The Roles Played by FP/EP3 Receptors During Pressure-lowering in Mouse Eyes Mediated by a Dual FP/EP3 Receptor Agonist.

Purpose: We investigated the intraocular pressure (IOP)-lowering effect of topical sepetaprost (SPT), a dual agonist of the FP and EP3 receptors. We explored whether certain receptors mediated the hypotensive effect of SPT and outflow facility changes in C57BL/6 mice (wild-type [WT]) and FP and EP3 receptor-deficient mice (FPKO and EP3KO mice, respectively). Methods: IOP was measured using a microneedle. Outflow facility was measured using a two-level, constant-pressure perfusion method. Results: SPT significantly reduced IOP for 8 hours after administration to WT mice. The 2-hour IOP reductions afforded by latanoprost were 15.3 ± 2.5, 1.8 ± 2.0, and 12.3 ± 2.4% in WT, FPKO, and EP3KO mice, respectively; the SPT figures were 13.6 ± 2.1, 5.9 ± 2.7, and 6.6 ± 2.6%, respectively. Latanoprost-mediated IOP reduction was significantly decreased in FPKO mice, and SPT-mediated IOP reduction was reduced in both FPKO and EP3KO mice. At 6 hours after administration, latanoprost did not significantly reduce the IOP in any tested mouse strain. SPT-mediated IOP reduction was reduced in both FPKO and EP3KO mice. IOP reduction at 6 hours was significantly higher after simultaneous administration of selective FP and EP3 receptor agonists, but IOP did not fall on administration of (only) a selective EP3 receptor agonist. SPT significantly increased outflow facility in WT mice, but less so in FPKO and EP3KO mice. Conclusions: The IOP-lowering effect of SPT lasted longer than that of latanoprost. Our data imply that this may be attributable to augmented outflow facility mediated by the FP and EP3 receptors.

Novel Pharmacologic Candidates for Treatment of Primary Open-Angle Glaucoma.

Primary open-angle glaucoma (OAG) affects approximately 45 million people worldwide and more than 2.5 million people aged 40 years or older in the United States. Pharmacologic treatment for glaucoma is directed towards lowering intraocular pressure (IOP) to slow disease progression and delay visual field loss. Current medical treatment options for the lowering of IOP include the following classes of topical medications: beta-adrenergic antagonists, alpha-adrenergic agonists, cholinergic agonists, carbonic anhydrase inhibitors, and prostaglandin analogs. Issues with existing drugs include failure to achieve target IOP with monotherapy, drug-related side effects, and low patient compliance with multiple daily administration of eye drops. In recent years, the scientific and medical community has seen encouraging development of novel classes of drugs for primary OAG, the majority of which lower IOP by targeting the trabecular meshwork outflow pathway to increase aqueous humor outflow. Among the most promising new pharmacologic candidates are rho kinase inhibitors including ripasudil (K-115), netarsudil (AR-13324), and AMA0076; adenosine receptor agonists including trabodenoson (INO-8875); and modified prostaglandin analogs including latanoprostene bunod (LBN, BOL-303259-X) and ONO-9054. This study aims to systematically review and summarize the most recent developments in clinical trials for new pharmacologic options for the treatment of primary open-angle glaucoma.

Prokineticin 2 antagonist, PKRA7 suppresses arthritis in mice with collagen-induced arthritis.

