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Considering the frequent use of netupitant in polytherapy, the elucidation of its oxidative metabolization pattern is of major importance. However, there is a lack of published research on the redox behavior of this novel neurokinin-1 receptor antagonist. Therefore, this study was performed to simulate the intensive hepatic biotransformation of netupitant using an electrochemically driven method. Most of the known enzyme-mediated reactions occurring in the liver (i.e., N -dealkylation, hydroxylation, and N -oxidation) were successfully mimicked by the electrolytic cell using a boron-doped diamond working electrode. The products were separated by reversed-phase high-performance liquid chromatography and identified by high-resolution mass spectrometry. Aside from its ability to pinpoint formerly unknown metabolites that could be responsible for the known side effects of netupitant or connected with any new perspective concerning future therapeutic indications, this electrochemical process also represents a facile alternative for the synthesis of oxidation products for further in vitro and in vivo studies. [Display omitted] • Study of the electrochemical behavior of netupitant, an NK 1 receptor antagonist. • Electrochemical simulation of the phase I oxidative metabolization of netupitant. • Identification of the generated oxidation species by LC/ESI(+)-MS. • Separation and identification of electrochemically generated isomers. [ABSTRACT FROM AUTHOR]

Background: NEPA, an oral fixed combination of the NK1RA netupitant (300 mg) and clinically/pharmacologically distinct 5-HT3RA palonosetron (PALO, 0.50 mg), is the first fixed antiemetic combination to have been approved. A single oral NEPA capsule plus dexamethasone (DEX) given before anthracycline-cyclophosphamide (AC) and non-AC highly emetogenic chemotherapy (HEC) showed superior prevention of chemotherapy-induced nausea and vomiting (CINV) over PALO plus DEX for 5 days postchemotherapy. The safety of NEPA was well-established in the phase II/III clinical program in 1169 NEPA-treated patients. An intravenous (i.v.) formulation of the NEPA combination (fosnetupitant 235 mg plus PALO 0.25 mg) has been developed. Patients and methods: This randomized, multinational, double-blind, stratified (by sex and country) phase III study (NCT02517021) in chemotherapy-naïve patients with solid tumors assessed the safety of a single dose of i.v. NEPA infused over 30 min before initial and repeated cycles of HEC. Patients received either i.v. NEPA or oral NEPA, both with oral DEX on days 1-4. Safety was assessed primarily by treatment-emergent adverse events (AEs) and electrocardiograms. Results: A total of 404 patients completed 1312 cycles. The incidence and type of treatment-emergent AEs were similar for both treatment groups with the majority of AEs as mild/moderate in intensity. There was no increased incidence of AEs in subsequent cycles in either group. The incidence of treatment-related AEs was similar and relatively low in both groups (12.8% i.v. NEPA and 11.4% oral NEPA during the entire study), with constipation being the most common (6.4% i.v. NEPA, 6.0% oral NEPA). No serious treatment-related AEs occurred in either group. No infusion site or anaphylactic reactions related to i.v. NEPA occurred. No clinically relevant changes in QTc and no cardiac safety concerns were observed. Conclusions: Intravenous NEPA was well-tolerated with a similar safety profile to oral NEPA in patients with various solid tumors receiving HEC. [ABSTRACT FROM AUTHOR]

