A phase 1 pharmacokinetic study of oral NEPA, the fixed combination of netupitant and palonosetron, in Chinese healthy volunteers.

PURPOSE: Oral NEPA, the only fixed-combination antiemetic, is composed of the neurokinin-1 receptor antagonist netupitant (300 mg) and the 5-hydroxytryptamine-3 receptor antagonist palonosetron (0.50 mg). This study was conducted to evaluate the pharmacokinetic profile of netupitant and its main metabolites M1 and M3, and palonosetron in Chinese subjects. Oral NEPA tolerability and safety were also analyzed. METHODS: This was a single-center, single-dose phase 1 study in healthy, adult Chinese volunteers. Eligible subjects received oral NEPA, and blood samples were collected on day 1 predose and at various time points up until day 10 postdose. Pharmacokinetic parameters were analyzed using noncompartmental methods. For safety assessments, adverse events (AEs) were monitored during the study. RESULTS: In total 18 Chinese healthy volunteers received oral NEPA. Netupitant mean maximum plasma concentration (Cmax) [± standard deviation] of 698 ± 217 ng/mL was reached at 3-6 h, with a mean total exposure (AUC0-inf) of 22,000 ± 4410 h·ng/mL. For palonosetron, a mean Cmax of 1.8 ± 0.252 ng/mL was reached at 2-6 h postadministration, with a mean AUC0-inf of 81.0 ± 14.0 h·ng/mL. The most common treatment-related AEs in > 2 subjects were constipation (n = 9) and tiredness (n = 3). No severe AEs were observed, and no subject withdrew due to AEs. CONCLUSION: Following single-dose administration of oral NEPA in Chinese subjects, the pharmacokinetic profiles of the NEPA components were mostly similar to those reported previously in Caucasians. NEPA was well tolerated with a safety profile in line with that observed in pivotal trials in Caucasians.

Extrapolation of Adult Efficacy to Pediatric Patients With Chemotherapy-Induced Nausea and Vomiting.

Chemotherapy-induced nausea and vomiting (CINV) is a common treatment-related adverse event that negatively impacts the quality of life of cancer patients. During pediatric drug development, extrapolation of efficacy from adult to pediatric populations is a pathway that can minimize the exposure of children to unnecessary clinical trials, improve efficiency, and increase the likelihood of success in obtaining a pediatric indication. The acceptability of the use of extrapolation depends on a series of evidence-based assumptions regarding the similarity of disease, response to intervention, and exposure-response relationships between adult and pediatric patients. This study evaluated publicly available summaries of data submitted to the US Food and Drug Administration for drugs approved for CINV to assess the feasibility of extrapolation for future development programs. Extracted data included trial design, emetogenic potential of chemotherapy, primary end points, participant enrollment criteria, and antiemetic pharmacokinetics. Adult and pediatric clinical trial designs for assessment of efficacy and safety shared key design elements. Antiemetic drugs found to be efficacious in adults were also efficacious in pediatric patients. Systemic drug concentrations at approved doses were similar for ondansetron, granisetron, and aprepitant, but an exposure-response analysis of palonosetron in children suggested that higher palonosetron systemic exposure is necessary for the prevention of CINV in the pediatric population. For 5-hydroxytryptamine-3 and neurokinin-1 receptor antagonist antiemetic drugs, efficacy in adults predicts efficacy in children, supporting the extrapolation of effectiveness of an antiemetic product in children from adequate and well-controlled studies in adult patients with CINV.

The safety of rolapitant for the treatment of nausea and vomiting associated with chemotherapy.

Introduction: Chemotherapy-induced nausea and vomiting is a significant clinical issue that affects patients' quality of life as well as treatment decisions. Significant improvements in the control of chemotherapy-induced nausea and vomiting have occurred in the past 15 years with the introduction of new antiemetic agents 5-HT3, receptor antagonists, neurokinin-1 receptor antagonists, and olanzapine. Oral (aprepitant, 2003; netupitant, 2014; rolapitant, 2015) neurokinin-1 receptor antagonists have been developed along with intravenous formulations (fosaprepitant, NEPA, rolapitant, HTX-019) for the prevention of chemotherapy-induced nausea and vomiting.Areas covered: This review presents a description of the safety and efficacy of rolapitant along with a comparison to the other oral and intravenous formulations of the neurokinin-1 receptor antagonists.Expert opinion: Oral rolapitant has been demonstrated in clinical trials to be safe and effective in controlling chemotherapy-induced nausea and vomiting in patients receiving moderately and highly emetogenic chemotherapy. Rolapitant has a longer half-life (180 h) than other commercially available NK-1 receptor antagonists and does not induce or inhibit CYP34A, unlike the other NK-1 receptor antagonists. Future studies may determine if these may be important clinical issues.

