Phase III trial of casopitant, a novel neurokinin-1 receptor antagonist, for the prevention of nausea and vomiting in patients receiving moderately emetogenic chemotherapy

Effect of Adding Electroacupuncture to Standard Triple Antiemetic Therapy on Chemotherapy-Induced Nausea and Vomiting: A Randomized Controlled Clinical Trial

PURPOSE

We aim to determine the effectiveness of adding electroacupuncture to standard triple antiemetic therapy for treating chemotherapy-induced nausea and vomiting (CINV).

METHODS

From March 2022 to December 2023, a randomized, blind, sham-controlled trial conducted across six Chinese hospitals investigated patients with breast cancer undergoing highly emetogenic chemotherapy (HEC). Patients were randomly assigned to either true electroacupuncture (n = 120) or sham electroacupuncture (n = 119) groups, with both groups receiving standard triple antiemetic therapy. The primary end point was the proportion of complete protection (no vomiting, no need for rescue treatment, and no significant nausea, as evaluated using the visual analog scale [VAS]) within 120 hours after receiving HEC.

RESULTS

Among 239 randomly assigned patients, 235 (98.3%) completed the trial. In the full analysis set, compared with the sham electroacupuncture group, the true electroacupuncture group demonstrated a significant increase in the complete protection rate from 34.5% to 52.9% (P = .004). Additionally, true electroacupuncture also showed enhanced total control (4.3% v 13.4%; P = .014), no significant nausea (37.9% v 58.8%; P = .001), no nausea (4.3% v 13.4%; P = .014), and nausea VAS score = 0 mm (4.3% v 12.6%; P = .023). However, the occurrence of no vomiting in the overall stage was similar (76.7% v 73.9%; P = .622) in both groups. Post hoc exploratory analysis showed a significantly higher rate of complete protection during the delayed stage in the true electroacupuncture group compared with the sham electroacupuncture group, with no significant difference observed during the acute stage.

CONCLUSION

Adding true electroacupuncture to standard triple antiemetic therapy significantly enhances the efficacy of CINV treatment in patients with breast cancer receiving HEC.

Dexamethasone-sparing strategies in anthracycline and cyclophosphamide-based chemotherapy with a focus on 5-HT3 receptor antagonists: a network meta-analysis

Background

The effectiveness of a dexamethasone-sparing strategy in the treatment of breast cancer with anthracycline-cyclophosphamide therapy when combined with first-generation 5-HT3 receptor antagonists (RAs) and neurokinin-1 RAs is unclear. This is attributable to a lack of evidence from direct comparison of multiple doses of DEX to a single dose of DEX in combination with first-generation 5-HT3 RAs in anthracycline-cyclophosphamide therapy. Our goal was to clarify the impact of dexamethasone-sparing strategies that involve both first-generation 5-HT3 RAs and palonosetron when combined with neurokinin-1 RAs, using a network meta-analysis.

Materials and methods

A literature search was conducted on PubMed/Medline for articles published up to July 4, 2023. We included randomized controlled trials which assessed the efficacy of antiemetic regimens which combined 5-HT3 RAs and dexamethasone, with or without neurokinin-1 RAs, for the initial dose in anthracycline-cyclophosphamide therapy for patients with breast cancer. The primary outcome was the proportion of patients achieving a complete response during the delayed phase (CR-DP).

Results

The difference in the proportion of patients achieving CR-DP between multiple and single doses of dexamethasone was 0.1% (95%CI: -12.4 to 12.5) with palonosetron and neurokinin-1 RAs, compared to 5.3% (95%CI: -13.4 to 23.0) with a single dose of a first-generation 5-HT3 receptor antagonist. Additionally, the difference was 12.7% (95% CI: -2.8 to 28.2) when comparing palonosetron against first-generation 5-HT3 RAs in combination with a single dose of dexamethasone and neurokinin-1 RAs.

Conclusion

Palonosetron is recommended rather than a single dose of first-generation 5-HT3 RAs in dexamethasone-sparing strategies for anthracycline-cyclophosphamide therapy.

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.

Olanzapine-Based Triple Regimens Versus Neurokinin-1 Receptor Antagonist-Based Triple Regimens in Preventing Chemotherapy-Induced Nausea and Vomiting Associated with Highly Emetogenic Chemotherapy: A Network Meta-Analysis

BACKGROUND

The current antiemetic prophylaxis for patients treated with highly emetogenic chemotherapy (HEC) included the olanzapine-based triplet and neurokinin-1 receptor antagonists (NK-1RAs)-based triplet. However, which one shows better antiemetic effect remained unclear.