Background: Co-administration of multiple antiemetics that inhibit several molecular pathways involved in emesis is required to optimize chemotherapy-induced nausea and vomiting (CINV) control in patients receiving highly emetogenic chemotherapy (HEC). NEPA, a fixed combination of a highly selective NK1 receptor antagonist, netupitant (300 mg), and the pharmacologically distinct 5-HT3RA, palonosetron (PALO 0.50 mg), has shown superior CINV prevention compared with PALO in cisplatin and anthracycline/cyclophosphamide-based settings. This study is the first head-to-head comparison of NEPA versus an aprepitant (APR)/granisetron (GRAN) regimen. Patients and methods: This randomized, double-blind phase III study conducted in Asia was designed with the primary objective to demonstrate non-inferiority of a single oral dose of NEPA compared with a 3-day oral APR/GRAN regimen in chemotherapy-naïve patients receiving cisplatin-based HEC. All patients also received oral dexamethasone (DEX) on days 1-4. The primary efficacy endpoint was complete response (CR: no emesis/no rescue medication) during the overall (0-120 h) phase. Non-inferiority was defined as a lower 95% CI greater than the non-inferiority margin set at -10%. Secondary efficacy endpoints included no emesis, no rescue medication, and no significant nausea (NSN). Results: Treatment groups were comparable for the 828 patients analyzed: predominantly male (71%); mean age 54.5 years; ECOG 0-1 (98%); lung cancer (58%). NEPA demonstrated non-inferiority to APR/GRAN for overall CR [NEPA 73.8% versus APR/GRAN 72.4%, 95% CI (-4.5%, 7.5%)]. No emesis [NEPA 75.0% versus APR/GRAN 74.0%, 95% CI (-4.8%, 6.9%)] and NSN rates [NEPA 75.7% versus APR/GRAN 70.4%, 95% CI (-0.6%, 11.4%)] were similar between groups, but significantly more NEPA patients did not take rescue medication [NEPA 96.6% versus APR/GRAN 93.5%, 95% CI (0.2%, 6.1%)]. NEPA was well tolerated with a similar safety profile to APR/GRAN. Conclusions: In this first study comparing NK1RA regimens and DEX, NEPA administered only on day 1 was non-inferior to a 3-day oral APR/GRAN regimen in preventing CINV associated with HEC. [ABSTRACT FROM AUTHOR]

We recently demonstrated the non-inferiority of two dexamethasone (DEX)-sparing regimens with an oral fixed-combination of netupitant and palonosetron (NEPA) versus the guideline-recommended DEX use for cisplatin-induced nausea and vomiting. Since prevention of chemotherapy-induced nausea and vomiting is critical in older patients, we retrospectively evaluated the efficacy of the DEX-sparing regimens in this subset. Chemo-naive patients aged >65 years treated with high-dose cisplatin (≥70 mg/m2) were eligible. Patients received NEPA and DEX on day 1 and were randomized to receive either (1) no further DEX (DEX1), (2) oral low-dose DEX (4 mg) on days 2–3 (DEX3), or (3) the guideline-recommended standard DEX (4 mg twice daily) on days 2–4 (DEX4). The primary efficacy endpoint of the parent study was complete response (CR; no vomiting and no use of rescue medication) during the overall phase (days 1–5). No significant nausea (NSN; none or mild nausea) and the proportion of patients reporting no impact on daily life (NIDL) which was evaluated by the Functional Living Index-Emesis questionnaire on day 6 (overall combined score > 108), were secondary endpoints. Among the 228 patients in the parent study, 107 were > 65 years. Similar CR rates [95% confidence intervals (CI)] were observed in patients over 65 years across treatment groups [DEX1: 75% (59.7–86.8%); DEX3: 80.6% (62.5–92.6%); DEX4: 75% (56.6–88.5%)] as well as versus the total study population. NSN rates were also similar in the older-patients across treatment groups (p = 0.480) but were higher compared with the total population. Similar rates of NIDL (95% CI) were reported in the older-patient subset across treatment groups [DEX1: 61.5% (44.6–76.6%); DEX3: 64.3% (44.1–81.4%); DEX4: 62.1% (42.3–79.3%); p = 1.0] during the overall phase, as well as versus total population. A similar proportion of older patients across treatment groups experienced DEX-related side effects. This analysis shows that older-patients who are fit for cisplatin benefit from a simplified regimen of NEPA plus single-dose DEX with neither loss in antiemetic efficacy nor the adverse impact on patient daily functioning. The study was registered on ClinicalTrials.gov (identifier NCT04201769) on 17/12/2019 (retrospectively registered). [ABSTRACT FROM AUTHOR]

