Association of ABCB1 Polymorphisms with the Antiemetic Efficacy of Granisetron plus Dexamethasone in Breast Cancer Patients

Metagenomics and chemotherapy-induced nausea: A roadmap for future research

Uncontrolled chemotherapy-induced nausea and vomiting can reduce patients' quality of life and may result in premature discontinuation of chemotherapy. Although nausea and vomiting are commonly grouped together, research has shown that antiemetics are clinically effective against chemotherapy-induced vomiting (CIV) but less so against chemotherapy-induced nausea (CIN). Nausea remains a problem for up to 68% of patients who are prescribed guideline-consistent antiemetics. Despite the high prevalence of CIN, relatively little is known regarding its etiology independent of CIV. This review summarizes a metagenomics approach to the study and treatment of CIN with the goal of encouraging future research. Metagenomics focuses on genetic risk factors and encompasses both human (ie, host) and gut microbial genetic variation. Little work to date has focused on metagenomics as a putative biological mechanism of CIN. Metagenomics has the potential to be a powerful tool in advancing scientific understanding of CIN by identifying new biological pathways and intervention targets. The investigation of metagenomics in the context of well-established demographic, clinical, and patient-reported risk factors may help to identify patients at risk and facilitate the prevention and management of CIN.

An Update in Our Understanding of the Relationships Between Gene Polymorphisms and Chemotherapy-Induced Nausea and Vomiting

The occurrence and severity of chemotherapy-induced nausea and vomiting (CINV) are influenced by many factors; this includes therapeutic factors, such as the dose, administration mode, and chemotherapeutic agent emetogenicity, as well as patient-related risk factors, such as the gender, age, alcohol consumption history, and anxiety level. However, these factors cannot fully explain the individual CINV differences. In recent years, the correlation between gene polymorphism and CINV has been a hot research topic; the present paper reviews current research on CINV-related gene polymorphisms, and the results indicate that the use of gene polymorphism for the optimization of CINV efficacy is of important clinical significance.

Clinical Observation of Gene Polymorphism of Olanzapine or Aprepitant in Prevention of CINV

Objective

The present study aims to investigate the correlation between the gene polymorphisms of the multidrug resistance protein 1 (ABCB1), the intron region of transcriptional factor (GTF2E1) and catechol-O-methyltransferase (COMT), dopamine receptor (DRD2), and the control of chemotherapy-induced nausea and vomiting (CINV) by olanzapine or aprepitant in a Chinese population under a fractionated cisplatin dosing pattern.

Methods

Antiemetic treatment with 5 mg of olanzapine or aprepitant triplet therapy was conducted in 210 patients with malignancies receiving cisplatin multi-day chemotherapy. The general data on the patients were collected with the evaluation of the rate of complete protection (TP), complete remission (CR), complete control (TC), and time to first vomiting, the functional living index-emesis (FLIE) scale, and side effects in the acute and delayed phases. The DNA mass spectrometry detected the gene polymorphisms of ABCB1, GTF2E1, COMT, and DRD2, and the correlation with TP was analyzed.

Results

1) There were no statistically significant differences in the TP, CR, TC, time of first vomiting, and FLIE index at different phases between the 5mg of olanzapine group and the aprepitant group (P > 0.05). 2) The main side effect in the olanzapine group was drowsiness (P = 0.00), and in the aprepitant group was constipation (P = 0.02). 3) The distributions of each genotype were in the Hardy–Weinberg (H–W) equilibrium. Univariate analysis showed that in the olanzapine group, delayed-phase TP was correlated with the ABCB1 rs1045642 non-TT (P = 0.01) genotype.

Conclusion

The present study revealed that females and the rs1045642TT genotype were independent risk factors for delayed-phase CINV in the northern Chinese population, which provided a scientific basis for subsequent CINV-related analysis of high-risk factors in Chinese patients.

International Union of Basic and Clinical Pharmacology. CX. Classification of Receptors for 5-hydroxytryptamine; Pharmacology and Function

5-HT receptors expressed throughout the human body are targets for established therapeutics and various drugs in development. Their diversity of structure and function reflects the important role 5-HT receptors play in physiologic and pathophysiological processes. The present review offers a framework for the official receptor nomenclature and a detailed understanding of each of the 14 5-HT receptor subtypes, their roles in the systems of the body, and, where appropriate, the (potential) utility of therapeutics targeting these receptors. SIGNIFICANCE STATEMENT: This review provides a comprehensive account of the classification and function of 5-hydroxytryptamine receptors, including how they are targeted for therapeutic benefit.

