Neurokinin-1 receptor antagonists for the prevention of postoperative nausea and vomiting

Despite the availability of several classes of antiemetics, postoperative nausea and vomiting (PONV) remains a substantial burden for patients following surgery, resulting in patient dissatisfaction and prolonged stays in post-anesthesia care units and ultimately increasing the cost of care. Enhanced recovery protocols and PONV management guidelines are now centered on the assessment of the individual patient's risk for developing PONV, as well as multimodal prophylaxis using antiemetics targeting different mechanisms of action. Over the last two decades, the neurokinin-1 receptor (NK1R) has emerged as a therapeutic target for the management of PONV. This review of the literature explains the role of the NK1R and its ligand-substance P-in vomiting, describes the pharmacologic and pharmacokinetic properties of NK1R antagonists (NK1RAs) and summarizes the clinical evidence supporting NK1RAs for PONV prophylaxis in patients undergoing surgery. In particular, we discuss the therapeutic application of NK1RA in PONV prophylaxis protocols owing to their advantages over other antiemetic classes in efficacy, duration of efficacy, safety, pharmacology, and ease of administration. Future studies will be aimed at further investigating the efficacy and safety of NK1RA-based multimodal combinations, particularly among vulnerable populations (e.g., children and elderly).

The Role of Substance P Within Traumatic Brain Injury and Implications for Therapy

This review examines the role of the neuropeptide substance P within the neuroinflammation that follows traumatic brain injury. It examines it in reference to its preferential receptor, the neurokinin-1 receptor, and explores the evidence for antagonism of this receptor in traumatic brain injury with therapeutic intent. Expression of substance P increases following traumatic brain injury. Subsequent binding to the neurokinin-1 receptor results in neurogenic inflammation, a cause of deleterious secondary effects that include an increased intracranial pressure and poor clinical outcome. In several animal models of TBI, neurokinin-1 receptor antagonism has been shown to reduce brain edema and the resultant rise in intracranial pressure. A brief overview of the history of substance P is presented, alongside an exploration into the chemistry of the neuropeptide with a relevance to its functions within the central nervous system. This review summarizes the scientific and clinical rationale for substance P antagonism as a promising therapy for human TBI.

The clinical research study for fosaprepitant to prevent chemotherapy-induced nausea and vomiting: A review

In recent years, chemotherapy-induced nausea and vomiting (CINV) has become the most common adverse effect of chemotherapy in oncology patients. The CINV may reduce the quality of life in mild cases, or even make the patients resist or delay further treatment. Fosaprepitant is a newly marketed neurokinin-1 receptor antagonist (NK-1RA), which can be combined with 5-hydroxytryptamine 3 receptor antagonists (5-HT3RAs) and dexamethasone to prevent chemotherapy-induced vomiting. The dimeglumine salt form of fosaprepitant can be utilized as an intravenous injectable drug, which surpasses aprepitant's oral admistration limits. Fosaprepitant is effective and safe in the control of CINV in cancer patients receiving highly emetogenic chemotherapy (HEC), and may be an alternative option for antiemetic therapy. In general, fosaprepitant is worthy of clinical promotion and has a large market potential. This article reviews the clinical studies on fosaprepitant conducted in recent years, with the aim of providing a basis for the rational clinical selection of antiemetic drugs.

Efficacy of the dexamethasone-sparing triplet regimen for preventing cisplatin-induced emesis: a combined analysis

Aim: To further evaluate the antiemetic efficacy of single-dose versus multiple-dose dexamethasone (DEX) against nausea and vomiting caused by cisplatin. Materials & methods: Two similar non-inferiority studies were pooled. Patients were randomized to single-day DEX or multiple-day DEX plus palonosetron and neurokinin-1 receptor-antagonists (NK-1RAs). The primary endpoint was complete response (CR; no vomiting and no rescue medication) during the overall phase. Results: The combined analysis included 242 patients. The absolute risk difference between single day versus multi-day DEX for CR was -2% (95% CI, -14 to 9%). Conclusion: Administration of single-dose DEX offers comparable antiemetic control to multiple-day DEX when combined with palonosetron and an NK-1RA in the setting of single-day cisplatin.

