Randomized phase II study of the neurokinin 1 receptor antagonist CJ-11,974 in the control of cisplatin-induced emesis

Efficacy and safety of antiemetic regimens for highly emetogenic chemotherapy-induced nausea and vomiting: A systematic review and network meta-analysis

BACKGROUND

Several regimens have been introduced in clinical practice in the last twenty years to treat chemotherapy-induced nausea and vomiting (CINV). However, direct comparative data remain insufficient, as many new regimes lack head-to-head comparisons. In this study, through an indirect comparison, we overcome this limit by providing the most up-to-date estimate of the efficacy and safety of all combinations used for HEC-induced nausea and vomiting.

PATIENTS AND METHODS

We retrieved randomized controlled trials (RCTs) published in Pubmed, Embase, and Cochrane Library until June, 30th 2022. We included phase II-III RCTs, including adults with any cancer receiving HEC, and compared different antiemetic regimes to prevent CINV. The primary outcome was the overall complete response (defined as the absence of vomiting and of the use of rescue drugs from 0 to 120 hrs since chemotherapy); secondary outcomes were acute (absence of vomiting and use of rescue medicine 0-24 hrs after chemotherapy) and delayed (24-120 hrs) response and adverse events.

RESULTS

A total of 53 RCTs enrolling 22 228 patients were included. We classified the different antiemetic regimes into 21 different groups. Overall, 3- or 4-drug regimens containing a combination of dexamethasone, 5HT3 antagonists, mirtazapine or olanzapine with or without NK antagonists, yielded the highest probability to be the most effective regimen in terms of complete response. Regimens containing a combination of dexamethasone and 5-HT3 antagonist have the lowest probability of being the most effective regimen in terms of complete, acute, and delayed response.

CONCLUSION

In our network meta-analysis, 4-drug regimens with olanzapine displayed the highest probability of efficacy in terms of complete response. A 3-drug regimen with olanzapine represents a valid option in a limited resource context.

Antiemetics for adults for prevention of nausea and vomiting caused by moderately or highly emetogenic chemotherapy: a network meta-analysis

BACKGROUND

About 70% to 80% of adults with cancer experience chemotherapy-induced nausea and vomiting (CINV). CINV remains one of the most distressing symptoms associated with cancer therapy and is associated with decreased adherence to chemotherapy. Combining 5-hydroxytryptamine-3 (5-HT₃) receptor antagonists with corticosteroids or additionally with neurokinin-1 (NK₁) receptor antagonists is effective in preventing CINV among adults receiving highly emetogenic chemotherapy (HEC) or moderately emetogenic chemotherapy (MEC). Various treatment options are available, but direct head-to-head comparisons do not allow comparison of all treatments versus another.  OBJECTIVES: • In adults with solid cancer or haematological malignancy receiving HEC - To compare the effects of antiemetic treatment combinations including NK₁ receptor antagonists, 5-HT₃ receptor antagonists, and corticosteroids on prevention of acute phase (Day 1), delayed phase (Days 2 to 5), and overall (Days 1 to 5) chemotherapy-induced nausea and vomiting in network meta-analysis (NMA) - To generate a clinically meaningful treatment ranking according to treatment safety and efficacy • In adults with solid cancer or haematological malignancy receiving MEC - To compare whether antiemetic treatment combinations including NK₁ receptor antagonists, 5-HT₃ receptor antagonists, and corticosteroids are superior for prevention of acute phase (Day 1), delayed phase (Days 2 to 5), and overall (Days 1 to 5) chemotherapy-induced nausea and vomiting to treatment combinations including 5-HT₃ receptor antagonists and corticosteroids solely, in network meta-analysis - To generate a clinically meaningful treatment ranking according to treatment safety and efficacy SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, conference proceedings, and study registries from 1988 to February 2021 for randomised controlled trials (RCTs).

SELECTION CRITERIA

We included RCTs including adults with any cancer receiving HEC or MEC (according to the latest definition) and comparing combination therapies of NK₁ and 5-HT₃ inhibitors and corticosteroids for prevention of CINV.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We expressed treatment effects as risk ratios (RRs). Prioritised outcomes were complete control of vomiting during delayed and overall phases, complete control of nausea during the overall phase, quality of life, serious adverse events (SAEs), and on-study mortality. We assessed GRADE and developed 12 'Summary of findings' tables. We report results of most crucial outcomes in the abstract, that is, complete control of vomiting during the overall phase and SAEs. For a comprehensive illustration of results, we randomly chose aprepitant plus granisetron as exemplary reference treatment for HEC, and granisetron as exemplary reference treatment for MEC.

