piperidines and casopitant

The difference in location between the receptor occupancy curve of an agonist and its functional response has been described as receptor reserve. This "reserve" for a specific receptor has been found to differ from tissue to tissue and between agonists acting on the same tissue. Recently, two structurally different neurokinin 1 (NK1) receptor antagonists were taken into human and both were tested as antidepressants and for insomnia. Vestipitant and Casopitant both have high affinity for the human NK1 receptor (pKi = 9.4 and 10.2, respectively). In human, at the chosen clinical doses, receptor occupancy was measured in the frontal cortex, at 24 hours post administration, as ∼90% for vestipitant (15 mg) and ∼100% for casopitant (30 mg). In patients with moderate to severe major depression, vestipitant given at 15 mg for 8 weeks showed no statistical significant benefit as measured by change in baseline in HAM-D total score; whereas casopitant at 80 mg achieved statistically significant improvement versus placebo at week 8 (LOCF HAMD17 = -2.7, p = 0.023). A lower dose of 30 mg showed a clear but not significant separation from placebo. However, in acute studies in insomnia, both vestipitant and casopitant at 15 mg and 30 mg, respectively, significantly reduced latency to persistent sleep, wakenings after sleep onset and increased total sleep time by similar amounts. These clinical results suggest that for major depression the receptor occupancy of an NK1 antagonist needs to be very high (almost 100%), whereas, for insomnia a lower occupation is sufficient to give clinical effect.

Topics: Antidepressive Agents; Depressive Disorder, Major; Fluorobenzenes; Humans; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Receptors, Neurokinin-1; Sleep Initiation and Maintenance Disorders; Tissue Distribution

The addition of neurokinin-1 receptor (NK1R) antagonists to antiemetic regimens has substantially reduced chemotherapy-induced nausea and vomiting (CINV). We sought to systematically review the overall impact of NK1R antagonists on CINV prevention.. We systematically searched the MEDLINE, EMBASE, and CENTRAL databases, and meeting proceedings for randomized controlled trials (RCTs) that evaluated NK1R antagonists plus standard antiemetic therapy for CINV prevention. Complete response (CR) to therapy was defined as the absence of emesis and the absence of rescue therapy. The endpoints were defined as CR in the overall phase (during the first 120 hours of chemotherapy), CR in the acute phase (first 24 hours), and the delayed phase (24-120 hours) after chemotherapy, nausea, and toxicity. Subgroup analyses evaluated the type of NK1R antagonist used, the emetogenic potential of the chemotherapy regimen, and prolonged use of 5-HT3 (serotonin) receptor antagonists, a class of standard antiemetic agents. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Statistical tests for heterogeneity were one-sided; statistical tests for effect estimates and publication bias were two-sided.. Seventeen trials (8740 patients) were included in this analysis. NK1R antagonists increased the CR rate in the overall phase from 54% to 72% (OR = 0.51, 95% CI = 0.46 to 0.57, P < .001). CR and nausea were improved in all phases and subgroups. The expected side effects from NK1R antagonists did not statistically significantly differ from previous reports; however, this analysis suggests that the incidence of severe infection increased from 2% to 6% in the NK1R antagonist group (three RCTs with a total of 1480 patients; OR = 3.10; 95% CI = 1.69 to 5.67, P < .001).. NK1R antagonists increased CINV control in the acute, delayed, and overall phases. They are effective for both moderately and highly emetogenic chemotherapy regimens. Their use might be associated with increased infection rates; however, additional appraisal of specific data from RCTs is needed.

Topics: Antiemetics; Antineoplastic Combined Chemotherapy Protocols; Aprepitant; Confidence Intervals; Humans; Infections; Morpholines; Nausea; Neoplasms; Neurokinin-1 Receptor Antagonists; Odds Ratio; Piperazines; Piperidines; Practice Guidelines as Topic; Randomized Controlled Trials as Topic; Serotonin 5-HT3 Receptor Antagonists; Vomiting

Chemotherapy-induced nausea and vomiting (CINV) is associated with a significant deterioration in quality of life. The emetogenicity of the chemotherapeutic agents, repeated chemotherapy cycles, and patient risk factors significantly influence CINV. 5-hydroxytryptamine-3 (5-HT(3)) receptor antagonists plus dexamethasone have significantly improved the control of acute CINV, but delayed CINV remains a significant clinical problem. Two new agents, palonosetron and aprepitant, have been approved for the prevention of both acute and delayed CINV. Palonosetron is a second-generation 5-HT(3) receptor antagonist with a longer half-life and a higher binding affinity than first-generation 5-HT(3) receptor antagonists. Aprepitant is the first agent available in the new drug class of neurokinin-1 (NK-1) receptor antagonists. Casopitant is another NK-1 receptor antagonist that is under review by the FDA after recent completion of Phase III clinical trials. The introduction of these new agents has generated revised antiemetic guidelines for the prevention of CINV. Future studies may consider the use of palonosetron, aprepitant and casopitant with other antiemetic agents (olanzapine, gabapentin, cannabinoids) in moderately and highly emetogenic chemotherapy, as well as in the clinical settings of multiple-day chemotherapy and bone marrow transplantation.

Topics: Antiemetics; Antineoplastic Agents; Aprepitant; Clinical Trials, Phase III as Topic; Humans; Isoquinolines; Morpholines; Nausea; Palonosetron; Piperazines; Piperidines; Quinuclidines; Serotonin Antagonists; Vomiting

The effective treatment of emetic complications of cancer therapies has remained a challenging task for cancer patients and their cancer care providers. Despite striking advances in antiemetic interventions, the need for more personalized targeted treatments in those who fail to response to the currently available antiemetic agents are yet to be met. Casopitant, a potent selective inhibitor of neurokinin-1 receptors, is a product of the increasingly heightened interest in this particular subset of cancer patients. The current review examines the emerging data about the benefits and safety of casopitant for treatment of chemotherapy-induced acute and delayed emesis, as well as the postoperative nausea/vomiting. Although preclinical studies promoted the notion of a potential superiority of casopitant over the already approved aprepitant in enhancing food and fluid intake, the limited comparison in clinical settings have yet to affirm a demonstratable meaningful superiority. The prevailing view from the published prospective studies supports a single 100 or 150 mg dose schedule of casopitant, orally or intravenously, as an effective and safe prophylaxis for acute and delayed emesis. The relative inferior outcomes of "nausea" control, as compared to a more impressive "vomiting" prevention, are similarly shared by both casopitant and aprepitant. This repeated and disappointing observation has challenged the precision and accuracy of our current understandings about the exact fabric of the "emesis axis." The future efforts should be directed to identify more effective agents for managing nausea and anticipatory emesis equally in both genders.

Topics: Antiemetics; Antineoplastic Agents; Humans; Nausea; Neoplasms; Piperazines; Piperidines; Vomiting

Tachykinins (TKs) are small peptides widely distributed in the central and peripheral nervous systems where they act as neurotransmitters. Potent and selective TKs antagonists have been developed in the last 20 years and many efforts have been made to prove their efficacy in the treatment of various diseases. Herein the most prominent results in the clinical development are reported and discussed. For aprepitant, the only compound of this class to have been launched to date, results of clinical studies and postmarketing cost-effectiveness data for the treatment of chemotherapy-induced emesis are discussed. The field is still well active, as currently proof-of-concept studies for indications initially missed (i.e., depression) are ongoing and new targets are under investigation.

Topics: Antiemetics; Aprepitant; Asthma; Clinical Trials as Topic; Gastrointestinal Diseases; Humans; Mental Disorders; Morpholines; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Receptors, Neurokinin-2; Receptors, Neurokinin-3; Sleep Initiation and Maintenance Disorders

Casopitant, an inhibitor of the neurokinin-1 receptor, and its mesylate salt, are being developed by GlaxoSmithKline plc for the potential treatment of chemotherapy-induced nausea and vomiting (CINV), post-operative nausea and vomiting (PONV), as well as for anxiety, depression and insomnia. Phase II trials are ongoing for anxiety, depression and insomnia, and further results are awaited from phase III trials of CINV and PONV. At the time of publication, it was expected that applications to the FDA for regulatory approval for CINV and PONV would be filed in 2008. Casopitant was previously being developed for the treatment of overactive bladder; however, in September 2007, this indication was no longer listed on the company's product pipeline.