Cost-effectiveness of palonosetron and dexamethasone-based triple and quadruple regimens in preventing highly emetogenic chemotherapy-induced nausea and vomiting

OBJECTIVE

Cost-effectiveness analyses that consider all currently used antiemetics in the case of emetogenic chemotherapy-induced nausea and vomiting (CINV) have not been performed yet. We aim to compare the cost-effectiveness of olanzapine (OLA), or/and neurokinin-1 receptor antagonists (NK-1-RAs), in combination with palonosetron (PAL) and dexamethasone (DEX) in preventing highly emetogenic CINV.

METHODS

Two decision analytic models were constructed. The first model was based on overall complete response (CR); the second model was based on rate of absence of nausea. Four antiemetic regimens PAL + DEX, NK-1-RAs + PAL + DEX, OLA + PAL + DEX, and PAL + NK-1-RA + DEX + OLA were compared in terms of cost, overall CR and rate of absence of nausea. Base case incremental cost-effectiveness ratio (ICER) estimates were calculated. The study was from the US payer perspective.

RESULTS

In terms of CR, the PAL + NK-1-RA + DEX + OLA was associated with the highest gains in the percentage of CR among all treatment regimens at base case ICERs of $4220 versus PAL + DEX, $4656 versus NK-1-RA + PAL + DEX, $16,471 versus OLA + PAL + DEX. In term of rate of absence of nausea, the PAL + NK-1-RA + DEX + OLA was associated with the highest rate of absence of nausea among all the treatment regimens at base case ICERs of $2291 versus PAL + DEX, $1304 versus NK-1-RA + PAL + DEX, $2657 versus OLA + PAL + DEX.

CONCLUSION

from an economic perspective, our study revealed that whether to use overall CR or/and rate of absence of nausea as determinants in the antiemetic decision for the CINV patients, the CR-based-, and rate of absence of nausea-based cost-effectiveness analyses, showed negotiable ICER estimates for the treatment PAL + NK-1-RA + DEX + OLA over the combinations PAL + DEX, NK-1-RA + PAL + DEX, and OLA + PAL + DEX regimens.

Substance P/neurokinin-1 receptor pathway blockade ameliorates limbal stem cell deficiency by modulating mTOR pathway and preventing cell senescence

Severe ocular surface diseases can lead to limbal stem cell deficiency (LSCD), which is accompanied by defective healing. We aimed to evaluate the role of the substance P (SP)/neurokinin-1 receptor (NK1R) pathway in corneal epithelium wound healing in a pre-clinical model of LSCD. SP ablation or NK1R blockade significantly increased epithelial wound healing (p < 0.001) and corneal transparency (p < 0.001), compared with wild type (WT). In addition, a reduced number of infiltrating goblet and conjunctival cells (p < 0.05) and increased number of epithelial stem cells (p < 0.01), which also expressed NK1R, was observed. The mammalian target of rapamycin (mTOR) pathway was significantly inhibited (p < 0.05) and expression of γH2AX was significantly reduced (p < 0.05) after SP ablation. These results suggest that excessive expression of SP is associated with LSCD and results in accelerated senescence and exhaustion of residual stem cells. Topical treatment with NK1R antagonist ameliorates clinical signs associated with LSCD and could be used as an adjuvant treatment in LSCD.

Novel NK1R-Targeted 68Ga-/177Lu-Radioconjugates with Potential Application against Glioblastoma Multiforme: Preliminary Exploration of Structure-Activity Relationships

Locoregionally administered, NK1 receptor (NK1R) targeted radionuclide therapy is a promising strategy for the treatment of glioblastoma multiforme. So far, the radiopharmaceuticals used in this approach have been based on the endogenous agonist of NK1R, Substance P or on its close analogues. Herein, we used a well-known, small molecular NK1R antagonist, L732,138, as the basis for the radiopharmaceutical vector. First, 14 analogues of this compound were evaluated to check whether extending the parent structure with linkers of different lengths would not deteriorate the NK1R binding. The tested analogues had affinity similar to or better than the parent compound, and none of the linkers had a negative impact on the binding. Next, five DOTA conjugates were synthesized and used for labelling with ⁶⁸Ga and ¹⁷⁷Lu. The obtained radioconjugates turned out to be fairly lipophilic but showed rather limited stability in human plasma. Evaluation of the receptor affinity of the (radio)conjugates showed that neither the chelator nor the metal negatively impacts the NK1R binding. The ¹⁷⁷Lu-radioconjugates exhibited the binding characteristics towards NK1R similar or better than that of the ¹⁷⁷Lu-labelled derivative of Substance P, which is in current clinical use. The experimental results presented herein, along with their structural rationalization provided by modelling, give insight for the further molecular design of small molecular NK1R-targeting vectors.