MATERIALS AND METHODS

We systematically reviewed 43 trials, involving 16,609 patients with HEC, which compared the following antiemetics at therapeutic dose range for the treatment of chemotherapy-induced nausea and vomiting: olanzapine, aprepitant, casopitant, fosaprepitant, netupitant, and rolapitant. The main outcomes were the proportion of patients who achieved no nausea, complete response (CR), and drug-related adverse events. A Bayesian network meta-analysis was performed.

RESULTS

Olanzapine-based triple regimens showed significantly better no-nausea rate in overall phase and delayed phase than aprepitant-based triplet (odds ratios 3.18, 3.00, respectively), casopitant-based triplet (3.78, 4.12, respectively), fosaprepitant-based triplet (3.08, 4.10, respectively), rolapitant-based triplet (3.45, 3.20, respectively), and conventional duplex regimens (4.66, 4.38, respectively). CRs of olanzapine-based triplet were roughly equal to different NK-1RAs-based triplet but better than the conventional duplet. Moreover, no significant drug-related adverse events were observed in olanzapine-based triple regimens when compared with NK-1RAs-based triple regimens and duplex regimens. Additionally, the costs of olanzapine-based regimens were obviously much lower than the NK-1RA-based regimens.

CONCLUSION

Olanzapine-based triplet stood out in terms of nausea control and drug price but represented no significant difference of CRs in comparison with NK-1RAs-based triplet. Olanzapine-based triple regimens should be an optional antiemetic choice for patients with HEC, especially those suffering from delayed phase nausea.

IMPLICATIONS FOR PRACTICE

According to the results of this study, olanzapine-based triple antiemetic regimens were superior in both overall and delayed-phase nausea control when compared with various neurokinin-1 receptor antagonists-based triple regimens in patients with highly emetogenic chemotherapy (HEC). Olanzapine-based triplet was outstanding in terms of nausea control and drug price. For cancer patients with HEC, especially those suffering from delayed-phase nausea, olanzapine-based triple regimens should be an optional antiemetic choice.

Bringing it all together in the treatment of CINV: application of current knowledge into routine clinical practice

For patients with cancer, the threat of chemotherapy-induced nausea and vomiting (CINV) can greatly influence treatment decisions and overall quality of life. Clinicians now have numerous effective antiemetic therapies to offer to patients, but selecting the optimal strategy can be complicated. Integration of current CINV guidelines, emerging data from recent clinical trials, and patient-specific risk factors can greatly improve antiemetic prophylaxis. Two challenging clinical scenarios are presented and discussed to provide insight on how to best approach these types of treatment decisions and apply recent advances in CINV prevention and management to patient care.

Rikkunshito for Preventing Chemotherapy-Induced Nausea and Vomiting in Lung Cancer Patients: Results from 2 Prospective, Randomized Phase 2 Trials

The herbal medicine rikkunshito has the potential to improve chemotherapy-induced nausea and vomiting (CINV) by stimulating ghrelin secretion. We aimed to evaluate the efficacy and safety of rikkunshito in preventing CINV for patients with lung cancer. Two separate prospective, randomized, phase II parallel design studies were conducted in patients with lung cancer. Fifty-eight and sixty-two patients scheduled to receive highly emetogenic chemotherapy (HEC) and moderately emetogenic chemotherapy (MEC), respectively, were randomized 1:1 to receive either standard antiemetic therapy in accordance with international guidelines (S group) or standard antiemetic therapy plus oral rikkunshito (R group). The primary endpoint was overall complete response (CR)-that is, no emesis and rescue medication in the first 120 h post-chemotherapy. Secondary endpoints included CR in the acute (0-24 h) and delayed (>24-120 h) phases and safety. Fifty-seven patients (S group, 28; R group, 29) receiving HEC and sixty-two patients (S group, 30; R group, 32) receiving MEC with comparable characteristics were evaluated. The CR rates were similar across the S and R groups for the HEC study in the overall (67.9% vs. 62.1%), acute (96.4% vs. 89.6%), and delayed (67.9% vs. 62.1%) phases, respectively, and for the MEC study in the overall (83.3% vs. 84.4%), acute (100% vs. 100%), and delayed (83.3% vs. 84.4%) phases, respectively. No severe adverse events were observed. Although rikkunshito was well tolerated, it did not demonstrate an additional preventative effect against CINV in lung cancer patients receiving HEC or MEC. Clinical Trial Registry Information: This study is registered with the University Hospital Medical Information Network (UMIN) Clinical Trial Registry, identification numbers UMIN 000014239 and UMIN 000014240.