Analysis of pharmacogenomic factors for chemotherapy-induced nausea and vomiting in patients with breast cancer receiving doxorubicin and cyclophosphamide chemotherapy

PURPOSE

Chemotherapy-induced nausea and vomiting (CINV) can lead to a significant deterioration in the quality of life of cancer patients receiving chemotherapy. This study aimed to determine whether ABCB1 2677G > T/A was associated with complete response (CR; defined as no vomiting and no rescue medication) in acute phase (CR_0-24), as well as to explore the genetic factors affecting delayed phase (CR_24-120) CINV in cancer patients treated with a standard triple antiemetic regimen that included aprepitant.

METHODS

This prospective single-center study included a total of 166 chemotherapy-naïve patients with breast cancer who received a standard dose of doxorubicin and cyclophosphamide combination chemotherapy; granisetron, dexamethasone, and aprepitant were administered prior to chemotherapy. CR_0-24 was compared between minor allele homozygous (TT, AA, and TA) and major allele homozygous plus heterozygous (GG, GA, and GT) groups of ABCB1 2677G > T/A. In addition, 14 genetic polymorphisms were genotyped and their associations with CRs were investigated.

RESULTS

The proportion of patients who achieved CR_0-24, which was the primary endpoint of this study, was 59% in the minor allele homozygous and 61% in the major allele homozygous plus heterozygous groups of ABCB1 2677G > T/A. Although this difference was not statistically significant, multivariate logistic regression analysis adjusted for potential risk factors showed that TACR1 1323TT (OR, 2.57; P = 0.014) was a significant determinant of CR_24-120.

CONCLUSION

No significant association was found between ABCB1 2677G > T/A and CR_0-24. However, it was observed that the polymorphism of TACR1, which encodes the neurokinin 1 receptor, might be a potential genetic risk factor for the development of delayed phase CINV.

Pharmacogenetics of antiemetics for chemotherapy-induced nausea and vomiting: A systematic review and meta-analysis

A substantial proportion of cancer patients experience chemotherapy-induced nausea and vomiting (CINV) despite the use of antiemetic drugs. Prevalent genetic polymorphisms involved in antiemetic drug metabolism, drug transport and receptor pathways likely affect the effectiveness of antiemetics. Knowledge on which polymorphisms to integrate into individualised clinical care is needed. We did a systematic review evaluating the association between polymorphisms and effectiveness of antiemetics in cancer patients receiving moderately to highly emetogenic chemotherapy. Twenty studies n = 2331 evaluated eight polymorphisms in five candidate genes involved in 5-HT₃ antagonist pathways. HTR3C C1214G increased the risk of acute chemotherapy-induced vomiting in the dominant model (odds ratio (OR) = 2.67, 95 % confidence interval (CI): 1.08-6.63). ABCB1 C3435T reduced the risk of acute CINV in the recessive model (OR = 0.60, 95 % CI: 0.44-0.81). Future studies should evaluate candidate genes that affect pharmacogenetics of other antiemetics beside 5-HT₃ antagonists.

Drug-drug-gene interactions and adverse drug reactions

The economic and health burden caused by adverse drug reactions has increased dramatically in the last few years. This is likely to be mediated by increasing polypharmacy, which increases the likelihood for drug–drug interactions. Tools utilized by healthcare practitioners to flag potential adverse drug reactions secondary to drug–drug interactions ignore individual genetic variation, which has the potential to markedly alter the severity of these interactions. To date there have been limited published studies on impact of genetic variation on drug–drug interactions. In this review, we establish a detailed classification for pharmacokinetic drug–drug–gene interactions, and give examples from the literature that support this approach. The increasing availability of real-world drug outcome data linked to genetic bioresources is likely to enable the discovery of previously unrecognized, clinically important drug–drug–gene interactions.

Neuroanesthesiology Update

We provide a synopsis of innovative research, recurring themes, and novel experimental findings pertinent to the care of neurosurgical patients and critically ill patients with neurological diseases. We cover the following broad topics: general neurosurgery, spine surgery, stroke, traumatic brain injury, monitoring, and anesthetic neurotoxicity.

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.

Prediction of chemotherapy-induced nausea and vomiting from patient-reported and genetic risk factors

PURPOSE

Chemotherapy-induced nausea and vomiting (CINV) is common among cancer patients. Early identification of patients at risk for CINV may help to personalize anti-emetic therapies. To date, few studies have examined the combined contributions of patient-reported and genetic risk factors to CINV. The goal of this study was to evaluate these risk factors.

METHODS

Prior to their first chemotherapy infusion, participants completed demographic and risk factor questionnaires and provided a blood sample to measure genetic variants in ABCB1 (rs1045642) and HTR3B (rs45460698) as well as CYP2D6 activity score. The M.D. Anderson Symptom Inventory was completed at 24 h and 5-day post-infusion to assess the severity of acute and delayed CINV, respectively.