Pharmacokinetics of morphine in combination with dexmedetomidine and maropitant following intramuscular injection in dogs anaesthetized with halothane

The purpose of this study was to evaluate the pharmacokinetics of morphine in combination with dexmedetomidine and maropitant injected intramuscularly in dogs under general anaesthesia. Eight healthy dogs weighing 25.76 ± 3.16 kg and 3.87 ± 1.64 years of age were used in a crossover study. Dogs were randomly allocated to four groups: (1) morphine 0.6 mg/kg; (2) morphine 0.3 mg/kg + dexmedetomidine 5 μg/kg; (3) morphine 0.3 mg/kg + maropitant 1 mg/kg; (4) morphine 0.2 mg/kg + dexmedetomidine 3 μg/kg + maropitant 0.7 mg/kg. Blood samples were collected before, 15 and 30 min, and 1, 2, 3 4, 6 and 8 hr after injection of the test drugs. Plasma concentration of the drugs was determined by liquid chromatography-mass spectrometry. The elimination half-life (T_1/2 ) of morphine was higher and the clearance rate (CL) was lower when combined with dexmedetomidine (T_1/2  = 77.72 ± 20.27 min, CL = 119.41 ± 23.34 ml kg^-1  min^-1 ) compared to maropitant (T_1/2  = 52.73 min ± 13.823 ml kg^-1  min^-1 , CL = 178.57 ± 70.55) or morphine alone at higher doses (T_1/2  = 50.53 ± 12.55 min, CL = 187.24 ± 34.45 ml kg^-1  min^-1 ). Combining morphine with dexmedetomidine may increase the dosing interval of morphine and may have a clinical advantage.

Population Pharmacokinetics of Rolapitant in Patients With Chemotherapy-Induced Nausea and Vomiting

Population pharmacokinetics of rolapitant and its active metabolite M19 were studied in 482 patients receiving this neurokinin-1 receptor antagonist in combination with a 5-hydroxytryptamine-3 receptor antagonist and dexamethasone for prevention of chemotherapy-induced nausea and vomiting (CINV). Patients received a single dose of rolapitant (range, 9-180 mg) before administration of moderately or highly emetogenic chemotherapy. Population pharmacokinetic analysis was performed via nonlinear mixed-effects modeling. Rolapitant pharmacokinetics was best characterized by a 2-compartment model. Population typical values were estimated to be 0.962 L/h for apparent oral clearance and 214 L for central compartment volume of distribution. The intercompartment clearance and peripheral compartment volume of distribution was estimated to be 2.79 L/h and 164 L, respectively. Metabolite M19 pharmacokinetics was described by a 1-compartment model with an apparent metabolite clearance of 1.83 L/h. Intersubject variability was moderate for pharmacokinetics parameters. Weight positively correlated with central compartment volume of distribution and peripheral compartment volume of distribution but not with apparent oral clearance. No other demographic, clinical, or pathophysiologic covariates, including liver and renal function, influenced rolapitant pharmacokinetics. A slight positive trend was observed between rolapitant exposure and efficacy (ie, complete response defined as no emesis and no use of rescue medication) in the delayed phase of CINV (>24-120 hours after chemotherapy). This further supports the 180-mg dose of rolapitant in CINV patients. In summary, this validated population pharmacokinetic model satisfactorily describes pharmacokinetics of rolapitant and M19 in patients with CINV. These results support the recommendation that no dose adjustment for patient variables investigated is necessary.

Risk Analysis for Chemotherapy-induced Nausea and Vomiting (CINV) in Patients Receiving FEC100 Treatment

BACKGROUND/AIM

Risk factors for chemotherapy-induced nausea and vomiting (CINV) with anthracycline-containing regimen for breast cancer patients remain unknown. The risk factors for CINV with FEC100 were investigated.

PATIENTS AND METHODS

Data on CINV events and patient backgrounds of 180 patients were collected from the first cycle of FEC100 treatment. In this regimen, patients were administered various antiemetics (ADs). The combinations of ADs were classified into four categories, while body mass index (BMI) was stratified into three categories. Risk factors were selected based on patient characteristics and combination of ADs. Risks for CINV were analyzed by univariate and multivariate analyses.

RESULTS

In the univariate analysis of nausea, BMI was a significant factor, while BMI and combination of ADs were significant in vomiting. In the multivariate analysis concerning nausea, BMI was a significant factor. In the analysis concerning vomiting, the combination of ADs and BMI were significant.