Antiemetic therapy for non-anthracycline and cyclophosphamide moderately emetogenic chemotherapy

Although antiemetic management in cancer therapy has improved, chemotherapy-induced nausea and vomiting remain common and troubling adverse events. Chemotherapeutic agents are classified based on their emetogenic effects, and appropriate antiemetics are recommended according to this categorization. Chemotherapy categorized as moderately emetogenic is associated with a wide spectrum of emetic risks. Combined anthracycline and cyclophosphamide regimens have been recently reclassified as highly emetogenic chemotherapy regimen. This review focuses on antiemetic pharmacotherapy in patients receiving non-anthracycline and cyclophosphamide-based moderately emetogenic chemotherapy regimens. Combination therapy with a 5-hydroxytryptamine-3 receptor agonist, preferably palonosetron, and dexamethasone is the standard therapy in moderately emetogenic chemotherapy, although triple therapy with add-on neurokinin-1 receptor antagonist is used as an alternative treatment strategy. Among moderately emetogenic chemotherapy regimens, carboplatin-containing chemotherapy has considerable emetic potential, particularly during the delayed phase. However, the additional of a neurokinin-1 receptor antagonist to the standard antiemetic therapy prevents carboplatin-induced nausea and vomiting. For regimens including oxaliplatin, the benefit of adding neurokinin-1 receptor antagonist requires further clarification.

Neurokinin-1 Receptor Antagonist-Based Triple Regimens in Preventing Chemotherapy-Induced Nausea and Vomiting: A Network Meta-Analysis

Background

Neurokinin-1 receptor antagonists (NK-1RAs) are widely used for chemotherapy-induced nausea and vomiting (CINV) control in patients with highly emetogenic chemotherapy (HEC) and/or moderately emetogenic chemotherapy (MEC). Whether the efficacy and toxicity of antiemesis are different among various NK-1RA-based triple regimens is unknown.

Methods

Data of complete responses (CRs) in the acute, delayed, and overall phases and treatment-related adverse events (TRAEs) were extracted from electronic databases. Efficacy and toxicity were integrated by pairwise and network meta-analyses.

Results

Thirty-six trials involving 18 889 patients using triple regimens (NK-1RA+serotonin receptor antagonists [5HT3RA] + dexamethasone) or duplex regimen (5HT3RA+dexamethasone) to control CINV were included in the analysis. Different NK-1RA-based triple regimens shared equivalent effect on CRs. In patients with HEC, almost all triple regimens showed statistically significantly higher CRs than duplex regimen (odds ratio [OR]duplex/triple = 0.47-0.66). However, in patients with MEC, only aprepitant-based triple regimen showed better effect than duplex regimen statistically significantly in CRs (ORduplex/triple = 0.52, 95% confidence interval [CI] = 0.34 to 0.68). No statistically significant difference of TRAEs was found among different triple regimens. Palonosetron-based triple regimens were equivalent to first-generation 5HT3RAs-based triple regimens for CRs. Moreover, different doses of dexamethasone plus NK-1RA and 5HT3RA showed no statistically significant difference in CRs.

Conclusions

Different NK-1RAs-based triple regimens shared equivalent effect on CINV control. Various triple regimens had superior antiemetic effect than duplex regimen in patients with HEC. Only aprepitant-based triple regimen showed better CINV control compared with duplex regimen in patients receiving MEC. Palonosetron and first-generation 5HT3RAs might share equivalent CINV control in the combination of NK-1RAs and dexamethasone. Lower doses of dexamethasone might be applied when used with NK-1RAs and 5HT3RAs.

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.

Fibromyalgia syndrome: novel therapeutic targets

Fibromyalgia syndrome (FMS) is a chronic disorder characterized by widespread pain and tenderness, accompanied by disturbed sleep, chronic fatigue and multiple additional functional symptoms. FMS continues to pose an unmet need regarding pharmacological treatment and many patients fail to achieve sufficient relief from existing treatments. As FMS is considered to be a condition in which pain amplification occurs within the CNS, therapeutic interventions, both pharmacological and otherwise, have revolved around attempts to influence pain processing in the CNS. In the current review, we present an update on novel targets in the search for effective treatment of FMS.

Corticosteroids, the oldest agent in the prevention of chemotherapy-induced nausea and vomiting: What about the guidelines?

Chemotherapy-induced nausea and vomiting (CINV) remains one of the most disturbing side effects of cancer treatment. Research in antiemetic therapy has progressed gradually since the early eighties, and the development of antiemetic agents continues. This review focuses on the current management of CINV based on the most recent guidelines, and adherence to the latter is examined more carefully. Setrons (5HT3 receptor antagonists), corticosteroids, and NK-1 receptor antagonists are the cornerstones of antiemetic therapy. Corticosteroids are one of the oldest agents in the prevention of CINV. They are highly effective, increase the effect of other antiemetic agents, and are cost-effective. The latest developed 5HT3 receptor antagonist palonosetron led to an update of the guidelines of CINV. Other types include benzodiazepines, cannabinoids, and olanzapine. Various factors contribute to the overall risk of developing CINV, such as patient characteristics, emetogenic potency of the chemotherapeutic agents, and correct prevention of CINV. Current guidelines determine which is the right preventive regimen for each cancer patient at risk for experiencing CINV. Adherence to these guidelines and implementation in daily practice seem to be below the optimal level. In Belgium, authorities use the guidelines as a base for reimbursement and this has increased the level of implementation.