BACKGROUND: Prokineticin 2 (PK2) expression is upregulated in mice with collagen-induced arthritis (CIA), an animal model of rheumatoid arthritis. The purpose of our study was to investigate the effects of PK2 inhibition on CIA. METHODS: PK2, prokineticin receptor (PKR) 1, and PKR2 mRNA transcripts in the joints of CIA mice were measured by real-time PCR on Days 21, 28, and 35 (n = 15/day). Localization of PKR1 and PKR2 proteins was examined immunohistochemically. PKRA7, a PK2 antagonist, was administered intraperitoneally for 2 weeks to CIA mice, and the severity of arthritis was compared between treated (n = 12) and untreated (n = 12) mice. The gene expression levels of inflammatory cytokines IL-1ß, IL-6, TNF-α, and VEGF were also measured by real-time PCR and compared between treated (n = 6) and untreated (n = 6) CIA mice. The data was statistically analyzed, and P values of less than 0.05 were considered significant. RESULTS: In the thickened synovial membrane, PKR1 protein was expressed in infiltrating neutrophils, while PKR2 expression was found in macrophage-like mononuclear cells. PK2 gene expression was significantly more pronounced on Days 28 and 35 than on Day 21 (2.15 and 2.03 versus 1.00, P = 0.0311 and 0.0247; Dunn's multiple comparison). PKR2 gene expression levels were significantly higher on Days 28 and 35 compared to Day 21 (25.4 and 39.3 versus 1.0, P = 0.002 and < 0.0001; Dunn's multiple comparison). Administration of PKRA7 suppressed the severity of arthritis (P < 0.001; two-way analysis of variance). A gene expression analysis of inflammatory cytokines revealed significantly reduced IL-1ß and lL-6 expression in the joints of PKRA7-treated mice compared to untreated mice (0.1 versus 1.0, P = 0.0043 and 0.04 versus 1.0, P = 0.0022, respectively; Mann-Whitney test). CONCLUSIONS: PK2 inhibition suppressed arthritis in mice with CIA.

Ocular Hypotensive Effect of ONO-9054, an EP3/FP Receptor Agonist: Results of a Randomized, Placebo-controlled, Dose Escalation Study.

PURPOSE: To assess pharmacodynamic and safety profiles of ONO-9054 following single and multiple day dosing in subjects with ocular hypertension or open-angle glaucoma. MATERIALS AND METHODS: This was a phase I, single-center, randomized, double-masked, placebo-controlled dose-escalation study. Nine subjects were randomized to each of ONO-9054 3, 10, 20, 30 µg/mL and 12 to placebo. Subjects received a single drop to each eye at 07:00±30 minutes (single dose). Following a 4-day no-treatment period, subjects were dosed once daily for 14 consecutive days (multiple day dosing). Intraocular pressure (IOP) was measured regularly and compared with baseline measurements. Ocular examinations assessed safety and tolerability. RESULTS: Mean IOP decreased dose dependently. Following single dosing, IOP decreased from 22.9±4.0 to 15.9±2.3 mm Hg (ONO-9054, 30 µg/mL) at peak effect 9 hours postdose; the reduction in placebo-treated subjects was from 22.3±2.4 to 21.5±3.3 mm Hg. Following multiple day dosing, the greatest reduction in IOP occurred 1 hour postdose on day 18, from 23.3±0.6 to 15.1±2.4 mm Hg (ONO-9054, 10 µg/mL); the smallest reduction at this time was from 23.9±0.8 to 18.6±2.0 mm Hg (ONO-9054, 3 µg/mL). Pressures remained reduced on day 19, 25 hours after the last dose, when the lowest measurement was 15.8±2.1 mm Hg (ONO-9054, 10 µg/mL). Anterior uveitis and vitreous detachment were each reported in 2 subjects and considered moderate by the Investigator. Ocular hyperemia and tolerability symptoms were generally mild and transient. CONCLUSIONS: ONO-9054 was well-tolerated and elicited dose-dependent reductions in IOP, which were sustained for at least 24 hours following 2 weeks of consecutive daily dosing.

Production benefit of treatment with a dual active oral formulation of derquantel-abamectin in slaughter lambs.