Timing flexibility of oral NEPA, netupitant-palonosetron combination, administration for the prevention of chemotherapy-induced nausea and vomiting (CINV).

PURPOSE: The administration timing of antiemetic and chemotherapeutic regimens is often determined by regulatory indications, based on registration studies. Oral NEPA, fixed combination of the neurokinin-1 receptor antagonist (NK1RA) netupitant and the 5-hydroxytryptamine-3 RA (5-HT3RA) palonosetron, is recommended to be administered approximately 60 min before chemotherapy. Reducing chair time for chemotherapy administration at oncology day therapy units would improve facility efficiency without compromising patient symptom management. The objective was to determine if oral NEPA can be administered closer to chemotherapy initiation without compromising patient symptom management. METHODS: NK1 receptor occupancy (NK1RO) time course in the brain was determined using positron emission tomography; netupitant and palonosetron plasma concentration-time profiles were described by pharmacokinetic (PK) models; and the rate, extent, and duration of RO by netupitant and palonosetron were predicted by pharmacodynamic modeling. Clinical efficacy data from a pivotal study in cisplatin and oral NEPA-receiving patients were reviewed in the context of symptom management. RESULTS: Striatal 90% NK1RO, assumed to correlate with NK1RA antiemetic efficacy, was predicted at netupitant plasma concentration of 225 ng/mL, reached at 2.23 h following NEPA administration. Palonosetron 90% 5-HT3RO was predicted at a 188-ng/L plasma concentration, reached at 1.05 h postdose. The mean time to first treatment failure for the 1.5% of NEPA-treated patients without complete response receiving highly emetogenic chemotherapy was 8 h. Antiemetic efficacy was sustained over 5 days despite the expected decrease of NK1RO and 5-HT3RO. CONCLUSIONS: Results suggest that administering oral NEPA closer to initiation of cisplatin administration would provide similar antiemetic efficacy. Prospective clinical validation is required.

Absorption, metabolism, and excretion of the antiemetic rolapitant, a selective neurokinin-1 receptor antagonist, in healthy male subjects.

Rolapitant is a neurokinin-1 receptor antagonist that is approved in combination with other antiemetic agents in adults for the prevention of delayed nausea and vomiting (CINV) associated with initial and repeat courses of emetogenic cancer chemotherapy, including but not limited to highly emetogenic chemotherapy. Here, we assessed the absorption, metabolism, and excretion of 14C-labeled rolapitant in healthy male subjects. Rolapitant was administered as a single 180-mg oral dose containing approximately 100 µCi of total radioactivity, with plasma, urine, and fecal samples collected at defined intervals after dosing. Rolapitant had a large apparent volume of distribution, indicating that it is widely distributed into body tissues. Rolapitant was slowly metabolized and eliminated with a mean half-life of 186 h. Exposure to the major metabolite of rolapitant, C4-pyrrolidinyl hydroxylated rolapitant or M19, was approximately 50% of rolapitant exposure in plasma. Renal clearance was not a significant elimination route for rolapitant-related entities. Total radioactivity recovered in urine accounted for 14.2% of the dose, compared to 72.7% recovery in feces. Adverse events (AEs) were generally mild; there were no serious AEs, and no clinically significant changes in laboratory or electrocardiogram parameters were observed. The combination of rolapitant safety, its long half-life, extensive tissue distribution, and slow elimination via the hepatobiliary route (rather than renal excretion) suggest suitability that a single dose of rolapitant may provide protection against CINV beyond the first 24 h after chemotherapy administration.

Complementary Pharmacokinetic Profiles of Netupitant and Palonosetron Support the Rationale for Their Oral Fixed Combination for the Prevention of Chemotherapy-Induced Nausea and Vomiting.