MAIN RESULTS

Highly emetogenic chemotherapy (HEC) We included 73 studies reporting on 25,275 participants and comparing 14 treatment combinations with NK₁ and 5-HT₃ inhibitors. All treatment combinations included corticosteroids. Complete control of vomiting during the overall phase We estimated that 704 of 1000 participants achieve complete control of vomiting in the overall treatment phase (one to five days) when treated with aprepitant + granisetron. Evidence from NMA (39 RCTs, 21,642 participants; 12 treatment combinations with NK₁ and 5-HT₃ inhibitors) suggests that the following drug combinations are more efficacious than aprepitant + granisetron for completely controlling vomiting during the overall treatment phase (one to five days): fosnetupitant + palonosetron (810 of 1000; RR 1.15, 95% confidence interval (CI) 0.97 to 1.37; moderate certainty), aprepitant + palonosetron (753 of 1000; RR 1.07, 95% CI 1.98  to 1.18; low-certainty), aprepitant + ramosetron (753 of 1000; RR 1.07, 95% CI 0.95 to 1.21; low certainty), and fosaprepitant + palonosetron (746 of 1000; RR 1.06, 95% CI 0.96 to 1.19; low certainty).  Netupitant + palonosetron (704 of 1000; RR 1.00, 95% CI 0.93 to 1.08; high-certainty) and fosaprepitant + granisetron (697 of 1000; RR 0.99, 95% CI 0.93 to 1.06; high-certainty) have little to no impact on complete control of vomiting during the overall treatment phase (one to five days) when compared to aprepitant + granisetron, respectively.  Evidence further suggests that the following drug combinations are less efficacious than aprepitant + granisetron in completely controlling vomiting during the overall treatment phase (one to five days) (ordered by decreasing efficacy): aprepitant + ondansetron (676 of 1000; RR 0.96, 95% CI 0.88 to 1.05; low certainty), fosaprepitant + ondansetron (662 of 1000; RR 0.94, 95% CI 0.85 to 1.04; low certainty), casopitant + ondansetron (634 of 1000; RR 0.90, 95% CI 0.79 to 1.03; low certainty), rolapitant + granisetron (627 of 1000; RR 0.89, 95% CI 0.78 to 1.01; moderate certainty), and rolapitant + ondansetron (598 of 1000; RR 0.85, 95% CI 0.65 to 1.12; low certainty). We could not include two treatment combinations (ezlopitant + granisetron, aprepitant + tropisetron) in NMA for this outcome because of missing direct comparisons.  Serious adverse events We estimated that 35 of 1000 participants experience any SAEs when treated with aprepitant + granisetron. Evidence from NMA (23 RCTs, 16,065 participants; 11 treatment combinations) suggests that fewer participants may experience SAEs when treated with the following drug combinations than with aprepitant + granisetron: fosaprepitant + ondansetron (8 of 1000; RR 0.23, 95% CI 0.05 to 1.07; low certainty), casopitant + ondansetron (8 of 1000; RR 0.24, 95% CI 0.04 to 1.39; low certainty), netupitant + palonosetron (9 of 1000; RR 0.27, 95% CI 0.05 to 1.58; low certainty), fosaprepitant + granisetron (13 of 1000; RR 0.37, 95% CI 0.09 to 1.50; low certainty), and rolapitant + granisetron (20 of 1000; RR 0.57, 95% CI 0.19 to 1.70; low certainty). Evidence is very uncertain about the effects of aprepitant + ondansetron (8 of 1000; RR 0.22, 95% CI 0.04 to 1.14; very low certainty), aprepitant + ramosetron (11 of 1000; RR 0.31, 95% CI 0.05 to 1.90; very low certainty), fosaprepitant + palonosetron (12 of 1000; RR 0.35, 95% CI 0.04 to 2.95; very low certainty), fosnetupitant + palonosetron (13 of 1000; RR 0.36, 95% CI 0.06 to 2.16; very low certainty), and aprepitant + palonosetron (17 of 1000; RR 0.48, 95% CI 0.05 to 4.78; very low certainty) on the risk of SAEs when compared to aprepitant + granisetron, respectively.  We could not include three treatment combinations (ezlopitant + granisetron, aprepitant + tropisetron, rolapitant + ondansetron) in NMA for this outcome because of missing direct comparisons.  Moderately emetogenic chemotherapy (MEC) We included 38 studies reporting on 12,038 participants and comparing 15 treatment combinations with NK₁ and 5-HT₃ inhibitors, or 5-HT₃ inhibitors solely. All treatment combinations included corticosteroids. Complete control of vomiting during the overall phase We estimated that 555 of 1000 participants achieve complete control of vomiting in the overall treatment phase (one to five days) when treated with granisetron. Evidence from NMA (22 RCTs, 7800 participants; 11 treatment combinations) suggests that the following drug combinations are more efficacious than granisetron in completely controlling vomiting during the overall treatment phase (one to five days): aprepitant + palonosetron (716 of 1000; RR 1.29, 95% CI 1.00 to 1.66; low certainty), netupitant + palonosetron (694 of 1000; RR 1.25, 95% CI 0.92 to 1.70; low certainty), and rolapitant + granisetron (660 of 1000; RR 1.19, 95% CI 1.06 to 1.33; high certainty).  Palonosetron (588 of 1000; RR 1.06, 95% CI 0.85 to 1.32; low certainty) and aprepitant + granisetron (577 of 1000; RR 1.06, 95% CI 0.85 to 1.32; low certainty) may or may not increase complete response in the overall treatment phase (one to five days) when compared to granisetron, respectively. Azasetron (560 of 1000; RR 1.01, 95% CI 0.76 to 1.34; low certainty) may result in little to no difference in complete response in the overall treatment phase (one to five days) when compared to granisetron. Evidence further suggests that the following drug combinations are less efficacious than granisetron in completely controlling vomiting during the overall treatment phase (one to five days) (ordered by decreasing efficacy): fosaprepitant + ondansetron (500 of 100; RR 0.90, 95% CI 0.66 to 1.22; low certainty), aprepitant + ondansetron (477 of 1000; RR 0.86, 95% CI 0.64 to 1.17; low certainty), casopitant + ondansetron (461 of 1000; RR 0.83, 95% CI 0.62 to 1.12; low certainty), and ondansetron (433 of 1000; RR 0.78, 95% CI 0.59 to 1.04; low certainty). We could not include five treatment combinations (fosaprepitant + granisetron, azasetron, dolasetron, ramosetron, tropisetron) in NMA for this outcome because of missing direct comparisons.  Serious adverse events We estimated that 153 of 1000 participants experience any SAEs when treated with granisetron. Evidence from pair-wise comparison (1 RCT, 1344 participants) suggests that more participants may experience SAEs when treated with rolapitant + granisetron (176 of 1000; RR 1.15, 95% CI 0.88 to 1.50; low certainty). NMA was not feasible for this outcome because of missing direct comparisons.  Certainty of evidence Our main reason for downgrading was serious or very serious imprecision (e.g. due to wide 95% CIs crossing or including unity, few events leading to wide 95% CIs, or small information size). Additional reasons for downgrading some comparisons or whole networks were serious study limitations due to high risk of bias or moderate inconsistency within networks.

AUTHORS' CONCLUSIONS

This field of supportive cancer care is very well researched. However, new drugs or drug combinations are continuously emerging and need to be systematically researched and assessed. For people receiving HEC, synthesised evidence does not suggest one superior treatment for prevention and control of chemotherapy-induced nausea and vomiting.  For people receiving MEC, synthesised evidence does not suggest superiority for treatments including both NK₁ and 5-HT₃ inhibitors when compared to treatments including 5-HT₃ inhibitors only. Rather, the results of our NMA suggest that the choice of 5-HT₃ inhibitor may have an impact on treatment efficacy in preventing CINV.  When interpreting the results of this systematic review, it is important for the reader to understand that NMAs are no substitute for direct head-to-head comparisons, and that results of our NMA do not necessarily rule out differences that could be clinically relevant for some individuals.

A History of Drug Discovery for Treatment of Nausea and Vomiting and the Implications for Future Research

The origins of the major classes of current anti-emetics are examined. Serendipity is a recurrent theme in discovery of their anti-emetic properties and repurposing from one indication to another is a continuing trend. Notably, the discoveries have occurred against a background of company mergers and changing anti-emetic requirements. Major drug classes include: (i) Muscarinic receptor antagonists-originated from historical accounts of plant extracts containing atropine and hyoscine with development stimulated by the need to prevent sea-sickness among soldiers during beach landings; (ii) Histamine receptor antagonists-searching for replacements for the anti-malaria drug quinine, in short supply because of wartime shipping blockade, facilitated the discovery of histamine (H1) antagonists (e.g., dimenhydrinate), followed by serendipitous discovery of anti-emetic activity against motion sickness in a patient undergoing treatment for urticaria; (iii) Phenothiazines and dopamine receptor antagonists-investigations of their pharmacology as "sedatives" (e.g., chlorpromazine) implicated dopamine receptors in emesis, leading to development of selective dopamine (D2) receptor antagonists (e.g., domperidone with poor ability to penetrate the blood-brain barrier) as anti-emetics in chemotherapy and surgery; (iv) Metoclopramide and selective 5-hydroxytryptamine3(5-HT3) receptor antagonists-metoclopramide was initially assumed to act only via D2 receptor antagonism but subsequently its gastric motility stimulant effect (proposed to contribute to the anti-emetic action) was shown to be due to 5-hydroxytryptamine4 receptor agonism. Pre-clinical studies showed that anti-emetic efficacy against the newly-introduced, highly emetic, chemotherapeutic agent cisplatin was due to antagonism at 5-HT3 receptors. The latter led to identification of selective 5-HT3 receptor antagonists (e.g., granisetron), a major breakthrough in treatment of chemotherapy-induced emesis; (v) Neurokinin1receptor antagonists-antagonists of the actions of substance P were developed as analgesics but pre-clinical studies identified broad-spectrum anti-emetic effects; clinical studies showed particular efficacy in the delayed phase of chemotherapy-induced emesis. Finally, the repurposing of different drugs for treatment of nausea and vomiting is examined, particularly during palliative care, and also the challenges in identifying novel anti-emetic drugs, particularly for treatment of nausea as compared to vomiting. We consider the lessons from the past for the future and ask why there has not been a major breakthrough in the last 20 years.