Choice of study endpoint significantly impacts the results of breast cancer trials evaluating chemotherapy-induced nausea and vomiting

Multiple endpoints can be used to evaluate chemotherapy-induced nausea and vomiting (CINV). These endpoints reflect the various combinations of vomiting, nausea and rescue antiemetic use in the acute (0-24 h), delayed (>24-120 h) and overall (0-120 h) periods after chemotherapy. As the choice of outcome measure could potentially change the interpretation of clinical trial results, we evaluated CINV rates using different endpoints on a single dataset from a prospective cohort. Data from 177 breast cancer patients receiving anthracycline and cyclophosphamide-based chemotherapy was used to calculate CINV control rates using the 15 most commonly reported CINV endpoints. As nausea remains such a significant symptom, we explored the frequency at which pharmaceutical and non-pharmaceutical company-funded studies included measures of nausea in their primary study endpoint. CINV control rates ranged from 12.5 %, 95 % (CI 7.6-17.4 %) for total control (no vomiting, no nausea and no rescue medication) in the overall period to 77.4 %, 95 % (CI 71.2-83.6 %) for no vomiting in the overall period. Similar differences were found in the acute and delayed periods. Non-pharmaceutical company-funded trials were more likely to include a measure of nausea in the primary study outcome (9/18, 50 %) than pharmaceutical-funded trials (1/12, 8.3 %). The choice of trial endpoint has an important impact on reported CINV control rates and could significantly impact on interpretation of the results. Primary endpoints of studies, including those mandated by regulatory bodies, should account for nausea to reflect patient experience. Reporting of endpoints should be more comprehensive to allow for cross-trial comparisons.

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.

Defining optimal control of chemotherapy-induced nausea and vomiting-based on patients' experience

PURPOSE

A considerable challenge when comparing antiemetic trials for chemotherapy-induced nausea and vomiting (CINV) is the large number of outcome measures for nausea and vomiting. The objective of this study is to determine the optimal definition of CINV control from the patients' perspective.

METHODS

Patients with early-stage breast cancer who had received anthracycline-cyclophosphamide-based chemotherapy were surveyed. They were asked about their experiences of CINV and perceptions of different CINV assessment tools.

RESULTS

Of 201 patients approached, 168 (83 %) completed the survey. Patients consistently ranked nausea over vomiting as the "worst side effect from chemotherapy." Despite the use of multi-agent antiemetic regimens, 71 % of patients experienced nausea and 26 % vomiting. Only 57 % of patients with any nausea or vomiting took rescue medications and only then when the symptom was severe. Most (76 %) patients believed that the primary end point of antiemetic trials should include the absence of both nausea and vomiting. Patients felt that CINV should be evaluated for the overall period post chemotherapy (i.e., days 1-5) and not simply the acute (the first 24 h) or delayed (days 2-5) periods.

CONCLUSIONS

Patients strongly favored a CINV end point that includes the absence of both nausea and vomiting. Patients' experience with CINV is underestimated when nausea is not included in composite end points. "Use of rescue medication," a commonly used surrogate for emesis control, is inappropriate as it underestimates nausea. A standardized primary end point that includes nausea is essential if CINV control is to be improved.

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.

Comparative effectiveness research in antineoplastic-induced nausea and vomiting control in children

Antineoplastic-induced nausea and vomiting (AINV) is one of the most distressing adverse effects experienced by adult and pediatric patients receiving antineoplastic agents. Despite this, evidence of the efficacy and safety of antiemetic interventions in children is limited, and prevention and treatment approaches vary widely between centers. The purpose of this review is: first, to describe the barriers to comparative antiemetic effectiveness research in AINV control in children; second, to highlight limitations of the currently available pediatric AINV evidence; third, to summarize and discuss comparative effectiveness research specific to AINV control in children, with a focus on agents recommended in evidence-based guidelines developed for acute phase AINV control; and finally, to offer guidance regarding future comparative effectiveness research in this field.