NEPA is the first fixed-combination antiemetic composed of the neurokinin-1 receptor antagonist netupitant (netupitant; 300 mg) and the 5-hydroxytryptamine-3 receptor antagonist palonosetron (palonosetron; 0.50 mg). This study evaluated the pharmacokinetic profiles of netupitant and palonosetron. The pharmacokinetic profiles of both drugs were summarized using data from phase 1-3 clinical trials. netupitant and palonosetron have high absolute bioavailability (63%-87% and 97%, respectively). Their overall systemic exposures and maximum plasma concentrations are similar under fed and fasting conditions. netupitant binds to plasma proteins in a high degree (>99%), whereas palonosetron binds to a low extent (62%). Both drugs have large volumes of distribution (cancer patients: 1656-2257 L and 483-679 L, respectively). netupitant is metabolized by cytochrome P450 3A4 to 3 major pharmacologically active metabolites (M1, M2, and M3). palonosetron is metabolized by cytochrome P450 2D6 to 2 major substantially inactive metabolites (M4 and M9). Both drugs have similar intermediate-to-low systemic clearances and long half-lives (cancer patients: netupitant, 19.5-20.8 L/h and 56.0-93.8 hours; palonosetron: 7.0-11.3 L/h and 43.8-65.7 hours, respectively). netupitant and its metabolites are eliminated via the hepatic/biliary route (87% of the administered dose), whereas palonosetron and its metabolites are mainly eliminated via the kidneys (85%-93%). Altogether, these data explain the lack of pharmacokinetic interactions between netupitant and palonosetron at absorption, binding, metabolic, or excretory level, thus highlighting their compatibility as the oral fixed combination NEPA, with administration convenience that may reduce dosing mistakes and increase treatment compliance.

HTX-019 via 2-min injection or 30-min infusion in healthy subjects.

AIM: HTX-019 (CINVANTI® [aprepitant injectable emulsion]) is a neurokinin 1 receptor antagonist approved for preventing acute and delayed chemotherapy-induced nausea and vomiting (CINV). HTX-019 is free of polysorbate 80 and other synthetic surfactants and showed bioequivalence to and a more favorable safety profile than fosaprepitant when administered as a 30-min infusion in healthy subjects. The shortage of small-volume parenteral solutions led to a recommendation to administer HTX-019 by intravenous push. The objectives were to evaluate pharmacokinetics, tolerability and safety following HTX-019 administration by injection versus infusion. MATERIALS & METHODS: Study comprised Part A, a pilot Phase I, single-center, randomized, pharmacokinetic, safety and tolerability, open-label study, followed by Part B, a two-sequence crossover study of HTX-019 130 mg in healthy adults, via injection and infusion. Blood samples were evaluated for aprepitant pharmacokinetics and bioequivalence. Safety evaluations included treatment-emergent adverse events (TEAEs), vital signs, clinical laboratory testing and electrocardiograms. RESULTS: In Part A, 24 subjects were randomly assigned to three cohorts (n = 8 per cohort) and received HTX-019 130 mg, administered intravenously over 15 min (cohort 1), 5 min (cohort 2) or 2 min (cohort 3). Progression to Part B occurred after acceptable tolerability was established in cohorts 2 and 3. In Part B, 50 randomized subjects received a 2-min injection (9 ml/min) and 30-min infusion (296 ml/h) of HTX-019 130 mg. Bioequivalence was demonstrated for HTX-019 injection and infusion. Both administration methods via a peripheral line were well tolerated; eight subjects experienced 11 TEAEs (six related) following injection and nine experienced 14 TEAEs (nine related) following infusion. Headache and fatigue were the most prevalent treatment-related TEAEs; one subject per group experienced feeling hot ≤30 min after drug administration. CONCLUSION: Pharmacokinetic and tolerability profiles of 2-min HTX-019 injection support this potential alternative administration method for CINV prevention.

Drug-drug interactions with aprepitant in antiemetic prophylaxis for chemotherapy.

