AbstractDesign and practical syntheses of a novel class of cyclic urea‐based CCR5‐antagonists demonstrating high antiviral activities against HIV‐1 infection in both HOS and PBL assays are described.
A new series of non-nucleoside reverse transcriptase inhibitors based on an imidazole-amide biarylether scaffold has been identified and shown to possess potent antiviral activity against HIV-1, including the NNRTI-resistant Y188L mutated virus. X-ray crystallography of inhibitors bound to reverse transcriptase, including a structure of the Y188L RT protein, was used extensively to help identify and optimize the key hydrogen-bonding motif. This led directly to the design of compound 43 that exhibits remarkable antiviral activity (EC50 < 1 nM) against a wide range of NNRTI-resistant viruses and a favorable pharmacokinetic profile across multiple species.
A novel series of cyclic urea-based CCR5 antagonists was designed aiming to resolve instability issue in the fasted simulated intestinal fluid (FSIF) associated with the acyclic urea moiety in 1. This class of CCR5 compounds demonstrated high antiviral activities against HIV-1 infection in both HOS and PBL assays. Further evaluation of these compounds indicated that 16-R not only substantially enhanced its stability, but also exhibited excellent pharmacokinetics properties.
A novel series of pyridyl carboxamide-based CCR5 inhibitors was designed, synthesized, and demonstrated to be highly potent against HIV-1 infection in both HOS and PBL assays. Attempts to evaluate this series of compounds in a rat PK model revealed its instability in rat plasma. A hypothesis for this liability was proposed, and strategies to overcome this issue were pursued, leading to discovery of highly potent 40 and 41, which featured dramatically improved rat PK profiles.
We describe the synthesis and potency of a novel series of N-substituted 2-phenyl- and 2-methyl-2-phenyl-1,4-diaminobutane- based CCR5 antagonists. Compounds 7a and 12f were found to be potent in anti-HIV assays and bioavailable in the low-dose rat PK model.
Several series of carbamate, urea and carboxamide-based CCR5 antagonists have been discovered via optimizations at the amine portion of lead compound 2. All compounds were evaluated for their antiviral activities. Lead urea 29 showed good pharmacokinetic properties, justifying further development of this series.
Modification of the acyl moiety in the CCR5 lead molecule 2 led to identification of several new classes of CCR5 antagonists. Antiviral activity and pharmacokinetic properties of the synthesized compounds were evaluated. Structure-activity relationship (SAR) derived from these studies further guided the optimization efforts, ultimately leading to the discovery of 36 with an acceptable drug-like profile.
ABSTRACT GSK812397 is a potent entry inhibitor of X4-tropic strains of HIV-1, as demonstrated in multiple in vitro cellular assays (e.g., in peripheral blood mononuclear cells [PBMCs] and a viral human osteosarcoma [HOS] assay, mean 50% inhibitory concentrations [IC 50 s] ± standard errors of the means were 4.60 ± 1.23 nM and 1.50 ± 0.21 nM, respectively). The primary in vitro potency of GSK812397 was not significantly altered by the addition of serum proteins (2.55 [±0.12]-fold shift in the presence of human serum albumin and α-acid glycoprotein in the PBMC assay). Pharmacological characterization of GSK812397 in cell-based functional assays revealed it to be a noncompetitive antagonist of the CXCR4 receptor, with GSK812397 producing a concentration-dependent decrease in both an SDF-1-mediated chemotaxis and intracellular calcium release (IC 50 s were 0.34 ± 0.01 nM and 2.41 ± 0.50 nM, respectively). With respect to the antiviral activity of GSK812397, it was effective against a broad range of X4- and X4R5-utilizing clinical isolates. The potency and efficacy of GSK812397 were dependent on the individual isolate, with complete inhibition of infection observed with 24 of 30 isolates. GSK812397 did not show any detectable in vitro cytotoxicity and was highly selective for CXCR4, as determined using a wide range of receptors, enzymes, and transporters. Moreover, GSK812397 demonstrated acceptable pharmacokinetic properties and bioavailability across species. The data demonstrate that GSK812397 has antiviral activity against a broad range of X4-utilizing strains of HIV-1 via a noncompetitive antagonism of the CXCR4 receptor.
