A dose-escalation study of recombinant human interleukin-18 using two different schedules of administration in patients with cancer.

PURPOSE: Interleukin-18 (IL-18) is an immunostimulatory cytokine with antitumor activity in preclinical models. A phase I study of recombinant human IL-18 (rhIL-18) was done to determine the toxicity, pharmacokinetics, and biological activities of rhIL-18 administered at different doses in two different schedules to patients with advanced cancer. EXPERIMENTAL DESIGN: Cohorts of three to four patients were given escalating doses of rhIL-18 as a 2-h i.v. infusion either on 5 consecutive days repeated every 28 days (group A) or once a week (group B) for up to 6 months. Toxicities were graded using standard criteria. Blood samples were obtained for safety, pharmacokinetic, and pharmacodynamic measurements. RESULTS: Nineteen patients (10 melanoma and 9 renal cell cancer) were given rhIL-18 in doses of 100, 500, or 1,000 microg/kg (group A) or 100, 1,000, or 2,000 microg/kg (group B). Common side effects included chills, fever, headache, fatigue, and nausea. Common laboratory abnormalities included transient, asymptomatic grade 1 to 3 lymphopenia, grade 1 to 4 hyperglycemia, grade 1 to 2 anemia, neutropenia, hypoalbuminemia, liver enzyme elevations, and serum creatinine elevations. No dose-limiting toxicities were observed. Biological effects of rhIL-18 included transient lymphopenia and increased expression of activation antigens on lymphocytes. Increases in serum concentrations of IFN-gamma, granulocyte macrophage colony-stimulating factor, and IL-18-binding protein were observed following dosing. CONCLUSIONS: rhIL-18 can be given in biologically active doses by either weekly infusions or daily infusions for 5 days repeated every 28 days to patients with advanced cancer. Toxicity was generally mild to moderate, and a maximum tolerated dose of rhIL-18 by either schedule was not determined.

Clinical and biological effects of recombinant human interleukin-18 administered by intravenous infusion to patients with advanced cancer.

PURPOSE: Interleukin-18 (IL-18) is an immunostimulatory cytokine with antitumor activity in preclinical animal models. A phase I study of recombinant human IL-18 (rhIL-18) was done to determine the toxicity, pharmacokinetics, and biological activities of rhIL-18 in patients with advanced cancer. EXPERIMENTAL DESIGN: Cohorts of patients were given escalating doses of rhIL-18, each administered as a 2-hour i.v. infusion on 5 consecutive days. Toxicities were graded using standard criteria. Serial blood samples were obtained for pharmacokinetic and pharmacodynamic measurements. RESULTS: Twenty-eight patients (21 with renal cell cancer, 6 with melanoma, and 1 with Hodgkin's lymphoma) were given rhIL-18 in doses ranging from 3 to 1,000 microg/kg. Common side effects included chills, fever, nausea, headache, and hypotension. Common laboratory abnormalities included transient, asymptomatic grade 1 to 2 neutropenia, thrombocytopenia, anemia, hypoalbuminemia, hyponatremia, and elevations in liver transaminases. One patient in the 100 microg/kg cohort experienced transient grade 3 hypotension and grade 2 bradycardia during the first infusion of rhIL-18. No other dose-limiting toxicities were observed. Plasma concentrations of rhIL-18 increased with increasing dose, and 2.5-fold accumulation was observed with repeated dosing. Biological effects of rhIL-18 included transient lymphopenia and increased expression of activation antigens on lymphocytes and monocytes. Increases in serum concentrations of IFN-gamma, granulocyte macrophage colony-stimulating factor, IL-18 binding protein, and soluble Fas ligand were observed. Two patients experienced unconfirmed partial responses after rhIL-18 treatment. CONCLUSIONS: rhIL-18 can be safely given in biologically active doses to patients with advanced cancer. A maximum tolerated dose of rhIL-18 was not determined. Further clinical studies of rhIL-18 are warranted.

MDDScore: confirmation of a blood test to aid in the diagnosis of major depressive disorder.