In the current guidelines to prevent hemotherapyinduced nausea and vomiting, multiple antiemetic drugs are administered simultaneously. In patients who receive highly emetogenic chemotherapy, aprepitant, an NK1-receptor antagonist, is combined with ondansetron and dexamethasone. Aprepitant can influence the pharmacokinetics of other drugs, as it is an inhibitor and inducer of CYP3A4. Some anticancer drugs and other co-medication frequently used in cancer patients are CYP3A4 or CYP29C substrates. We give an overview of the metabolism and current data on clinically relevant drug-drug interactions with aprepitant during chemotherapy. Physicians should be aware of the potential risk of drug-drug interactions with aprepitant, especially in regimens with curative intent. More research should be performed on drug-drug interactions with aprepitant and their clinical consequences to make evidence-based recommendations.

Neurokinin 1 receptor antagonists in the prevention of chemotherapy-induced nausea and vomiting: focus on fosaprepitant.

Chemotherapy-induced nausea and vomiting (CINV) remains a challenge in cancer care. Improved understanding of CINV pathophysiology has triggered the development of new antiemetic therapeutic options, such as selective neurokinin-1 (NK1) receptor antagonists (RAs), which effectively prevent CINV when added to a standard antiemetic regimen (serotonin-3 RA and dexamethasone). Aprepitant and its water-soluble prodrug, fosaprepitant dimeglumine, are the most widely used NK1 RAs, with extensive clinical use worldwide. Recently, a Phase III trial prospectively evaluated fosaprepitant-based antiemetic therapy for CINV prevention in a large, well-defined nonanthracycline- and cyclophosphamide-based moderately emetogenic chemotherapy population. Fosaprepitant demonstrated significantly improved efficacy outcomes compared with a control regimen and was generally well tolerated, indicating that NK1 RAs are a valuable therapeutic option in this setting.

Clinical pharmacology of neurokinin-1 receptor antagonists for the treatment of nausea and vomiting associated with chemotherapy.

INTRODUCTION: Five NK-1 RA formulations are commercially available to treat the delayed phase of chemotherapy-induced nausea and vomiting (CINV) occurring between days 2-5 post chemotherapy (aprepitant oral capsule and suspension, fosaprepitant intravenous infusion, netupitant/palonosetron capsules and rolapitant tablet) but no direct comparative studies have been conducted to determine their relative clinical utility. Areas covered: Information on pharmacology and safety of the NK-1 RAs derived from PubMed showed that all bind the NK-1 receptor with high affinity and selectivity. There is substantial variation in the disposition and time course in the body of NK-1 RAs because of the differential effects of hepatic metabolism. Unlike netupitant and rolapitant, aprepitant is metabolized extensively by cytochrome P450 (CYP) 3A4. Aprepitant and netupitant also both inhibit CYP3A4. Consequently, aprepitant not only has a much shorter elimination half-life than netupitant and rolapitant but also a more prolific drug interaction profile. All of the NK-1 RAs are efficacious and safe, and are suitable for use in a range of different patient populations, including those with mild or moderate hepatic or renal impairment. Expert opinion: While discovery of NK-1 RAs represents a major breakthrough in CINV control, further work is needed to improve control of chemotherapy-induced nausea.

5-HT3 receptors as important mediators of nausea and vomiting due to chemotherapy.

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. The use of a combination of a 5-hydroxytryptamine-3 (5-HT3) receptor antagonist, dexamethasone, and a neurokinin-1 (NK-1) receptor antagonist has significantly improved the control of acute and delayed emesis in single-day chemotherapy. The first generation 5-HT3 receptor antagonists have been very effective in the control of chemotherapy induced emesis in the first 24 h postchemotherapy (acute emesis), but have not been as effective against delayed emesis (24-120 h postchemotherapy). Palonosetron, a second generation 5-HT3 receptor antagonist with a different half-life, a different binding capacity, and a different mechanism of action than the first generation 5-HT3 receptor antagonists appears to be the most effective agent in its class. Despite the control of emesis, nausea has not been well controlled by current agents. Olanzapine, a FDA approved antipsychotic that blocks multiple neurotransmitters: dopamine at D1, D2, D3, D4 brain receptors, serotonin at 5-HT2a, 5-HT2c, 5-HT3, 5-HT6 receptors, catecholamines at alpha1 adrenergic receptors, acetylcholine at muscarinic receptors, and histamine at H1 receptors, has emerged in recent trials as an effective preventative agent for chemotherapy-induced emesis and nausea, as well as a very effective agent for the treatment of breakthrough emesis and nausea. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.