Evolving role of neurokinin 1-receptor antagonists for chemotherapy-induced nausea and vomiting

Rapid elucidation of agonist-driven regulation of the neurokinin 1 receptor using a GPCR phosphorylation immunoassay

Agonist-induced phosphorylation is a crucial step in the activation/deactivation cycle of G protein-coupled receptors (GPCRs), but direct determination of individual phosphorylation events has remained a major challenge. We have recently developed a bead-based immunoassay for the quantitative assessment of agonist-induced GPCR phosphorylation that can be performed entirely in 96-well plates, thus eliminating the need for western blot analysis. In the present study, we adapted this assay to three novel phosphosite-specific antibodies directed against the neurokinin 1 (NK1) receptor, namely pS338/pT339-NK1, pT344/pS347-NK1, and pT356/pT357-NK1. We found that substance P (SP) stimulated concentration-dependent phosphorylation of all three sites, which could be completely blocked in the presence of the NK1 receptor antagonist aprepitant. The other two endogenous ligands of the tachykinin family, neurokinin A (NKA) and neurokinin B (NKB), were also able to induce NK1 receptor phosphorylation, but to a much lesser extent than substance P. Interestingly, substance P promoted phosphorylation of the two distal sites more efficiently than that of the proximal site. The proximal site was identified as a substrate for phosphorylation by protein kinase C. Analysis of GPCR kinase (GRK)-knockout cells revealed that phosphorylation was mediated by all four GRK isoforms to similar extents at the T344/S347 and the T356/T357 cluster. Knockout of all GRKs resulted in abolition of all phosphorylation signals highlighting the importance of these kinases in agonist-mediated receptor phosphorylation. Thus, the 7TM phosphorylation assay technology allows for rapid and detailed analyses of GPCR phosphorylation.

Neiguan (PC6) acupoint stimulation for preventing chemotherapy-induced nausea and vomiting: a cost-effective supplement in guideline-inconsistent chemotherapy-induced nausea and vomiting prophylaxis subgroup

OBJECTIVE

To assess the efficacy and safety of Neiguan (PC6) acupoint acustimulation in preventing chemotherapy-induced nausea and vomiting (CINV), especially for patients with guideline-inconsistent CINV prophylaxis (GICP) due to personal reasons METHODS: From January 2021 to December 2021, 373 patients suffered from solid malignancy were recruited according to the inclusion criteria. Complete response (no emesis and no rescue medication use) rate during the overall phase (0-120 h of each chemo-cycle) was the primary assessment of CINV control. The Functional Living Index-Emesis (FLIE) questionnaire was investigated among these patients as a secondary 'quality of life' objective to assess the impact of CINV on patients' daily life by recording score of nausea and vomiting.

RESULTS

With acustimulation of Neiguan (PC6) acupuncture point through a portable, noninvasive and user-friendly device, in terms of complete response rate and scores in nausea/vomiting by FLIE questionnaire, patients achieve a better outcome in highly emetogenic chemotherapy (HEC) induced CINV, especially GICP subgroup. Meanwhile, analysis also demonstrated this tendency existed in other patients with HEC/GCCP (guideline consistent CINV prophylaxis) and moderate emetogenic chemotherapy, although the difference was not significant.

CONCLUSION

Considering advantages of Neiguan (PC6) acustimulation such as noninvasive, covered by medical insurance and few side effects, we believe it would be an ideal auxiliary tool in CINV control, especially in patients who receive highly emetogenic chemo-protocol and are reluctant to GCCP for economic reasons.

A Postoperative Nausea and Vomiting Update: Current information on New Drugs, Old Drugs, Rescue/Treatment, Combination Therapies and Nontraditional Modalities

This article's objective is to present the latest evidence and information on the management of postoperative nausea and vomiting (PONV). PONV continues to affect 30% of the surgical population causing patient dissatisfaction, extending length of stay, and increasing overall costs. This review includes the introduction of 2 new intravenous formulations of antiemetics (amisulpride, aprepitant), updates on nontraditional therapies, suggestions for combination prophylaxis, emerging data on rescue treatment, and considerations for special populations and settings. Both of the new antiemetics provide promising options for pharmacologic interventions for PONV with favorable safety profiles.