Topics: Animals; Antiemetics; Anxiety Disorders; Clinical Trials as Topic; Contraindications; Depressive Disorder, Major; Drug Evaluation, Preclinical; Female; Fibromyalgia; Humans; Nausea; Neurokinin-1 Receptor Antagonists; Patents as Topic; Piperazines; Piperidines; Postoperative Nausea and Vomiting; Structure-Activity Relationship; Urinary Bladder, Overactive; Vomiting

Two studies were conducted in subjects with mild or moderate hepatic or renal impairment and subjects with normal organ function to evaluate the pharmacokinetics of casopitant and to assess its safety in these populations. A total of 26 subjects were enrolled in the hepatic impairment study and 18 subjects in the renal impairment study. All subjects received oral casopitant 100 mg once-daily for 5 days. Casopitant area under the concentration-time curve (AUC) increased 11% and 24% in subjects with mild or moderate hepatic impairment, respectively, on Day 1, compared with subjects with normal hepatic function; a similar increase was observed on Day 5. The AUC of the active major metabolite, GSK525060, was reduced 29% and 19% on Days 1 and 5, respectively, in subjects with moderate hepatic impairment, but not altered by mild hepatic impairment. Casopitant AUC increased 34% and 22% on Day 1 in subjects with mild or moderate renal impairment, respectively, and 28% and 11% on Day 5, respectively, compared with subjects with normal renal function. GSK525060 AUC was increased 17% and 24% on Days 1 and 5, respectively, in subjects with mild renal impairment; but did not significantly change in subjects with moderate renal impairment. Further age-adjusted analysis showed no meaningful effect of renal impairment on casopitant or GSK525060 AUC. Plasma protein binding of casopitant and GSK525060 was similar in all subjects. The pharmacokinetics of casopitant is not altered to a clinically significant extent in subjects with mild or moderate, hepatic or renal impairment. The impact of severe hepatic or renal impairment was not evaluated.

Topics: Administration, Oral; Adult; Analysis of Variance; Antiemetics; Area Under Curve; Biotransformation; Drug Administration Schedule; Female; Humans; Kidney Diseases; Least-Squares Analysis; Liver Diseases; Male; Middle Aged; Models, Biological; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Protein Binding; Severity of Illness Index; United States

The primary objective was to determine if a single dose of casopitant 90 mg added to ondansetron and dexamethasone would improve the control of chemotherapy-induced nausea and vomiting (CINV) over 0-120 h following initiation of oxaliplatin-based moderately emetic chemotherapy (MEC) compared to ondansetron and dexamethasone alone.. Patients with colorectal cancer received either casopitant or placebo intravenously (IV) added to ondansetron 8 mg bid oral on study days 1 to 3 and one dose of dexamethasone 8 mg IV given prior to starting the oxaliplatin on day 1. The primary endpoint was the percentage of subjects achieving complete response (CR; no vomiting/retching or use of rescue medication) during 120 h after initiation of chemotherapy in cycle 1.. No difference in the rate of CR was noted in the casopitant group compared to the placebo group for the overall (placebo 85%, casopitant 86%, p = 0.7273), acute (placebo 96%, casopitant 97%), or delayed phases (placebo 85%, casopitant 86%). The average area under curve (0-∞) of casopitant after a single 90-mg IV dose was 8,390 ng h/mL. At 24 h after casopitant 90-mg IV dosing, the plasma casopitant concentration was 24% lower than the values noted in prior studies with 150 mg oral administration, and the plasma exposure of the major metabolite (GSK525060) was 18% lower.. Addition of single-dose casopitant 90 mg IV did not improve the control of CINV at any time during 120 h following initiation of oxaliplatin-based MEC. Excellent control of CINV was achieved in this study population with the combination of ondansetron and dexamethasone alone.

Topics: Aged; Antiemetics; Antineoplastic Combined Chemotherapy Protocols; Area Under Curve; Colorectal Neoplasms; Dexamethasone; Double-Blind Method; Drug Therapy, Combination; Female; Humans; Infusions, Intravenous; Male; Middle Aged; Nausea; Ondansetron; Organoplatinum Compounds; Oxaliplatin; Piperazines; Piperidines; Time Factors; Treatment Outcome; Vomiting

The neurokinin-1 receptor antagonist, casopitant, is a weak-to-moderate inhibitor of cytochrome P450 isoenzyme 3A4 (CYP3A) and has the potential to inhibit the metabolism of CYP3A substrates such as docetaxel.. Fourteen cancer patients were enrolled in this phase 1, open-label, randomized, two-period crossover study. Intravenous (i.v.) docetaxel was coadministered with oral ondansetron and dexamethasone with (Regimen B) or without (Regimen A) 150 mg single-dose oral casopitant.. The geometric least-squares mean Regimen B: Regimen A ratios (90% confidence interval) for docetaxel maximum plasma concentration and area under the concentration-time curve from time 0 extrapolated to infinity were 0.97 (0.83, 1.12) and 1.06 (0.94, 1.19), respectively. Coadministration of casopitant and docetaxel was well tolerated, with adverse event profiles and absolute neutrophil count nadirs similar for both treatments.. C(max) and AUC of docetaxel were similar when given as monotherapy or when given in combination with casopitant. Likewise, absolute neutrophil count nadirs were similar for docetaxel alone or docetaxel with casopitant.

Topics: Aged; Aged, 80 and over; Antiemetics; Antineoplastic Agents; Area Under Curve; Cross-Over Studies; Cytochrome P-450 CYP3A; Cytochrome P-450 CYP3A Inhibitors; Dexamethasone; Docetaxel; Drug Therapy, Combination; Enzyme Inhibitors; Female; Humans; Least-Squares Analysis; Leukocyte Count; Male; Middle Aged; Neoplasms; Neurokinin-1 Receptor Antagonists; Neutrophils; Ondansetron; Piperazines; Piperidines; Taxoids

Postoperative nausea and vomiting (PONV) are associated with a variety of complications. Neurokinin subtype 1 receptor antagonists have antiemetic activity in the postoperative setting, and the neurokinin subtype 1 receptor antagonist casopitant mesylate (GW679769) was well tolerated and effective at reducing the incidence of PONV in phase 1 and phase 2 trials.. A multicenter, randomized, double-blind, parallel-group, phase 3 analysis was designed to evaluate the safety and efficacy of casopitant in combination with a single intravenous dose of the serotonin subtype 3 receptor antagonist ondansetron hydrochloride for the prevention of PONV in the perioperative setting.. Forty-three centers in 11 countries.. We studied 484 women at high risk for developing PONV scheduled to undergo operations associated with high emetogenic risk.. The women were randomized to receive a single dose of intravenous ondansetron, 4 mg, or oral casopitant, 50 mg, in combination with intravenous ondansetron, 4 mg.. The primary end point was the proportion of patients who achieved a complete response, defined as no vomiting, retching, or rescue therapy. Patients received a balanced anesthetic regimen.. Between March 20 and August 31, 2006, 484 patients were enrolled in the study. Patients in the casopitant plus ondansetron group had a 68.7% rate of complete response during the first 24 hours after surgery compared with 58.7% in the ondansetron-only group (P = .03). The difference between groups in complete response from 24 to 48 hours (63.4% with ondansetron only vs 70.0% with ondansetron plus casopitant) was not significant. No vomiting for 0 to 24 hours was observed in 89.7% of the casopitant plus ondansetron group compared with 74.9% of the ondansetron-only group (P < .001). Oral casopitant administered in combination with ondansetron was well tolerated.. The results of this pivotal phase 3 study demonstrate that the combination of casopitant and ondansetron was superior to ondansetron only in patients at high risk for PONV. Trial Registration clinicaltrials.gov Identifier: NCT00326248.