The introduction of second generation serotonin 5-HT 3 receptor (5-HT 3 ) antagonist palonosetron combined with long-acting substance P neurokinin NK 1 receptor (NK 1 ) antagonists (e.g. netupitant) has substantially improved antiemetic therapy against early- and delayed-phases of emesis caused by highly emetogenic chemotherapeutics such as cisplatin. However, the improved efficacy comes at a cost that many patients cannot afford. We introduce a new class of antiemetic, the antiasthmatic leukotriene CysLT1 receptor antagonist pranlukast for the suppression of cisplatin-evoked vomiting. Pranlukast (10 mg/kg) by itself significantly reduced the mean frequency of vomits (70%) and fully protected least shrews from vomiting (46%) during the delayed-phase of cisplatin (10 mg/kg)-evoked vomiting. Although, pranlukast tended to substantially reduce both the mean frequency of vomits and the number of shrews vomiting during the early-phase, these reductions failed to attain significance. When combined with a first (tropisetron)- or a second (palonosetron)-generation 5-HT 3 receptor antagonist, pranlukast potentiated their antiemetic efficacy during both phases of vomiting. In addition, pranlukast by itself prevented several intracellular signal markers of cisplatin-evoked delayed-vomiting such as phosphorylation of ERK1/2 and PKA. When pranlukast was combined with either palonosetron or tropisetron, these combinations suppressed the evoked phosphorylation of: i) ERK1/2 during both acute- and delayed-phase, ii) PKCα/β at the peak acute-phase, and iii) PKA at the peak delayed-phase. The current and our published findings suggest that overall behavioral and intracellular signaling effects of pranlukast via blockade of CysLT1 receptors generally appear to be similar to the NK 1 receptor antagonist netupitant with some differences. [ABSTRACT FROM AUTHOR]

Objectives Breast cancer (BC) patients represent a high-risk population for experiencing chemotherapy-induced nausea and vomiting (CINV), since they frequently receive highly emetogenic anthracycline-cyclophosphamide–based (AC) chemotherapy, and are often female and young, two predisposing risk factors for CINV. Guidelines recommend the combination of a neurokinin-1 receptor antagonist (NK 1 RA), 5-hydroxytryptamine-3 RA (5-HT 3 RA), and dexamethasone (DEX) for CINV prophylaxis in AC-treated patients. This post-hoc analysis evaluated the efficacy of NEPA, a fixed combination of netupitant (NETU [NK 1 RA]) and palonosetron (PALO [5-HT 3 RA]) in BC patients from two phase III studies. Methods Overall, 1460 BC patients received AC (Study 1) or non-AC (Study 2) therapy over 6060 cycles. Randomized patients received DEX with either NEPA or oral PALO (Study 1), or NEPA or aprepitant+oral PALO (Study 2) before chemotherapy. Results In AC-receiving patients, overall complete response (CR) rates with NEPA+DEX were statistically significantly higher than oral PALO+DEX rates (cycles 1–4: 73.9% vs 65.9%, 80.0% vs 66.0%, 83.6% vs 69.9%, 83.6% vs 74.4%, respectively). Overall, no significant nausea (NSN) rates were also superior with NEPA+DEX vs oral PALO+DEX (respectively, 74.2%–79.9% vs 68.5%–74.9%). A greater proportion of NEPA+DEX patients experienced “no-impact-on-daily-life” due to CINV (78.4% vs 71.4%) in cycle 1. In non-AC–receiving patients, prophylaxis with NEPA+DEX resulted in high CR and NSN rates across 1–4 chemotherapy cycles; no formal comparison with the control arm was performed. Conclusion NEPA+DEX administered as a single dose is an effective option for preventing CINV in BC patients receiving AC and non-AC, across multiple chemotherapy cycles. Clinical trials registration numbers Study 1 : NCT01339260 , Study 2: NCT01376297 . [ABSTRACT FROM AUTHOR]

