Netupitant is a new, selective NK1 receptor antagonist under development for the prevention of chemotherapy-induced nausea and vomiting. Two studies were conducted to evaluate the brain receptor occupancy (RO) and disposition (ADME) of netupitant in humans. Positron emission tomography (PET) imaging with the NK1 receptor-binding–selective tracer [11C]-GR205171 was used to evaluate the brain penetration of different doses of netupitant (100, 300, and 450 mg) and to determine the NK1-RO duration. A NK1-RO of 90% or higher was achieved with all doses in the majority of the tested brain regions at Cmax, with a long duration of RO. The netupitant minimal plasma concentration predicted to achieve a NK1-RO of 90%, C90%, in the striatum was 225 ng/mL; after administration of netupitant 300 mg, concentrations exceeded the C90%. In the ADME study, a single nominal dose of [14C]-netupitant 300 mg was used to assess its disposition. Absorption was rapid and netupitant was extensively metabolized via Phase I and II hepatic metabolism. Elimination of >90% was predicted at day 29 and was principally via hepatic/biliary route (>85%) with a minor contribution of the renal route (<5%). In conclusion, these studies demonstrate that netupitant is a potent agent targeting NK1 receptors with long lasting RO. In addition, netupitant is extensively metabolized and is mainly eliminated through the hepatic/biliary route and to a lesser extent via the kidneys.

SummaryBackground Palonosetron has demonstrated efficacy in the prevention of chemotherapy-

Chemotherapy-induced nausea and vomiting is ranked among the worst side effects of chemotherapy. NEPA is an oral fixed-dose combination antiemetic under development, consisting of netupitant 300 mg, a highly selective NK1 receptor antagonist (RA), and palonosetron 0.5 mg, a pharmacologically and clinically distinct 5-HT3 RA. Although palonosetron is not associated with relevant ECG effects, this study evaluated cardiovascular safety of netupitant in combination with palonosetron, as well as its tolerability.This randomised, placebo- and positively controlled study in 197 subjects included 4 treatment groups: placebo, 200 mg netupitant + 0.5 mg palonosetron (NEPA200/0.5), 600 mg netupitant + 1.5 mg palonosetron (NEPA600/1.5, a supratherapeutic dose), and 400 mg moxifloxacin. Assessments included a 24-h baseline ECG recording, followed by a single dose of treatment and ECG measurements for 2 days.Mean placebo-corrected time-averaged changes from baseline were similar in NEPA200/0.5 and NEPA600/1.5 groups primarily for individually heart rate-corrected QT interval (QTcI: +4.7 and +3.6 ms, respectively) and for heart rate (HR: –3.3 bpm and –3.0 bpm), PR interval (–0.4 ms and 0.2 ms), and QRS interval (1 ms and 0.5 ms). The time-matched analysis showed no upper confidence interval >10 ms, with no suggestion of a QTc effect by pharmacokinetic-pharmacodynamic modeling for parent/metabolites. Moxifloxacin showed the expected placebo-corrected change from baseline (+8.4 ms time average) and the expected profile to establish assay sensitivity. No new morphologic changes of clinical relevance were observed. Treatment-related adverse events were comparable among groups.This study showed that NEPA treatments produced no significant effects on QTcI, HR, PR interval, QRS interval, and cardiac morphology relative to placebo, even at supratherapeutic doses.

aim:To investigate across multiple cycles the efficacy and safety of palonosetron in the prevention of chemotherapy-induced nausea and vomiting in pediatric cancer patients receiving highly or moderately emetogenic chemotherapy (HEC/MEC). Patients & methods: Patients were randomly assigned to 10, 20 μg/kg palonosetron or 3 × 150 μg/kg ondansetron for up to four cycles of HEC/MEC. Results: In all on-study chemotherapy cycles, complete response rates were higher in patients in the 20 μg/kg palonosetron group than the ondansetron group. Treatment-emergent adverse events were comparable between the palonosetron 20 μg/kg and ondansetron groups. conclusion: Over four cycles of HEC/ MEC, 20 μg/kg palonosetron was an efficacious and safe treatment for the prevention of chemotherapy-induced nausea and vomiting in pediatric cancer patients. Chemotherapy-induced nausea and vomiting (CINV) are common and distressing side effects in cancer patients receiving highly emetogenic chemotherapy (HEC) and moderately emetogenic chemotherapy (MEC) regimens [1,2]. CINV negatively impacts on patient quality of life [3], and can lead to medical complications and to noncompliance or premature discontinuation of anticancer therapy [4]. It is recognized that children receiving chemotherapy are more prone to vomiting than adults, and it is estimated that 70% of pediatric cancer patients receiving chemotherapy will develop CINV [2].Prevention of CINV in adult cancer patients receiving HEC or MEC regimens can be achieved through the use of antiemetic agents, a combination of a 5-hydroxytryptamine-3 (5-HT 3 ) receptor antagonist, a corticosteroid and a neurokinin-1 (NK 1 ) receptor antagonist is recommended [5][6][7]. While fewer studies of these agents have been performed in pediatric cancer patients than in adults, at the time of the study design, the combination of a 5-HT 3 receptor antagonist with a corticosteroid was recommended for pediatric patients receiving HEC or MEC chemotherapy regimens [2,5,6]. In later guidance from the Pediatric Oncology Group of Ontario (POGO), children scheduled to receive HEC are recommended to receive antiemetic prophylactic therapy of ondansetron or granisetron plus dexamethasone and aprepitant (≥12 years of age and receiving antineoplastic drugs not known to interact with aprepitant) or ondansetron or granisetron plus dexamethasone (<12 years of For reprint orders, please contact: reprints@futuremedicine.com

Neurokinin-1 (NK1) receptor antagonists (RAs) are commonly coadministered with serotonin (5-HT3) RAs (e.g. palonosetron (PALO)) to prevent chemotherapy-induced nausea/vomiting. Netupitant/palonosetron (NEPA), an oral fixed combination of netupitant (NETU)—a new NK1 RA—and PALO, is currently under development. In vitro data suggest that NETU inhibits CYP3A4 and is a substrate for and weak inhibitor of P-glycoprotein (P-gp). This review evaluates potential drug–drug interactions between NETU or NEPA and CYP3A4 substrates/inducers/inhibitors or P-gp substrates in healthy subjects. Pharmacokinetic (PK) parameters were evaluated for each drug when NETU was coadministered with PALO (single doses) and when single doses of NETU or NEPA were coadministered with CYP3A4 substrates (erythromycin (ERY), midazolam (MID), dexamethasone (DEX), or oral contraceptives), inhibitors (ketoconazole (KETO)), or inducers (rifampicin (RIF)), or a P-gp substrate (digoxin (DIG)). Results showed no relevant PK interactions between NETU and PALO. Coadministration of NETU increased MID and ERY exposure and significantly increased DEX exposure in a dose-dependent manner; NETU exposure was unaffected. NEPA coadministration had no clinically significant effect on oral contraception, although levonorgestrel exposure increased. NETU exposure increased after coadministration of NEPA with KETO and decreased after coadministration with RIF; PALO exposure was unaffected. NETU coadministration did not influence DIG exposure. In conclusion, there were no clinically relevant interactions between NETU and PALO, or NEPA and oral contraceptives (based on levonorgestrel and ethinylestradiol exposure). Coadministration of NETU or NEPA with CYP3A4 inducers/inhibitors/substrates should be done with caution. Dose reduction is recommended for DEX. Dose adjustments are not needed for NETU coadministration with P-gp substrates.