Exploring Chemotherapy-Induced Toxicities through Multivariate Projection of Risk Factors: Prediction of Nausea and Vomiting

Many risk factors exist for chemotherapy-induced nausea and vomiting (CINV). This study utilized a multivariate projection technique to identify which risk factors were predictive of CINV in clinical practice. A single-centre, prospective, observational study was conducted from January 2007~July 2010 in Singapore. Patients were on highly (HECs) and moderately emetogenic chemotherapies with/without radiotherapy. Patient demographics and CINV risk factors were documented. Daily recording of CINV events was done using a standardized diary. Principal component (PC) analysis was performed to identify which risk factors could differentiate patients with and without CINV. A total of 710 patients were recruited. Majority were females (67%) and Chinese (84%). Five risk factors were potential CINV predictors: histories of alcohol drinking, chemotherapy-induced nausea, chemotherapy-induced vomiting, fatigue and gender. Period (ex-/current drinkers) and frequency of drinking (social/chronic drinkers) differentiated the CINV endpoints in patients on HECs and anthracycline-based, and XELOX regimens, respectively. Fatigue interference and severity were predictive of CINV in anthracycline-based populations, while the former was predictive in HEC and XELOX populations. PC analysis is a potential technique in analyzing clinical population data, and can provide clinicians with an insight as to what predictors to look out for in the clinical assessment of CINV. We hope that our results will increase the awareness among clinician-scientists regarding the usefulness of this technique in the analysis of clinical data, so that appropriate preventive measures can be taken to improve patients' quality of life.

Management of chemotherapy-induced nausea and vomiting : focus on newer agents and new uses for older agents

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. The use of a combination of a serotonin 5-HT3 receptor antagonist, dexamethasone and a neurokinin 1 (NK1) receptor antagonist has significantly improved the control of acute and delayed emesis in single-day chemotherapy. Palonosetron, a second-generation 5-HT3 receptor antagonist with a different half-life, a different binding capacity and a different mechanism of action than the first-generation 5-HT3 receptor antagonists appears to be the most effective agent in its class. Aprepitant, the first and only agent clinically available in the NK1 receptor antagonist drug class has been used effectively as an additive agent to the 5-HT3 receptor antagonists and dexamethasone to control CINV. Rolapitant and netupitant are other NK1 receptor antagonists that are currently in phase III clinical trials. Despite the control of emesis, nausea has not been well controlled by current agents. Olanzapine, a US-FDA approved antipsychotic, has emerged in recent trials as an effective preventative agent for CINV, as well as a very effective agent for the treatment of breakthrough emesis and nausea. Clinical trials using gabapentin, cannabinoids and ginger have not been definitive regarding their efficacy in the prevention of CINV. Additional studies are necessary for the control of nausea and for the control of CINV in the clinical settings of multiple-day chemotherapy and bone marrow transplantation.

Fibromyalgia syndrome--novel therapeutic targets

Fibromyalgia is a syndrome characterized by the presence of chronic widespread pain, representing sensitization of the central nervous system. The pthophysiology of fibromyalgia is a complex and remains in evolution, encompassing diverse issues such as disturbed patterns of sleep, alter processing and decreased conditioned pain modulation at the spinal level, as well as increased connectivity between various pain - processing areas of the brain. This evolution is continuously uncovering potential novel therapeutic targets. Treatment of fibromyalgia is a multi - faceted endeavor, inevitably combining pharmacological as well as non - pharmacological approaches. 2δ ligands and selective nor-epinephrine - serotonin reuptake inhibitors are the current mainstays of pharmacological treatment. Novel re-uptake inhibitors targeting both nor -epinephrine and dopamine are potential additions to this armamentarium as are substance P antagonists, Opiod antagonism is another intriguing possibility. Canabinoid agonists hold promise in the treatment of fibromyalgia although current evidence is incomplete. Sodium Oxybate is a unique sleep - promoting medication while drugs those promot arousals such as modafilnil are also under investigation. In the current review, current and emerging therapeutic options for the syndrome of fibromyalgia are covered.

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.

Prevention of chemotherapy-induced nausea and vomiting and the role of neurokinin 1 inhibitors: from guidelines to clinical practice in solid tumors

A significant proportion of cancer patients experience nausea or vomiting during the course of their disease, either because of the cancer itself or because of the treatment received. Highly or moderately emetogenic drugs are part of the standard chemotherapy regimens frequently used in patients with lung cancer, breast cancer, ovarian cancer, and several other common solid tumors. In this review, we describe the impact of nausea and vomiting in patients receiving chemotherapy, and the main progress achieved in the prophylaxis of chemotherapy-induced nausea and vomiting with the introduction of neurokinin 1 inhibitors. The adherence to existing guidelines is particularly important to avoid suboptimal prophylaxis and maximize patients' outcome. This review is focused on lung, breast, ovarian, and colorectal cancer, which are among the solid tumors characterized by a numeric and clinical relevance of the chemotherapy-induced nausea and vomiting issue because of the wide use of highly and/or moderately emetogenic chemotherapy regimens.

Adherence to national guidelines for antiemesis prophylaxis in patients undergoing chemotherapy for lung cancer: a population-based study

BACKGROUND

Nausea and vomiting (N/V) during chemotherapy can have profound clinical and economic consequences. Effective antiemetic agents are available for prophylaxis, but barriers may prevent their use. For this population-based study, the authors assessed the rates of antiemetic prophylaxis use, and predictors of such use, among patients who were receiving platinum-based chemotherapy for lung cancer between 2001 and 2007.