Comparison of conditional bias-adjusted estimators for interim analysis in clinical trials with survival data

Group sequential designs are widely used in clinical trials to determine whether a trial should be terminated early. In such trials, maximum likelihood estimates are often used to describe the difference in efficacy between the experimental and reference treatments; however, these are well known for displaying conditional and unconditional biases. Established bias-adjusted estimators include the conditional mean-adjusted estimator (CMAE), conditional median unbiased estimator, conditional uniformly minimum variance unbiased estimator (CUMVUE), and weighted estimator. However, their performances have been inadequately investigated. In this study, we review the characteristics of these bias-adjusted estimators and compare their conditional bias, overall bias, and conditional mean-squared errors in clinical trials with survival endpoints through simulation studies. The coverage probabilities of the confidence intervals for the four estimators are also evaluated. We find that the CMAE reduced conditional bias and showed relatively small conditional mean-squared errors when the trials terminated at the interim analysis. The conditional coverage probability of the conditional median unbiased estimator was well below the nominal value. In trials that did not terminate early, the CUMVUE performed with less bias and an acceptable conditional coverage probability than was observed for the other estimators. In conclusion, when planning an interim analysis, we recommend using the CUMVUE for trials that do not terminate early and the CMAE for those that terminate early. Copyright © 2017 John Wiley & Sons, Ltd.

Efficacy and Safety of Neurokinin-1 Receptor Antagonists for Prevention of Chemotherapy-Induced Nausea and Vomiting: Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVES

Can addition of neurokinin-1 receptor antagonists (NK1-RAs) be considered as an ideal strategy for the prevention of chemotherapy-induced nausea and vomiting (CINV)? Researchers differ on this question.

MATERIALS AND METHODS

Electronic databases were searched for randomized control trials (RCTs) that evaluated the effectiveness and safety of NK1-RAs in preventing CINV. The primary end point was complete response (CR) in the acute, delayed, and overall phases after chemotherapy. Subgroup analyses evaluated the types of NK1-RAs, routines of administration, types of malignancies, regimens used in combination with NK1-RAs, and age of patients included in the studies. The incidences of different types of adverse events were also extracted to estimate the safety of NK1-RAs.

RESULTS

A total of 38 RCTs involving 13,923 patients were identified. The CR rate of patients receiving NK-RAs was significantly higher than patients in the control groups during overall phase (70.8% vs 56.0%, <0.001), acute phase (85.1% vs 79.6%, <0.001), and delayed phase (71.4% vs 58.2%, <0.001). There were three studies including patients of children or adolescents, the CR rate was also significantly higher in the treatment group (overall phase: OR=2.807, <0.001; acute phase: OR=2.863, P =0.012; delayed phase: OR=2.417, <0.001). For all the other outcomes, patients in the NK1-RAs groups showed improvements compared to the control groups (incidence of nausea: 45.2% vs 45.9%, <0.001; occurrence of vomiting: 22.6% vs 38.9%, <0.001; usage of rescue drugs: 23.5% vs 34.1%, <0.001). The pooled side effects from NK1-RAs did not significantly differ from previous reports and the toxicity rates in patients less than eighteen years old also did not diff between the two groups (P=0.497). However, we found that constipation and insomnia were more common in the patients of control groups, whereas diarrhea and hiccups were more frequently detected in patients receiving NK1-RAs.

CONCLUSIONS

NK1-RAs improved the CR rate of CINV. They are effective for both adults and children. The use of NK1-RAs might be associated with the appearance of diarrhea and hiccups, while decreasing the possibility of constipation and insomnia.

Chemotherapy-Induced Delayed Emesis: What is the Role of 5-HT3Antagonists?

Objective:

To review the current literature assessing the efficacy of different antiemetics, with a focus on comparison between serotonin (5-HT3) antagonists and other antiemetics, in the treatment of delayed emesis induced by either cisplatin or non-cisplatin cytotoxic agents.

Data Sources:

A MEDLINE search (1966–July 2002) was performed using delayed emesis, vomiting, nausea, chemotherapy, cisplatin, moderately emetogenic, selective serotonin subtype-3 (5-HT3) receptor antagonists, metoclopramide, domperidone, corticosteroids, dexamethasone, prognostic factors, risk factors, and neurokinin-1 (NK1) receptor antagonists as key words or subject headings. Only English-language articles were identified and included. Additional references were retrieved from selected articles.

Data Synthesis:

Various antiemetic consensus guidelines have recommended the use of different pharmacologic treatment, including the use of 5-HT3antagonists, for the prevention of chemotherapy-induced delayed emesis. In some instances, it has been suggested that combinations containing a 5-HT3antagonist may be superior to others. Current data have been synthesized in an attempt to demonstrate the efficacy of 5-HT3antagonists in the treatment of chemotherapy-induced delayed emesis.

Conclusions:

Dexamethasone has consistently shown its antiemetic efficacy for delayed emesis induced by cisplatin and non-cisplatin agents, whereas the role of 5-HT3antagonists alone remains controversial. Metoclopramide has been shown to be as efficacious as 5-HT3antagonists when combined with dexamethasone for the prevention of delayed emesis. As a result, 5-HT3antagonists should be reserved as second-line agents to metoclopramide in addition to dexamethasone. NK1 receptor antagonists have shown some early promising results. However, many questions need to be addressed before their extensive use in clinical practice.

Chemotherapy-induced nausea and vomiting: incidence and characteristics of persistent symptoms and future directions NCCTG N08C3 (Alliance)

BACKGROUND

Despite newer agents, chemotherapy-induced nausea and vomiting (CINV) continues to remain a distressing side effect to a proportion of patients undergoing systemic anti-cancer therapy.

METHODS

We recently performed an unplanned secondary analysis on a previously reported negative phase III trial (N08C3) looking at the efficacy of gabapentin/placebo in combination with dexamethasone and a 5HT3 receptor antagonist in the prevention of CINV for 413 patients undergoing regimens with highly emetogenic chemotherapy (HEC). In the current study, we attempted to better understand the higher than expected rate of overall patient satisfaction, despite a low complete response rate in both arms. Additionally, we looked at patient variables and their relationship to rates of CINV.

RESULTS

Approximately one third of patients experienced more than mild nausea and reported scores on the Functional Living Index-Emesis that indicated interference with activities. Thirty-five percent reported nausea greater than 2.5 on a scale of 0 to 10 (0 being none), 19 % reported at least one emetic episode, and 49 % reported taking rescue medication. Nausea and vomiting on day 1, cisplatin therapy, and history of motion sickness significantly predicted delayed CINV. Age, combination chemotherapy (HEC with moderately emetogenic), and getting treatment for breast cancer predicted CINV on day 1.

DISCUSSION

These data confirm previous reports that subgroups of patients may be more prone to acute and delayed CINV. Future CINV study design may benefit from a more individualized approach to CINV management, targeting those patients who are truly at risk for CINV despite continued drug development efforts.

Defining the efficacy of neurokinin-1 receptor antagonists in controlling chemotherapy-induced nausea and vomiting in different emetogenic settings-a meta-analysis

PURPOSE

This meta-analysis was performed to evaluate the efficacy of neurokinin-1 receptor antagonists (NK1RAs) for the prevention of chemotherapy-induced nausea and vomiting (CINV) across different categories of chemotherapeutic emetogenicity.

METHODS

A systematic review of MEDLINE (via PubMed) and OVID databases, plus major oncology conferences, identified randomized, controlled trials evaluating NK1RAs in combination with a 5-HT3 RA plus a glucocorticoid for management of CINV. Efficacy end points were no emesis, no nausea, and complete response (CR) rates. Data were analyzed using a random effects model.

RESULTS

Twenty-three trials (N = 11,814) were identified. Based on absolute differences (AD) for no emesis (21 %), no nausea (8 %), CR (16 %), and odd ratios (OR) of 2.62, 1.43, and 2.16, respectively, NK1RA regimens provided better CINV protection versus control groups (all p < 0.00001) in patients receiving cisplatin-based highly emetogenic chemotherapy (HEC). In patients receiving anthracycline/cyclophosphamide (AC)-based HEC, respective ADs and ORs were 14, 4, and 11 % and 1.97 (p < 0.0001), 1.17 (p = 0.04), and 1.62 (p < 0.00001). In patients receiving moderately emetogenic chemotherapy (3 trials), no statistically significant benefit of NK1RAs was found; however, positive trends were detected for CR and no emesis. NK1RAs were effective for CINV prevention in a small number of studies using high-dose chemotherapy as conditioning prior to stem cell transplant and cisplatin-based multiple-day chemotherapy (MDC).

