Design of substituted imidazolidinylpiperidinylbenzoic acids as chemokine receptor 5 antagonists: potent inhibitors of R5 HIV-1 replication.

The redesign of the previously reported thiophene-3-yl-methyl urea series, as a result of potential cardiotoxicity, was successfully accomplished, resulting in the identification of a novel potent series of CCR5 antagonists containing the imidazolidinylpiperidinyl scaffold. The main redesign criteria were to reduce the number of rotatable bonds and to maintain an acceptable lipophilicity to mitigate hERG inhibition. The structure-activity relationship (SAR) that was developed was used to identify compounds with the best pharmacological profile to inhibit HIV-1.

Early glottic carcinoma treated by radiotherapy: defining a population for surgical salvage.

Objectives/hypothesis: Not all patients with early Glottis squamous cell carcinoma will be cured by radiotherapy. This is an audit of a single center's experience with those patients who fail by this approach.

Study Design: This retrospective study was approved by the IRB (Institutional Review Board); eligibility criterion was patients treated between 1967 and December 2006, T(IS), T(1), T(2) N(0) SCC glottic carcinoma, with analysis occurring in 2009, and with a minimum follow-up of 2 years.

Floor of mouth carcinoma: surgery still the dominant mode of treatment.

Introduction: To evaluate the care and outcomes for patients presenting with floor of mouth (FOM) cancers.

Methods: In this Ethics-approved audit, all eligible patients were evaluated with eligibility defined as having a squamous cell carcinoma originating in the FOM. Patient, disease and treatment factors were defined.

Plerixafor plus granulocyte colony-stimulating factor versus placebo plus granulocyte colony-stimulating factor for mobilization of CD34(+) hematopoietic stem cells in patients with multiple myeloma and low peripheral blood CD34(+) cell count: results of a subset analysis of a randomized trial.

Preapheresis peripheral blood (PB) CD34(+) cell count is a strong predictor of hematopoietic stem cell (HSC) mobilization and is routinely used to optimize the timing, cost, and success of HSC collection in patients with multiple myeloma. However, a uniform PB CD34(+) cell count that predicts mobilization failure has not been defined, resulting in the development of institute-specific algorithms for mobilization, particularly regarding the decision of when to use the novel stem cell mobilization agent plerixafor. In this post hoc analysis, we evaluated the mobilization efficacy of plerixafor plus granulocyte colony-stimulating factor (G-CSF) versus placebo plus G-CSF in patients with multiple myeloma, stratified by preapheresis PB CD34(+) cell count: <10, <15, <20, and ≥20 cells/μL.

Mitigating hERG Inhibition: Design of Orally Bioavailable CCR5 Antagonists as Potent Inhibitors of R5 HIV-1 Replication.

A series of CCR5 antagonists representing the thiophene-3-yl-methyl ureas were designed that met the pharmacological criteria for HIV-1 inhibition and mitigated a human ether-a-go-go related gene (hERG) inhibition liability. Reducing lipophilicity was the main design criteria used to identify compounds that did not inhibit the hERG channel, but subtle structural modifications were also important. Interestingly, within this series, compounds with low hERG inhibition prolonged the action potential duration (APD) in dog Purkinje fibers, suggesting a mixed effect on cardiac ion channels.

Design and synthesis of pyridin-2-ylmethylaminopiperidin-1-ylbutyl amide CCR5 antagonists that are potent inhibitors of M-tropic (R5) HIV-1 replication.

A series of CCR5 antagonists were optimized for potent inhibition of R5 HIV-1 replication in peripheral blood mononuclear cells. Compounds that met acceptable ADME criteria, selectivity, human plasma protein binding, potency shift in the presence of α-glycoprotein were evaluated in rat and dog pharmacokinetics.

Prospective CCR5 small molecule antagonist compound design using a combined mutagenesis/modeling approach.

The viral resistance of marketed antiviral drugs including the emergence of new viral resistance of the only marketed CCR5 entry inhibitor, maraviroc, makes it necessary to develop new CCR5 allosteric inhibitors. A mutagenesis/modeling approach was used (a) to remove the potential hERG liability in an otherwise very promising series of compounds and (b) to design a new class of compounds with an unique mutant fingerprint profile depending on residues in the N-terminus and the extracellular loop 2. On the basis of residues, which were identified by mutagenesis as key interaction sites, binding modes of compounds were derived and utilized for compound design in a prospective manner.

Retained role of surgery for olfactory neuroblastoma.

Background: Olfactory neuroblastoma is a rare paranasal sinus malignancy. The traditional approach was craniofacial resection (CFR) and then postoperative radiotherapy until 1998. This review will chart development of a new protocol.

Design and synthesis of pyridin-2-yloxymethylpiperidin-1-ylbutyl amide CCR5 antagonists that are potent inhibitors of M-tropic (R5) HIV-1 replication.

A novel series of CCR5 antagonists were identified based on the redesign of Schering C. An SAR was established based on inhibition of CCR5 (RANTES) binding and these compounds exhibited potent inhibition of R5 HIV-1 replication in peripheral blood mononuclear cells.

HIV-1 entry inhibition by small-molecule CCR5 antagonists: a combined molecular modeling and mutant study using a high-throughput assay.

Based on the attrition rate of CCR5 small molecule antagonists in the clinic the discovery and development of next generation antagonists with an improved pharmacology and safety profile is necessary. Herein, we describe a combined molecular modeling, CCR5-mediated cell fusion, and receptor site-directed mutagenesis approach to study the molecular interactions of six structurally diverse compounds (aplaviroc, maraviroc, vicriviroc, TAK-779, SCH-C and a benzyloxycarbonyl-aminopiperidin-1-yl-butane derivative) with CCR5, a coreceptor for CCR5-tropic HIV-1 strains. This is the first study using an antifusogenic assay, a model of the interaction of the gp120 envelope protein with CCR5.