METHODS

The authors searched the Texas Cancer Registry-Medicare-linked database for individuals aged >65 years who received platinum-based chemotherapy within 12 months after a first diagnosis of lung cancer from 2001 to 2007; and all patients had continuous Medicare Part A and Part B coverage for the same period. Adherence to recommended regimens for N/V prophylaxis (established by the National Comprehensive Cancer Network) was scored as a binary variable (adherent vs nonadherent) and was calculated as the percentages of treated patients receiving each recommended agent within 1 day of beginning chemotherapy. Logistic regression with stepwise selection was used to examine whether patient characteristics influenced adherence.

RESULTS

Of 4566 selected patients, adherence rates for the receipt of serotonin antagonists (eg, ondansetron) with dexamethasone were 60% to 90% regardless of whether the chemotherapy agent was considered moderately or highly emetogenic. The receipt of substance-P antagonists was much less common (<10%) during any period. On multivariate logistic regression modeling, variables that predicted adherence were older age, white race, higher median income, and concurrent radiation therapy.

CONCLUSIONS

Recommended use of antiemetics for prophylaxis, especially substance-P antagonists, during chemotherapy for lung cancer is suboptimal. Factors that were correlated with adherence suggest socioeconomic barriers in the community.

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.

Computational prediction of state anxiety in Asian patients with cancer susceptible to chemotherapy-induced nausea and vomiting

State anxiety, a risk factor for chemotherapy-induced nausea and vomiting (CINV), is a subjective symptom and difficult to quantify. Clinicians need appropriate anxiety measures to assess patients' risks of CINV. This study aimed to determine the anxiety characteristics that can predict CINV based on computational analysis of an objective assessment tool. A single-center, prospective, observational study was carried out between January 2007 and July 2010. Patients with breast, head and neck, and gastrointestinal cancers were recruited and treated with a variety of chemotherapy protocols and appropriate antiemetics. Chemotherapy-induced nausea and vomiting characteristics and antiemetic use were recorded using a standardized diary, whereas patients' anxiety characteristics were evaluated using the Beck Anxiety Inventory. Principal component (PC) analysis was performed to analyze the anxiety characteristics. A subset known as principal variables, which had the highest PC weightings, was identified for patients with and without complete response, complete protection, and complete control. Chemotherapy-induced nausea and vomiting events and anxiety characteristics of 710 patients were collated; 51%, 30%, and 20% were on anthracycline-, oxaliplatin-, and cisplatin-based therapies, respectively. Most patients suffered from delayed CINV, with decreasing proportions achieving complete response (58%), complete protection (42%), and complete control (27%). Seven symptoms (fear of dying, fear of the worst, unable to relax, hot/cold sweats, nervousness, faintness, numbness) were identified as potential CINV predictors. This study demonstrates the usefulness of PC analysis, an unsupervised machine learning technique, to identify 7 anxiety characteristics that are useful as clinical CINV predictors. Clinicians should be aware of these characteristics when assessing CINV in patients on emetogenic chemotherapies.

The potential role for corticosterone in the induction of cleft palate in mice after treatment with a selective NK-1 receptor antagonist, casopitant (GW679769B)

BACKGROUND

Casopitant is a potent and selective NK-1 receptor antagonist that has shown clinical efficacy in the prevention of chemotherapy-induced and postoperative-induced nausea and vomiting.

METHODS

In an embryo-fetal development study, pregnant mice were given vehicle (sterile water) or doses of 30, 100, or 300 mg/kg/day casopitant on Gestation Day (GD) 6 to 15. Fetuses were evaluated for external, visceral, and skeletal abnormalities on GD 18. In a follow-on study to investigate casopitant-induced hormonal changes during the developmental period for palate formation, pregnant mice were given vehicle (sterile water) or 300 mg/kg/day casopitant once daily on GD 6 to 13. Blood was collected on GD 13 at various time-points for measurement of plasma adrenocorticotropic hormone and corticosterone (CRT) concentrations.

RESULTS

There was no evidence of developmental toxicity in mice at 30 or 100 mg/kg/day but 9% of fetuses at 300 mg/kg/day had cleft palate. Mice are sensitive to glucocorticoid-induced cleft palates, and NK-1 antagonists are known to modulate the hypothalamic-pituitary-adrenal axis leading to increases in corticosterone. On GD 13, mean plasma adrenocorticotropic hormone levels at 300 mg/kg/day were elevated by approximately twofold from vehicle-treated levels at 1 hr post-dose and mean plasma CRT levels were elevated by 3, 5, and 10-fold at 0.5, 1, and 2 hr post-dose, respectively.

CONCLUSIONS

The increased level of CRT was in the range previously shown in the literature to cause cleft palates in mice and was likely the underlying mechanism behind casopitant-induced cleft palate in mice.