CONCLUSION

BMI was the most important risk factor for nausea and vomiting, while the combination of ADs was for vomiting.

Pharmacokinetic Interactions of Rolapitant With Cytochrome P450 3A Substrates in Healthy Subjects

Rolapitant (Varubi) is a neurokinin-1 receptor antagonist approved for the prevention of chemotherapy-induced nausea and vomiting. Rolapitant is primarily metabolized by the cytochrome P450 3A4 (CYP3A4) enzyme. Unlike other neurokinin-1 receptor antagonists, rolapitant is neither an inhibitor nor an inducer of CYP3A4 in vitro. The objective of this analysis was to examine the pharmacokinetics of rolapitant in healthy subjects and assess drug-drug interactions between rolapitant and midazolam (a CYP3A substrate), ketoconazole (a CYP3A inhibitor), or rifampin (a CYP3A4 inducer). Three phase 1, open-label, drug-drug interaction studies were conducted to examine the pharmacokinetic interactions of orally administered rolapitant with midazolam, rolapitant with ketoconazole, and rolapitant with rifampin. The pharmacokinetic profiles of midazolam and 1-hydroxy midazolam metabolites were essentially unchanged when coadministered with rolapitant, indicating the lack of a clinically relevant inhibition or induction of CYP3A by rolapitant. Coadministration of ketoconazole with rolapitant had no effects on rolapitant maximum concentration and resulted in an approximately 20% increase in the area under the concentration-time curve of rolapitant, suggesting that strong CYP3A inhibitors have minimal inhibitory effects on rolapitant exposure. Repeated administrations of rifampin appeared to reduce rolapitant exposure, resulting in a 33% decrease in maximum concentration and 87% decrease in area under the concentration-time curve from time zero to infinity. Coadministration of rolapitant did not affect the exposure of midazolam. Rifampin coadministration resulted in lower concentrations of rolapitant, and ketoconazole coadministration had no or minimal effects on rolapitant exposure. Rolapitant was safe and well tolerated when coadministered with ketoconazole, rifampin, or midazolam. No new safety signals were reported compared with previous studies of rolapitant.

Rolapitant for the prevention of nausea in patients receiving highly or moderately emetogenic chemotherapy

Most patients receiving highly or moderately emetogenic chemotherapy experience chemotherapy-induced nausea and vomiting without antiemetic prophylaxis. While neurokinin-1 receptor antagonists (NK-1RAs) effectively prevent emesis, their ability to prevent nausea has not been established. We evaluated the efficacy of the long-acting NK-1RA rolapitant in preventing chemotherapy-induced nausea using post hoc analyses of data from 3 phase 3 trials. Patients were randomized to receive 180 mg oral rolapitant or placebo approximately 1-2 hours before chemotherapy in combination with a 5-hydroxytryptamine type 3 RA and dexamethasone. Nausea was assessed by visual analog scale during the acute (≤24 hours), delayed (>24-120 hours), and overall (0-120 hours) phases. Post hoc analyses by treatment group (rolapitant vs control) were performed on pooled data within patient subgroups receiving cisplatin-based, carboplatin-based, or anthracycline/cyclophosphamide (AC)-based chemotherapy. In the cisplatin-based chemotherapy group, significantly more patients receiving rolapitant than control reported no nausea (NN) in the overall (52.3% vs 41.7% [P < .001]; absolute benefit [AB] = 10.6%), delayed (55.7% vs 44.3% [P < .001]; AB = 11.4%), and acute (70.5% vs 64.3% [P = .030]; AB = 6.2%) phases. Similar results were observed in the carboplatin-based chemotherapy group, with significantly more patients receiving rolapitant than control reporting NN in the overall (62.5% vs 51.2% [P = .023]; AB = 11.3%) and delayed (64.1% vs 53.6% [P = .034]; AB = 10.5%) phases. In the AC-based chemotherapy group, patients receiving rolapitant or control reported similar NN rates during the overall and delayed phases. Rolapitant effectively prevents nausea during the overall and delayed phases in patients receiving cisplatin- or carboplatin-based chemotherapy.

