during until 5-10 min after SUNY4001 infusion at the higher rates without any significant dose-related changes in plasma adenosine, inosine, xanthine or uric acid, or in urinary adenosine and all metabolites compared with the placebo. There was a dose-related increase in the incidence of subjective symptoms such as heat sensation, flushed face, dyspnoea, chest discomfort, etc. Transient and self-subsiding episodes of second-degree atrioventricular block were found in two subjects each at the higher doses. Adenosine infusion at < or = 140 microg kg-1 min-1 was concluded to be generally well tolerated.