Gabapentin for the prevention of chemotherapy- induced nausea and vomiting: a pilot study

INTRODUCTION

Chemotherapy-induced nausea and vomiting (CINV) is a distressing side effect that affects many patients undergoing emetogenic chemotherapy, despite the use of antiemetic medications. The purpose of this trial was to evaluate the efficacy and safety of gabapentin for the prevention of CINV during the first cycle of treatment in patients receiving moderately or highly emetogenic chemotherapy.

METHODS

Eighty chemotherapy-naive patients, scheduled to receive moderately and highly emetogenic chemotherapy, were enrolled in this randomised, double-blind, placebo-controlled clinical trial. All patients received intravenous ondansetron 8 mg, dexamethasone 10 mg and ranitidine 50 mg before chemotherapy on day 1 and oral dexamethasone 4 mg twice a day on days 2 and 3. Patients were randomly assigned to take gabapentin 300 mg or placebo on the following schedule: 5 and 4 days before chemotherapy once daily, 3 and 2 days before chemotherapy twice daily, 1 day before to 5 days after chemotherapy thrice daily. The primary endpoint was complete overall protection from both vomiting and nausea over the course of the entire study (day 1 through day 5), and complete protection during the delayed period (24-120 h after chemotherapy).

RESULTS

The proportion of patients achieving complete response improved from 40% to 62.5%, (p = 0.04) when comparing the control group and the gabapentin group, respectively. In the subset of patients who achieved complete control in the acute phase, the percentage of patients who achieved delayed complete control was higher in the gabapentin group (89.3 × 60.7%, p = 0.01). Adverse events did not significantly differ between study arms.

CONCLUSIONS

Gabapentin is a low-cost strategy to improve complete control of CINV, specially delayed CINV control.

Safety evaluation of aprepitant for the prevention of chemotherapy-induced nausea and vomiting

INTRODUCTION

Aprepitant is the only neurokinin (NK(1)) receptor antagonist (RA) approved for prevention of chemotherapy-induced nausea and vomiting (CINV). Aprepitant is co-administered with a 5-HT(3) RA and a corticosteroid. Although aprepitant is safe, in most clinical settings potential drug-drug interactions need to be considered before prescription.

AREAS COVERED

This article thoroughly reviews aprepitant and, in particular, clinically relevant safety aspects of the drug. The literature review was performed using Medline with the following search terms: adverse events, aprepitant, chemotherapy, CYP3A4, MK-0869, neurokinin(1) receptor antagonist, safety and tolerability.

EXPERT OPINION

The recommended antiemetic regimen of aprepitant, a 5-HT(3) RA and a corticosteroid is safe. The combination of aprepitant, a 5-HT(3) RA and dexamethasone is now the gold standard of antiemetic treatment in prevention of CINV induced by HEC, or by the combination of an anthracycline and cyclophosphamide. The intravenous formulation of aprepitant used as a single dose is expected to be of benefit to cancer patients.

Casopitant: in vitro data and SimCyp simulation to predict in vivo metabolic interactions involving cytochrome P450 3A4

Casopitant [1-piperidinecarboxamide,4-(4-acetyl-1-piperazinyl)-N-((1R)-1-(3,5-bis(trifluoromethyl)phenyl)-ethyl)-2-(4-fluoro-2-methylphenyl)-N-methyl-(2R,4S), GW679769] has previously been shown to be a potent and selective antagonist of the human neurokinin-1 receptor, the primary receptor of substance P, both in vitro and in vivo, with good brain penetration properties. On the basis of this mode of action it was evaluated for the prevention of chemotherapy-induced and postoperative nausea and vomiting, and for the chronic treatment of anxiety, depression, insomnia, and overactive bladder. Casopitant is shown to be a substrate, an inhibitor, and an inducer of CYP3A4, and, because of this complex behavior, it was difficult to identify the primary mechanism by which it may give rise to drug-drug interactions (DDIs) of clinical relevance. Moreover, the major circulating metabolite is itself an inhibitor of CYP3A4 in vitro. On the basis of the different clinical indications and the various potential comedications of casopitant, a relevant part of the clinical development plan was focused on the assessment of the importance of clinical DDIs. The present study provides an overview of the DDI potential profile of casopitant, based on in vitro data and clinical evidence of its interaction with CYP3A4 probe substrates midazolam and nifedipine, the strong inhibitor ketoconazole, and the inducer rifampin. Overall, the clinical data confirm the ability of casopitant to interact with CYP3A4 substrates, inhibitors, or inducers. The in vitro data are accurate and robust enough to build a reliable SimCyp population-based model to estimate the potential DDIs of casopitant and to minimize the clinical studies recommended.