Recent developments in the clinical pharmacology of rolapitant: subanalyses in specific populations

Knowledge of the involvement of the neurokinin substance P in emesis has led to the development of the neurokinin-1 receptor antagonists (NK-1 RAs) for control of chemotherapy-induced nausea and vomiting (CINV), in combination with serotonin type 3 receptor antagonists and corticosteroids. The NK-1 RA rolapitant, recently approved in oral formulation, has nanomolar affinity for the NK-1 receptor, as do the other commercially available NK-1 RAs, aprepitant and netupitant. Rolapitant is rapidly absorbed and has a long half-life in comparison to aprepitant and netupitant. All three NK-1 RAs undergo metabolism by cytochrome P450 (CYP) 3A4, necessitating caution with the concomitant use of CYP3A4 inhibitors, but in contrast to aprepitant and netupitant, rolapitant does not inhibit or induce CYP3A4. However, rolapitant is a moderate inhibitor of CYP2D6, and concomitant use with CYP2D6 substrates with narrow therapeutic indices should be avoided. Aprepitant, netupitant, and rolapitant have all demonstrated efficacy in the control of delayed CINV in patients receiving moderately and highly emetogenic chemotherapy in randomized controlled trials, including over multiple cycles of chemotherapy. We reviewed recent post hoc analyses of clinical trial data demonstrating that rolapitant is efficacious in the control of CINV in patient populations with specific tumor types, namely, breast cancers, gastrointestinal/colorectal cancers, and lung cancers. In addition, we show that rolapitant has efficacy in the control of CINV in specific age groups of patients receiving chemotherapy (<65 and ≥65 years of age). Overall, the safety profile of rolapitant in these specific patient populations was consistent with that observed in primary analyses of phase 3 trials.

Dihydroavenanthramide D inhibits mast cell degranulation and exhibits anti-inflammatory effects through the activation of neurokinin-1 receptor

Chronic pruritus is difficult to treat. Current treatment options are frequently ineffective and new therapeutic approaches are urgently needed. Avenanthramides are active substances in oats that exhibit anti-inflammatory effects. Their potential to interrupt pruritus mechanisms was investigated in this study. It was found that the synthetic analog dihydroavenanthramide D (DHAvD) can interact with the neurokinin-1 receptor (NK1R) and inhibit mast cell degranulation. DHAvD also affects inflammatory processes and reduces secretion of the cytokine interleukin-6. Our findings indicate that DHAvD may act as a NK1R inhibitor and could be a promising candidate for topical treatments of chronic pruritus.

Efficacy of the neurokinin-1 receptor antagonist rolapitant in preventing nausea and vomiting in patients receiving carboplatin-based chemotherapy

BACKGROUND

Rolapitant, a novel neurokinin‐1 receptor antagonist, provided effective protection against chemotherapy‐induced nausea and vomiting (CINV) in a randomized, double‐blind phase 3 trial of patients receiving moderately emetogenic chemotherapy or an anthracycline and cyclophosphamide regimen. The current analysis explored the efficacy and safety of rolapitant in preventing CINV in a subgroup of patients receiving carboplatin.

METHODS

Patients were randomized 1:1 to receive oral rolapitant (180 mg) or a placebo 1 to 2 hours before chemotherapy administration; all patients received oral granisetron (2 mg) on days 1 to 3 and oral dexamethasone (20 mg) on day 1. A post hoc analysis examined the subgroup of patients receiving carboplatin in cycle 1. The efficacy endpoints were as follows: complete response (CR), no emesis, no nausea, no significant nausea, complete protection, time to first emesis or use of rescue medication, and no impact on daily life.

RESULTS

In the subgroup administered carboplatin‐based chemotherapy (n = 401), a significantly higher proportion of patients in the rolapitant group versus the control group achieved a CR in the overall phase (0‐120 hours; 80.2% vs 64.6%; P < .001) and in the delayed phase (>24‐120 hours; 82.3% vs 65.6%; P < .001) after chemotherapy administration. Superior responses were also observed by the measures of no emesis, no nausea, and complete protection in the overall and delayed phases and by the time to first emesis or use of rescue medication. The incidence of treatment‐emergent adverse events was similar for the rolapitant and control groups.

CONCLUSIONS

Rolapitant provided superior CINV protection to patients receiving carboplatin‐based chemotherapy in comparison with the control. These results support rolapitant use as part of the antiemetic regimen in carboplatin‐treated patients. Cancer 2016;122:2418–2425. © 2016 American Cancer Society.