Olanzapine With or Without Fosaprepitant for Preventing Chemotherapy Induced Nausea and Vomiting in Patients Receiving Highly Emetogenic Chemotherapy: A Phase III Randomized, Double-Blind, Placebo-Controlled Trial (ALLIANCE A221602)

PURPOSE

A protocol was developed to evaluate the value of an NK-1 receptor antagonist for preventing nausea and vomiting resulting from highly emetogenic chemotherapy when an olanzapine-based antiemetogenic regimen was used.

MATERIALS AND METHODS

A221602, a prospective double-blind, placebo-controlled clinical trial, was developed to compare 2 -olanzapine-containing antiemetic regimens, one with an NK-1 receptor antagonist (aprepitant or fosaprepitant) and one without. Trial patients had a malignant disease for which they received intravenous highly emetogenic chemotherapy (single day cisplatin ≥ 70 mg/m2 or doxorubicin plus cyclophosphamide on 1 day). Patients on both arms received commonly administered doses of a 5-HT3 receptor antagonist, dexamethasone, and olanzapine. Additionally, patients were randomized to receive an NK-1 receptor antagonist (fosaprepitant 150 mg IV or aprepitant 130 mg IV) or a corresponding placebo. The primary objective was to compare the proportion of patients with no nausea for 5 days following chemotherapy between the 2 study arms. This trial was designed to test for the noninferiority of deleting the NK-1 receptor antagonist, with noninferiority defined as a decrease in freedom from nausea by less than 10%.

RESULTS

A total of 690 patients were entered on this trial, 50% on each arm. The proportion of patients without nausea for the complete 5-day study period was 7.4% lower (upper limit of the one-sided 95% confidence interval was 13.5%) in the arm without an NK-1 receptor antagonist compared with the arm with an NK-1 receptor antagonist.

CONCLUSION

This trial did not provide sufficient evidence to support that deletion of the NK-1 receptor antagonist was as good as keeping it, as a part of a 4-drug antiemetic regimen for highly emetogenic chemotherapy (ClinicalTrials.gov Identifier: NCT03578081).

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.

Regional differences of tachykinin effects on smooth muscle and pacemaker potentials of the stomach, duodenum, ileum and colon of an emetic model, the house musk shrews

BACKGROUND AND AIMS

The contractile effects of tachykinins on the gastrointestinal tract are well-known, but how they modulate slow-waves, particularly in species capable of emesis, remains largely unknown. We aimed to elucidate the effects of tachykinins on myoelectric and contractile activity of isolated gastrointestinal tissues of the Suncus murinus.

METHODS

The effects of substance P (SP), neurokinin (NK)A, NKB and selective NK₁ (CP122,721, CP99,994), NK₂ (SR48,968, GR159,897) and NK₃ (SB218,795, SB222,200) receptor antagonists on isolated stomach, duodenum, ileum and colon segments were studied. Mechanical contractile activity was recorded using isometric force displacement transducers. Electrical pacemaker activity was recorded using a microelectrode array.

RESULTS

Compared with NKA, SP induced larger contractions in stomach tissue and smaller contractions in intestinal segments, where oscillation magnitudes increased in intestinal segments, but not the stomach. CP122,721 and GR159,897 inhibited electrical field stimulation-induced contractions of the stomach, ileum and colon. NKB and NK₃ had minor effects on contractile activity. The inhibitory potencies of SP and NKA on the peristaltic frequency of the colon and ileum, respectively, were correlated with those on electrical pacemaker frequency. SP, NKA and NKB inhibited pacemaker activity of the duodenum and ileum, but increased that of the stomach and colon. SP elicited a dose-dependent contradictive pacemaker frequency response in the colon.