Topics: Administration, Oral; Adolescent; Adult; Aged; Aged, 80 and over; Antiemetics; Dose-Response Relationship, Drug; Double-Blind Method; Female; Follow-Up Studies; Humans; Incidence; Injections, Intravenous; Middle Aged; Neurokinin-1 Receptor Antagonists; Ondansetron; Piperazines; Piperidines; Postoperative Care; Postoperative Nausea and Vomiting; Retrospective Studies; Risk Factors; Treatment Outcome; United States; Young Adult

Clinical study results for neurokinin (NK) receptor antagonists in the treatment of depression have been mixed, with Phase III studies failing to fulfill the early promise demonstrated in Phase II studies. Casopitant, a selective NK1 antagonist that achieves nearly complete receptor occupancy was studied in 2 randomized, placebo-controlled, double-blind, Phase II trials in depressed outpatients to test the hypothesis that nearly complete NK1 receptor occupancy is required to achieve antidepressant efficacy. Study 092 used an interactive voice response system to recruit depressed patients with baseline Hamilton Depression (17-item, HAMD17) total scores higher than 24 who were randomized to fixed-dose casopitant 30 mg/d, 80 mg/d, or placebo for 8 weeks (n = 356). Study 096 required Carroll Depression Scale-Revised self-assessment scores of higher than 24 for randomization to casopitant 120 mg/d, paroxetine 30 mg/d (both reached via forced titration), or placebo for 8 weeks (n = 362). In study 092, casopitant 80 mg but not 30 mg achieved statistically significant improvement versus placebo on the primary outcome measure, week 8 last observation carried forward change from baseline HAMD17 (difference = -2.7; 95% confidence interval, -5.1 to -0.4, P = 0.023). In study 096, neither casopitant nor paroxetine achieved statistical separation from placebo at end point on HAMD17 (casopitant difference = -1.7; 95% CI, -3.8 to 0.4, P = 0.282). Casopitant and paroxetine were generally well tolerated in most patients. These studies suggest that NK1 antagonists that have nearly complete receptor occupancy may be effective in the treatment of depression.

Topics: Adult; Antidepressive Agents, Second-Generation; Depressive Disorder, Major; Dose-Response Relationship, Drug; Double-Blind Method; Female; Humans; Male; Middle Aged; Neurokinin-1 Receptor Antagonists; Paroxetine; Piperazines; Piperidines; Psychiatric Status Rating Scales; Treatment Outcome

The control of chemotherapy-induced nausea and vomiting (CINV) is critical in preventing poor health outcomes and increasing patient quality of life. The objective of this study was to evaluate the impact of the addition of casopitant to dual-combination therapy of dexamethasone and ondansetron on quality of life in patients receiving highly emetogenic chemotherapy (HEC).. In a multicenter, double-blind, randomized, placebo-controlled, add-on trial (N = 810), patients were randomized to intravenous (IV) ondansetron/dexamethasone alone (control) or in combination with either a single 150-mg oral dose of casopitant or 3-day IV/oral casopitant. Quality of life was assessed as impact of nausea and vomiting on daily life using the Functional Living Index Emesis (FLIE) questionnaire. Patients completed the FLIE questionnaire at baseline prior to receiving chemotherapy and after completion of the first cycle of HEC.. Patients in the single oral dose and 3-day IV/oral casopitant groups scored higher mean total FLIE scores (115.7 and 114.0, respectively; p ≤ 0.0332) than patients in the control group (107.5), indicating that casopitant patients experienced less impact from nausea and vomiting on daily life. The overall absolute difference in the proportion of patients reporting CINV with no impact on daily life between the single oral casopitant group and the control group was 13%; the difference between the 3-day IV/oral casopitant group and the control group was 14%.. The addition of casopitant to ondansetron and dexamethasone in patients receiving HEC was significantly more effective in reducing the impact of nausea and vomiting on all daily life activities as assessed by the FLIE compared with ondansetron/dexamethasone dual therapy.

Topics: Activities of Daily Living; Administration, Oral; Adult; Aged; Aged, 80 and over; Antiemetics; Antineoplastic Agents; Dexamethasone; Double-Blind Method; Drug Therapy, Combination; Female; Humans; Male; Middle Aged; Nausea; Neoplasms; Ondansetron; Piperazines; Piperidines; Quality of Life; Surveys and Questionnaires; Vomiting; Young Adult

Casopitant, an antiemetic, is a neurokinin-1 receptor antagonist metabolized primarily by cytochrome P450 3A4 (CYP3A4). Three phase 1 studies with 131 healthy subjects examined the impact of a strong CYP3A inhibitor (ketoconazole) and inducer (rifampin) on the pharmacokinetics and safety of casopitant. Oral casopitant was administered alone (study 1, 100-mg single dose; study 2, 150 mg on day 1, 50 mg on days 2 and 3; study 3, 150-mg single dose) with either 400 mg daily of oral ketoconazole or 600 mg daily of oral rifampin. Ketoconazole increased the maximum observed plasma concentration (C(max)) and area under the plasma concentration time curve to the last sampling time, t (AUC(0-t)) of single-dose casopitant 2.7-fold and 12-fold and increased the C(max) of 3-day casopitant 2.5-fold on day 1 and 2.9-fold on day 3, whereas AUC((0-tau)) increased 4.3-fold on day 1 and 5.8-fold on day 3. Neither safety signals nor prolongation of Fredericia-corrected QT was observed at these increased exposures in study 2. Repeat-dose rifampin reduced the C(max) and AUC((0-t)) of casopitant 96% and 90%, respectively. These clinical studies confirmed the role of CYP3A in the metabolism and disposition of casopitant. Coadministration of casopitant with strong inhibitors of CYP3A is likely to increase plasma exposure of casopitant, whereas coadministration with strong inducers of CYP3A is likely to decrease casopitant exposure and compromise efficacy.

Topics: Adolescent; Adult; Antiemetics; Area Under Curve; Cytochrome P-450 CYP3A Inhibitors; Electrocardiography; Enzyme Induction; Humans; Ketoconazole; Middle Aged; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Rifampin; Young Adult

Casopitant, a novel NK-1 receptor antagonist under investigation for the prevention of postoperative and chemotherapy-induced nausea and vomiting, is a weak to moderate inhibitor of CYP3A and a moderate inducer of CYP2C9 in vitro. Furthermore, both CYP enzymes are involved in the metabolism of R- and S-warfarin, respectively. This clinical study was conducted to explore the potential drug-drug interaction between casopitant and warfarin. In total, 97 healthy participants were enrolled and 54 completed the study. Participants received individualized daily dosing of warfarin to an international normalized ratio (INR) of 1.3 to 2.3 over a 14-day period (period 1). Immediately following period 1, participants entered period 2 and were randomized to receive either regimen A (oral casopitant [150 mg day 1, 50 mg days 2 and 3] and warfarin [days 1-10]) or regimen B (oral casopitant 60 mg and warfarin [days 1-14]). INR assessments were performed daily. The steady-state C(max) and AUC of R- and S-warfarin were not altered by regimen A, but R-warfarin AUC was increased 1.31-fold (90% confidence interval [CI]: 1.22, 1.41), and S-warfarin AUC was increased 1.27-fold (90% CI: 1.18, 1.38) on day 14 in regimen B. Steady-state INR values were not affected by either casopitant regimen.

Topics: Administration, Oral; Adolescent; Adult; Aged; Anticoagulants; Antiemetics; Area Under Curve; Cytochrome P-450 CYP2D6; Cytochrome P-450 CYP3A; Cytochrome P-450 CYP3A Inhibitors; Dose-Response Relationship, Drug; Drug Interactions; Female; Humans; International Normalized Ratio; Male; Middle Aged; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Stereoisomerism; Time Factors; Warfarin; Young Adult

In recent years, there has been an increased interest in using a multimodal approach with combined agents to treat postoperative nausea and vomiting. This study evaluated whether the addition of an oral dose of the neurokinin-1 receptor antagonist casopitant improved the antiemetic efficacy of an intravenous dose of ondansetron hydrochloride.. The authors enrolled 702 premenopausal or perimenopausal, nonsmoking, female patients aged 18-55 yr with a history of postoperative nausea and vomiting and/or motion sickness undergoing a laparoscopic or laparotomic gynecologic surgical procedure or laparoscopic cholecystectomy with general anesthesia. Subjects were randomized to one of five treatment arms: standard ondansetron 4 mg with casopitant at 0, 50, 100, or 150 mg, or 0 mg ondansetron with casopitant at 150 mg (the latter arm was considered an exploratory study group and was included in the safety analysis but not in the efficacy analysis).. A significantly greater proportion of patients in all of the active casopitant plus ondansetron groups achieved a complete response (i.e., no vomiting, retching, rescue medication, or premature withdrawal) during the first 24 h postoperatively versus those in the ondansetron-alone group (59-62% vs. 40%, respectively; P = 0.0006). All active doses seemed to be well tolerated; headache, dizziness, and constipation were the most frequently reported adverse events.. Compared with ondansetron alone, the casopitant and ondansetron combination results in superior emesis prevention during the first 24 h postoperatively in female patients with known risk factors for postoperative nausea and vomiting.