BACKGROUND: Previously, a biomarker panel was developed for use as an aid to major depressive disorder (MDD) diagnosis; it consisted of 9 biomarkers associated with the neurotrophic, metabolic, inflammatory, and hypothalamic-pituitary-adrenal axis pathways. This panel and associated algorithm produced good clinical sensitivity and specificity (92% and 81%, respectively) in differentiating MDD patients from individuals without MDD. To further validate the panel, we performed a prospective study using a larger set of new prospectively acquired MDD patients and a similarly collected population of nondepressed subjects. The addition of gender and body mass index (BMI) effects to the algorithm was also evaluated. METHOD: Blood samples were obtained from MDD patients (n = 68) clinically evaluated at multiple sites in 2011 and 2012 using standard psychiatric assessment tools and structured clinical interviews according to DSM-IV criteria. Blood samples (n = 86) from nondepressed subjects were obtained as controls. MDD and nondepressed samples were randomized into independent training (n = 102) and validation sets (n = 52). Analytes in sera were quantified by immunoassay. RESULTS: Training set biomarker data were used to develop a logistic regression model that included gender and BMI in a manner that allowed for their interaction with the biochemical analytes. For the training set, the sensitivity and specificity of the test (with 95% CI) were 93% (0.80-0.98) and 95% (0.85-0.99), respectively. This method (designated the MDDScore) was then applied to the independent validation set and had a sensitivity and specificity of 96% (0.77-0.98) and 86% (0.66-0.95), respectively. The overall accuracy for the training set was 94%; the validation set accuracy was 91%. CONCLUSION: Examination of a randomized independent set of samples confirms the ability of the previously established biomarker panel to identify persons with MDD; the accuracy was over 90%. The improved model that adds gender and BMI to the previously established panel of 9 biomarkers is robust and simple; it provides the most rigorously tested, objective diagnostic test for MDD to date.

The metabolic activation of abacavir by human liver cytosol and expressed human alcohol dehydrogenase isozymes.

Abacavir (ZIAGEN) is a reverse transcriptase inhibitor marketed for the treatment of HIV-1 infection. A small percentage of patients experience a hypersensitivity reaction indicating immune system involvement and bioactivation. A major route of metabolism for abacavir is oxidation of a primary betagamma unsaturated alcohol to a carboxylic acid via an aldehyde intermediate. This process was shown to be mediated in vitro by human cytosol and NAD, and subsequently the alphaalpha and gamma2gamma2 human isoforms of alcohol dehydrogenase (ADH). The alphaalpha isoform effected two sequential oxidation steps to form the acid metabolite and two isomers, qualitatively reflective of in vitro cytosolic profiles. The gamma2gamma2 isozyme generated primarily an isomer of abacavir, which was minor in the alphaalpha profiles. The aldehyde intermediate could be trapped in incubations with both isozymes as an oxime derivative. These metabolites can be rationalized as arising via the aldehyde which undergoes isomerization and further oxidation by the alphaalpha enzyme or reduction by the gamma2gamma2 isozyme. Non-extractable abacavir protein residues were generated in cytosol, and with alphaalpha and gamma2gamma2 incubations in the presence of human serum albumin (HSA). Metabolism and residue formation were blocked by the ADH inhibitor 4-methyl pyrazole (4-MP). The residues generated by the alphaalpha and gamma2gamma2 incubations were analyzed by SDS-PAGE with immunochemical detection. The binding of rabbit anti-abacavir antibody to abacavir-HSA was shown to be dependent on metabolism (i.e. NAD-dependent and 4-MP sensitive). The mechanism of covalent binding remains to be established, but significantly less abacavir-protein residue was detected with an analog of abacavir in which the double bond was removed, suggestive of a double bond migration and 1,4 addition process.

Intracellular cytokines may model immunoregulation of abacavir hypersensitivity in HIV-infected subjects.

BACKGROUND: The clinical treatment of patients with HIV and adverse drug events may be enhanced by an understanding of the underlying mechanisms. About 4% of patients with HIV receiving the potent antiretroviral drug abacavir develop a hypersensitivity reaction. This idiosyncratic reaction appears to have an immunologic component that has yet to be defined. Given that the T-cell type 2 cytokine IL-4 may be overproduced by patients with allergy or other immunologic dysregulation, an index cytokine profile could help elucidate the character of a drug-specific hypersensitivity reaction. OBJECTIVE: Quantitation of the production of the type 2 IL-4 and the counterregulatory type 1 cytokine IFN-gamma in patients with abacavir-related hypersensitivity. METHODS: Intracellular cytokines were enumerated in blood T cells by flow cytometry. Subjects were grouped for evaluation as patients with a hypersensitive response after abacavir treatment, patients initiating abacavir who also were evaluated again after 1 month on abacavir, patients on abacavir for 6 months without hypersensitivity, and HIV-naive control individuals. RESULTS: There was a significant association between increased IL-4 production by CD4 and CD8 T lymphocytes and hypersensitivity reactions to abacavir. Lymphocytes from hypersensitive subjects expressed CD28 and the anti-HIV chemokine macrophage inflammatory protein 1beta with a frequency comparable with HIV-naive control cells, suggesting the possibility that the activated T cells from patients with hypersensitivity are functional. CONCLUSION: The expansion of type 0 and type 2 T cells phenotyped by IL-4 production may correlate with abacavir-associated hypersensitivity. The data suggest a cytokine bias that may facilitate B-cell differentiation and downregulate T-cell cytotoxic responses.