CONCLUSION

This study revealed distinct effects of tachykinins on the mechanical and electrical properties of the stomach and colon vs. the proximal intestine, providing a unique aspect on neuromuscular correlation in terms of the effects of tachykinin on peristaltic and pacemaker activity in gastrointestinal-related symptoms.

Fosaprepitant: current options to prevent chemotherapy-induced nausea and vomiting: A review

Background. Chemotherapy (CT) is a mainstay of treatment for malignant tumors. CT-induced nausea and vomiting are observed in 3090% of patients within 0120 h after moderate and highly emetogenic CT administration. These adverse events can severely impact the quality of treatment, daily life, and adherence to treatment, thus reducing the effectiveness of therapy and survival. Materials and methods. The author provides the results of a systematic review of research papers, including clinical studies, on the efficacy of the neurokinin-1 receptor antagonist fosaprepitant to prevent CT-induced nausea and vomiting. Data from the PubMed database were reviewed. Results. The prevention and treatment of CT-associated nausea and vomiting are vital during special therapy, including symptomatic therapy. International organizations recommend using a triple combination with antagonists of neurokinin-1 and 5-hydroxytryptamine-3 receptors and dexamethasone. According to the data obtained, the efficacy of fosaprepitant has been proven in delayed and general phases in several large, well-planned studies; the drug reduces the incidence of adverse events by 2.74.4 times compared with aprepitant. Conclusion. Fosaprepitant is an antagonist of neurokinin-1 receptors; when administered intravenously, it rapidly converts into aprepitant. When used as part of a triple combination with 5-hydroxytryptamine-3 receptor antagonists and dexamethasone in patients receiving moderate and highly emetogenic CT leads to a higher rate of complete response when controlling nausea and vomiting. In general, fosaprepitant is well tolerated.

Migraine and Gastroparesis

PURPOSEOF REVIEW

Migraine is a chronic and disabling disease affecting a significant proportion of the world's population. There is evidence that gastroparesis, a gastrointestinal (GI) dysmotility disorder in which transit of gastric contents is delayed, can occur in the setting of migraine. This article aims to review recent literature on overlap in the pathophysiology and clinical manifestations of migraine and gastroparesis and highlight management considerations when these disorders coexist.

RECENT FINDINGS

There has been increasing recognition of the importance of the connection between the GI tract and the brain, and mounting evidence for the overlap in the pathophysiology of migraine and gastroparesis specifically. There exists a complex interplay between the central, autonomic, and enteric nervous systems. Studies show that gastroparesis may be present during and between acute migraine attacks necessitating modification of management to optimize outcomes. Gastric dysmotility in the setting of migraine can impact absorption of oral migraine medications and alternate formulations should be considered for some patients. Noninvasive vagus nerve stimulation has been FDA cleared for migraine treatment and is also being studied in gastroparesis. Dysfunction of the autonomic nervous system is a significant feature in the pathophysiology of gut motility and migraine, making treatments that modulate the vagus nerve attractive for future research.

AGA Clinical Practice Update on Management of Medically Refractory Gastroparesis: Expert Review

DESCRIPTION

Delayed gastric emptying on objective testing defines gastroparesis, but symptoms overlap with functional dyspepsia and do not correlate well with gastric emptying delay. This review outlines a strategy for defining, diagnosing, and managing refractory gastroparesis.

METHODS

The Best Practice Advice statements presented here were developed from review of existing literature combined with expert opinion to provide practical advice. Because this was not a systematic review, formal rating of the quality of evidence or strength of recommendations was not performed. BEST PRACTICE ADVICE.

Management of Intractable Symptoms in Oncologic Care

PURPOSE OF REVIEW

For patients undergoing evaluation and treatment of cancers, symptom management is a critical component of their treatment plan. For some patients, symptoms may become intractable or refractory to common therapies. Here, we review treatment options for these severe symptom conditions.