Transplanted CD34(+) cell dose is associated with long-term platelet count recovery following autologous peripheral blood stem cell transplant in patients with non-Hodgkin lymphoma or multiple myeloma.

Autologous hematopoietic stem cell transplantation (ASCT) is an established treatment for patients with hematologic malignancies, yet the impact of transplanted CD34(+) cell dose on clinical outcomes is unresolved. We conducted post hoc analyses of transplanted CD34(+) cell dose and hematopoietic recovery following ASCT in 438 patients with non-Hodgkin lymphoma (NHL) or multiple myeloma (MM), using data from 2 multicenter phase 3 clinical studies that compared plerixafor plus granulocyte-colony stimulating factor (G-CSF) versus placebo plus G-CSF as stem cell mobilization regimens. Days to engraftment and the proportion of patients who reached predetermined blood count thresholds were compared across 3 CD34(+) cell dose levels: 2-4 × 10(6) cells/kg, 4-6 × 10(6) cells/kg, and >6 × 10(6) cells/kg, regardless of mobilization treatment.

CXCR4 in clinical hematology.

Pharmacological manipulation of CXCR4 has proven clinically useful for mobilization of stem and progenitor cells and in several preclinical models of disease. It is a key component in the localization of leukocytes and stem cells. For patients with multiple myeloma and non-Hodgkin's Lymphoma, treatment with plerixafor, an inhibitor of CXCL12 binding to CXCR4, plus G-CSF mobilizes stem cells for autologous transplantation to a greater degree than the treatment with G-CSF alone, and in some cases when patients could not be mobilized with cytokines, chemotherapy, or the combination.

Synthesis and structure-activity relationships of azamacrocyclic C-X-C chemokine receptor 4 antagonists: analogues containing a single azamacrocyclic ring are potent inhibitors of T-cell tropic (X4) HIV-1 replication.

Bis-tetraazamacrocycles such as the bicyclam AMD3100 (1) are a class of potent and selective anti-HIV-1 agents that inhibit virus replication by binding to the chemokine receptor CXCR4, the coreceptor for entry of X4 viruses. By sequential replacement and/or deletion of the amino groups within the azamacrocyclic ring systems, we have determined the minimum structural features required for potent antiviral activity in this class of compounds. All eight amino groups are not required for activity, the critical amino groups on a per ring basis are nonidentical, and the overall charge at physiological pH can be reduced without compromising potency.

Role of radiotherapy in early glottic carcinoma.

Background: Early glottic carcinoma has a high local control prospect with radiotherapy. This review evaluates a single center's experience.

Methods: All patients from 1967 to 2006 diagnosed with Tis/T1/T2/N0 early glottic carcinoma treated definitively with radiotherapy at Prince of Wales Hospital were reviewed.

Recurrent nasopharyngeal carcinoma: current management approaches.

Objectives: Providing the primary recurrence is localized, salvage treatment is possible for nasopharyngeal carcinoma (NPC). This is a review of the experience of retreatment of this malignancy highlighting the roles of surgery and repeat radiotherapy.

Methods: The Tumor Registry of the Prince of Wales Cancer Centre was audited for patients with an initial diagnosis of squamous/nonsquamous cell NPC who had primary treatment with radiotherapy, and now presented for retreatment.

Successful stem cell remobilization using plerixafor (mozobil) plus granulocyte colony-stimulating factor in patients with non-hodgkin lymphoma: results from the plerixafor NHL phase 3 study rescue protocol.

In a phase 3 multicenter, randomized, double-blinded, placebo-controlled study of 298 patients with non-Hodgkin lymphoma (NHL), granulocyte colony-stimulating factor (G-CSF) plus plerixafor increased the proportion of patients who mobilized >or=5 x 10(6) CD34(+) hematopoietic stem cells (HSCs)/kg compared with placebo plus G-CSF (P < .001). Patients in either study arm who failed mobilization (< 0.

Phase III prospective randomized double-blind placebo-controlled trial of plerixafor plus granulocyte colony-stimulating factor compared with placebo plus granulocyte colony-stimulating factor for autologous stem-cell mobilization and transplantation for patients with non-Hodgkin's lymphoma.

Purpose: This study evaluates the safety and efficacy of plerixafor (AMD3100), a CXCR4 antagonist, in mobilizing hematopoietic stem cells for autologous stem-cell transplantation in non-Hodgkin's lymphoma (NHL) patients.

Patients And Methods: This is a phase III, multicenter, randomized (1:1), double-blind, placebo-controlled study. Patients with non-Hodgkin's lymphoma requiring an autologous hematopoietic stem-cell transplantation in first or second complete or partial remission were eligible.

Pharmacology of AMD3465: a small molecule antagonist of the chemokine receptor CXCR4.

CXCR4 is widely expressed in multiple cell types, and is involved in neonatal development, hematopoiesis, and lymphocyte trafficking and homing. Disruption of the CXCL12/CXCR4 interaction has been implicated in stem cell mobilization. Additionally CXCR4 is a co-receptor for HIV.

Safety and preliminary efficacy of plerixafor (Mozobil) in combination with chemotherapy and G-CSF: an open-label, multicenter, exploratory trial in patients with multiple myeloma and non-Hodgkin's lymphoma undergoing stem cell mobilization.

Plerixafor, a novel CXCR4 inhibitor, is effective in mobilizing PBSCs particularly when used in conjunction with G-CSF. In four cohorts, this pilot study explored the safety of plerixafor mobilization when incorporated into a conventional stem cell mobilization regimen of chemotherapy and G-CSF. Forty (26 multiple myeloma and 14 non-Hodgkin's lymphoma) patients were treated with plerixafor.