The efficacy of rolapitant, a neurokinin‐1 receptor antagonist with a long duration of action, was examined in a subgroup of 401 patients with cancer who received carboplatin‐based chemotherapy in a phase 3 trial. In this population, a single oral dose of rolapitant (180 mg) combined with granisetron and dexamethasone provided statistically superior protection against chemotherapy‐induced nausea and vomiting in the delayed and overall phases in comparison with granisetron and dexamethasone alone, and it was well tolerated.

A phase III study evaluating the safety and efficacy of NEPA, a fixed-dose combination of netupitant and palonosetron, for prevention of chemotherapy-induced nausea and vomiting over repeated cycles of chemotherapy

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.

Efficacy and safety of NEPA, an oral combination of netupitant and palonosetron, for prevention of chemotherapy-induced nausea and vomiting following highly emetogenic chemotherapy: a randomized dose-ranging pivotal study

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.

A randomized phase III study evaluating the efficacy and safety of NEPA, a fixed-dose combination of netupitant and palonosetron, for prevention of chemotherapy-induced nausea and vomiting following moderately emetogenic chemotherapy

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.

Safety, efficacy, and patient acceptability of single-dose fosaprepitant regimen for the prevention of chemotherapy-induced nausea and vomiting

Control of chemotherapy-induced nausea and vomiting (CINV) is a crucial factor in ensuring that patients undergoing cancer chemotherapy can get the full benefit of therapy. Current antiemetic guidelines recommend that the neurokinin-1 receptor (NK-1R) antagonist aprepitant should be used as part of a combination regimen with dexamethasone and a serotonin receptor antagonist for the prevention of CINV in patients receiving highly emetogenic chemotherapy (HEC). Fosaprepitant is a water-soluble N-phosphoryl derivative of aprepitant that, when infused, is rapidly metabolized back to an active aprepitant. The existing literature in PubMed about fosaprepitant was screened and selected in order to address the emerging data from two randomized clinical trials evaluating the efficacy and safety of a single-dose fosaprepitant regimen. These phase III trials demonstrated that fosaprepitant given as a single intravenous dose of 150 mg was either noninferior to the conventional 3-day aprepitant or significantly superior to placebo for the prevention of acute and delayed CINV in patients receiving high-dose cisplatin. In both trials, fosaprepitant was well tolerated although more frequent infusion-site adverse events were observed with fosaprepitant. The new dosage regimen of fosaprepitant, therefore, would be an option for CINV control in patients receiving cisplatin-based chemotherapy. The clinical efficacy is consistent with the findings from a time-on-target, positron-emission tomography study evaluating the NK-1R occupancy in the central nervous system (CNS) over 5 days after a single-dose infusion of 150 mg fosaprepitant in healthy participants. The single-dose regimen is capable of blocking more than 90% of the NK-1Rs in the CNS for at least 48 hours after infusion, which is sufficient to control delayed CINV for 2 to 5 days after HEC. The new dosage regimen of fosaprepitant can provide a simplified treatment option that maintains high protection while ensuring adherence to scheduled antiemetic medication throughout most of the 5-day period encompassing the major risk for CINV.

Pharmacokinetic evaluation of fosaprepitant dimeglumine

IMPORTANCE OF THE FIELD

Chemotherapy induced nausea and vomiting (CINV) is a common complication in the treatment of patients with cancer. The introduction of the first in class neurokinin-1 receptor antagonist aprepitant provided additive control on CINV in combination to existing antiemetics. Due to formulation issues, aprepitant is only available for oral administration. Fosaprepitant, a prodrug of aprepitant, was introduced to the market in 2008 as an intravenous bioequivalent to aprepitant.

AREAS COVERED IN THIS REVIEW

This review examines the chemical development of fosaprepitant, its pharmacokinetic properties, approved uses and potential applications.

WHAT THE READER WILL GAIN

The reader will get up-to-date information on the pharmacology and clinical uses of fosaprepitant. Clinical studies have demonstrated pharmacokinetic bioequivalence of aprepitant 125 mg to fosaprepitant 115 mg, as well as comparable efficacy in prevention of acute and delayed emesis following the first day of chemotherapy regimens.

TAKE HOME MESSAGE

Fosaprepitant is an intravenous prodrug of aprepitant that offers a new alternative to patients with CINV. Currently, fosaprepitant can substitute oral aprepitant in day 1 of a 3-day regimen. Current studies show that a single-day fosaprepitant regimen is also bioequivalent to the 3-day aprepitant regimen; this could significantly simplify the care for CINV patients in the future.