CONCLUSIONS

This meta-analysis demonstrated the efficacy of NK1RA in preventing vomiting in patients receiving HEC (including AC), with smaller effects on prevention of nausea. Efficacy is also seen with high-dose chemotherapy and cisplatin-based MDC.

Phase III double-blind, placebo-controlled study of gabapentin for the prevention of delayed chemotherapy-induced nausea and vomiting in patients receiving highly emetogenic chemotherapy, NCCTG N08C3 (Alliance)

BACKGROUND

Despite targeted antiemetics, data support an unmet need related to the management of delayed nausea and vomiting (NV). Promising pilot data informed this phase III trial evaluating gabapentin for delayed NV from highly emetogenic chemotherapy (HEC).

METHODS

Participants were randomized to receive prophylactic treatment with 20 mg of dexamethasone and a 5HT3 receptor antagonist (RA) on the day of chemotherapy, followed by gabapentin 300 mg twice a day and dexamethasone (dex) or placebo and dex after HEC. Gabapentin/placebo was started the day of chemotherapy and continued through day 5 for the first chemotherapy cycle, whereas dex was titrated down on days 2-4. The primary end point was complete response (CR), defined as no emesis and no use of rescue medications on days 2-6, using an NV diary. The percentages of those in each group with a CR were compared by Fisher's exact test.

RESULTS

Four hundred thirty patients were enrolled in this study. Forty-seven percent of patients in the gabapentin arm and 41% in the placebo arm had a CR (P = .23). Mean number of emesis episodes was <0.5 daily, and mean nausea severity was < 2 (mild). In both arms, patient satisfaction with NV control was greater than 8 (with 10 being perfectly satisfied). There were no significant differences in unwanted side effects.

CONCLUSIONS

In this study, gabapentin did not significantly improve delayed NV. Patients were satisfied with the control of their nausea and vomiting irrespective of arm. The use of a 5HT3 RA and dexamethasone provided good control of nausea and vomiting for most patients.

Involvement of substance P and the NK-1 receptor in human pathology

The peptide substance P (SP) shows a widespread distribution in both the central and peripheral nervous systems, but it is also present in cells not belonging to the nervous system (immune cells, liver, lung, placenta, etc.). SP is located in all body fluids, such as blood, cerebrospinal fluid, breast milk, etc. i.e. it is ubiquitous in human body. After binding to the neurokinin-1 (NK-1) receptor, SP regulates many pathophysiological functions in the central nervous system, such as emotional behavior, stress, depression, anxiety, emesis, vomiting, migraine, alcohol addiction, seizures and neurodegeneration. SP has been also implicated in pain, inflammation, hepatitis, hepatotoxicity, cholestasis, pruritus, myocarditis, bronchiolitis, abortus, bacteria and viral infection (e.g., HIV infection) and it plays an important role in cancer (e.g., tumor cell proliferation, antiapoptotic effects in tumor cells, angiogenesis, migration of tumor cells for invasion, infiltration and metastasis). This means that the SP/NK-1 receptor system is involved in the molecular bases of many human pathologies. Thus, knowledge of this system is the key for a better understanding and hence a better management of many human diseases. In this review, we update the involvement of the SP/NK-1 receptor system in the physiopathology of the above-mentioned pathologies and we suggest valuable future therapeutic interventions involving the use of NK-1 receptor antagonists, particularly in the treatment of emesis, depression, cancer, neural degeneration, inflammatory bowel disease, viral infection and pruritus, in which that system is upregulated.

Tachykinins and their receptors: contributions to physiological control and the mechanisms of disease

The tachykinins, exemplified by substance P, are one of the most intensively studied neuropeptide families. They comprise a series of structurally related peptides that derive from alternate processing of three Tac genes and are expressed throughout the nervous and immune systems. Tachykinins interact with three neurokinin G protein-coupled receptors. The signaling, trafficking, and regulation of neurokinin receptors have also been topics of intense study. Tachykinins participate in important physiological processes in the nervous, immune, gastrointestinal, respiratory, urogenital, and dermal systems, including inflammation, nociception, smooth muscle contractility, epithelial secretion, and proliferation. They contribute to multiple diseases processes, including acute and chronic inflammation and pain, fibrosis, affective and addictive disorders, functional disorders of the intestine and urinary bladder, infection, and cancer. Neurokinin receptor antagonists are selective, potent, and show efficacy in models of disease. In clinical trials there is a singular success: neurokinin 1 receptor antagonists to treat nausea and vomiting. New information about the involvement of tachykinins in infection, fibrosis, and pruritus justifies further trials. A deeper understanding of disease mechanisms is required for the development of more predictive experimental models, and for the design and interpretation of clinical trials. Knowledge of neurokinin receptor structure, and the development of targeting strategies to disrupt disease-relevant subcellular signaling of neurokinin receptors, may refine the next generation of neurokinin receptor antagonists.

Treatment of chemotherapy-induced nausea and vomiting

BACKGROUND

Recent improvements in medical oncology include both development of anticancer and supportive therapy. Serotonin receptor antagonists were introduced in clinical practice 20 years ago. Since then, the prevention and treatment of chemotherapy-induced nausea and vomiting allows continuing efficacious chemotherapy that earlier had to be stopped sometimes for intolerance.

AIM

This anniversary review summarises the current antiemetic arsenal focussing on the most potent antiemetic drugs such as serotonin and substance P receptor antagonists.

RESULT

Antiemetic treatment improves quality of life under chemotherapy and contributes to the survival benefit as well. In spite of the use of these new drugs, a significant number of patients still experience nausea and vomiting. Special complications like delayed emesis can be alleviated by combination therapies.

CONCLUSION

Prevention and optimal management of chemotherapy-induced nausea and vomiting should be a goal for most patients receiving emetogenic chemotherapy.

Safety of neurokinin-1 receptor antagonists

INTRODUCTION

The substance P (SP)/neurokinin (NK)-1 receptor system is involved in many pathological processes. NK-1 receptor antagonists have many promising therapeutic indications. However, the only NK-1 receptor antagonist used in clinical practice is the drug aprepitant and its intravenously administered prodrug, fosaprepitant. In general, NK-1 receptor antagonists are safe and well tolerated.

AREAS COVERED

A search was carried out in Medline using the following terms: adverse events, aprepitant, casopitant, clinical trials, CP-122,721, ezlopitant, fosaprepitant, NK-1 receptor antagonists, randomized, safety, side effects, tolerability and vofopitant.

EXPERT OPINION

Most clinical trials have focused on the antiemetic action of aprepitant in cancer patients treated with chemotherapy. However, the efficacy and safety of aprepitant have not been fully tested in other diseases in which the SP/NK-1 receptor system is involved (e.g., cancer, HIV, alcoholism); thus, clinical trials are required. The use of NK-1 receptor antagonists in oncology therapy is quite promising, but to date pharmacological therapy has not exploited the many possible therapies offered by such antagonists.

Neurokinin-1 receptor antagonists for chemotherapy-induced nausea and vomiting: a systematic review

BACKGROUND

The addition of neurokinin-1 receptor (NK1R) antagonists to antiemetic regimens has substantially reduced chemotherapy-induced nausea and vomiting (CINV). We sought to systematically review the overall impact of NK1R antagonists on CINV prevention.