Inhibitory activity of synthetic peptide antibiotics on feline immunodeficiency virus infectivity in vitro.

Natural peptide antibiotics are part of host innate immunity against a wide range of microbes, including some viruses. Synthetic peptides modeled after natural peptide antibiotics interfere with microbial membranes and are termed peptidyl membrane-interactive molecules (peptidyl-MIM [Demegen Inc, Pittsburgh, Pa.]). Sixteen peptidyl-MIM candidates were tested for activity against feline immunodeficiency virus (FIV) on infected CrFK cells. Three of them (D4E1, DC1, and D1D6) showed potent anti-FIV activity in chronically infected CrFK cells as measured by decreased reverse transcriptase (RT) activity, having 50% inhibitory concentrations of 0.46, 0.75, and 0.94 micro M, respectively, which were approximately 10 times lower than their direct cytotoxic concentrations. Treatment of chronically infected CrFK cells with 2 micro M D4E1 for 3 days completely reversed virus-induced cytopathic effect. Immunofluorescence revealed reduced p26 staining in these cells. Treatment of chronically infected CrFK cells with 2 micro M D4E1 suppressed virus production ( approximately 50%) for up to 7 days, The virions from the D4E1-treated culture had impaired infectivity, as measured by the 50% tissue culture infectious dose and nested PCR analysis of proviral DNA. However, these noninfectious virions were able to bind and internalize, suggesting a defect at some postentry step. After chronically infected CrFK cells were treated with D4E1 for 24 h, increased cell-associated mature p26 Gag and decreased extracellular virus-associated p26 Gag were observed by Western blot analysis, suggesting that virus assembly and/or release may be blocked by D4E1 treatment, whereas virus binding, penetration, RNA synthesis, and protein synthesis appear to be unaffected. Synthetic peptide antibiotics may be useful tools in the search for antiviral drugs having a wide therapeutic window for host cells.

Adenocarcinoma cells exposed in vitro to Navelbine or Taxol increase Ep-CAM expression through a novel mechanism.

Ep-CAM antigen expression was shown to vary by phase across the cell cycle. Following pretreatment of various adenocarcinoma cells in culture with clinically relevant concentrations of vinorelbine tartrate (Navelbine) or paclitaxel (Taxol), cell surface expression of Ep-CAM antigen increased by two- to ten-fold compared to that of untreated control cells and was associated with arrest of cell cycle progression and accumulation of cells in the S and G2/M phases. We demonstrated that increases in cell surface antigen expression resulted in improved biological effectiveness of the targeting antibody as measured in vitro by antibody-dependent cellular cytotoxicity and in vivo by enhanced antibody targeting to Ep-CAM-expressing xenografts in mice pretreated with Navelbine. No effect on cell cycle progression or Ep-CAM antigen expression was seen with human interferon-alpha and interferon-gamma, agents that increase gene expression of various tumor and normal antigens and may upregulate some antigens. Thus, the upregulation of cell surface Ep-CAM expression following pretreatment with G2/M blockers is through a novel mechanism involving residence time of the antigen on the cell surface. This significant increase in Ep-CAM expression appears to be tumor-specific since we saw no increase in antigen expression on normal epithelial cells. Studies to reveal relative internalization rates suggest that the increase in cell surface expression of Ep-CAM following pretreatment with G2/M blockers is a consequence of an inhibition of normal cycles of antigen endocytosis and expression on the cell surface. The present work provides a mechanism for the improved clinical efficacy of therapeutic antibodies used in combination with traditional cell cycle-specific chemotherapeutic drugs.

Genetic variations in HLA-B region and hypersensitivity reactions to abacavir.

Hypersensitivity to abacavir affects about 4% of patients who receive the drug for HIV-1 infection. We did a retrospective, case-control study to identify multiple markers in the vicinity of HLA-B associated with hypersensitivity reactions. HLA-B57 was present in 39 (46%) of 84 patients versus four (4%) of 113 controls (p<0 small middle dot0001). However, because of low numbers of women and other ethnic groups enrolled, these findings relate largely to white men. The lower sensitivity of HLA-B57 for predicting hypersensitivity to abacavir identified in this study compared with a previous report highlights that predictive values for markers will vary across populations. Clinical monitoring and management of hypersensitivity reactions among patients receiving abacavir must remain unchanged.