RECENT FINDINGS

Medication options and regimens have improved to treat refractory symptoms. Medications can be tailored to treat chemotherapy-induced nausea and vomiting based on current guidelines. Interventions such as venting gastrostomy can mitigate symptoms associated with malignant bowel obstruction, when life expectancy is long enough to realize this benefit. Opiates can reduce refractory dyspnea, consistent with guidelines from the American Thoracic Society. Interventional therapies for intractable pain, such as neurolytic blocks and intrathecal pumps, have shown promise in managing symptoms when traditional therapies have been ineffective. Refractory symptoms can be managed in cancer care. The use of multimodal therapies delivered by interdisciplinary teams appears to be the most effective way to approach these clinical situations.

Mechanisms of Nausea and Vomiting: Current Knowledge and Recent Advances in Intracellular Emetic Signaling Systems

Nausea and vomiting are common gastrointestinal complaints that can be triggered by diverse emetic stimuli through central and/or peripheral nervous systems. Both nausea and vomiting are considered as defense mechanisms when threatening toxins/drugs/bacteria/viruses/fungi enter the body either via the enteral (e.g., the gastrointestinal tract) or parenteral routes, including the blood, skin, and respiratory systems. While vomiting is the act of forceful removal of gastrointestinal contents, nausea is believed to be a subjective sensation that is more difficult to study in nonhuman species. In this review, the authors discuss the anatomical structures, neurotransmitters/mediators, and corresponding receptors, as well as intracellular emetic signaling pathways involved in the processes of nausea and vomiting in diverse animal models as well as humans. While blockade of emetic receptors in the prevention of vomiting is fairly well understood, the potential of new classes of antiemetics altering postreceptor signal transduction mechanisms is currently evolving, which is also reviewed. Finally, future directions within the field will be discussed in terms of important questions that remain to be resolved and advances in technology that may help provide potential answers.

The efficacy of aprepitant in salvage treatment of chemotherapy-induced nausea and vomiting associated with moderately emetogenic chemotherapy for patients with gastrointestinal cancer

PURPOSE

To evaluate the efficacy of aprepitant and its effect on the quality of life when added to standard antiemetic therapy as salvage therapy.

PATIENTS AND METHODS

This is an open-label, noncomparative prospective phase II clinical trial. A total of 224 patients receiving initial moderately emetogenic chemotherapy (MEC) were enrolled. Patients received standard antiemetic treatment (5-hydroxytryptamine (5-HT₃) antagonists + dexamethasone) in the first cycle. Patients failing to achieve a complete response (CR) during cycle 1 entered cycle 2 with the addition of aprepitant as salvage treatment.

RESULTS

Of the 224 patients eligible for cycle 1, 159 (71.0%, 95% CI 65.0-77.0) had a CR, and 65 patients with a noncomplete response (NCR) proceeded to cycle 2 to receive aprepitant-based salvage therapy. Then, 49 (75.4%, 95% CI 64.6-84.1) of these patients achieved a CR. The Functional Living Index-Emesis (FLIE) questionnaire showed that NCR patients in cycle 1 had an improved quality of life after receiving aprepitant-based salvage therapy in cycle 2 (cycle 1 and 2: 80.3 vs 114.0, P < 0.001). Failing to achieve a CR had a significant impact on the quality of life in both cycle 1 (FLIE score of NCR and CR patients: 80.3 vs 119.7, P < 0.001) and cycle 2 (FLIE score of NCR and CR patients: 88.3 vs 122.4, P < 0.001).

CONCLUSION

The addition of aprepitant as salvage therapy for patients with gastrointestinal cancer is effective and has a positive effect on quality of life.

Efficacy of intravenous NEPA, a fixed NK1/5-HT3 receptor antagonist combination, for the prevention of chemotherapy-induced nausea and vomiting (CINV) during cisplatin- and anthracycline cyclophosphamide (AC)-based chemotherapy: A review of phase 3 studies

This paper presents an overview of the efficacy of intravenous (IV) NEPA (fixed combination of the NK₁RA, fosnetupitant, and 5-HT₃RA, palonosetron) relative to oral NEPA and also to historical data for other NK₁RA 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 NK₁RA 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 NK₁RA 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 NK₁RA regimens due to its lack of associated hypersensitivity and injection-site reactions.