Gastrointestinal nematodes have a negative impact on the productivity of grazing sheep. Control of these infections has relied for decades on the use of anthelminics, leading to anthelmintic resistance (AR) worldwide, including the UK. The use of combination anthelmintics has been advocated as one of the tools in managing AR and decreasing the economic losses associated with AR. In this study, the benefit of a new combination (derquantel plus abamectin; DQL+ABA: Startect(®) Dual Active Oral Solution for Sheep, Zoetis, at 1 mL/5 kg bodyweight) was evaluated on a farm with suspected AR to benzimidazoles, by incorporating it into the existing treatment regime. In total 100 lambs were selected and allocated to one of two treatment groups, which were treated either with DQL+ABA or fenbendazole/levamisole at monthly intervals. All lambs were co-grazing the same pasture. Weight gain and carcass quality was evaluated, as well as treatment efficacy. The efficacy of DQL+ABA was high throughout the grazing season, whereas the efficacy of the fenbendazole/levamisole treatment regime was below the threshold for anthelmintic efficacy. The high efficacy of a monthly treatment with DQL+ABA resulted in a significantly higher average daily weight gain and shorter time to reach slaughter.

The efficacy of a combined oral formulation of derquantel-abamectin against anthelmintic resistant gastro-intestinal nematodes of sheep in the UK.

The objective of the present studies was to evaluate the efficacy of a combined formulation (Startect(®) Dual Active Oral Solution for Sheep, Pfizer Animal Health) of derquantel (DQL) and abamectin (ABA) for the treatment of: (1) sheep experimentally infected with a moxidectin (MOX)-resistant isolate of Teladorsagia circumcincta, and (2) multi-drug resistant gastrointestinal nematode parasites under UK field conditions. In the first study, a total of 40 animals were allocated into 4 treatment groups, and were either left untreated or treated with DQL+ABA, MOX or ABA. Faecal samples were collected on days 1-5 and on day 7 after treatment to examine the reduction in faecal egg excretion and to evaluate the egg viability. On day 14 post treatment all animals were euthanised for abomasal worm counts. There was a 100% reduction in geometric mean worm counts for the DQL+ABA treated animals compared to the untreated control animals (P<0.0001), whereas the percentage reduction in worm counts for the MOX- (P>0.05) and ABA-treated (P=0.0004) animals was 12.4% and 71.8%, respectively. The data from the egg hatch assay (EHA) indicated that in the MOX-treated and the ABA-treated animals, the majority of the eggs hatched after treatment. In the field study, performed on four farms, animals were allocated into 6 groups of 11-15 animals each in order to conduct a faecal egg count reduction test (FECRT), based on arithmetic mean egg counts. One group of animals remained untreated, whereas the other animals were treated with DQL+ABA, MOX, fenbendazole (FBZ), levamisole (LV) or ivermectin (IVM). On each of the farms the reduction in egg excretion after treatment with FBZ, LV or IVM was below 95.0%, indicating anthelmintic resistance. The efficacy of DQL+ABA ranged from 99.1 to 100%, yielding significantly lower egg counts compared to the untreated control group (P ≤ 0.003). For MOX the egg counts were significantly (P ≤ 0.003) lower compared to the untreated group at each farm, with reductions varying from 98.2 to 100%. The post-treatment copro-cultures for larva identification indicated that T. circumcincta was the most abundant worm species after treatment (52-99% of the larvae). The results of these studies confirm the high efficacy of the DQL+ABA combination formulation against anthelmintic resistant nematodes in the UK.

The comparative efficacy of abamectin, monepantel and an abamectin/derquantel combination against fourth-stage larvae of a macrocyclic lactone-resistant Teladorsagia spp. isolate infecting sheep.