Six allosteric HIV-1 entry inhibitor modulators of the chemokine (C-C motif) receptor 5 (CCR5) receptor are compared for their potency as inhibitors of HIV-1 entry [infection of human osteosarcoma (HOS) cells and peripheral blood mononuclear cells (PBMC)] and antagonists of chemokine (C-C motif) ligand 3-like 1 [CCL3L1]-mediated internalization of CCR5. This latter activity has been identified as a beneficial action of CCL3L1 in prolonging survival after HIV-1 infection ( Science 307: 1434-1440, 2005 ). The allosteric nature of these modulators was further confirmed with the finding of a 58-fold (HOS cells) and 282-fold (PBMC) difference in relative potency for blockade of CCL3L1-mediated internalization versus HIV-1 entry. For the CCR5 modulators, statistically significant differences in this ratio were found for maraviroc, vicriviroc, aplaviroc, Sch-C, TAK652, and TAK779. For instance, although TAK652 is 13-fold more potent as an HIV-1 inhibitor (over blockade of CCL3L1-mediated CCR5 internalization), this ratio of potency is reversed for Sch-C (22-fold more potent for CCR5-mediated internalization over HIV-1 entry). Quantitative analyses of the insurmountable antagonism of CCR5 internalization by these ligands suggest that all of them reduce the efficacy of CCL3L1 for CCR5 internalization. The relatively small magnitude of dextral displacement accompanying the depression of maximal responses for aplaviroc, maraviroc and vicriviroc suggests that these modulators have minimal effects on CCL3L1 affinity, although possible receptor reserve effects obscure complete interpretation of this effect. These data are discussed in terms of the possible benefits of sparing natural CCR5 chemokine function in HIV-1 entry inhibition treatment for AIDS involving allosteric inhibitors.
American Journal of HematologyVolume 72, Issue 2 p. 154-154 Letters and CorrespondenceFree Access Unusual case of antiphospholipid antibody syndrome presenting with extensive cutaneous infarcts in a patient on long-term procainamide therapy Basil F. El-Rayes, Basil F. El-Rayes Department of Medicine, Department of Hematology, VA Medical Center, Wayne State University, Detroit, MichiganSearch for more papers by this authorMark Edelstein, Mark Edelstein Department of Medicine, Department of Hematology, VA Medical Center, Wayne State University, Detroit, MichiganSearch for more papers by this author Basil F. El-Rayes, Basil F. El-Rayes Department of Medicine, Department of Hematology, VA Medical Center, Wayne State University, Detroit, MichiganSearch for more papers by this authorMark Edelstein, Mark Edelstein Department of Medicine, Department of Hematology, VA Medical Center, Wayne State University, Detroit, MichiganSearch for more papers by this author First published: 28 January 2003 https://doi.org/10.1002/ajh.10274Citations: 6AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL References 1Williams PE. Lupus anticoagulant. J Ark Med Soc 1990; 86(12): 493– 497. 2Abernethy ML, McGuinn JL, Callen JP. Widespread cutaneous necrosis as the initial manifestation of the antiphospholipid antibody syndrome. J Rheumatol 1995; 22(7): 1380– 1383. 3Whitmore SE, Horn TD. Cutaneous necrosis. Arch Dermatol 1996; 132(3): 341– 342, 344–345. 4Nick J, Combrisson A, Reignier A, Verdy E, Gally AM, Bakouche P, et al. [Iatrogenic procaine amide-induced lupus with circulating anticoagulant]. Ann Med Interne (Paris) 1978; 129(4): 259– 263. Citing Literature Volume72, Issue2February 2003Pages 154-154 ReferencesRelatedInformation
This study was directed at defining the optimal in vitro screening methodology for the selection of new anti-myelogenous leukemia agents. Using thousands of samples of synthetic compounds from the Eastman Pharmaceutical, Inc. and Sterling Research Corporation (Eastman/Sterling) inventory, a number of sequential combinations of 8 cell lines were employed to optimize the model. The cells in these lines were of either murine (L1210 lymphocytic leukemia, C1498 myelogenous leukemia, and colony-forming unit-granulocyte macrophage [CFU-GM]) or human (HL-60, K-562, HEL, and THP-1 myelogenous leukemias, and CFU-GM) origin. The focus of the study was to find the most efficient and cost-effective manner in which to test compounds for both cytotoxicity against the tumor cells and for differential cytotoxicity against tumor as compared with normal cells.
Ascites due to congestive heart failure (CHF) is characteristically serous in gross appearance. Although hemorrhage into ascites commonly indicates a malignant or inflammatory cause, cirrhosis of the liver is a well known cause of bloody ascites. We report a case of hemorrhagic ascites due to biventricular congestive heart failure in which workup for other causes was negative and hemorrhage cleared after 4 months. In as much as the mechanism of ascites is similar in both cirrhosis and CHF, we propose that a similar mechanism could cause bleeding into ascites in CHF.
(1996). New In Vitro Screening Model for the Discovery of Antileukemic Anticancer Agents. Cancer Investigation: Vol. 14, No. 2, pp. 124-141.