RESULTS

Participants were 88 patients (55% female, M = 60 years). A total of 23% experienced acute nausea and 55% delayed nausea. Younger age, history of pregnancy-related nausea, fewer hours slept the night prior to infusion, and variation in ABCB1 were associated with more severe acute nausea; advanced-stage cancer and receipt of highly emetogenic chemotherapy were associated with more severe delayed nausea (p values < 0.05). In multivariable analyses, ABCB1 added an additional 5% predictive value beyond the 13% variance explained by patient-reported risk factors.

CONCLUSIONS

The current study identified patient-reported and genetic factors that may place patients at risk for acute nausea despite receipt of guideline-consistent anti-emetic prophylaxis. Additional studies examining other genetic variants are needed, as well as the development of risk prediction models including both patient-reported and genetic risk factors.

Genetic risk factors for chemotherapy-induced nausea and vomiting in patients with cancer receiving cisplatin-based chemotherapy

PURPOSE

Younger age and female sex have already been well-known risk factors for chemotherapy-induced nausea and vomiting (CINV), and 30-50% of cancer patients still suffer from CINV. Genetic polymorphisms are suggested to influence antiemetic treatment response.

METHODS

This study included a subset of patients previously enrolled in a randomised controlled trial; 156 patients were evaluated. This study aimed to evaluate the role of pharmacogenomic polymorphisms relevant to antiemetic response in patients with cancer receiving cisplatin-based chemotherapy. The study's efficacy endpoint was the proportion of patients with complete response (CR). The study endpoint was evaluated separately in the acute (CR_0-24) and delayed (CR_24-120) phases. Thirteen polymorphisms were genotyped, and the association of these genotypes with the efficacy of prophylactic antiemetics was then investigated. Confounding variables for the CR were identified using stepwise multivariate logistic regression analysis. Age and sex were included as independent variables by the forced-entry method, and the stepwise method was used to select the pharmacogenomic factors for inclusion as independent variables.

RESULTS

Multivariate logistic regression analysis revealed that the ERCC1 8092AA (odds ratio [OR] = 11.25; 95% confidence interval [CI] 1.74-72.71; p = 0.011) and female sex (OR = 3.63; 95% CI 1.14-11.58; p = 0.029) were significant predictors of CR_0-24. No significant association of CR_24-120 with pharmacogenomic polymorphisms was found via multivariate logistic regression analysis.

CONCLUSIONS

ERCC1 polymorphism influenced the extent of CINV control in patients receiving cisplatin-based chemotherapy.

TRIAL REGISTRATION

Clinical trial information: UMIN 000009335.

A review of the literature on the relationships between genetic polymorphisms and chemotherapy-induced nausea and vomiting

Despite current advances in antiemetic treatments, between 30% to and 60% of oncology patients experience chemotherapy-induced nausea (CIN) and 13% to 33% report chemotherapy-induced vomiting (CIV). Inter-individual differences are observed in the occurrence and severity of chemotherapy-induced nausea and vomiting (CINV). This review summarizes and critiques studies on associations between occurrence and severity of CINV and polymorphisms in serotonin receptor, drug metabolism, and drug transport pathway genes. Sixteen studies evaluated the associations between the occurrence and/or severity of CINV and single nucleotide polymorphisms (SNPs). Across these studies, three SNPs in 5-hydroxytryptamine receptor (5-HT3R) genes, two alleles of the cytochrome P450 family 2 subfamily D member 6 (CYP2D6) gene, and three SNPs in ATP binding cassette subfamily B member 1 (ABCB1) gene were associated with the occurrence and severity of CINV. Given the limited number of polymorphisms evaluated, additional research is warranted to identify new mechanisms to develop more targeted therapies.

Genetic Risk Factors Associated With Antiemetic Efficacy of Palonosetron, Aprepitant, and Dexamethasone in Japanese Breast Cancer Patients Treated With Anthracycline-based Chemotherapy

INTRODUCTION

Breast cancer patients often receive anthracycline-based chemotherapy, and chemotherapy-induced nausea and vomiting (CINV) remains one of the most uncomfortable and distressing adverse reactions. Poor control of CINV reduces the relative dose intensity of chemotherapy agents, which has been associated with poor clinical outcomes and shorter survival. The aim of the present study was to identify genetic risk factors associated with anthracycline-based CINV.

PATIENTS AND METHODS

We evaluated CINV attributable to anthracycline-based chemotherapy in Japanese breast cancer patients treated with an antiemetic regimen that included palonosetron, aprepitant, and dexamethasone. Furthermore, we investigated the associations between CINV and single nucleotide polymorphisms in 6 candidate genes.