Efficacy of acupuncture in the prevention and treatment of chemotherapy-induced nausea and vomiting in patients with advanced cancer: a multi-center, single-blind, randomized, sham-controlled clinical research

Background

Chemotherapy-induced nausea and vomiting (CINV) is a common and distressing side effect. We conducted this clinical trial to compare the effectiveness of true acupuncture vs. sham acupuncture in controlling chemotherapy-induced nausea and vomiting (CINV) among patients with advanced cancer.

Methods

A total of 134 participants were randomly allocated into true acupuncture (TA) (n = 68) and sham acupuncture (SA) (n = 66) groups. Participants in both groups received acupuncture session twice on the first day of chemotherapy, and once consecutively on the following 4 days. The primary outcome was using the Common Terminology Criteria for Adverse Events (CTCAE) to assess CINV. The secondary outcome measures were the Eastern Cooperative Oncology Group score (ECOG), Simplified Nutritional Appetite Questionnaire (SNAQ), and Hospital Anxiety and Depression scale (HADS).

Results

Compared to the SA group, the TA group didn’t show significant improvement in complete response rates of chemotherapy-induced nausea and vomiting (all P > 0.05). However, the TA group could modestly reduce the severity of nausea (from day-3 to day-21, P < 0.05) or vomiting (from day-4 to day-21, P < 0.05), which is notably superior to the control group. Besides, TA promoted the nutritional status of patients with a significantly higher score comparing to the SA group on day 14 (21.82 vs.20.12, P = 0.003) and day 21 (22.39 vs. 20.43, P = 0.001). No apparent differences were found in anxiety and depression assessment between these groups. Participants in both groups were well tolerant of acupuncture therapy. There was no adverse event occurs in our study.

Conclusion

Acupuncture as an adjunctive approach could alleviate the severity of chemotherapy-induced nausea and vomiting compared to the sham control, even though the effect of acupuncture in preventing CINV occurring is relatively modest.

Evaluating the anti-inflammatory and analgesic properties of maropitant: A systematic review and meta-analysis

The neurotransmitter Substance P, and its neurokinin-1 receptor (NK-1R) are involved in the regulation of many pathophysiological processes including emesis, inflammation and nociceptive processing. This review provides a brief summary of the anti-inflammatory and analgesic properties of experimental NK-1R antagonists followed by a systematic review and meta-analysis on maropitant, the only NK-1R antagonist with a label indication for emesis in veterinary patients. There is very limited evidence based information on the putative clinical utilisation of maropitant for pain and inflammation. The aim of this systematic review and meta-analysis was to evaluate published reports on anti-inflammatory, analgesic and anaesthesia-sparing effects of maropitant. Medline, Pubmed, Science direct and Web of Science were searched to identify all published studies on maropitant, followed by a meta-analysis. Fourteen studies with 128 animals receiving maropitant and 127 controls met the inclusion criteria. Overall, maropitant had a significant inhalation anaesthetic-sparing effect (SMD -0.92, 95% CI -1.30, -0.54; P < 0.00001). However, treatment with maropitant had no effect on pain (SMD 0.06, 95% CI -0.37, 0.48; P = 0.80), or leukocyte cell infiltration in different inflammatory conditions (SMD -0.60, 95% CI -1.31, 0.11; P = 0.10). Based on all eligible studies for this review, it can be deduced that maropitant significantly reduced the minimum alveolar concentrations for isoflurane and sevoflurane for many different surgical procedures but it had no clearly proven effect on inflammation and pain.