Topics: Administration, Oral; Adolescent; Adult; Anesthesia, General; Antiemetics; Cholecystectomy, Laparoscopic; Constipation; Dizziness; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Female; Gynecologic Surgical Procedures; Headache; Humans; Middle Aged; Neurokinin-1 Receptor Antagonists; Ondansetron; Piperazines; Piperidines; Postoperative Nausea and Vomiting; Risk Factors; Treatment Outcome; Young Adult

Drug rechallenge (or reinitiation), following an event of drug-induced liver injury, is associated with 13% mortality in prospective series. Rechallenge generally results in much more rapid injury than the initial liver event. The neurokinin-1 antagonist casopitant or its placebo was administered cyclically with ondansetron and dexamethasone in two randomized chemotherapy-induced nausea and vomiting clinical trials in nearly 3000 subjects. Grade 3 ALT elevations were observed in up to 2% of subjects receiving casopitant or placebo treatment. Similar rates of positive rechallenge were observed in the casopitant 8/29 (28%) and placebo groups 2/8 (25%), with no Grade 4 ALT elevations, hypersensitivity or liver-related serious adverse events. Publishing available rechallenge data (positive and negative) will advance our clinical understanding. Rechallenge should only be considered when the potential drug benefit exceeds the risk.

Topics: Administration, Oral; Antiemetics; Antineoplastic Agents; Dexamethasone; Dose-Response Relationship, Drug; Female; Humans; Male; Nausea; Neurokinin-1 Receptor Antagonists; Ondansetron; Piperazines; Piperidines; Serotonin Antagonists; Vomiting

Pharmacokinetic interactions between casopitant (a substrate and weak to moderate inhibitor of CYP3A), dexamethasone (a substrate and weak inducer of CYP3A), and ondansetron (a mixed CYP substrate) were evaluated in a two-part, three-period, single-sequence study in two groups of healthy subjects.. Part 1: subjects received oral casopitant (regimen A); oral dexamethasone and IV ondansetron (regimen B); and oral casopitant, a reduced dose of oral dexamethasone, and IV ondansetron (regimen C). Part 2: subjects received oral casopitant (regimen D); IV dexamethasone and oral ondansetron (regimen E); and oral casopitant, IV dexamethasone, and oral ondansetron (regimen F). Each regimen was separated by 14 days.. Casopitant AUC in regimen C was increased 28% on day 1 but decreased 34% on day 3 compared to casopitant alone in regimen A. When given with casopitant and ondansetron in regimen C, dexamethasone AUC was 17% lower on day 1, but similar on day 3, compared to regimen B (representing dose-normalized increases in exposure of 39% and 108%, respectively). Ondansetron exposure was equivalent in regimens B and C. Casopitant AUC in regimen F was similar to regimen D on days 1 and 3. Dexamethasone AUC increased 21% when given with oral casopitant and oral ondansetron (regimen F compared to regimen E). Ondansetron exposure was equivalent in regimens E and F.. When repeat-dose oral dexamethasone is to be coadministered with oral casopitant, a reduction in dexamethasone dose may be considered; however, no change in casopitant dose is required. Ondansetron exposure was not affected by coadministration with casopitant.

Topics: Adolescent; Adult; Antiemetics; Dexamethasone; Drug Therapy, Combination; Drug-Related Side Effects and Adverse Reactions; Female; Humans; Male; Middle Aged; Nausea; Neurokinin-1 Receptor Antagonists; Ondansetron; Piperazines; Piperidines; Vomiting; Young Adult

The objective of this study was to characterize the impact of casopitant, a novel neurokinin-1 receptor antagonist under investigation for the prevention of postoperative and chemotherapy-induced nausea and vomiting, on the pharmacokinetics of the commonly prescribed 5-hydroxytryptamine receptor 3 receptor antagonists, dolasetron or granisetron.. In a phase I, open-label, two-part, two-period, single-sequence study, two cohorts of healthy subjects received either oral dolasetron (100 mg once daily for 3 days) or oral granisetron (2 mg once daily for 3 days) alone (period 1) and combined with oral casopitant, 150 mg day 1, 50 mg days 2 and 3 (period 2). Pharmacokinetics of hydrodolasetron and granisetron were assessed on days 1 and 3 of each period. Log-transformed area under the curve (AUC) and Cmax were statistically analyzed by performing an analysis of variance. Eighteen subjects were enrolled in the dolasetron cohort; nine subjects were CYP2D6 extensive metabolizers (EMs) and nine subjects were CYP2D6 poor metabolizers. Nineteen subjects were enrolled in the granisetron cohort.. The largest changes in hydrodolasetron exposure after coadministration with casopitant were seen in CYP2D6 EMs, with a 24% increase in hydrodolasetron AUC on day 1 and 30% increase in Cmax on days 1 and 3. All other changes in hydrodolasetron exposure were <20%, and granisetron exposure was not altered to any relevant extent (<11%).. None of the changes observed are considered clinically meaningful, and coadministration of casopitant with dolasetron or granisetron was well tolerated.

Topics: Adolescent; Adult; Antiemetics; Drug Therapy, Combination; Drug-Related Side Effects and Adverse Reactions; Female; Granisetron; Humans; Indoles; Male; Middle Aged; Nausea; Piperazines; Piperidines; Quinolizines; Vomiting; Young Adult

Casopitant [1-piperidinecarboxamide,4-(4-acetyl-1-piperazinyl)-N-((1R)-1-(3,5-bis(trifluoromethyl)phenyl)-ethyl)-2-(4-fluoro-2-methylphenyl)-N-methyl-(2R,4S)-(GW679769)] is a novel neurokinin-1 receptor antagonist being developed for the prevention of chemotherapy-induced and postoperative nausea and vomiting. The disposition of [(14)C]casopitant was determined in a single-sequence study in six healthy male subjects after single-dose 90-mg i.v. and 150-mg oral administration. Blood, urine, and feces were collected at frequent intervals after dosing. Plasma, urine, and fecal samples were analyzed by high-performance liquid chromatography/mass spectrometry coupled with off-line radiodetection for metabolite profiling. Moreover, urine was also analyzed with (1)H-NMR to further characterize metabolites. Plasma pharmacokinetic parameters for casopitant, a major metabolite (M13, coded as GSK525060), and total radioactivity were determined. Absorption of radioactivity after oral administration appeared to be nearly complete; elimination was principally via the feces both after oral and intravenous administration. Urinary elimination accounted for only <8% of total radioactivity. The main circulating metabolites were a hydroxylated derivative, M13 (coded as GSK525060), and, after oral administration, a deacetylated and oxidized metabolite, M12 (coded as GSK631832). In addition, many other metabolites were identified in plasma and excreta: the principal route of metabolism included multiple oxidations, loss of the N-acetyl group, modifications or loss of the piperazine group, and cleavage of the molecule. Casopitant was extensively metabolized, and only negligible amounts were excreted as unchanged compound. Some phase II metabolites were also observed, particularly in urine.

Topics: Acetylation; Administration, Oral; Adult; Antiemetics; Biological Availability; Biotransformation; Carbon Radioisotopes; Chromatography, High Pressure Liquid; Feces; Humans; Hydroxylation; Infusions, Intravenous; Magnetic Resonance Spectroscopy; Male; Metabolomics; Middle Aged; Oxidation-Reduction; Piperazines; Piperidines; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Tissue Distribution