METHODS

We systematically searched the MEDLINE, EMBASE, and CENTRAL databases, and meeting proceedings for randomized controlled trials (RCTs) that evaluated NK1R antagonists plus standard antiemetic therapy for CINV prevention. Complete response (CR) to therapy was defined as the absence of emesis and the absence of rescue therapy. The endpoints were defined as CR in the overall phase (during the first 120 hours of chemotherapy), CR in the acute phase (first 24 hours), and the delayed phase (24-120 hours) after chemotherapy, nausea, and toxicity. Subgroup analyses evaluated the type of NK1R antagonist used, the emetogenic potential of the chemotherapy regimen, and prolonged use of 5-HT3 (serotonin) receptor antagonists, a class of standard antiemetic agents. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Statistical tests for heterogeneity were one-sided; statistical tests for effect estimates and publication bias were two-sided.

RESULTS

Seventeen trials (8740 patients) were included in this analysis. NK1R antagonists increased the CR rate in the overall phase from 54% to 72% (OR = 0.51, 95% CI = 0.46 to 0.57, P < .001). CR and nausea were improved in all phases and subgroups. The expected side effects from NK1R antagonists did not statistically significantly differ from previous reports; however, this analysis suggests that the incidence of severe infection increased from 2% to 6% in the NK1R antagonist group (three RCTs with a total of 1480 patients; OR = 3.10; 95% CI = 1.69 to 5.67, P < .001).

CONCLUSIONS

NK1R antagonists increased CINV control in the acute, delayed, and overall phases. They are effective for both moderately and highly emetogenic chemotherapy regimens. Their use might be associated with increased infection rates; however, additional appraisal of specific data from RCTs is needed.

Inhibiting substance p pathway for prevention of chemotherapy-induced emesis: preclinical data, clinical trials of neurokinin-1 receptor antagonists

Neurokinin-1 (NK-1) receptor antagonists are a new class of antiemetic agents that have activity in controlling cisplatin-induced acute and delayed emesis. Preclinical data in animal models show that the NK-1 receptor antagonists have broad antiemetic activity. The NK-1 receptor antagonists have activity in controlling emesis induced by peripherally acting and centrally acting emetogens, suggesting a mechanism of action at multiple sites. The effects at central and peripheral sites to control acute and delayed emesis cannot be determined at this time based on available studies. When added to a standard regimen of a 5-hydroxytryptamine-3 (5- HT3) receptor antagonist and dexamethasone, the NK-1 receptor antagonists improve control of acute emesis. The NK-1 receptor antagonists improve delayed emesis compared with placebo, and when used in combination with dexamethasone, compared with dexamethasone alone. Acute and delayed nausea may also be improved by the NK-1 receptor antagonists when they are used in combination with a 5-HT3 receptor antagonist and dexamethasone prechemotherapy or with daily dosing for 5 days after chemotherapy. The current data suggest that the mechanism of action of the NK-1 receptor antagonists appears to be different from that of the 5-HT3 receptor antagonists. Future studies may consider using NK-1 receptor antagonists with moderately emetogenic chemotherapy as well as bone marrow transplantation.

Aprepitant use in children, adolescents, and young adults for the control of chemotherapy-induced nausea and vomiting (CINV)

BACKGROUND

One of the most common and distressing side effects for cancer patients is chemotherapy-induced nausea and vomiting (CINV). New antiemetics, such as the NK-1 receptor inhibitor aprepitant, have been reported to improve control of this side effect in adults. However, little is known about its effect in the pediatric oncology population, with only a few reported cases in the literature.

METHODS

This was a retrospective chart review on the use of aprepitant in the pediatric oncology population in our institution.

RESULTS

Thirty-two charts and a total of 146 cycles of chemotherapy were reviewed. Mean age was 10 years. Highly emetogenic chemotherapy was used in 23/32 patients and moderately emetogenic chemotherapy in 9/32. Antiemetic regimens consisted of aprepitant+5-HT3 RA+dexamethasone (Regimen 1, 20/32 patients) or aprepitant +5-HT3 RA (Regimen 2, in 12/32). Eight out of thirty-two patients were chemotherapy-naïve and received aprepitant on their first cycle. In 24/32 patients, aprepitant was added later in their treatment, with 12/24 reporting resolution of CINV after its addition.

CONCLUSIONS

Aprepitant when combined with standard antiemetics, was well tolerated in the pediatric oncology population studied. However, there is still a need to conduct prospective studies to determine the optimal efficacy of aprepitant in the pediatric oncology population.

The neurokinin 1 receptor antagonist, ezlopitant, reduces appetitive responding for sucrose and ethanol

BACKGROUND

The current obesity epidemic is thought to be partly driven by over-consumption of sugar-sweetened diets and soft drinks. Loss-of-control over eating and addiction to drugs of abuse share overlapping brain mechanisms including changes in motivational drive, such that stimuli that are often no longer 'liked' are still intensely 'wanted' [7], . The neurokinin 1 (NK1) receptor system has been implicated in both learned appetitive behaviors and addiction to alcohol and opioids; however, its role in natural reward seeking remains unknown.

METHODOLOGY/PRINCIPAL FINDINGS

We sought to determine whether the NK1-receptor system plays a role in the reinforcing properties of sucrose using a novel selective and clinically safe NK1-receptor antagonist, ezlopitant (CJ-11,974), in three animal models of sucrose consumption and seeking. Furthermore, we compared the effect of ezlopitant on ethanol consumption and seeking in rodents. The NK1-receptor antagonist, ezlopitant decreased appetitive responding for sucrose more potently than for ethanol using an operant self-administration protocol without affecting general locomotor activity. To further evaluate the selectivity of the NK1-receptor antagonist in decreasing consumption of sweetened solutions, we compared the effects of ezlopitant on water, saccharin-, and sodium chloride (NaCl) solution consumption. Ezlopitant decreased intake of saccharin but had no effect on water or salty solution consumption.

CONCLUSIONS/SIGNIFICANCE

The present study indicates that the NK1-receptor may be a part of a common pathway regulating the self-administration, motivational and reinforcing aspects of sweetened solutions, regardless of caloric value, and those of substances of abuse. Additionally, these results indicate that the NK1-receptor system may serve as a therapeutic target for obesity induced by over-consumption of natural reinforcers.

Consensus recommendations for the prevention of vomiting and nausea following high-emetic-risk chemotherapy

In this update of our 2005 document, we used an evidence-based approach whenever possible to formulate recommendations, emphasizing the results of controlled trials concerning the best use of antiemetic agents for the prevention of emesis and nausea following anticancer chemotherapies of high emetic risk. A three-drug combination of a 5-hydroxytryptamine type 3 receptor (5-HT(3)) receptor antagonist, dexamethasone, and aprepitant beginning before chemotherapy and continuing for up to 4 days remains the standard of care. We address issues of dose, schedule, and route of administration of five selective 5-HT(3) receptor antagonists. We conclude that, for each of these five drugs, there is a plateau in therapeutic efficacy above which further dose escalation does not improve outcome. In trials designed to prove the equivalence of palonosetron to ondansetron and granisetron, palonosetron proved superior in emesis prevention, while adverse effects were comparable. Furthermore, for all classes of antiemetic agents, a single dose is as effective as multiple doses or a continuous infusion. The oral route is as efficacious as the intravenous route of administration.

Chemotherapy-induced nausea and vomiting: antiemetic trials that impacted clinical practice

Objective. To review the scientific evidence related to serotonin and substance P and the clinical impact targeting these two neurotransmitters have had managing chemotherapy-induced nausea and vomiting (CINV).