Cisplatin-like chemotherapeutics cause vomiting via calcium (Ca 2 + )-dependent release of multiple neurotransmitters (dopamine, serotonin, substance P, etc.) from the gastrointestinal enterochromaffin cells and/or the brainstem. Intracellular Ca 2 + signaling is triggered by activation of diverse emetic receptors (including tachykininergic NK 1 , serotonergic 5-HT 3 , dopaminergic D 2 , cholinergic M 1 , or histaminergic H 1 ) , whose activation in vomit-competent species can evoke emesis. Other emetogens such as cisplatin, rotavirus NSP4 protein and bacterial toxins can also induce intracellular Ca 2 + elevation. Netupitant is a highly selective neurokinin NK 1 receptor (NK 1 R) antagonist and palonosetron is a selective second-generation serotonin 5-HT 3 receptor (5-HT 3 R) antagonist with a distinct pharmacological profile. An oral fixed combination of netupitant/palonosetron (NEPA; Akynzeo(®)) with > 85% antiemetic efficacy is available for use in the prevention of acute and delayed chemotherapy-induced nausea and vomiting (CINV). Cannabinoid CB 1 receptor agonists possess broad-spectrum antiemetic activity since they prevent vomiting caused by a variety of emetic stimuli including the chemotherapeutic agent cisplatin, 5-HT 3 R agonists, and D 2 R agonists. Our findings demonstrate that application of the L-type Ca 2 + channel (LTCC) agonist FPL 64176 and the intracellular Ca 2 + mobilizing agent thapsigargin (a sarco/endoplasmic reticulum Ca 2 + -ATPase inhibitor) cause vomiting in the least shrew. On the other hand, blockade of LTCCs by corresponding antagonists (nifedipine or amlodipine) not only provide broad-spectrum antiemetic efficacy against diverse agents that specifically activate emetogenic receptors such as 5-HT 3 , NK 1 , D 2 , and M 1 receptors, but can also potentiate the antiemetic efficacy of palonosetron against the non-specific emetogen, cisplatin. In this review, we will provide an overview of Ca 2 + involvement in the emetic process; discuss the relationship between Ca 2 + signaling and the prevailing therapeutics in control of vomiting; highlight the evidence for Ca 2 + -signaling blockers/inhibitors in suppressing emetic behavior in the least shrew model of emesis as well as in the clinical setting; and also draw attention to the clinical benefits of Ca 2 + -signaling blockers/inhibitors in the treatment of nausea and vomiting. [ABSTRACT FROM AUTHOR]

Objectives Prevention of chemotherapy-induced nausea and vomiting is critical in older patients with cancer. NEPA is an oral fixed combination of netupitant 300 mg, a new NK 1 receptor antagonist (RA), and palonosetron 0.5 mg, a pharmacologically distinct 5-HT 3 RA. This retrospective analysis evaluated the efficacy and safety of NEPA in older patients. Methods Patients aged ≥ 65 and ≥ 70 years from one phase II and two phase III trials were considered. Chemotherapy-naive patients with malignant tumors were treated with anthracycline–cyclophosphamide (AC), non-AC-based moderately emetogenic chemotherapy (non-AC MEC), or highly emetogenic chemotherapy (HEC). Following single-dose NEPA, patients received oral dexamethasone on day 1 (AC and non-AC MEC) or days 1–4 (HEC). Efficacy was evaluated through complete response (CR) in cycle 1. Safety was evaluated by AEs and ECGs. Data were summarized by descriptive statistics. Results Overall, 214 patients were ≥ 65 years and 80 were ≥ 70 years. A higher CR was observed in older patients versus the total population; in the acute phase > 90% of patients ≥ 65 years experienced CR. Efficacy was maintained over multiple cycles of chemotherapy. No significant nausea rates were generally higher in the older patients versus total population. Similar rates of AEs in the first treatment cycle were reported for patients ≥ 65 years, ≥ 70 years, and total population (72.9% vs 67.5% vs 70.0%, respectively). No cardiac safety concerns were raised. Conclusion NEPA is highly effective in older patients receiving MEC or HEC regimens. NEPA is also well tolerated, demonstrating suitability for use in older patients who may have comorbidities. [ABSTRACT FROM AUTHOR]