Chemotherapy-induced nausea and vomiting (CINV) remains a clinical management problem after treatment with highly emetogenic chemotherapy (HEC). We therefore designed and carried out a multicentre, randomised, double-blind, placebo-controlled trial to assess whether a three-drug antiemetic regimen of ondansetron, dexamethasone, and the neurokinin-1-receptor antagonist casopitant mesylate was able to prevent acute and delayed CINV events in patients naive to chemotherapy with a malignant solid tumour who were scheduled to receive cisplatin-based HEC regimens.. The study was done between Nov 6, 2006, and Oct 9, 2007, in 77 participating centres in 22 countries. All 810 patients enrolled in the trial received dexamethasone and ondansetron. Patients were randomly assigned to also receive placebo (n=269), single oral dose of casopitant mesylate (150 mg oral, n=271), or 3-day intravenous plus oral casopitant mesylate (90 mg intravenous on day 1 plus 50 mg oral on days 2 and 3, n=270). Randomisation was done using a central telephone system at the study level, because some centres were expected to recruit only a few patients during the study period. The primary endpoint was the proportion of patients achieving complete response (no vomiting, retching, or use of rescue medications) in the first 120 h after receiving HEC. Efficacy analysis was done on the modified intention-to-treat population (n=800), which included all patients who received placebo or study drug and HEC (n=265 control, n=266 single-dose oral casopitant mesylate, n=269 3-day intravenous and oral casopitant mesylate). Safety was reported in 802 patients who received either placebo or study medication. This study is registered with ClinicalTrials.gov, NCT00431236.. Significantly more patients in each casopitant group achieved complete response in cycle 1 of HEC treatment than did those in the control group (175 [66%] patients in the control group, 228 [86%] in the single-dose oral casopitant mesylate group [p<0.0001 vs control], and 214 [80%] in the 3-day intravenous plus oral casopitant mesylate group (p=0.0004 vs control]). This improvement was sustained over multiple cycles of HEC. Adverse events occurred in 205 (77%) patients in the single-dose oral casopitant mesylate group and 203 (75%) patients in the 3-day intravenous and oral casopitant mesylate group compared with 194 (73%) of patients in the control group. The most common serious adverse events were neutropenia (n=5 [3%] in the control group, n=3 [1%] in the single-dose oral casopitant mesylate group, and n=11 [4%] in the 3-day intravenous plus oral casopitant mesylate group), febrile neutropenia (n=1 [<1%] in the control group, n=4 [1%] in the single-dose oral casopitant mesylate group, and n=6 [2%] in the 3-day intravenous plus oral casopitant mesylate group), and dehydration (n=4 [2%] in the control group, n=2 [<1%] in the single-dose oral casopitant mesylate group, and n=1 [<1%] in the 3-day intravenous plus oral casopitant mesylate group).. A three-drug regimen including a single oral dose or 3-day intravenous plus oral regimen of casopitant mesylate plus dexamethasone and ondansetron significantly reduced CINV events in patients receiving HEC compared with a two-drug regimen of dexamethasone and ondansetron.. GlaxoSmithKline.

Topics: Administration, Oral; Adolescent; Adult; Aged; Aged, 80 and over; Antiemetics; Antineoplastic Agents; Cisplatin; Double-Blind Method; Drug Therapy, Combination; Female; Humans; Infusion Pumps; Male; Middle Aged; Molecular Structure; Nausea; Neoplasms; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Vomiting; Young Adult

Casopitant mesylate is a novel, oral neurokinin-1 receptor antagonist with demonstrated antiemetic efficacy. We conducted a randomized, double-blind, controlled phase II trial to evaluate three casopitant doses as part of a triple-therapy regimen for the prevention of nausea and vomiting associated with high-dose cisplatin. The aim of the study was to detect a dose response.. A total of 493 patients with solid tumors receiving a first cycle of cisplatin > or =70 mg/m(2) were randomly assigned among six treatment arms. The primary analysis compared a control arm [ondansetron/dexamethasone (Ond/Dex)] with three investigational treatments (Ond/Dex plus oral casopitant 50, 100, or 150 mg administered daily for 3 days). Two exploratory arms were included: one evaluating a single oral casopitant dose of 150 mg added to standard Ond/Dex and another with 3-day oral aprepitant-based therapy (Ond/Dex plus aprepitant 125 mg day 1, 80 mg days 2-3).. The complete response (CR) rate (defined as no vomiting, retching, rescue therapy, or premature discontinuation) was significantly increased in each casopitant arm relative to control over the 120-h evaluation period: 76% (50 mg), 86% (100 mg), 77% (150 mg), and 60% with control (P = 0.0036). The CR rate for the single oral dose regimen was similar to the CR rate reported for the 3-day regimens. No differences were observed in the incidence of nausea or significant nausea among groups in the primary analysis. The most common adverse events related to treatment included headache (n = 10) and hiccups (n = 14).. All doses of oral casopitant as a 3-day regimen (and likely as a 150-mg single oral dose) in combination with Ond/Dex provided significant improvement in the prevention of cisplatin-induced emesis.

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Antiemetics; Antineoplastic Agents; Cisplatin; Dexamethasone; Double-Blind Method; Drug Therapy, Combination; Female; Humans; Male; Middle Aged; Nausea; Neoplasms; Neurokinin-1 Receptor Antagonists; Ondansetron; Piperazines; Piperidines; Receptors, Neurokinin-1; Vomiting

The purpose of this phase III trial was to evaluate the efficacy and safety of regimens containing casopitant, a novel neurokinin-1 receptor antagonist, for the prevention of chemotherapy-induced nausea and vomiting during the first cycle in patients receiving moderately emetogenic chemotherapy (MEC).. Predominantly female patients (98%) diagnosed with breast cancer (96%) who were chemotherapy-naïve and scheduled to receive an anthracycline and cyclophosphamide (AC) -based regimen were enrolled onto this multinational, randomized, double-blind, parallel-group, placebo-controlled clinical trial. All patients received dexamethasone 8 mg intravenously (IV) on day 1 and oral ondansetron 8 mg twice daily on days 1 to 3. Patients were randomly assigned to a control arm (placebo), a single oral dose casopitant arm (150 mg orally [PO] on day 1), a 3-day oral casopitant arm (150 mg PO on day 1 plus 50 mg PO on days 2 to 3), or a 3-day IV/oral casopitant arm (90 mg IV on day 1 plus 50 mg PO on days 2 to 3). The primary end point was the proportion of patients achieving complete response (no vomiting/retching or rescue medications) in the first 120 hours after the initiation of MEC.. A significantly greater proportion of patients in the single-dose oral casopitant arm, 3-day oral casopitant arm, and 3-day IV/oral casopitant arm achieved complete response (73%, 73%, and 74%, respectively) versus control (59%; P < .0001). The study did not demonstrate a reduced proportion of patients with nausea or significant nausea in those receiving casopitant. Adverse events were balanced among study arms.. All casopitant regimens studied were more effective than the control regimen. Casopitant was generally well tolerated.

Topics: Administration, Oral; Alopecia; Anthracyclines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Constipation; Cyclophosphamide; Dexamethasone; Double-Blind Method; Drug Therapy, Combination; Female; Headache; Humans; Injections, Intravenous; Kaplan-Meier Estimate; Male; Middle Aged; Nausea; Neoplasms; Neurokinin-1 Receptor Antagonists; Neutropenia; Ondansetron; Piperazines; Piperidines; Treatment Outcome; Vomiting

This randomized, double-blind, dose-ranging, placebo-controlled, phase 2 trial evaluated the neurokinin-1 receptor antagonist casopitant mesylate in combination with ondansetron/dexamethasone (ond/dex) for the prevention of chemotherapy-induced nausea and vomiting (CINV) related to moderately emetogenic chemotherapy (MEC).. Chemotherapy-naive patients who were receiving MEC (N=723) were randomized to receive either oral placebo or casopitant at doses of 50 mg, 100 mg, or 150 mg daily (on Days 1-3) plus ondansetron (on Days 1-3) and dexamethasone (Day 1). Two exploratory arms evaluated single-dose casopitant (150 mg) plus ond/dex and a 3-day casopitant regimen with once-daily ondansetron and dexamethasone. Primary endpoints were rates of complete response (CR) (no vomiting, retching, rescue therapy, or premature discontinuation) and significant nausea (SN) (>or=25 mm on a visual analog scale) over the first 120 hours after Cycle 1 of MEC. Secondary endpoints included acute and delayed CR and SN rates, rates of nausea, vomiting, and safety.. All casopitant doses that were tested significantly increased the proportion of patients with CR: The CR rates were 80.8% with casopitant 50 mg, 78.5% with casopitant 100 mg, and 84.2% with casopitant 150 mg compared with 69.4% in the control group (P=.0127); casopitant 150 mg was identified as the minimally effective dose. In exploratory analyses, single-dose casopitant demonstrated a 79.2% CR rate, and once-daily ondansetron plus casopitant produced an 83.5% CR rate. Vomiting rates in the first 5 days after MEC were reduced with casopitant-containing regimens (from 23% to 10%-16%). Rates of SN did not differ among treatment arms (range, 28%-29%). Casopitant appeared to be well tolerated with no notable differences in overall adverse event frequency.. Casopitant plus ond/dex was more effective than ond/dex alone for the prevention of CINV.