Gravid female rats were subjected to one hour of restraint stress twice daily or left undisturbed from days 14-21 of gestation. Adult 105-day old male non-stressed (NS) and stressed (S) offspring were treated once daily with saline, desipramine (DMI) (10 mg/kg, sc) or phenelzine (5.0 mg/kg, sc) for 14 days. Twenty-four hours after the last injection, animals were challenged with saline or 1-(m-trifluoromethylphenyl)piperazine (TFMPP) (5.0 mg/kg, sc), a serotonin1B/2C (5-HT1B/2C) agonist, and plasma prolactin and corticosterone concentrations were measured one hour later. As compared to acute saline administration, TFMPP significantly increased prolactin and corticosterone concentrations in all groups. In NS offspring, both DMI and phenelzine treatment augmented the prolactin response, but blunted the corticosterone response, to TFMPP. In S offspring, the prolactin response to TFMPP also was augmented by phenelzine or DMI treatment, whereas the corticosterone response to TFMPP was blunted during phenelzine treatment. However, DMI treatment was not able to desensitize the corticosterone response to TFMPP in the S rats. The results indicate the adaptive capacity of 5-HT systems to DMI administration was compromised in adult animals exposed to stress in utero.
Groups of gravid female rats were injected subcutaneously with saline (SAL), a low-dose of nicotine (LN) (0.05 mg/kg, bid) or a high-dose of nicotine (HN) (3.0 mg/kg, bid) from day 4 to day 20 of gestation, or were left undisturbed. In adult 120-day-old male offspring, the ACTH and prolactin responses to acute nicotine challenge were evaluated. The experiment was performed on three separate occasions. Based upon dose-response and time-course studies with nicotine in normal animals, the neuroendocrine responses to nicotine (0.75 and 1.0 mg/kg, sc) were measured 7.5 min after nicotine administration, the peak response-time for both hormones. The ACTH response to acute nicotine administration was blunted significantly in the HN rats, but normal in the LN rats, for all three experiments. In two experiments, the prolactin response to acute nicotine administration was blunted significantly in the HN rats, but enhanced significantly in the LN offspring. The results indicate that prenatal nicotine administration can produce long-term neuroendocrine effects involving nicotinic-receptor coupled circuits, with long-term functional sequelae produced by dosages of nicotine considerably smaller than previously shown to be pharmacologically/toxicologically active.
Alkaline elution was done on a variety of cells following cyclophosphamide (CY) treatment in vivo. Cells used were L1210 leukemia, normal mouse bone marrow, and peripheral blood cells obtained from a patient with chronic lymphatic leukemia (CLL). Endpoints used were determination of single strand breaks, DNA-DNA interstrand and DNA-protein cross-links. After treatment of mice with CY (4 mg/mouse), low levels of single strand breaks were observed in both L1210 leukemia and CDF1 normal bone marrow. When a patient with CLL was treated with CY (750 mg/m2), no evidence of single strand breaks could be demonstrated. Maximum levels of DNA-DNA interstrand cross-links were observed in mice 2 h after injection of CY for the L1210 leukemia cells [175 +/- 25 rad-equivalents (req)] and at 4 h for the CDF1 normal bone marrow cells (47 +/- 9 req). In human CLL, maximum levels were observed 12 h after injection of CY. Peak levels of DNA-DNA interstrand cross-links were approximately 4-fold lower in CDF1 normal bone marrow cells than in L1210 leukemia. The frequencies measured in human CLL cells were relatively low at any timepoint (mean at 12 h = 36 req). Maximum levels of DNA-protein cross-links were observed 4 h after injection of CY (4 mg/mouse) for both L1210 leukemia [123 req (mean)] and normal bone marrow cells [50 req (mean)]. DNA-protein cross-links were measurable in CLL at timepoints later than 4 h after the start of injection of CY. In order to obtain equitoxicity between L1210 leukemia and CDF1 normal bone marrow cells, about 18-fold higher doses of CY had to be given than in the case of the normal bone marrow cells. In contrast, only 4-fold higher doses had to be given to the normal bone marrow to obtain equivalent peak levels of DNA-DNA interstrand cross-links.
Initial phase I trials of intraperitoneal chemotherapy in ovarian cancer patients demonstrated that a pharmacologic advantage was achieved with the direct instillation of drugs into the peritoneal cavity. Recent trials have reported that approximately 30% of patients who have small-volume residual disease following induction chemotherapy will achieve a complete remission with intraperitoneal cisplatin. The demonstrated effectiveness and acceptable toxicity makes cisplatin the current drug of choice in the intraperitoneal therapy of ovarian cancer patients. Additional clinical studies are required to determine the role of combinations intraperitoneally, the necessity of intravenous sodium thiosulfate for use with intraperitoneal cisplatin, the activity of other agents, the optimum techniques to deliver intraperitoneal drugs, and the appropriate clinical situations where intraperitoneal therapy should be used in the overall management of ovarian cancer.