A simple liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was firstly developed and validated for simultaneous determination of netupitant and palonosetron in human plasma using ibrutinib as the internal standard (IS). Following liquid–liquid extraction, the compounds were eluted isocratically on a Phenomenex C18 column (50mm × 2.0 mm, 3 μm) with the mobile phase consisting of acetonitrile and 10 mM ammonium acetate buffer (pH 9.0) (89:11, v/v) at the flow rate of 0.3 mL/min. The monitored ion transitions were m / z 579.5 → 522.4 for netupitant, m / z 297.3 → 110.2 for palonosetron and m / z 441.2 → 138.1 for IS. Chromatographic run time was 2.5 min per injection, which made it possible to analyze more than 300 of samples per day. The assay exhibited a linear dynamic range of 5–1000 ng/mL for netupitant and 0.02–10 ng/mL for palonosetron in plasma. The values for both within- and between-day precision and accuracy were well within the generally accepted criteria for analytical methods (<15%). Selectivity, linearity, lower limit of quantification (LLOQ), accuracy, precision, stability, matrix effect, recovery and carry-over effect were evaluated for all analytes. The method is simple, rapid, and has been applied successfully to a pharmacokinetic study of netupitant and palonosetron in healthy volunteers. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the pharmacological activity of Pronetupitant, a novel compound designed to act as prodrug of the NK 1 antagonist Netupitant. In receptor binding experiments Pronetupitant displayed high selectivity for the NK 1 receptor. In a calcium mobilization assay performed on CHO NK1 cells Pronetupitant (100 nM, 15 min preincubation) behaved as an NK 1 antagonist more potent than Netupitant (p K B 8.72 and 7.54, respectively). In the guinea pig ileum bioassay Pronetupitant antagonized the contractile effect of SP showing a similar potency as Netupitant (p K B ≈ 9). Similar results were obtained with 5 min preincubation time while at 2 min only Pronetupitant produced significant effects. In vivo in mice the intrathecal injection of 0.1 nmol SP elicited the typical scratching, biting and licking (SBL) nociceptive response. This effect of SP was dose dependently (0.1–10 mg/kg) antagonized by Pronetupitant given intravenously 2 h before the peptide. Superimposable results were obtained using Netupitant. Pharmacokinetic studies performed in rats demonstrate that Pronetupitant, after i.v. administration, is quickly (few minutes) and completely converted to Netupitant. Collectively the present results indicated that Pronetupitant acts in vitro as selective NK 1 antagonist more potent than Netupitant. However based on the short half-life measured for Pronetupitant in rats, the in vivo action of Pronetupitant can be entirely interpreted as due to its conversion to Netupitant. [ABSTRACT FROM AUTHOR]

NEPA is an oral single, fixed-dose combination of netupitant, a new highly selective NK1 RA and palonosetron (PALO), a pharmacologically/clinically distinct 5-HT3 RA. It delivers antiemetic guideline-recommended prophylaxis by targeting two critical molecular pathways associated with chemotherapy-induced nausea/vomiting. This Phase III study demonstrated the superiority of NEPA compared with PALO.Background Antiemetic guidelines recommend co-administration of agents that target multiple molecular pathways involved in emesis to maximize prevention and control of chemotherapy-induced nausea and vomiting (CINV). NEPA is a new oral fixed-dose combination of 300 mg netupitant, a highly selective NK1 receptor antagonist (RA) and 0.50 mg palonosetron (PALO), a pharmacologically and clinically distinct 5-HT3 RA, which targets dual antiemetic pathways. Patients and methods This multinational, randomized, double-blind, parallel group phase III study (NCT01339260) in 1455 chemotherapy-naïve patients receiving moderately emetogenic (anthracycline–cyclophosphamide) chemotherapy evaluated the efficacy and safety of a single oral dose of NEPA versus a single oral dose (0.50 mg) of PALO. All patients also received oral dexamethasone (DEX) on day 1 only (12 mg in the NEPA arm and 20 mg in the PALO arm). The primary efficacy end point was complete response (CR: no emesis, no rescue medication) during the delayed (25–120 h) phase in cycle 1. Results The percentage of patients with CR during the delayed phase was significantly higher in the NEPA group compared with the PALO group (76.9% versus 69.5%; P = 0.001), as were the percentages in the overall (0–120 h) (74.3% versus 66.6%; P = 0.001) and acute (0–24 h) (88.4% versus 85.0%; P = 0.047) phases. NEPA was also superior to PALO during the delayed and overall phases for all secondary efficacy end points of no emesis, no significant nausea and complete protection (CR plus no significant nausea). NEPA was well tolerated with a similar safety profile as PALO. Conclusions NEPA plus a single dose of DEX was superior to PALO plus DEX in preventing CINV following moderately emetogenic chemotherapy in acute, delayed and overall phases of observation. As a fixed-dose antiemetic drug combination, NEPA along with a single dose of DEX on day 1 offers guideline-based prophylaxis with a convenient, single-day treatment. [ABSTRACT FROM AUTHOR]