Effect of single and repeat doses of casopitant on the pharmacokinetics of CYP450 3A4 substrates midazolam and nifedipine

AIM

To evaluate the impact of single and repeated doses casopitant on the pharmacokinetics of single dose midazolam and nifedipine (CYP3A substrates) in healthy subjects. The effect on debrisoquine metabolism (CYP2D6 substrate) was also assessed.

METHODS

Three open-label studies were conducted in healthy subjects. In the first study subjects received single dose 50 or 100 mg oral casopitant, single dose 5 mg oral midazolam and single dose 10 mg oral debrisoquine. In the other two studies subjects received repeated doses of 10 mg (study 2), 30, or 120 mg oral casopitant and single doses of 5 mg oral midazolam (study 2) and single doses of 10 mg oral nifedipine (study 3). Plasma concentration-time data were analyzed using standard non-compartmental methods. The effect of casopitant on all probes was assessed using geometric means ratios and corresponding 90% confidence intervals (CIs).

RESULTS

The AUC(0,∞) of midazolam was increased 1.44-fold (90% CI 1.35, 1.54) and 1.52-fold (90% CI 1.41, 1.65) after co-administration with a single dose of 50 or 100 mg casopitant, respectively. Debrisoquine metabolism was unchanged. After 3 days of casopitant administration, midazolam AUC(0,∞) was increased 1.45- (90% CI 1.32, 1.59), 2.02- (90% CI 1.75, 2.32), and 2.67-fold (90% CI 2.18, 3.27) after co-administration with 10, 30 or 120 mg casopitant, respectively. After 14 days of casopitant administration, midazolam AUC(0,∞) was increased 1.51- (90% CI 1.40, 1.63) to 3.49-fold (90% CI 2.98, 4.08). After 3 days of casopitant administration, nifedipine AUC(0,∞) was increased 1.56- (90% CI 1.37, 1.78) and 1.77-fold (90% CI 1.54, 2.04) after co-administration with 30 or 120 mg casopitant, respectively. Similar increases in nifedipine exposure were observed after 14 days of casopitant administration.

CONCLUSIONS

Casopitant is a dose- and duration-dependent weak to moderate inhibitor of CYP3A.

Tissue distribution and characterization of drug-related material in rats and dogs after repeated oral administration of casopitant

Casopitant [1-piperidinecarboxamide,4-(4-acetyl-1-piperazinyl)-N-((1R)-1-(3,5-bis(trifluoromethyl)phenyl)-ethyl)-2-(4-fluoro-2-methylphenyl)-N-methyl-(2R,4S)] has been shown to be a potent and selective antagonist of the human neurokinin 1 receptor, the primary receptor for substance P. During long-term toxicity studies conducted in rat and dog, evidence of cardiomyopathy and increased cardiac weight were observed. The distribution and metabolism of casopitant were studied in both species evaluating the accumulation of drug-related material (DRM) after repeat dosing and its potential relationship with pathological findings observed in myocardium. After repeat oral administration of [(14)C]casopitant to rats (20 days) and dogs (14 days), DRM was quantifiable in all of the tissues examined with lung and liver containing the highest level of radioactivity. The concentration of radioactivity was significantly higher in tissues than in plasma, declining slowly and still quantifiable after a recovery period of 20 days. The principal circulating components identified in both species were casopitant, M12 (oxidized deacetylated), M13 (hydroxylated piperazine), and M31 and M134 (two N-dealkylated piperazines). In tissues, a similar metabolic pattern was observed, in which casopitant, M31, M134, M76 (N-deacetylated), and M200 (N-deacetylated N,N-deethylated) were the major components quantified. After a 26-week repeat dose study in dog, casopitant and M13 were the major circulating components, whereas in myocardium, M200 and M134 were the major ones and their levels increased over time, reaching considerable concentrations (millimolar magnitude). After a washout period, all circulating derivatives decreased to undetectable levels, whereas M200 was still the major component in myocardium. Overall DRM in plasma did not correlate with the respective concentrations in tissues.

The evaluation of drug rechallenge: the casopitant Phase III program

Drug rechallenge (or reinitiation), following an event of drug-induced liver injury, is associated with 13% mortality in prospective series. Rechallenge generally results in much more rapid injury than the initial liver event. The neurokinin-1 antagonist casopitant or its placebo was administered cyclically with ondansetron and dexamethasone in two randomized chemotherapy-induced nausea and vomiting clinical trials in nearly 3000 subjects. Grade 3 ALT elevations were observed in up to 2% of subjects receiving casopitant or placebo treatment. Similar rates of positive rechallenge were observed in the casopitant 8/29 (28%) and placebo groups 2/8 (25%), with no Grade 4 ALT elevations, hypersensitivity or liver-related serious adverse events. Publishing available rechallenge data (positive and negative) will advance our clinical understanding. Rechallenge should only be considered when the potential drug benefit exceeds the risk.