Anthelmintic resistance by gastrointestinal nematodes of sheep continues to be an issue of global interest. While the recent introduction in some countries of one or two new anthelmintic classes (amino-acetonitrile derivatives [AAD] and spiroindoles [SI]) has been welcomed, it is important that there is no relaxation in parasite control and the management of drug resistance. Monepantel (an AAD) was the first new anthelmintic to be approved for use (New Zealand, 2009) and was followed a year later in the same country by a combination of derquantel (a SI) and abamectin. The present study determined the efficacy of the new anthelmintic products and abamectin against fourth-stage larvae of macrocyclic lactone-resistant Teladorsagia spp. in lambs. Efficacies were calculated by comparing post-mortem nematode burdens of treated animals with those of untreated control sheep, and were 98.5, 86.3 and 34.0% for monepantel, abamectin/derquantel and abamectin, respectively. The nematode burdens of monepantel- and abamectin/derquantel-treated sheep were significantly lower than those sheep treated with abamectin and the untreated controls. Similarly, the burden of the monepantel group was significantly lower than that of the abamectin/derquantel group. These findings provide an opportunity to reinforce the recommendation that farmers and animal health advisors need to know the resistance status of nematode populations on subject farms to ensure effective control programs are designed and implemented. Such control programs should include an appropriate choice of anthelmintic(s), monitoring parasite burdens for correct timing of treatments, and pasture management to reduce larval challenge balanced with the maintenance of drug-susceptible populations in refugia.

Modelling the benefits of a new class of anthelmintic in combination.

Since 2009 two new classes of anthelmintics have been registered for use in sheep in New Zealand. This raises challenging questions about how such new actives should be used, not only to minimise the development of resistance to them, thereby ensuring their availability as effective treatments for as long as possible, but also to minimise the further development of resistance to the other anthelmintic classes. One strategy which appears to offer considerable potential for slowing the development of resistance is the use of combinations of different anthelmintic classes, although this approach remains contentious in some countries. The potential benefit of using anthelmintics in combination is particularly relevant to two recently released anthelmintic compounds because one, monepantel, is presently only available as a single active product while the other, derquantel, is only available in combination with abamectin. A simulation modelling approach was used to investigate the potential benefits of using anthelmintics in combination. The rate at which resistance develops to a new 'active' when used alone was compared to an equivalent compound used in combination with a second compound from an alternative class (in this case, abamectin), when various levels of resistance occur to the second active. In addition, the potential of a new active to reduce further development of resistance to the second compound in the combination was evaluated. Finally, the use of combinations as compared to sequential or rotational use patterns, in the presence of side resistance between two actives was investigated. The modelling simulations suggest a significant advantage to both compounds when they are used in combination, especially if both initially have high efficacy. The development of resistance to the new active was delayed, although to a lesser extent, even when the efficacy of the second active in the combination was only 50%. Under a 'low-refugia' management environment resistance to all actives developed more rapidly, and the advantage of using actives in combination was reduced. When used in conjunction with other resistance management strategies, a combination containing a new active prevented further development of resistance to the older class. Using actives in combination was superior to using them individually either sequentially or in rotation, even in the presence of side-resistance between the two anthelmintic classes.

Omigapil ameliorates the pathology of muscle dystrophy caused by laminin-alpha2 deficiency.

Laminin alpha2-deficient congenital muscular dystrophy, called MDC1A, is a rare, devastating genetic disease characterized by severe neonatal hypotonia ("floppy infant syndrome"), peripheral neuropathy, inability to stand or walk, respiratory distress, and premature death in early life. Transgenic overexpression of the apoptosis inhibitor protein BCL-2, or deletion of the proapoptotic Bax gene in a mouse model for MDC1A prolongs survival and mitigates pathology, indicating that apoptotic events are involved in the pathology. Here we demonstrate that the proapoptotic glyceraldehyde-3-phosphate dehydrogenase (GAPDH)-Siah1-CBP/p300-p53 pathway is activated in a mouse model for MDC1A. Moreover, we show that omigapil, which inhibits GAPDH-Siah1-mediated apoptosis, ameliorates several pathological hallmarks in the MDC1A mouse model. Specifically, we demonstrate that treatment with omigapil inhibits apoptosis in muscle, reduces body weight loss and skeletal deformation, increases locomotive activity, and protects from early mortality. These data qualify omigapil, which is in late phase of clinical development for human use, as a drug candidate for the treatment of MDC1A.

Targets for neuroprotection in Parkinson's disease.