This study was designed to determine the appropriate clinical dose of netupitant (NETU), a new NK1 receptor antagonist (RA), to combine with the 5-HT3 RA, palonosetron (PALO) in a fixed-dose antiemetic combination (NEPA). All NEPA doses provided superior prevention of chemotherapy-induced nausea and vomiting compared with PALO, with NEPA300 (300mg NETU + 0.50 mg PALO) being the best dose studied.Background NEPA is a novel oral fixed-dose combination of netupitant (NETU), a new highly selective neurokinin-1 (NK1) receptor antagonist (RA) and palonosetron (PALO), a pharmacologically and clinically distinct 5-hydroxytryptamine type 3 (5-HT3) RA. This study was designed to determine the appropriate clinical dose of NETU to combine with PALO for evaluation in the phase 3 NEPA program. Patients and methods This randomized, double-blind, parallel group study in 694 chemotherapy naïve patients undergoing cisplatin-based chemotherapy for solid tumors compared three different oral doses of NETU (100, 200, and 300 mg) + PALO 0.50 mg with oral PALO 0.50 mg, all given on day 1. A standard 3-day aprepitant (APR) + IV ondansetron (OND) 32 mg regimen was included as an exploratory arm. All patients received oral dexamethasone on days 1–4. The primary efficacy endpoint was complete response (CR: no emesis, no rescue medication) during the overall (0–120 h) phase. Results All NEPA doses showed superior overall CR rates compared with PALO (87.4%, 87.6%, and 89.6% for NEPA100, NEPA200, and NEPA300, respectively versus 76.5% PALO; P < 0.050) with the highest NEPA300 dose studied showing an incremental benefit over lower NEPA doses for all efficacy endpoints. NEPA300 was significantly more effective than PALO and numerically better than APR + OND for all secondary efficacy endpoints of no emesis, no significant nausea, and complete protection (CR plus no significant nausea) rates during the acute (0–24 h), delayed (25–120 h), and overall phases. Adverse events were comparable across groups with no dose response. The percent of patients developing electrocardiogram changes was also comparable. Conclusions Each NEPA dose provided superior prevention of chemotherapy-induced nausea and vomiting (CINV) compared with PALO following highly emetogenic chemotherapy; however, NEPA300 was the best dose studied, with an advantage over lower doses for all efficacy endpoints. The combination of NETU and PALO was well tolerated with a similar safety profile to PALO and APR + OND. [ABSTRACT FROM AUTHOR]

In this multinational, phase III study, the safety and efficacy of NEPA, a convenient, fixed-dose antiemetic combination of netupitant, a highly selective NK1 receptor antagonist (RA), and palonosetron, a distinct 5-HT3 RA, were evaluated over multiple cycles of highly and moderately emetogenic chemotherapy. NEPA was shown to be safe, well tolerated and highly effective over 1961 chemotherapy cycles.Background Safe, effective and convenient antiemetic regimens that preserve benefit over repeated cycles are needed for optimal supportive care during cancer treatment. NEPA, an oral fixed-dose combination of netupitant, a highly selective NK1 receptor antagonist (RA), and palonosetron (PALO), a distinct 5-HT3 RA, was shown to be superior to PALO in preventing chemotherapy-induced nausea and vomiting after a single cycle of highly (HEC) or moderately (MEC) emetogenic chemotherapy in recent trials. This study was designed primarily to assess the safety but also to evaluate the efficacy of NEPA over multiple cycles of HEC and MEC. Patients and methods This multinational, double-blind, randomized phase III study (NCT01376297) in 413 chemotherapy-naïve patients evaluated a single oral dose of NEPA (NETU 300 mg + PALO 0.50 mg) given on day 1 with oral dexamethasone (DEX). An oral 3-day aprepitant (APR) regimen + PALO + DEX was included as a control (3:1 NEPA:APR randomization). In HEC, DEX was administered on days 1–4 and in MEC on day 1. Safety was assessed primarily by adverse events (AEs), including cardiac AEs; efficacy by complete response (CR: no emesis, no rescue). Results Patients completed 1961 total chemotherapy cycles (76% MEC, 24% HEC) with 75% completing ≥4 cycles. The incidence/type of AEs was comparable for both groups. Most frequent NEPA-related AEs included constipation (3.6%) and headache (1.0%); there was no indication of increasing AEs over multiple cycles. The majority of AEs were mild/moderate and there were no cardiac safety concerns based on AEs and electrocardiograms. The overall (0–120 h) CR rates in cycle 1 were 81% and 76% for NEPA and APR + PALO, respectively, and antiemetic efficacy was maintained over repeated cycles. Conclusions NEPA, a convenient single oral dose antiemetic targeting dual pathways, was safe, well tolerated and highly effective over multiple cycles of HEC/MEC. [ABSTRACT FROM AUTHOR]