Topics: Adult; Aged; Aged, 80 and over; Antiemetics; Antineoplastic Combined Chemotherapy Protocols; Dexamethasone; Double-Blind Method; Drug Administration Schedule; Female; Humans; Male; Middle Aged; Nausea; Neurokinin-1 Receptor Antagonists; Ondansetron; Piperazines; Piperidines; Vomiting

The last two decades have provided a large weight of preclinical data implicating the neurokinin-1 receptor (NK1) and its cognate ligand substance P (SP) in a broad range of both central and peripheral disease conditions. However, to date, only the NK1 receptor antagonist aprepitant has been approved as a therapeutic and this is to prevent chemotherapy-induced nausea & vomiting (CINV). The belief remained that the full therapeutic potential of NK1 receptor antagonists had yet to be realized; therefore clinical evidence that NK1 receptor antagonists may be effective in major depression disorder, resulted in a significant further investment in discovering novel CNS penetrant druggable NK1 receptor antagonists to address this condition. At GlaxoSmithKline after the discovery of casopitant, that went on to demonstrate efficacy as a novel antidepressant in the clinic, additional novel analogues of this NK1 receptor antagonist were designed to further enhance its drug developability characteristics. Herein, we therefore describe the discovery process and the vivo pharmacological and pharmacokinetic profile of the new NK1 receptor antagonist 3a (also called orvepitant), selected as clinical candidate and further progressed into clinical studies for major depressive disorder. Moreover, molecular modeling studies enabled us to improve the pharmacophore model of the NK1 receptor antagonists with the identification of a region able to accommodate a variety of heterocycle moieties.

Topics: Animals; Antidepressive Agents; Behavior, Animal; Bridged Bicyclo Compounds, Heterocyclic; CHO Cells; Cricetinae; Cricetulus; Dogs; Female; Gerbillinae; Half-Life; Humans; Male; Models, Molecular; Molecular Conformation; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Protein Binding; Rats; Receptors, Neurokinin-1

There is growing recognition of the importance of integrating drug occupancy data acquired by positron emission tomography (PET) with the plasma pharmacokinetics of the drug, in order to establish proper dose selection in subsequent clinical trials. Here we present a study in human subjects of the occupancy of NK(1) receptors achieved following different doses of casopitant, a selective NK(1) antagonist.. Two PET scans were carried out in each of eight human subjects, with the PET radioligand [(11)C]GR205171, a high-affinity and selective NK(1) receptor antagonist. The first scan was under baseline conditions and the second 24 h after a single oral dose of casopitant (2-120 mg). Arterial blood was collected throughout the scans for determination of plasma and whole blood input functions. Venous blood samples were taken prior to and following oral dosing up to 24 h for a pharmacokinetic study of casopitant concentration in plasma.. It was first necessary to establish a suitable kinetic model for the estimation of [(11)C]GR205171 NK(1) receptor binding parameters in human brain tissue. A three-tissue compartment model with simultaneous estimation of multiple regions sharing common variables across regions was found suitable for the analysis. Because of the injected cold mass of the tracer and the high affinity of [(11)C]GR205171 a correction for tracer occupancy effects was also incorporated into the analysis. We then developed a pharmacokinetic-receptor occupancy (PK-RO) model of the relationship between casopitant plasma concentrations and receptor binding, using a population approach.. These results indicate that after chronic dosing, casopitant can achieve a degree of NK(1) receptor occupancy higher than those that have previously been tested in studies of clinical depression.

Topics: Administration, Oral; Adult; Aged; Antiemetics; Carbon Isotopes; Depression; Humans; Kinetics; Male; Middle Aged; Piperazines; Piperidines; Positron-Emission Tomography; Receptors, Neurokinin-1; Tetrazoles; Time Factors

Casopitant is a potent and selective NK-1 receptor antagonist that has shown clinical efficacy in the prevention of chemotherapy-induced and postoperative-induced nausea and vomiting.. In an embryo-fetal development study, pregnant mice were given vehicle (sterile water) or doses of 30, 100, or 300 mg/kg/day casopitant on Gestation Day (GD) 6 to 15. Fetuses were evaluated for external, visceral, and skeletal abnormalities on GD 18. In a follow-on study to investigate casopitant-induced hormonal changes during the developmental period for palate formation, pregnant mice were given vehicle (sterile water) or 300 mg/kg/day casopitant once daily on GD 6 to 13. Blood was collected on GD 13 at various time-points for measurement of plasma adrenocorticotropic hormone and corticosterone (CRT) concentrations.. There was no evidence of developmental toxicity in mice at 30 or 100 mg/kg/day but 9% of fetuses at 300 mg/kg/day had cleft palate. Mice are sensitive to glucocorticoid-induced cleft palates, and NK-1 antagonists are known to modulate the hypothalamic-pituitary-adrenal axis leading to increases in corticosterone. On GD 13, mean plasma adrenocorticotropic hormone levels at 300 mg/kg/day were elevated by approximately twofold from vehicle-treated levels at 1 hr post-dose and mean plasma CRT levels were elevated by 3, 5, and 10-fold at 0.5, 1, and 2 hr post-dose, respectively.. The increased level of CRT was in the range previously shown in the literature to cause cleft palates in mice and was likely the underlying mechanism behind casopitant-induced cleft palate in mice.

Topics: Adrenocorticotropic Hormone; Animals; Cesarean Section; Cleft Palate; Corticosterone; Feeding Behavior; Female; Fetal Development; Mice; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Pregnancy; Receptors, Neurokinin-1; Weight Gain

The aggregation behaviour of casopitant mesylate, a new NK1 antagonist drug, was investigated by means of NMR spectroscopy and surface tension measurements. The critical micelle concentration (CMC) in glycine buffer at pH 3.5 was determined by analyzing the (1)H NMR chemical shifts variation and the surface tension in function of the concentration in a series of solutions. The temperature dependence of the CMC was also evaluated by NMR spectroscopy as well as the thermodynamic parameters contributing to the aggregation discussed. Surface tension measurements were conducted as well in the formulation conditions, e.g. in the presence of sodium chloride.

Topics: Chemistry, Pharmaceutical; Drug Design; Humans; Hydrogen-Ion Concentration; Magnetic Resonance Spectroscopy; Micelles; Models, Chemical; Neurokinin-1 Receptor Antagonists; Piperazine; Piperazines; Piperidines; Surface Properties; Technology, Pharmaceutical; Temperature; Thermodynamics

During late phase development of the selective NK1 receptor antagonist casopitant mesylate, a de-fluorinated impurity was discovered and quantified by an orthogonal analytical approach, using NMR and LC-MS. A dedicated (19)F NMR method was initially developed for first line identification and semi-quantification of the impurity. Subsequently, a more accurate quantification was achieved by means of a selective normal-phase LC-MS method, which was fully validated. The results obtained on the development batches of the drug substance were used by the project team to set up a suitable control strategy and ultimately to ensure patient safety and the progression of the project.

Topics: Chemistry Techniques, Analytical; Chemistry, Pharmaceutical; Chromatography, Liquid; Drug Contamination; Fluorine; Halogenation; Magnetic Resonance Spectroscopy; Mass Spectrometry; Models, Chemical; Pharmaceutical Preparations; Piperazines; Piperidines; Quality Control; Reproducibility of Results

Casopitant [1-piperidinecarboxamide,4-(4-acetyl-1-piperazinyl)-N-((1R)-1-(3,5-bis(trifluoromethyl)phenyl)-ethyl)-2-(4-fluoro-2-methylphenyl)-N-methyl-(2R,4S)] has been shown to be a potent and selective antagonist of the human neurokinin 1 receptor, the primary receptor for substance P. During long-term toxicity studies conducted in rat and dog, evidence of cardiomyopathy and increased cardiac weight were observed. The distribution and metabolism of casopitant were studied in both species evaluating the accumulation of drug-related material (DRM) after repeat dosing and its potential relationship with pathological findings observed in myocardium. After repeat oral administration of [(14)C]casopitant to rats (20 days) and dogs (14 days), DRM was quantifiable in all of the tissues examined with lung and liver containing the highest level of radioactivity. The concentration of radioactivity was significantly higher in tissues than in plasma, declining slowly and still quantifiable after a recovery period of 20 days. The principal circulating components identified in both species were casopitant, M12 (oxidized deacetylated), M13 (hydroxylated piperazine), and M31 and M134 (two N-dealkylated piperazines). In tissues, a similar metabolic pattern was observed, in which casopitant, M31, M134, M76 (N-deacetylated), and M200 (N-deacetylated N,N-deethylated) were the major components quantified. After a 26-week repeat dose study in dog, casopitant and M13 were the major circulating components, whereas in myocardium, M200 and M134 were the major ones and their levels increased over time, reaching considerable concentrations (millimolar magnitude). After a washout period, all circulating derivatives decreased to undetectable levels, whereas M200 was still the major component in myocardium. Overall DRM in plasma did not correlate with the respective concentrations in tissues.