Expert Consensus on Effective Management of Chemotherapy-Induced Nausea and Vomiting: An Indian Perspective

Chemotherapy-induced nausea and vomiting (CINV) is one of the most common and feared side effects in cancer patients undergoing chemotherapy. Scientific evidence proves its detrimental impact on a patient's quality of life (QoL), treatment compliance, and overall healthcare cost. Despite the CINV-management landscape witnessing a radical shift with the introduction of novel, receptor-targeting antiemetic agents, this side effect remains a chink in the armor of a treating oncologist. Though global guidelines acknowledge patient-specific risk factors and chemotherapeutic agent emetogenic potential in CINV control, a “one-fit-for-all” approach cannot be followed across all geographies. Hence, in a pioneering attempt, India-based oncologists conveyed easily implementable, region-specific, consensus-based statements on CINV prevention and management. These statements resulted from integrating the analysis of scientific evidence and guidelines on CINV by the experts, with their clinical experience. The statements will strengthen decision-making abilities of Indian oncologists/clinicians and help in achieving consistency in CINV prevention and management in the country. Furthermore, this document shall lay the foundation for developing robust Indian guidelines for CINV prevention and control.

Phase IIIb Safety and Efficacy of Intravenous NEPA for Prevention of Chemotherapy-Induced Nausea and Vomiting (CINV) in Patients with Breast Cancer Receiving Initial and Repeat Cycles of Anthracycline and Cyclophosphamide (AC) Chemotherapy

BACKGROUND

NEPA, a combination antiemetic of a neurokinin-1 (NK1 ) receptor antagonist (RA) (netupitant [oral]/fosnetupitant [intravenous; IV]) and 5-HT3 RA, palonosetron] offers 5-day CINV prevention with a single dose. Fosnetupitant solution contains no allergenic excipients, surfactant, emulsifier, or solubility enhancer. A phase III study of patients receiving cisplatin found no infusion-site or anaphylactic reactions related to IV NEPA. However, hypersensitivity reactions and anaphylaxis have been reported with other IV NK1 RAs, particularly fosaprepitant in patients receiving anthracycline-cyclophosphamide (AC)-based chemotherapy. This study evaluated the safety and efficacy of IV NEPA in the AC setting.

MATERIALS AND METHODS

This phase IIIb, multinational, randomized, double-blind study enrolled females with breast cancer naive to highly or moderately emetogenic chemotherapy. Patients were randomized to receive a single 30-minute infusion of IV NEPA or single oral NEPA capsule on day 1 prior to AC, in repeated (up to 4) cycles. Oral dexamethasone was given to all patients on day 1 only.

RESULTS

A total of 402 patients were included. The adverse event (AE) profiles were similar for IV and oral NEPA and consistent with those expected. Most AEs were mild or moderate with a similarly low incidence of treatment-related AEs in both groups. There were no treatment-related injection-site AEs and no reports of hypersensitivity or anaphylaxis. The efficacy of IV and oral NEPA were similar, with high complete response (no emesis/no rescue) rates observed in cycle 1 (overall [0-120 hours] 73.0% IV NEPA, 77.3% oral NEPA) and maintained over subsequent cycles.

CONCLUSION

IV NEPA was highly effective and safe with no associated hypersensitivity and injection-site reactions in patients receiving AC.

IMPLICATIONS FOR PRACTICE

As a combination of a neurokinin-1 (NK1 ) receptor antagonist (RA) and 5-HT3 RA, NEPA offers 5-day chemotherapy-induced nausea and vomiting prevention with a single dose and an opportunity to improve adherence to antiemetic guidelines. In this randomized multinational phase IIIb study, intravenous (IV) NEPA (fosnetupitant/palonosetron) was safe and highly effective in patients receiving multiple cycles of anthracycline-cyclophosphamide (AC)-based chemotherapy. Unlike other IV NK1 RAs, the IV NEPA combination solution does not require any surfactant, emulsifier, or solubility enhancer and contains no allergenic excipients. Hypersensitivity reactions and anaphylaxis have been reported with other IV NK1 RAs, most commonly with fosaprepitant in the AC setting. Importantly, there were no injection-site or hypersensitivity reactions associated with IV NEPA.