Abstract: Nausea and vomiting are major side effects of chemotherapy and one key reason for non-compliance with cancer treatment. The introduction of 5-HT3 receptor antagonists in the 1990s was a major advance in the prevention of acute emesis, and highlighted the critical role of serotonin in the emetic response. The next major advance in the treatment of chemotherapy induced nausea and vomiting (CINV) occurred in 2003 with the introduction of aprepitant, a tachykinin 1 (NK1) receptor antagonist. Aprepitant not only reduced acute emesis but also helped in the reduction of delayed emesis. Also in 2003, palonosetron, a second generation 5-HT3 receptor antagonist became available. Unlike the first generation 5-HT3 receptor antagonists, palonosetron demonstrated efficacy in preventing both acute and delayed emesis. This review focuses on the mechanism of action of 5-HT3 and NK1 receptor antagonists in acute and delayed CINV prevention. We discuss first, the medicinal chemistry that led to the discovery of these antagonists to underline their common structural features. Second, we discuss their performance in the clinic and what it tells us about the emetic response. Finally, we present recent mechanistic studies that help provide a rationale for efficacy differences between palonosetron and other 5-HT3 receptor antagonists in the clinic. In vitro and in vivo experiments have shown that palonosetron can inhibit substance P-mediated responses, presumably through its unique interactions with the 5-HT3 receptor. The crossroads of acute and delayed emesis seem to include interactions among the 5-HT3 and NK1 receptor signaling pathways and inhibitions of these interactions could lead to improved treatment of CINV. [Copyright &y& Elsevier]

Abstract: The novel NK1 receptor ligand Netupitant has been characterized in vitro and in vivo. In calcium mobilization studies CHO cells expressing the human NK receptors responded to a panel of agonists with the expected order of potency. In CHO NK1 cells Netupitant concentration-dependently antagonized the stimulatory effects of substance P (SP) showing insurmountable antagonism (pK B 8.87). In cells expressing NK2 or NK3 receptors Netupitant was inactive. In the guinea pig ileum Netupitant concentration-dependently depressed the maximal response to SP (pK B 7.85) and, in functional washout experiments, displayed persistent (up to 5h) antagonist effects. In mice the intrathecal injection of SP elicited the typical scratching, biting and licking response that was dose-dependently inhibited by Netupitant given intraperitoneally in the 1–10mg/kg dose range. In gerbils, foot tapping behavior evoked by the intracerebroventricular injection of a NK1 agonist was dose-dependently counteracted by Netupitant given intraperitoneally (ID50 1.5mg/kg) or orally (ID50 0.5mg/kg). In time course experiments in gerbils Netupitant displayed long lasting effects. In all the assays Aprepitant elicited similar effects as Netupitant. These results suggest that Netupitant behaves as a brain penetrant, orally active, potent and selective NK1 antagonist. Thus this molecule can be useful for investigating the NK1 receptor role in the control of central and peripheral functions. Netupitant has clinical potential in conditions such as chemotherapy induced nausea and vomiting, in which the blockade of NK1 receptors has been demonstrated valuable for patients. [Copyright &y& Elsevier]