Data Source. A PubMed search (January 1968 to December 2008), restricted to English-language publications, was conducted using the key words antiemetics, cancer chemotherapy, cisplatin, serotonin, substance P, NK1, and 5-HT3. Abstracts emanating from the meetings of the American Society of Clinical Oncology and Multinational Association of Supportive Care in Cancer during the period May 2000 to June 2008 were also reviewed.

Data Synthesis. Two important outcomes emanated from well-conducted antiemetic clinical trials (Table 1): first, evidence that serotonin and substance P are major mediators of acute and delayed symptoms and second, improved, though not complete, control of CINV.

Conclusion. Serotonin-type 3 and neurokinin-1 receptor antagonists are the most effective agents currently available. In most cases, these agents are used in conjunction with glucocorticoids. The use of these three types of agents is incorporated into current clinical practice guidelines. Further understanding of the biological and biochemical basis of nausea and vomiting may enhance management of this potentially debilitating adverse effect.

Casopitant improves the quality of life in patients receiving highly emetogenic chemotherapy

PURPOSE

The control of chemotherapy-induced nausea and vomiting (CINV) is critical in preventing poor health outcomes and increasing patient quality of life. The objective of this study was to evaluate the impact of the addition of casopitant to dual-combination therapy of dexamethasone and ondansetron on quality of life in patients receiving highly emetogenic chemotherapy (HEC).

METHODS

In a multicenter, double-blind, randomized, placebo-controlled, add-on trial (N = 810), patients were randomized to intravenous (IV) ondansetron/dexamethasone alone (control) or in combination with either a single 150-mg oral dose of casopitant or 3-day IV/oral casopitant. Quality of life was assessed as impact of nausea and vomiting on daily life using the Functional Living Index Emesis (FLIE) questionnaire. Patients completed the FLIE questionnaire at baseline prior to receiving chemotherapy and after completion of the first cycle of HEC.

RESULTS

Patients in the single oral dose and 3-day IV/oral casopitant groups scored higher mean total FLIE scores (115.7 and 114.0, respectively; p ≤ 0.0332) than patients in the control group (107.5), indicating that casopitant patients experienced less impact from nausea and vomiting on daily life. The overall absolute difference in the proportion of patients reporting CINV with no impact on daily life between the single oral casopitant group and the control group was 13%; the difference between the 3-day IV/oral casopitant group and the control group was 14%.

CONCLUSION

The addition of casopitant to ondansetron and dexamethasone in patients receiving HEC was significantly more effective in reducing the impact of nausea and vomiting on all daily life activities as assessed by the FLIE compared with ondansetron/dexamethasone dual therapy.

Antiemetic control: toward a new standard of care for emetogenic chemotherapy

Chemotherapy-induced nausea and vomiting (CINV) is associated with a significant deterioration in quality of life. The emetogenicity of the chemotherapeutic agents, repeated chemotherapy cycles, and patient risk factors significantly influence CINV. 5-hydroxytryptamine-3 (5-HT(3)) receptor antagonists plus dexamethasone have significantly improved the control of acute CINV, but delayed CINV remains a significant clinical problem. Two new agents, palonosetron and aprepitant, have been approved for the prevention of both acute and delayed CINV. Palonosetron is a second-generation 5-HT(3) receptor antagonist with a longer half-life and a higher binding affinity than first-generation 5-HT(3) receptor antagonists. Aprepitant is the first agent available in the new drug class of neurokinin-1 (NK-1) receptor antagonists. Casopitant is another NK-1 receptor antagonist that is under review by the FDA after recent completion of Phase III clinical trials. The introduction of these new agents has generated revised antiemetic guidelines for the prevention of CINV. Future studies may consider the use of palonosetron, aprepitant and casopitant with other antiemetic agents (olanzapine, gabapentin, cannabinoids) in moderately and highly emetogenic chemotherapy, as well as in the clinical settings of multiple-day chemotherapy and bone marrow transplantation.

Antiemetics: an update and the MASCC guidelines applied in clinical practice

Nausea and vomiting are two of the most severe problems for patients treated with chemotherapy. Until the late 1970s, nausea and vomiting induced by chemotherapy was an almost neglected research area. With the introduction of cisplatin, the cytotoxin with the highest emetic potential, research was stimulated and has now resulted in the development of two new classes of antiemetics, the serotonin and neurokinin antagonists. A large number of trials have fine-tuned antiemetic therapy and made evidence-based recommendations possible for the majority of patients receiving chemotherapy. This Review discusses the pathophysiology of nausea and vomiting, the development of antiemetics, highlights some of the newest antiemetics, and finally summarizes recommendations from the evidence-based guidelines developed by the Multinational Association of Supportive Care in Cancer.

Metabolism, Pharmacokinetics, and Excretion of a Nonpeptidic Substance P Receptor Antagonist, Ezlopitant, in Normal Healthy Male Volunteers: Characterization of Polar Metabolites by Chemical Derivatization with Dansyl Chloride

The excretion, biotransformation, and pharmacokinetics of ezlopitant [(2-benzhydryl-1-aza-bicyclo[2.2.2]oct-3-yl)-(5-isopropyl-2-methoxy-benzyl)-amine], a substance P receptor antagonist, were investigated in healthy male volunteers after oral administration of a single 200-mg (approximately 93 microCi/subject) dose of [(14)C]ezlopitant. The total recovery of administered radioactive dose was 82.8 +/- 5.1, with 32.0 +/- 4.2% in the urine and 50.8 +/- 1.4% in the feces. Mean observed maximal serum concentrations for ezlopitant and total radioactivity were achieved at approximately 2 h after oral administration; thus, ezlopitant was rapidly absorbed. Ezlopitant was extensively metabolized in humans, since no unchanged drug was detected in urine and feces. The major pathway of ezlopitant in humans was the result of the oxidation of the isopropyl side chain to form the omega-hydroxy and omega-1-hydroxy (M16) metabolites. M16 and omega,omega-1-dihydroxy (1,2-dihydroxy, M12) were identified as the major circulating metabolites accounting for 64.6 and 15.4% of total circulating radioactivity, respectively. In feces, the major metabolite M14 was characterized as the propionic acid metabolite and formed by further oxidation of the omega-hydroxy metabolite. The urinary metabolites were the result of cleaved metabolites caused by oxidative dealkylation of the 2-benzhydryl-1-aza-bicyclo[2.2.2]oct-3-yl moiety. The metabolites (M1A, M1B, and M4), approximately 34% of the total radioactivity in urine, were identified as benzyl amine derivatives. These were polar metabolites that were further characterized using the reaction with dansyl chloride to derivatize the primary amines and phenol moieties to less polar analytes. The other metabolites were the result of O-demethylation, dehydrogenation of the isopropyl group, and oxidation on the quinuclidine moiety.

Comparative activity of antiemetic drugs

Nausea and vomiting continues to be an important problem for cancer patients receiving chemotherapy. Chemotherapy-induced nausea and vomiting (CINV) are classified as acute, occurring within the first 24h, or delayed, occurring after the first 24h. A number of antiemetic agents are available for the management of nausea and vomiting, including 5-HT3-receptor-antagonists, corticosteroids, NK-1-receptor-antagonists, dopamine-receptor antagonists, benzodiazepines, neuroleptics and cannabinoids. With modern antiemetic therapy, vomiting can be prevented in 70-80% of patients, whereas the control of nausea remains suboptimal. The development of acute emesis is known to depend on serotonin. The pathophysiology of delayed emesis is less well understood, and multiple mechanisms may contribute, including substance P. Here, the most recent developments in the antiemetic therapy, including new antiemetic drugs and the latest guidelines for antiemetic prophylaxis, are reviewed.