Current therapies for Parkinson's disease significantly improve the quality of life for patients suffering from this neurodegenerative disease, yet none of the current therapies has been convincingly shown to slow or prevent the progression of disease. Much has been learned about the pathophysiology of Parkinson's disease in recent years, and these discoveries offer a variety of potential targets for protective therapy. Mechanisms implicated in the disease process include oxidative stress, mitochondrial dysfunction, protein aggregation and misfolding, inflammation, excitotoxicity, and apoptosis. At the same time, the involvement of these diverse processes makes modeling the disease and evaluation of potential treatments difficult. In addition, available clinical tools are limited in their ability to monitor the progression of the disease. In this review, we summarize the different pathogenic mechanisms implicated in Parkinson's disease and neuroprotective strategies targeting these mechanisms currently under clinical study or under preclinical development, with a view towards strategies that seem most promising.

Post-translational protein modifications in type 1 diabetes: a role for the repair enzyme protein-L-isoaspartate (D-aspartate) O-methyltransferase?

AIMS/HYPOTHESIS: Post-translational modifications, such as isomerisation of native proteins, may create new antigenic epitopes and play a role in the development of the autoimmune response. Protein-L-isoaspartate (D-aspartate) O-methyltransferase (PIMT), encoded by the gene PCMT1, is an enzyme that recognises and repairs isomerised Asn and Asp residues in proteins. The aim of this study was to assess the role of PIMT in the development of type 1 diabetes. MATERIALS AND METHODS: Immunohistochemical analysis of 59 normal human tissues was performed with a monoclonal PIMT antibody. CGP3466B, which induces expression of Pcmt1, was tested on MIN6 and INS1 cells, to assess its effect on Pcmt1 mRNA and PIMT levels (RT-PCR and western blot) and apoptosis. Forty-five diabetes-prone BioBreeding (BB) Ottawa Karlsburg (OK) rats were randomised to receive 0, 14 or 500 microg/kg (denoted as the control, low-dose and high-dose group, respectively) of CGP3466B from week 5 to week 20. RESULTS: A high level of PIMT protein was detected in beta cells. CGP3466B induced a two- to threefold increase in Pcmt1 mRNA levels and reduced apoptosis by 10% in MIN6 cells. No significant effect was seen on cytokine-induced apoptosis or PIMT protein levels in INS1 cells. The onset of diabetes in the BB/OK rats was significantly delayed (85.6+/-9.0 vs 84.3+/-6.8 vs 106.6+/-13.5 days, respectively; p<0.01 for high-dose vs low-dose and control groups), the severity of the disease was reduced (glucose 22.2+/-3.2 vs 16.9+/-2.6 vs 15.8+/-2.7 mmol; p<0.01 for high- and low-dose groups vs control group) and residual beta cells were more frequently identified (43% vs 71% vs 86%; p<0.05 for high-dose vs control group) in the treated animals. CONCLUSIONS/INTERPRETATION: The results support a role for post-translational modifications and PIMT in the development of type 1 diabetes in the diabetes-prone BB rat, and perhaps also in humans.

TCH346 as a neuroprotective drug in Parkinson's disease: a double-blind, randomised, controlled trial.

BACKGROUND: There is an important unmet medical need in Parkinson's disease for a neuroprotective treatment that slows or stops disease progression. TCH346 is a potent anti-apoptotic drug that protects against loss of dopaminergic neurons in laboratory models. Our aim was to assess TCH346 as a neuroprotective drug in patients with Parkinson's disease. METHODS: Patients presenting at 45 international movement disorder clinics with early untreated Parkinson's disease were assessed as part of this parallel-group, double-blind, randomised controlled trial. 301 eligible patients were randomly assigned 12-18 months' treatment with TCH346 at a daily dose of 0.5 mg (n=78), 2.5 mg (n=79), or 10 mg (n=73), or placebo (n=71), followed by a 4 week washout period. The primary outcome measure was time to development of a disability requiring dopaminergic treatment. Secondary outcome measures were the annual rate of change in the unified Parkinson's disease rating scale (UPDRS) and the PDQ-39, a measure of quality of life. Analyses were by intention-to-treat. This study is pending registration with . FINDINGS: 255 patients completed the study. TCH346 did not differ from placebo for any of the study outcomes. Treatment was needed in 26 (34%) patients in the TCH346 0.5 mg group, 30 (38%) in the TCH346 2.5 mg group, 24 (33%) in the TCH346 10 mg group, and 23 (32%) in the placebo group. There were no significant differences between groups. There were no differences between groups in the annual change in the UPDRS or PDQ-39 either. Few patients withdrew because of adverse events and none was judged to be related to the study intervention. INTERPRETATION: TCH346 did not show evidence of a neuroprotective effect. The discrepancy between the preclinical promise of TCH346 and the clinical outcome could have arisen because of the use of laboratory models that do not accurately reflect the pathogenesis of Parkinson's disease, the doses of study drug used, insensitive clinical endpoints, and the patient population selected for study.