Topics: Administration, Oral; Animals; Chemistry, Pharmaceutical; Chromatography, High Pressure Liquid; Dogs; Dose-Response Relationship, Drug; Female; Male; Molecular Structure; Myocardium; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Rats; Rats, Sprague-Dawley; Species Specificity; Tandem Mass Spectrometry; Tissue Distribution

Casopitant [1-piperidinecarboxamide,4-(4-acetyl-1-piperazinyl)-N-((1R)-1-(3,5-bis(trifluoromethyl)phenyl)-ethyl)-2-(4-fluoro-2-methylphenyl)-N-methyl-(2R,4S), GW679769] has previously been shown to be a potent and selective antagonist of the human neurokinin-1 receptor, the primary receptor of substance P, both in vitro and in vivo, with good brain penetration properties. On the basis of this mode of action it was evaluated for the prevention of chemotherapy-induced and postoperative nausea and vomiting, and for the chronic treatment of anxiety, depression, insomnia, and overactive bladder. Casopitant is shown to be a substrate, an inhibitor, and an inducer of CYP3A4, and, because of this complex behavior, it was difficult to identify the primary mechanism by which it may give rise to drug-drug interactions (DDIs) of clinical relevance. Moreover, the major circulating metabolite is itself an inhibitor of CYP3A4 in vitro. On the basis of the different clinical indications and the various potential comedications of casopitant, a relevant part of the clinical development plan was focused on the assessment of the importance of clinical DDIs. The present study provides an overview of the DDI potential profile of casopitant, based on in vitro data and clinical evidence of its interaction with CYP3A4 probe substrates midazolam and nifedipine, the strong inhibitor ketoconazole, and the inducer rifampin. Overall, the clinical data confirm the ability of casopitant to interact with CYP3A4 substrates, inhibitors, or inducers. The in vitro data are accurate and robust enough to build a reliable SimCyp population-based model to estimate the potential DDIs of casopitant and to minimize the clinical studies recommended.

Topics: Adult; Cells, Cultured; Computer Simulation; Cytochrome P-450 CYP3A; Cytochrome P-450 CYP3A Inhibitors; Drug Evaluation, Preclinical; Drug Interactions; Enzyme Induction; Enzyme Inhibitors; Female; Hepatocytes; Humans; Male; Metabolic Clearance Rate; Microsomes, Liver; Middle Aged; Models, Molecular; Neurokinin-1 Receptor Antagonists; Neurotransmitter Agents; Piperazines; Piperidines; Recombinant Proteins; Young Adult

Topics: Antiemetics; Dose-Response Relationship, Drug; Drug Therapy, Combination; Humans; Ondansetron; Piperazines; Piperidines; Postoperative Nausea and Vomiting; Treatment Outcome

A large body of compelling preclinical evidence supports the clinical use of neurokinin (NK) receptor antagonists in a plethora of CNS and non-CNS therapeutic areas. The significant investment made in this area over the past 2 decades culminated with the observation that NK(1) receptor antagonists elicited clinical efficacy in major depression disorders. In addition, aprepitant (Merck) was launched as a new drug able to prevent chemotherapy-induced nausea and vomiting (CINV). After the discovery by GlaxoSmithKline of vestipitant, a wide drug discovery program was launched aimed at identifying additional clinical candidates. New compounds were designed to maximize affinity at the NK(1) receptor binding site while retaining suitable physicochemical characteristics to ensure excellent pharmacokinetic and pharmacodynamic properties in vivo. Herein we describe the discovery process of a new NK(1) receptor antagonist (casopitant) selected as clinical candidate and progressed into clinical studies to treat major depression disorders.

Topics: Animals; Behavior, Animal; Brain; CHO Cells; Cricetinae; Cricetulus; Depressive Disorder; Drug Discovery; Gerbillinae; Half-Life; Humans; Magnetic Resonance Spectroscopy; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Regression Analysis; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry, Infrared; Stereoisomerism

Cardiovascular toxicity represents one of the major reasons for the termination of the development of drugs, even in late development phases. This growing issue is often not restricted to specific therapeutic areas, and it is gaining critical importance, in particular for chronically administered drugs, highlighting the limitations in terms of sensitivity of the current investigational paradigms. Furthermore, drug-related changes may become evident after long-term administration for different reasons, including accumulation of the drug in the heart. This article describes how the integrated use of investigational tools represents a powerful approach for the early identification and characterization of cardiotoxicity in preclinical development. Cardiac changes were observed in the dog after long-term oral administration of casopitant, a neurokinin 1 receptor antagonist, developed for the treatment of depression and anxiety. Different approaches and sensitive biomarkers were used in a time-course study to investigate the onset, progression, and reversibility of the lesion. The integrated evaluation of cardiovascular parameters, electron microscopy, troponin I, and natriuretic peptide results highlighted any minimal early changes, allowing the full and deep characterization of the lesion. The outcome of this study was the driver for drug development decision making on casopitant and backup drugs.

Topics: Administration, Oral; Animals; Biomarkers; Creatine Kinase, MB Form; Dogs; Drug Evaluation, Preclinical; Heart Diseases; Male; Microscopy, Electron, Transmission; Models, Animal; Myocardium; Natriuretic Peptide, Brain; Neurokinin-1 Receptor Antagonists; Peptide Fragments; Piperazines; Piperidines; Troponin I

The amino-terminal pro-brain natriuretic peptide (NT-proBNP) is released into the plasma predominantly from ventricular cardiomyocytes, particularly in patients with chronic cardiac diseases, although small amounts are detectable in the plasma of healthy subjects. While NT-proBNP has been widely exploited in human medicine, limited literature is available related to its characterization in veterinary medicine (e.g., correlation with damage and specificity) and, particularly, in the context of preclinical drug safety assessment. This paper describes the analytical performance characteristics and the biological variability of NT-proBNP in male beagle dogs by using a commercially available enzyme-linked immunosorbent assay. Male beagle dogs were treated with Casopitant, an NK1 receptor antagonist under development for depression and anxiety, which, when administered chronically to dogs, caused cardiac toxicity. Heart weight increase, myocardial necrosis, degeneration, and inflammation associated with high serum levels of cardiac troponin I characterized the end stage pathology observed in dogs treated orally at 40 mg/kg for 39 weeks. Based on these data, ad hoc studies were designed in order to evaluate the possible relationship between NT-proBNP serum levels and both standard toxicology endpoints, such as the organ weight and histology, as well as nonstandard endpoints such as macroscopic morphometry and echocardiography. Early changes of NT-proBNP serum levels were observed following 2 weeks of treatment onward, preceding most, if not all of the anatomical and functional changes. The results obtained demonstrate that NT-proBNP acts as an early biomarker of cardiac changes, representing a sensitive and predictive marker of drug-induced cardiac liability.

Topics: Administration, Oral; Animals; Antidepressive Agents; Anxiety Disorders; Biomarkers; Depression; Dogs; Drug Administration Schedule; Echocardiography; Enzyme-Linked Immunosorbent Assay; Heart Diseases; Humans; Male; Natriuretic Peptide, Brain; Neurokinin-1 Receptor Antagonists; Organ Size; Peptide Fragments; Piperazines; Piperidines; Predictive Value of Tests; Risk Factors; Troponin I

Casopitant [1-piperidinecarboxamide,4-(4-acetyl-1-piperazinyl)-N-((1R)-1-(3,5-bis(trifluoromethyl)phenyl)-ethyl)-2-(4-fluoro-2-methylphenyl)-N-methyl-(2R,4S)] is a potent and selective antagonist of the neurokinin-1 (NK1) receptor, developed for the prevention of chemotherapy-induced nausea and vomiting and postoperative nausea and vomiting. Absorption, distribution, metabolism, and elimination of [(14)C]casopitant have been investigated in the mouse, rat, and dog after single oral administration and compared with those in humans. [(14)C]Casopitant was rapidly absorbed in all three species: the maximum plasma concentration of radioactivity was generally observed 0.5 to 2 h after a single oral dose. In dog and female rat, as observed for humans, the principal circulating radiolabeled components were unchanged casopitant and its hydroxylated derivative M13. In rats, there was an evident sex-related difference in the rate of elimination of drug-related material with elimination being more rapid in males than in females. In dogs and mice, no notable sex differences were observed in the pattern of excretion. The elimination of drug-related radioactivity was largely by metabolism, with metabolites excreted primarily in the feces. The predominant route of metabolism was the oxidation of the parent molecule, observed together with loss of the N-acetyl group, N-demethylation, and modification of piperazine with consequent opening and cleavage of the ring, giving a complex pattern of metabolites. Conjugation of some of those oxidized products with glucuronic acid was observed. Urinary excretion in all three species was a minor route of elimination, accounting for between 2 and 7% of the dose, with unchanged parent drug never quantifiable.