RESULTS

Emesis episodes were rarely observed in the 125 patients included in the present survey (7.2%; n = 9); however, significant nausea occurred in more than one half of the patients (52.8%; n = 66). In particular, acute significant nausea was not effectively controlled. Multivariate logistic regression analysis revealed that the ABCG2 (rs2231142) AA genotype is significantly associated with acute significant nausea (odds ratio, 4.87; 95% confidence interval, 1.01-23.60; P = .049).

CONCLUSION

The findings of the present study provide significant insights for developing personalized antiemetic strategies for breast cancer patients receiving anthracycline-based chemotherapy.

Polymorphisms in CYP1A1 and CYP3A5 Genes Contribute to the Variability in Granisetron Clearance and Exposure in Pregnant Women with Nausea and Vomiting

BACKGROUND

Nausea and vomiting affect up to 90% of pregnant women. Granisetron is a potent and highly selective serotonin receptor antagonist and is an effective antiemetic. Findings from a prior study in pregnant women demonstrated a large interindividual variability in granisetron exposure. Granisetron is primarily metabolized by the cytochrome P450 (CYP) enzymes CYP1A1 and CYP3A and is likely a substrate of the ABCB1 transporter. Single-nucleotide polymorphisms (SNPs) in CYP3A, CYP1A1, and ABCB1 can alter drug metabolism.

OBJECTIVE

This study evaluated the influence of polymorphisms in CYP3A4, CYP3A5, CYP1A1, and ABCB1 on the pharmacokinetic properties of granisetron in pregnant women.

METHODS

The study enrolled 16 pregnant women (gestational age of 12-19 wks). All patients had nausea and vomiting and were treated with granisetron 1 mg. Granisetron plasma concentrations were determined using liquid chromatography tandem-mass spectrometry. The patients' genotype was determined using TaqMan SNP Genotyping Assays. The Hardy-Weinberg equilibrium was assessed by comparing observed and expected genotype frequencies, using the exact test. Intravenous granisetron clearance was used as the dependent variable for analysis of associations.

RESULTS

Of 16 patients, 25% were homozygous for the allele variant CYP3A5*3 and had a significantly lower granisetron clearance and increased area under the plasma concentration-versus-time curve (AUC) compared with nonhomozygous patients. Approximately one-third of patients (n=5) were carriers for the allele variant CYP1A1*2A and had a significantly higher granisetron clearance and decreased AUC. We did not find significant differences in the AUC or clearance for any SNPs in CYP3A4 and ABCB1 genes.

CONCLUSIONS

Polymorphisms in CYP3A5 and CYP1A1 account for some of the variability in systemic clearance and exposure of granisetron in pregnant women.

Influence of ABCB1 and ABCG2 polymorphisms on the antiemetic efficacy in patients with cancer receiving cisplatin-based chemotherapy: a TRIPLE pharmacogenomics study

Resistance to antiemetic treatment with 5-hydroxytryptamine-3 receptor antagonist is an issue. This study evaluated the potential roles of ABCB1 and ABCG2 polymorphisms in antiemetic treatment resistance in patients with cancer previously enrolled in a randomized controlled trial. A total of 156 patients were evaluated for their responses to antiemetic therapy and then subdivided into granisetron or palonosetron groups. The genotypes were evaluated for their association with antiemetic efficacy in each treatment groups. Additional risk factors associated with complete response (CR) were examined using a multivariate regression analysis. No significant associations were identified for genetic polymorphisms in the palonosetron group. In the granisetron group, patients with ABCB1 2677TT and 3435TT genotypes had higher proportion of CR. In addition to ABCB1 polymorphisms, gender and cisplatin dose were associated with granisetron response by univariate analysis. Multivariate logistic regression analysis revealed that the ABCB1 3435C>T polymorphism and cisplatin dose were significant predictors of CR.

Pharmacogenetics of chemotherapy-induced nausea and vomiting

Chemotherapy-induced nausea and vomiting (CINV) is associated with distressing adverse effects observed in patients during cytotoxic chemotherapy. One of the potential factors explaining suboptimal response to currently used antiemetics is variability in genes encoding enzymes and proteins that play a role in the action of antiemetic drugs. Pharmacogenomics studies of CINV are sparse and focus mainly on polymorphisms associated with serotonin receptor, drug metabolism and drug transport. Currently, the role of pharmacogenetics in mechanisms of CINV has not been fully unraveled, and it is premature to implement results of pharmacogenetic association studies of antiemetic drugs in clinical practice. More uniform studies, with genetic profiles and biomarkers relevant for the proposed target and transporter mechanisms, are needed.