Amyotrophic lateral sclerosis: a consensus viewpoint on designing and implementing a clinical trial.

In November 2002, an advisory board meeting was convened by Novartis Pharma to provide recommendations and rationale for clinical trials designed to evaluate new treatments, such as TCH346, for amyotrophic lateral sclerosis (ALS). In terms of selecting appropriate outcome measures, the panel recommended the use of the ALS Functional Rating Scale (ALSFRS-R) to measure primary endpoints. A review of other key issues in this area including regional variations in the epidemiology, diagnosis and management of ALS, defining patient populations and doses of trial medication, and accommodating the likelihood of co-medication with pre-existing treatment in trial design, are discussed.

CGP 3466B has no effect on disease course of (G93A) mSOD1 transgenic mice.

BACKGROUND: There is an accumulating body of evidence that apoptosis is involved in the motor neuron death that occurs in ALS, and in the (G93A) mSOD1 transgenic mouse model (mSOD1 mice). CGP 3466B, a tricyclic propargylamine structurally related to (-)-deprenyl, was found to inhibit apoptosis in a wide variety of in vitro and in vivo models. We therefore studied the effect of CGP 3466B in mSOD1 mice. METHODS: As the effect of CGP 3466B was previously reported to have a bell-shaped curve, we performed a dose-ranging study. High-copy G93A mSOD1 mice were treated subcutaneously from the age of 50 days until death with four concentrations of CGP 3466B (0.39 microg kg(-1), 3.9 microg kg(-1), 39 microg kg(-1), and 390 microg kg(-1)). Behavioural tests were performed daily to determine disease onset, disease progression and survival. At the age of 110 days, two mice per group were sacrificed for histopathological analysis of the lumbar ventral horn and for semiquantitative analysis of motor neuron number. RESULTS: We observed no effect on disease onset, disease progression, or survival of the mice. We also did not observe a significant effect on the number of motor neurons due to CGP 3466B. CONCLUSIONS: We conclude that in high-copy G93A mSOD1 mice, chronic subcutaneous treatment with CGP 3466B offers no clinical benefit.

A novel metabolite, an oxepin formed from cannabidiol with guinea-pig hepatic microsomes.

The metabolic formation of an oxepin derivative, 3-pentyl-6,7,7a,8,9,11a-hexahydro-1,7-dihydroxy-7,10- dimethyldibenzo-[b,d]-oxepin, from cannabidiol was studied in-vitro using guinea-pig hepatic microsomes. The hepatic microsomes catalysed the formation of the metabolite from cannabidiol and 8S, 9-epoxycannabidiol in the presence of an NADPH-generating system and 3, 3, 3-trichloropropene-1, 2-oxide. 8S, 9-Epoxycannabidiol was thought to be an intermediate in the formation of the metabolite, which was identified by gas chromatography-mass spectrometry. The metabolite synthesized from 8S, 9-epoxycannabidiol diacetate exhibited catalepsy, hypothermia and pentobarbitone-induced sleep prolongation in mice, although the pharmacological effect was less potent than that of delta 9-tetrahydrocannabinol.