Aprepitant as salvage therapy in patients with chemotherapy-induced nausea and emesis refractory to prophylaxis with 5-HT(3) antagonists and dexamethasone

BACKGROUND

Despite prophylaxis with 5-HT(3) antagonists and dexamethasone, nausea/emesis are common chemotherapy- induced toxicities. The aim of this trial was to evaluate the efficacy of adding the NK1 antagonist aprepitant in patients refractory to standard prophylaxis.

PATIENTS AND METHODS

Patients with significant nausea/vomiting despite prophylaxis with 5-HT(3) antagonists and dexamethasone were eligible. Aprepitant was added to the same antiemetic regimen used during previous cycles.

RESULTS

34 patients received 92 cycles of chemotherapy with aprepitant which was applied orally at 125 mg on day 1 and 80 mg on days 2 and 3. All patients were refractory to standard antiemetic prophylaxis during cisplatin-based (n = 12) or other chemotherapy (n = 22). With the addition of aprepitant, all patients reported subjective improvement. The number of patients with nausea for >4 days decreased from 24 (71%) to 4 (12%) (p < 0.001), and the number of those with emesis for >2 days decreased from 26 (77%) to 0 (0%) (p < 0.001). In 12 patients receiving aprepitant for >2 cycles (3-8) the efficacy was maintained. No toxicity possibly related to aprepitant was observed.

CONCLUSION

Aprepitant demonstrated significant activity in patients with nausea/vomiting refractory to prophylaxis with 5-HT(3) antagonists and dexamethasone.

Gastrointestinal toxicity of chemotherapeutic agents

Chemotherapy-induced toxicities commonly occur in sites within the gastrointestinal (GI) tract and account for dose-limiting effects. These toxicities are major contributing factors to dose reduction, delays, and cessation of cancer treatment. Through intensive therapies including surgery, combination chemotherapy, hormonal therapy, and targeted therapy, an increasing number of patients with cancer are experiencing improved survival and long-term disease-free survival, as well as palliation of disease-related symptoms. Thus, GI toxicities should be predicted and appropriate interventions initiated to prevent them when possible and provide effective supportive measures and comprehensive follow-up care. This review will discuss the etiology, incidence, prevention, and treatment of GI toxicities of cancer chemotherapy.

Neurokinin-1-receptor antagonists: a new approach in antiemetic therapy

Aprepitant (Emend), the first neurokinin-1-receptor antagonist (NK-1-RA), represents a new class of antiemetics. Aprepitant has been approved for the prevention and treatment of acute (0-24 h after chemotherapy) and delayed (1-5 days after chemotherapy) emesis resulting from cisplatin-based chemotherapy and moderately emetogenic chemotherapy. The addition of aprepitant to standard antiemetic therapy in cisplatin-based chemotherapy significantly improves emesis protection in general and, in particular, in the delayed phase by approximately 20%. Results from a recently published study in patients receiving moderately emetogenic chemotherapy suggest a benefit of aprepitant when combined with dexamethasone and a 5-HT(3) receptor antagonist for the prevention of acute emesis, followed by aprepitant as a single agent in the prevention of delayed emesis. Altogether, the addition of aprepitant to the standard antiemetic regimen (5-HT(3) receptor antagonist and dexamethasone) significantly improves the protection against vomiting in the acute as well as in the delayed phase in highly and moderately emetogenic chemotherapies. Therefore, the combination of a 5-HT(3) receptor antagonist, dexamethasone and aprepitant should be considered as a new standard antiemetic therapy.

Emerging drugs for chemotherapy-induced emesis

Chemotherapy-induced nausea and vomiting (CINV) is associated with a significant deterioration in quality of life. The emetogenicity of the chemotherapeutic agents, repeated chemotherapy cycles and patient risk factors (female gender, younger age, no alcohol consumption, history of motion sickness) are the major risk factors for CINV. The use of 5-hydroxytryptamine-3 (5-HT3) receptor antagonists plus dexamethasone has significantly improved the control of acute CINV, but delayed nausea and vomiting remains a significant clinical problem. Two new agents, palonosetron and aprepitant, have recently been approved for the prevention of both acute and delayed CINV. Palonosetron is a 5-HT3 receptor antagonist with a longer half-life and a higher binding affinity than first-generation 5-HT3 receptor antagonists. Aprepitant is the first agent available in the new drug class of neurokinin-1 receptor (NK-1) antagonists. There are a number of 5-HT3 receptor antagonists and NK-1 receptor antagonists currently in Phase II and III clinical trials. Revised antiemetic guidelines for the prevention of CINV are reviewed. Future studies may consider the use of palonosetron and aprepitant with current and other new agents (olanzapine, gabapentin) in moderately and highly emetogenic chemotherapy, as well as in the clinical settings of multiple-day chemotherapy and bone marrow transplantation.

A randomized, double-blind trial assessing the efficacy and safety of sublingual metopimazine and ondansetron in the prophylaxis of chemotherapy-induced delayed emesis

The prevention of delayed emesis following chemotherapy remains an important challenge. This randomized, double-blind, double-dummy, multicenter study was designed to compare the efficacy and tolerance of metopimazine and ondansetron at preventing nausea and emesis in patients receiving chemotherapy. Two hundred patients were evaluated for efficacy: 103 patients received metopimazine (7.5 mg x 2 t.i.d.) and 97 received ondansetron (8 mg b.i.d.) for 5 days. Patients were asked to report episodes of nausea and emesis in a diary, and quality of life (QoL) was evaluated using the Functional Living Index--Emesis questionnaire. The incidence of complete response (defined as no nausea and emesis for 5 days) did not differ between the two treatment arms (53.4% for metopimazine versus 49.5% for ondansetron; P=0.58). No significant difference was found for the incidence of emesis (23.3% for metopimazine versus 30.9% for ondansetron) or QoL. Tolerance was as expected for both drugs and comparable, except for the incidence of gastrointestinal disorders, which was significantly lower in the metopimazine group (19.4 versus 32.7%; P=0.03). We conclude that metopimazine is an alternative to ondansetron that is better tolerated for the prevention of delayed emesis in patients receiving chemotherapy.

Management of chemotherapy-induced nausea, vomiting, oral mucositis, and diarrhoea

The past 10 years have seen substantial advances in molecularly targeted therapies for treatment of patients with cancer; however, chemotherapy will continue to be used. Therefore, the toxic effects of chemotherapy must be readily managed-especially nausea, vomiting, mucositis, and diarrhoea. For moderately to highly emetogenic chemotherapy, standard prophylactic treatment is an antagonist for 5-hydroxytryptamine 3 receptors (5-HT3R) combined with dexamethasone for the acute phase, and dexamethasone with another agent for prevention of the delayed phase. Palonoestron (a 5-HT3R antagonist) and aprepitant (an antagonist for the protachykinin 1 receptor) have been introduced for the prevention of emesis. Other agents such as cannabinoids, gabapentin, and olanzapine might also be effective. There is no standard prophylactic regimen for chemotherapy-induced mucositis. The most common treatment is optimum care of the mouth by use of mouthwashes. Keratinocyte growth factor, molgromastim, and transforming growth factor beta3 may also reduce chemotherapy-induced mucositis. Severe diarrhoea is another potentially fatal complication of chemotherapy and is most common in patients treated with irinotecan. Several interventions have been assessed for prevention and treatment of diarrhoea such as high-dose loperamide, non-absorbable antibiotics, budesonide, thalidomide, and fish oils, but only loperamide is used routinely. Symptom management has become a focus of clinical research, and development of personalised medicine should identify patients at increased risk of toxic effects because of molecular or biochemical factors, thus leading to changes in dose, early intervention, or use of alternative therapies.