Topics: Administration, Oral; Animals; Antiemetics; Chromatography, High Pressure Liquid; Dogs; Feces; Female; Humans; Inactivation, Metabolic; Male; Mice; Mice, Inbred Strains; Molecular Structure; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Rats; Rats, Sprague-Dawley; Species Specificity; Tandem Mass Spectrometry; Tissue Distribution

The introduction of Quality by Design (QbD) in Drug Development has resulted in a greater emphasis on chemical process understanding, in particular on the origin and fate of impurities. Therefore, the identification and quantitation of low level impurities in new Active Pharmaceutical Ingredients (APIs) play a crucial role in project progression and this has created a greater need for sensitive and selective analytical methodology. Consequently, scientists are constantly challenged to look for new applications of traditional analytical techniques. In this context a normal-phase liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) method was developed to determine the amount of a de-fluorinated analogue impurity in Casopitant Mesylate, a new API under development in GlaxoSmithKline, Verona. Normal-phase LC provided the selectivity needed between our target analyte and Casopitant, while a single quadrupole mass spectrometer was used to ensure the sensitivity needed to detect the impurity at <0.05%w/w. Standard solutions and samples were prepared in heptane/ethanol (50:50, v/v) containing 1% of 2 M NH(3) in ethanol; the mobile phase consisted of heptane/ethanol (95:5, v/v) with isocratic elution (flow rate: 1.0 mL/min, total run time: 23 min). To allow the formation of ions in solutions under normal-phase (apolar) conditions, a post-column infusion of a solution of 0.1% v/v of formic acid in methanol was applied (flow rate: 200 microL/min). The analysis was carried out in positive ion mode, monitoring the impurity by single ion monitoring (SIM). The method was fully validated and its applicability was demonstrated by the analysis of real-life samples. This work is an example of the need for selective and accurate methodology during the development of a new chemical entity in order to develop an appropriate control strategy for impurities to ultimately ensure patient safety.

Topics: Chromatography, Liquid; Drug Contamination; Drug Discovery; Halogenation; Piperazines; Piperidines; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization

To evaluate the impact of single and repeated doses casopitant on the pharmacokinetics of single dose midazolam and nifedipine (CYP3A substrates) in healthy subjects. The effect on debrisoquine metabolism (CYP2D6 substrate) was also assessed.. Three open-label studies were conducted in healthy subjects. In the first study subjects received single dose 50 or 100 mg oral casopitant, single dose 5 mg oral midazolam and single dose 10 mg oral debrisoquine. In the other two studies subjects received repeated doses of 10 mg (study 2), 30, or 120 mg oral casopitant and single doses of 5 mg oral midazolam (study 2) and single doses of 10 mg oral nifedipine (study 3). Plasma concentration-time data were analyzed using standard non-compartmental methods. The effect of casopitant on all probes was assessed using geometric means ratios and corresponding 90% confidence intervals (CIs).. The AUC(0,∞) of midazolam was increased 1.44-fold (90% CI 1.35, 1.54) and 1.52-fold (90% CI 1.41, 1.65) after co-administration with a single dose of 50 or 100 mg casopitant, respectively. Debrisoquine metabolism was unchanged. After 3 days of casopitant administration, midazolam AUC(0,∞) was increased 1.45- (90% CI 1.32, 1.59), 2.02- (90% CI 1.75, 2.32), and 2.67-fold (90% CI 2.18, 3.27) after co-administration with 10, 30 or 120 mg casopitant, respectively. After 14 days of casopitant administration, midazolam AUC(0,∞) was increased 1.51- (90% CI 1.40, 1.63) to 3.49-fold (90% CI 2.98, 4.08). After 3 days of casopitant administration, nifedipine AUC(0,∞) was increased 1.56- (90% CI 1.37, 1.78) and 1.77-fold (90% CI 1.54, 2.04) after co-administration with 30 or 120 mg casopitant, respectively. Similar increases in nifedipine exposure were observed after 14 days of casopitant administration.. Casopitant is a dose- and duration-dependent weak to moderate inhibitor of CYP3A.

Topics: Adult; Calcium Channel Blockers; Cohort Studies; Cytochrome P-450 Enzyme System; Dose-Response Relationship, Drug; Drug Interactions; Female; Humans; Hypnotics and Sedatives; Male; Midazolam; Middle Aged; Neurokinin-1 Receptor Antagonists; Nifedipine; Piperazines; Piperidines; Young Adult

A sensitive, selective and quantitative method for the simultaneous determination of casopitant, a potent and selective antagonist of the human Neurokinin 1 (NK-1) receptor, and its three major metabolites M12, M13 and M31 was developed and validated in dog and rat plasma. Acetonitrile containing stable labeled internal standards for the four analytes was used to precipitate proteins in plasma. Chromatographic separation was obtained using a reversed phase column with multiple reaction monitoring turboionspray positive ion detection. The lower and upper limits of quantification for casopitant and its metabolites were 15 and 15,000 ng/mL, using a 50 μL of dog or rat plasma aliquot, respectively. The inter-day precision (relative standard deviation) and accuracy (relative error) in dog plasma, derived from the analysis of validation samples at 5 concentrations, ranged from 4.1% to 10.0% and -10.8% to 8.7%, respectively, for casopitant and its 3 major metabolites. The intra-day precision (relative standard deviation) and accuracy (relative error) in rat plasma, derived from the analysis of validation samples at 5 concentrations, ranged from 3.9% to 6.6% and -9.6% to 8.3%, respectively, for casopitant and its three metabolites. All analytes were found to be stable in analytical solutions for at least 43 days at 4°C, in dog and rat plasma at room temperature for at least 24 h, at the storage temperature of -20°C for at least 6 months, and following the action of three freeze-thaw cycles from -20°C to room temperature. All analytes were also found to be stable in processed extracts at 4°C for at least 72 h. This assay proved to be accurate, precise, fast and was used to support long-term toxicology studies in dog and rat.

Topics: Animals; Chromatography, High Pressure Liquid; Dogs; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Rats; Tandem Mass Spectrometry

The pharmacokinetics and brain penetration of the novel neurokinin (NK)-1 receptor antagonist casopitant [1-piperidinecarboxamide, 4-(4-acetyl-1-piperazinyl)-N-((1R)-1-(3,5-bis(trifluoromethyl)phenyl)ethyl)-2-(4-fluoro-2-methylphenyl)-N-methyl-, (2R,4S)-; GW679769] were examined in ferrets. The ferret is known to respond to the full spectrum of agents recognized to induce emesis in humans, and the cisplatin-induced emesis models in the ferret have been used to establish the antiemetic potential of casopitant. Following single i.p. dosing to the ferret, casopitant was rapidly absorbed, with plasma and brain concentrations being approximately equal at 2 h postdose. The predominant radioactive component present in the ferret brain after a single dose of [(14)C]casopitant was parent compound, accounting for approximately 76% of the radioactivity. The major metabolites present in brain tissue following administration of [(14)C]casopitant were hydroxylated casopitant (M1) and the corresponding ketone product of the M1 metabolite (M2), which accounted for approximately 19 and 3% of the radioactivity in the brain extracts, respectively. All three molecules had relatively similar potency against ferret brain cortical NK-1, suggesting that the pharmacologic activity of casopitant in the ferret is largely attributable to parent compound and, to a lesser extent, to its oxidative metabolites. Because casopitant is intended to be administered in combination with ondansetron and because therapeutic synergy has been observed with this combination in the ferret, a drug interaction study was conducted. The additional pharmacodynamic benefit of the combination dose was not because of an alteration in the pharmacokinetics of either agent but is likely the result of the complementary mechanisms of pharmacologic action of the two drugs.

Topics: Animals; Area Under Curve; Biotransformation; Brain; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Ferrets; Male; Neurokinin-1 Receptor Antagonists; Piperazines; Piperidines; Tandem Mass Spectrometry