Fatty acid amide hydrolase inhibitors. 3: tetra-substituted azetidine ureas with in vivo activity.

We describe here our attempts to optimise the human fatty acid amide hydrolase (FAAH) inhibition and physicochemical properties of our previously reported tetrasubstituted azetidine urea FAAH inhibitor, VER-156084. We describe the SAR of a series of analogues and conclude with the demonstration of in vivo dose-dependant FAAH inhibition in an anandamide-loading study in rats.

Targeting conserved water molecules: design of 4-aryl-5-cyanopyrrolo[2,3-d]pyrimidine Hsp90 inhibitors using fragment-based screening and structure-based optimization.

Inhibitors of the Hsp90 molecular chaperone are showing promise as anti-cancer agents. Here we describe a series of 4-aryl-5-cyanopyrrolo[2,3-d]pyrimidine ATP competitive Hsp90 inhibitors that were identified following structure-driven optimization of purine hits revealed by NMR based screening of a proprietary fragment library. Ligand-Hsp90 X-ray structures combined with molecular modeling led to the rational displacement of a conserved water molecule leading to enhanced affinity for Hsp90 as measured by fluorescence polarization, isothermal titration calorimetry and surface plasmon resonance assays. This displacement was achieved with a nitrile group, presenting an example of efficient gain in binding affinity with minimal increase in molecular weight. Some compounds in this chemical series inhibit the proliferation of human cancer cell lines in vitro and cause depletion of oncogenic Hsp90 client proteins and concomitant elevation of the co-chaperone Hsp70. In addition, one compound was demonstrated to be orally bioavailable in the mouse. This work demonstrates the power of structure-based design for the rapid evolution of potent Hsp90 inhibitors and the importance of considering conserved water molecules in drug design.

A qualitative evaluation of community and acute hospital nursing oncology services in Ireland.

PURPOSE: Cancer patients are a particularly vulnerable population group, facing an increase in physical, mental, logistical and financial difficulties. This, as well as Ireland's increased focus on primary care with the Sláintecare health plan, led to the development of the Community Oncology Nursing Programme, where community nurses are trained to provide cancer care in the community. This paper sought to explore the lived experiences of the patients and nurses involved in this programme in order to examine its impact as well as determine facilitators and roadblocks for future development. METHODS: A qualitative examination of the service was carried out by interviewing cancer patients receiving care as part of the programme as well as the nurses delivering care, both in the community and hospital day-ward. Thematic analysis was used. RESULTS: Themes of improved patient experience, nurse-patient relationship, the importance of location and roadblocks to further implementation of the programme emerged. There was a universal belief that the programme offered benefits to the patient and improved their care in some manner. CONCLUSIONS: The Community Oncology Nursing Programme has been well received by both nurses and patients. The service provided by community nurses as part of this programme offers benefits to patients and an improved cancer service.

A cost comparison study to review community versus acute hospital models of nursing care delivered to oncology patients.

PURPOSE: Ireland's Sláintecare health plan is placing an increased focus on primary care. A community oncology nursing programme was developed to train community nurses to deliver care in the community. While the initial pilot was proven to be clinically safe, no cost evaluation was carried out. This study aims to compare the costs of providing cancer support services in a day-ward versus in the community. METHODS: 183 interventions (40 in day-ward and 143 in community) were timed and costed using healthcare professional salaries and the Human Capital method. RESULTS: From the healthcare provider perspective, the day-ward was a significantly cheaper option by an average of €17.13 (95% CI €13.72 - €20.54, p < 0.001). From the societal perspective, the community option was cheaper by an average of €2.77 (95% CI -€3.02 - €8.55), although this was a non-significant finding. Sensitivity analyses indicate that the community service may be significantly cheaper from the societal perspective. CONCLUSIONS: Given the demand for cost-viable options for primary care services, this programme may represent a national option for cancer care in Ireland when viewed from the societal perspective.

The determinants of therapeutic levels of continuous positive airway pressure in elderly sleep apnea patients.

We have examined the role of age on the continuous positive airway pressure (CPAP) levels required to treat two groups of elderly (n=70) and young (n=70) sleep apneic patients, matched for disease severity (apnea/hypopnea index), body mass index and neck circumference. Elderly patients required lower CPAP levels compared to young [mean (sd): 6.9(1.9)cm H(2)O and 9.4(3.5)cm H(2)O, respectively; P<0.0001]. To investigate this finding, we studied the effects of CPAP and its components (inspiratory and expiratory positive airway pressure) on lung volume and upper airway resistance in two groups of elderly [n=9, age 71.7(3.3) years] and young [n=9, age 36.7(4.4)] patients with sleep apnea during wakefulness. CPAP produced a greater decrease in airway resistance (P=0.009) and a greater increase in lung volume (P=0.008) in the elderly compared to young patients. We conclude that both the greater lung inflation and the greater direct splinting of the upper airway contributed to the lower CPAP level required by the elderly. Ageing may be an important determinant of therapeutic CPAP levels in clinical practice, especially in older sleep apneic patients.

Safety, Tolerability and Pharmacokinetics of FAAH Inhibitor V158866: A Double-Blind, Randomised, Placebo-Controlled Phase I Study in Healthy Volunteers.