Consensus proposals for the prevention of acute and delayed vomiting and nausea following high-emetic-risk chemotherapy

This paper uses an evidence-based approach whenever possible to formulate recommendations, emphasizing the results of controlled trials concerning the best use of antiemetic agents. We address issues of dose, schedule, and route of administration of five selective 5-HT(3) antagonists. We conclude that for each of these five drugs, there is a plateau in therapeutic efficacy above which further dose escalation does not improve outcome. Furthermore, for all classes of antiemetic agents, a single dose is as effective as multiple doses or a continuous infusion. The oral route is as efficacious as the intravenous route of administration, even with chemotherapy of high emetic risk. Selective antagonists of the type 3 serotonin receptor (5-HT(3)) in combination with dexamethasone and aprepitant are the standard of care for the prevention of emesis following chemotherapy of high emetic risk.

Role of Neurokinin-1 Receptor Antagonists in Chemotherapy-Induced Emesis: Summary of Clinical Trials

Chemotherapy-induced nausea and vomiting (CINV) is associated with a significant deterioration in quality of life, and although the use of 5-hydroxytryptamine3 (5-HT3) receptor antagonists plus dexamethasone has significantly improved the control of acute CINV, delayed nausea and vomiting remain a significant clinical problem. Aprepitant is the first agent available in the new drug class of neurokinin-1 receptor antagonists. When added to a standard regimen of a 5-HT3 receptor antagonist and dexamethasone in patients receiving highly emetogenic chemotherapy, it improves the complete response rate of acute CINV. Aprepitant also improves the complete response of delayed CINV when used in combination with dexamethasone compared to dexamethasone alone. The use of aprepitant in patients receiving moderately emetogenic chemotherapy will await the review and analysis of recently completed phase III trials. The control of nausea is improved in some studies with the use of aprepitant when it is combined with a 5HT3 receptor antagonist and dexamethasone, but nausea control remains suboptimal. The current data suggest that the mechanism of action of the NK-1s appears to be different from the 5-HT3 receptor antagonists. Future studies may explore the use of aprepitant and other NK-1s in moderately and highly emetogenic chemotherapy, as well in the clinical settings of multiple-day chemotherapy and bone marrow transplantation.

Symptom control

Symptom control has become increasingly recognized as an important goal in patient care. In this article, advances in symptom assessment, and various definitions of symptom improvement are reviewed. Theoretical concepts underlying symptom control and clinically significant change are presented, as well as the role of symptom control as an endpoint in clinical trials. Symptom control is then surveyed in two broad categories for selected symptoms. The first area is therapy related symptoms, secondary to chemotherapy, radiation, hormonal therapy, and surgery. Symptoms reviewed include chemotherapy related mucositis, emesis, fatigue; hot flashes; and radiation related dermatitis, xerostomia, and mucositis. The second area is palliative oncologic approaches to disease-related symptoms. Results in palliative chemotherapy, palliative radiation therapy, cancer pain, and lack of appetite are summarized. Areas requiring further research are noted. Findings are presented in both a clinical and research context to help guide the reader with interpreting symptom control studies.

Current position of 5HT3 antagonists and the additional value of NK1 antagonists; a new class of antiemetics

The advent of the 5HT(3) receptor antagonists (5HT(3) antagonists) in the 1990 s and the combination with dexamethasone has resulted in acute emesis protection in 70% of patients receiving highly emetogenic chemotherapy. Despite complete protection in the acute phase, however, 40% of patients as yet have symptoms in the delayed phase. 5HT(3) antagonists and dexamethasone are only modestly effective in this delayed phase. Moreover, the antiemetic protection over repeated cycles is not sustained. Neurokinine 1 receptor antagonists (NK(1) antagonists) belong to a new class of antiemetic agents that specifically target the NK(1) receptor, which is involved in both the acute and, particularly, the delayed phase of emesis. Clinical studies have demonstrated that the addition of NK(1) antagonists to dual therapy with a 5HT(3) antagonist plus dexamethasone improves the acute emesis protection by a further 10-15%. In the delayed phase, the proportion of patients remaining free of emesis increases by even 20-30%. Since the effectiveness of this triplet combination was found to be sustained over six cycles of chemotherapy, the chance for an individual patient to remain completely protected during both the acute and the delayed phase over six chemotherapy cycles is nearly doubled.

Peripheral tachykinin receptors as potential therapeutic targets in visceral diseases

More than 10 years of intensive preclinical investigation of selective tachykinin (TK) receptor antagonists has provided a rationale to the speculation that peripheral neurokinin (NK)-1, -2 and -3 receptors may be involved in the pathophysiology of various human diseases at the visceral level. In the airways, despite promising effects in animal models of asthma, pilot clinical trials with selective NK-1 or -2 receptor antagonists in asthmatics have been ambiguous, whereas the potential antitussive effects of NK-1, -2 or -3 antagonists have not yet been verified in humans. In the gastrointestinal (GI) tract, irritable bowel syndrome (IBS) and pancreatitis are appealing targets for peripherally-acting NK-1 and -2 antagonists, respectively. In the genito-urinary tract, NK-1 receptor antagonists could offer some protection against nephrotoxicity and cytotoxicity induced by chemotherapeutic agents, whereas NK-2 receptor antagonists appear to be promising new agents for the treatment of neurogenic bladder hyperreflexia. Finally, there is preclinical evidence for hypothesising an effect of NK-3 receptor antagonists on the cardiovascular disturbance that characterises pre-eclampsia. Other more speculative applications are also mentioned.

Identification of the degradation product of ezlopitant, a non-peptidic substance P antagonist receptor, by hydrogen deuterium exchange, electrospray ionization tandem mass spectrometry (ESI/MS/MS) and nuclear magnetic resonance (NMR) spectroscopy

The degradation product of ezlopitant was isolated from low specific activity material and identified by solution phase hydrogen/deuterium (H/D) exchange and electrospray ionization tandem mass spectrometry (ESI/MS/MS) to be an isopropyl peroxide analog of ezlopitant. The structure of the degradant was further confirmed by nuclear magnetic resonance (NMR) spectroscopy utilizing complete 1H and 13C assignments. Studies were also performed to identify the factors responsible for the oxidative degradation of ezlopitant, which included salt form, storage conditions and salt formation solvent. Of all the variable studies over a 3 weeks period, only a change in the salt form prevented this oxidative degradation.

The effect of electroacupuncture as an adjunct on cyclophosphamide-induced emesis in ferrets

The effect of electroacupuncture (EA) on cyclophosphamide-induced emesis in ferrets was studied at acupuncture point Neiguan (P6) with various electrical stimulation parameters (5-100 Hz, 1.5-3 V, 5-20 min, n=6/group). The combination therapy of EA (100 Hz, 1.5 V and 10 min) with the lower doses of ondansetron (0.04 mg/kg), droperidol (0.25 mg/kg) and metoclopramide (2.24 mg/kg) significantly reduced the total number of emetic episodes by 52%, 36% and 73%, respectively, as well as the number of emetic episodes in the first phase as compared to the sham acupuncture control (P<.01). These EA/drug combinations also showed a significant effect in preventing emesis as compared to either EA or drug alone (P<.05). The present study suggests that acupuncture may be useful as an adjunctive therapy in the treatment of chemotherapy-induced emesis.

Control of nausea and vomiting after chemotherapy: what is the evidence?

The control of nausea and vomiting is an important problem for patients undergoing chemotherapy. With the introduction of newer agents, including 5-HT3 antagonists, nausea and vomiting control after chemotherapy has much improved but is not always optimal. While there is an intrinsic limitation to the efficacy of anti-emetic drugs, their efficacy can be further reduced if the drugs are not used appropriately. In some circumstances newer anti-emetics may be unnecessary and better nausea and vomiting control may be established by use of older agents. This paper summarizes current evidence regarding the optimal approach to management of nausea and vomiting in patients undergoing chemotherapy.