Nausea and Vomiting in Advanced Cancer

OPINION STATEMENT

Nausea and vomiting is a common clinical issue in the advanced cancer patient. The etiology may be related to treatment (chemotherapy, radiation, surgery) or non-treatment clinical issues related to the advanced cancer. A very detailed initial assessment of nausea/vomiting is indicated including frequency, duration, intensity, associated activities, and the presence of anorexia or cachexia and is necessary in order to determine a specific etiology which may allow a potentially specific successful intervention. Various international antiemetic guidelines have been developed for the successful prevention of chemotherapy- and radiotherapy-induced nausea and emesis but the treatment of post-chemotherapy nausea/vomiting and of radiation-induced nausea/vomiting has been less successful. Chronic nausea/vomiting in the advanced cancer patient unrelated to treatment remains a significant clinical problem with few successful treatments and interventions. NCCN and ASCO palliative care guidelines provide various treatment suggestions but these are based on empiric evidence with very few clinical trials available to provide demonstrated effective treatments. Recent randomized clinical trials have demonstrated that olanzapine may be an effective agent for the prevention and treatment of chemotherapy-induced nausea and emesis as well as treatment of chronic nausea and vomiting unrelated to treatment.

The pivotal role of glycogen synthase kinase 3 (GSK-3) in vomiting evoked by specific emetogens in the least shrew (Cryptotis parva)

Glycogen synthase kinase 3 (GSK-3) is a constitutively active multifunctional serine-threonine kinase which is involved in diverse physiological processes. GSK-3 has been implicated in a wide range of diseases including neurodegeneration, inflammation, diabetes and cancer. GSK-3 is a downstream target for protein kinase B (Akt) which phosphorylates GSK-3 and suppresses its activity. Based upon our preliminary findings, we postulated Akt's involvement in emesis. The aim of this study was to investigate the participation of GSK-3 and the antiemetic potential of two GSK-3 inhibitors (AR-A014418 and SB216763) in the least shrew model of vomiting against fully-effective emetic doses of diverse emetogens, including the nonselective and/or selective agonists of serotonin type 3 (e.g. 5-HT or 2-Methyl-5-HT)-, neurokinin type 1 receptor (e.g. GR73632), dopamine D₂ (e.g. apomorphine or quinpirole)-, and muscarinic 1 (e.g. pilocarpine or McN-A-343) receptors, as well as the L-type Ca²⁺ channel agonist (FPL64176), the sarco/endoplasmic reticulum Ca²⁺-ATPase inhibitor thapsigargin, and the chemotherapeutic agent, cisplatin. We first determined if these emetogens could regulate the phosphorylation level of GSK-3 in the brainstem emetic loci of least shrews and then investigated whether AR-A014418 and SB216763 could protect against the evoked emesis. Phospho-GSK-3α/β Ser21/9 levels in the brainstem and the enteric nerves of jejunum in the small intestine were upregulated following intraperitoneal (i.p.) administration of all the tested emetogens. Furthermore, administration of AR-A014418 (2.5-20 mg/kg, i.p.) dose-dependently attenuated both the frequency and percentage of shrews vomiting in response to i.p. administration of 5-HT (5 mg/kg), 2-Methyl-5-HT (5 mg/kg), GR73632 (5 mg/kg), apomorphine (2 mg/kg), quinpirole (2 mg/kg), pilocarpine (2 mg/kg), McN-A-343 (2 mg/kg), FPL64176 (10 mg/kg), or thapsigargin (0.5 mg/kg). Relatively lower doses of SB216763 exerted antiemetic efficacy, but both inhibitors barely affected cisplatin (10 mg/kg)-induced vomiting. Collectively, these results support the notion that vomiting is accompanied by a downregulation of GSK-3 activity and pharmacological inhibition of GSK-3 protects against pharmacologically evoked vomiting.

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.