Abstract: Netupitant is a potent and selective NK1 receptor antagonist under development in combination with a fixed dose of palonosetron for the prevention of chemotherapy induced nausea and vomiting. Palonosetron is a 5-HT3 receptor antagonist approved for both the prevention of acute and delayed chemotherapy induced nausea and vomiting after moderately emetogenic chemotherapy. Accumulating evidence suggests that substance P (SP), a ligand acting largely on tachykinin (NK1) receptors, is the dominant mediator of delayed emesis. Interestingly, palonosetron does not bind to the NK1 receptor so that the mechanism behind palonosetron''s unique efficacy against delayed emesis is not clear. Palonosetron exhibits a distinct ability among 5-HT3 receptor antagonists to inhibit crosstalk between NK1 and 5-HT3 receptor signaling pathways. The objective of the current work was to determine if palonosetron''s ability to inhibit receptor signaling crosstalk would influence netupitant''s inhibition of the SP-mediated response when the two drugs are dosed together. We first studied the inhibition of SP-induced Ca2+ mobilization in NG108-15 cells by palonosetron, ondansetron and granisetron. Unexpectedly, in the absence of serotonin, palonosetron inhibited the SP-mediated dose response 15-fold; ondansetron and granisetron had no effect. Netupitant also dose-dependently inhibited the SP response as expected from an NK1 receptor antagonist. Importantly, when both palonosetron and netupitant were present, they exhibited an enhanced inhibition of the SP response compared to either of the two antagonists alone. The results further confirm palonosetron''s unique pharmacology among 5-HT3 receptor antagonists and suggest that it can enhance the prevention of delayed emesis provided by NK1 receptor antagonists. [Copyright &y& Elsevier]

Abstract: Nausea and vomiting are among the most common and distressing consequences of cytotoxic chemotherapies. Nausea and vomiting can be acute (0–24h) or delayed (24–72h) after chemotherapy administration. The introduction of 5-HT3 receptor antagonists in the 90s was a major advance in the prevention of acute emesis. These receptor antagonists exhibited similar control on acute emesis but had no effect on delayed emesis. These findings led to the hypothesis that serotonin plays a central role in the mechanism of acute emesis but a lesser role in the pathogenesis of delayed emesis. In contrast, delayed emesis has been largely associated with the activation of neurokinin 1 (NK1) receptors by substance P. However, in 2003, a new 5-HT3 receptor antagonist was introduced into the market; unlike first generation 5-HT3 receptor antagonists, palonosetron was found to be effective in preventing both acute and delayed chemotherapy induced nausea and vomiting. Recent mechanistic studies have shown that palonosetron, in contrast to first generation receptor antagonists, exhibits allosteric binding to the 5-HT3 receptor, positive cooperativity, persistent inhibition of receptor function after the drug is removed and triggers 5-HT3 receptor internalization. Further, in vitro and in vivo experiments have shown that palonosetron can inhibit substance P-mediated responses, presumably through its unique interactions with the 5-HT3 receptor. It appears that the crossroads of acute and delayed emeses include interactions among the 5-HT3 and NK1 receptor neurotransmitter pathways and that inhibitions of these interactions lend the possibility of improved treatment that encompasses both acute and delayed emeses. [Copyright &y& Elsevier]

• An NK 1 RA, 5-HT 3 RA, and dexamethasone are recommended to prevent CINV in patients at high emetic risk. • IV NEPA is an innovative fixed combination antiemetic, comprised of the NK 1 RA, fosnetupitant, and 5-HT 3 RA, palonosetron. • IV NEPA has had no associated injection-site or hypersensitivity reactions. • This paper presents the efficacy of IV NEPA relative to oral NEPA and also to historical data for other NK 1 RA regimens. This paper presents an overview of the efficacy of intravenous (IV) NEPA (fixed combination of the NK 1 RA, fosnetupitant, and 5-HT 3 RA, palonosetron) relative to oral NEPA and also to historical data for other NK 1 RA regimens. Data is compiled from 5 pivotal NEPA studies in adult chemotherapy-naïve patients with solid tumors undergoing either cisplatin- or anthracycline cyclophosphamide (AC)-based chemotherapy. Additionally, data was reviewed from 10 pivotal Phase 3 studies utilizing other NK 1 RA regimens approved for clinical use. The overall (0−120 h) complete response (no emesis, no rescue use), no emesis, and no significant nausea rates for IV NEPA were similar to that of oral NEPA and were consistently numerically higher than historical NK 1 RA regimens. As a single-dose prophylactic antiemetic combination given with dexamethasone, IV NEPA is a highly effective and convenient guideline-compliant antiemetic agent which may offer a safety benefit over other IV NK 1 RA regimens due to its lack of associated hypersensitivity and injection-site reactions. [ABSTRACT FROM AUTHOR]