BACKGROUND AND OBJECTIVE: The inhibition of fatty acid amide hydrolase 1 (FAAH) has been proposed as a novel mechanism for treating pain syndromes by increasing the levels of endogenous cannabinoids (ECs). This study describes the safety, tolerability, pharmacokinetics and pharmacodynamics of V158866, a reversible FAAH inhibitor, after first administration to man. METHODS: 51 healthy male subjects were recruited into this double-blind, randomised, placebo-controlled, adaptive dose, phase I single (Part A) and repeated ascending dose (Part B) study. The primary outcome was the safety and tolerability of V158866. Secondary outcomes were (1) pharmacokinetics of V158866 and (2) pharmacodynamics of V158866, as assessed by changes in plasma EC concentrations. RESULTS: Single oral doses of 5-300 mg and repeated oral doses of 50-500 mg were evaluated. V158866 was well tolerated, with no apparent treatment-related effects on laboratory variables. V158866 was rapidly absorbed with a mean terminal elimination half-life of 9.6-18.3 h (Day 7; Part B). V158866 reached steady state within 2-3 days of administration, with an accumulation ratio, based on AUC0-24h, of approximately 2 on Day 7. V158866 showed a linear relationship between dose and AUC across the entire dose range. V158866 caused reversible, dose-related increases in plasma ECs. At hemi-equilibrium, there was a sigmoidal maximum effect relationship between plasma V158866 concentrations and changes in plasma ECs. CONCLUSIONS: V158866 is well tolerated, with linear pharmacokinetics suitable for once-daily administration, and reversible effects on plasma ECs. Maximum increases in plasma ECs occur with V158866 doses of 300-500 mg/day.

Identification of novel, in vivo active Chk1 inhibitors utilizing structure guided drug design.

Chk1 kinase is a critical component of the DNA damage response checkpoint especially in cancer cells and targeting Chk1 is a potential therapeutic opportunity for potentiating the anti-tumor activity of DNA damaging chemotherapy drugs. Fragment elaboration by structure guided design was utilized to identify and develop a novel series of Chk1 inhibitors culminating in the identification of V158411, a potent ATP-competitive inhibitor of the Chk1 and Chk2 kinases. V158411 abrogated gemcitabine and camptothecin induced cell cycle checkpoints, resulting in the expected modulation of cell cycle proteins and increased cell death in cancer cells. V158411 potentiated the cytotoxicity of gemcitabine, cisplatin, SN38 and camptothecin in a variety of p53 deficient human tumor cell lines in vitro, p53 proficient cells were unaffected. In nude mice, V158411 showed minimal toxicity as a single agent and in combination with irinotecan. In tumor bearing animals, V158411 was detected at high levels in the tumor with a long elimination half-life; no pharmacologically significant in vivo drug-drug interactions with irinotecan were identified through analysis of the pharmacokinetic profiles. V158411 potentiated the anti-tumor activity of irinotecan in a variety of human colon tumor xenograft models without additional systemic toxicity. These results demonstrate the opportunity for combining V158411 with standard of care chemotherapeutic agents to potentiate the therapeutic efficacy of these agents without increasing their toxicity to normal cells. Thus, V158411 would warrant further clinical evaluation.

A novel, small molecule inhibitor of Hsc70/Hsp70 potentiates Hsp90 inhibitor induced apoptosis in HCT116 colon carcinoma cells.

PURPOSE: The anti-apoptotic function of the 70 kDa family of heat shock proteins and their role in cancer is well documented. Dual targeting of Hsc70 and Hsp70 with siRNA induces proteasome-dependent degradation of Hsp90 client proteins and extensive tumor specific apoptosis as well as the potentiation of tumor cell apoptosis following pharmacological Hsp90 inhibition. METHODS: We have previously described the discovery and synthesis of novel adenosine-derived inhibitors of the 70 kDa family of heat shock proteins; the first inhibitors described to target the ATPase binding domain. The in vitro activity of VER-155008 was evaluated in HCT116, HT29, BT474 and MDA-MB-468 carcinoma cell lines. Cell proliferation, cell apoptosis and caspase 3/7 activity was determined for VER-155008 in the absence or presence of small molecule Hsp90 inhibitors. RESULTS: VER-155008 inhibited the proliferation of human breast and colon cancer cell lines with GI(50)s in the range 5.3-14.4 microM, and induced Hsp90 client protein degradation in both HCT116 and BT474 cells. As a single agent, VER-155008 induced caspase-3/7 dependent apoptosis in BT474 cells and non-caspase dependent cell death in HCT116 cells. VER-155008 potentiated the apoptotic potential of a small molecule Hsp90 inhibitor in HCT116 but not HT29 or MDA-MB-468 cells. In vivo, VER-155008 demonstrated rapid metabolism and clearance, along with tumor levels below the predicted pharmacologically active level. CONCLUSION: These data suggest that small molecule inhibitors of Hsc70/Hsp70 phenotypically mimic the cellular mode of action of a small molecule Hsp90 inhibitor and can potentiate the apoptotic potential of a small molecule Hsp90 inhibitor in certain cell lines. The factors determining whether or not cells apoptose in response to Hsp90 inhibition or the combination of Hsp90 plus Hsc70/Hsp70 inhibition remain to be determined.

Antitumor benzothiazoles. Frontier molecular orbital analysis predicts bioactivation of 2-(4-aminophenyl)benzothiazoles to reactive intermediates by cytochrome P4501A1.

The antitumor and metabolic activities of 2-(4-aminophenyl)benzothiazoles and their fluorinated analogues cannot be explained or predicted by conventional chemical means. Their mode of anti-cancer action involves metabolism of the benzothiazoles to an as yet unidentified reactive species. This species then forms DNA adducts which provoke cell death. The electronic structures and possible intermediates of these compounds have been computed quantum mechanically. The counter-intuitive patterns of metabolism can only be explained by considering the active intermediate to be a nitrenium ion. The distribution of the highest occupied molecular orbital for the nitrenium species derived from each fluorinated analogue correlates perfectly with the production, or otherwise, of an exportable metabolite. Further related compounds have been analyzed by this method and the predictions of their metabolism have subsequently been verified experimentally.