Open-label comparison of the antiemetic efficacy of single intravenous doses of dolasetron mesylate in pediatric cancer patients receiving moderately to highly emetogenic chemotherapy

A review of dolasetron as management of nausea and vomiting in cancer patients

Objective. To systematically review the literature about the pharmacology, pharmacokinetics, efficacy, dosing, and adverse effects of dolasetron, and to define its role in the management of chemotherapy-and radiation-induced nausea and vomiting.

Data Synthesis. A MedLine search was conducted using 5-HT3-receptor antagonists, antiemetics, chemotherapy toxicity, dolasetron, emesis, nausea, and vomiting as search terms. Reference lists and bibliographies of pertinent articles were also identified and reviewed. Both preclinical and clinical literature were reviewed and analyzed.

Data Synthesis. Dolasetron is a serotonin type 3 (5-HT3)-receptor antagonist with potent antiemetic effects in the management of nausea and vomiting. Following administration, dolasetron is rapidly converted to hydrodolasetron, which is believed to be responsible for the drug's antiemetic activity. Results of multiple studies have demonstrated the efficacy of this agent in the prevention of chemotherapy-induced emesis, including that induced by cisplatin. As a single agent, dolasetron produces a complete response rate (RR) in 44% to 57% of patients treated with cisplatin (≥70 mg/m2) and in 59% to 80% of patients treated with moderately emetogenic chemotherapy, such as cyclophosphamide, methotrexate, and fluorouracil (CMF) therapy. When combined with dexamethasone, the RRs are increased. Dolasetron is well tolerated, with headache (24%) and diarrhea (12%) the most commonly reported adverse effects. The efficacy and safety of dolasetron are comparable to those observed with other 5-HT3-receptor antagonists. According to four recently published clinical practice guidelines for use of antiemetics, dolasetron is an appropriate first-line option for the prevention of nausea and vomiting due to moderately to highly emetogenic chemotherapy. Further clinical trials will determine the optimal dose and the role of this highly effective antiemetic agent for other purposes, such as treatment of delayed emesis and emesis resulting from radiation therapy and high-dose chemotherapy followed by bone marrow transplantation.

Exposure-Response of Palonosetron for Prevention of Chemotherapy-Induced Nausea and Vomiting in Pediatric Patients

OBJECTIVES

Extrapolation of efficacy from adult populations to pediatrics may be appropriate if it is reasonable to assume that the 2 populations have similar disease progression and response to intervention. When full extrapolation of efficacy is deemed appropriate, the pediatric dose can be determined by "matching" exposure to a drug with that observed in adult patients. This approach has been used in certain therapeutic areas to alleviate the burden of pediatric clinical trials. We present here a case in which exposure matching is not appropriate.

METHODS

Data analyses including pharmacokinetics and exposure-response were performed using data obtained from 2 pediatric chemotherapy-induced nausea and vomiting trials for intravenously administered palonosetron (Aloxi; a 5-HT3 receptor antagonist) injection and the results were compared with adult findings.

RESULTS

At the approved doses for adults (0.25 mg) and pediatric patients (20 μg/kg), mean systemic exposure (area under the curve) of palonosetron in pediatric patients was approximately 3-fold higher than that in adults, whereas the response rate was similar between the 2 populations. Across pediatric patients, those younger than 6 years of age appeared to have a higher response than those ages 6 years or older, even though estimated systemic exposure was comparable between these age groups.

CONCLUSIONS

Overall, these analyses provide an example in which pediatric and adult exposure data alone are insufficient to adequately identify effective pediatric doses and raise questions about the appropriateness of exposure matching for other drugs in the same therapeutic class. In such cases, pediatric dose-ranging and efficacy studies are needed.

Considerations for a Pediatric Biopharmaceutics Classification System (BCS): application to five drugs

It has been advocated that biopharmaceutic risk assessment should be conducted early in pediatric product development and synchronized with the adult product development program. However, we are unaware of efforts to classify drugs into a Biopharmaceutics Classification System (BCS) framework for pediatric patients. The objective was to classify five drugs into a potential BCS. These five drugs were selected since both oral and intravenous pharmacokinetic data were available for each drug, and covered the four BCS classes in adults. Literature searches for each drug were conducted using Medline and applied to classify drugs with respect to solubility and permeability in pediatric subpopulations. Four pediatric subpopulations were considered: neonates, infants, children, and adolescents. Regarding solubility, dose numbers were calculated using a volume for each subpopulation based on body surface area (BSA) relative to 250 ml for a 1.73 m(2) adult. Dose numbers spanned a range of values, depending upon the pediatric dose formula and subpopulation. Regarding permeability, pharmacokinetic literature data required assumptions and decisions about data collection. Using a devised pediatric BCS framework, there was agreement in adult and pediatric BCS class for two drugs, azithromycin (class 3) and ciprofloxacin (class 4). There was discordance for the three drugs that have high adult permeability since all pediatric permeabilities were low: dolasetron (class 3 in pediatric), ketoprofen (class 4 in pediatric), and voriconazole (class 4 in pediatric). A main contribution of this work is the identification of critical factors required for a pediatric BCS.

Central nervous system tumors

Central nervous system (CNS) tumors comprise 15% to 20% of all malignancies occurring in childhood and adolescence. They may present in a myriad of ways, often delaying diagnosis. Symptoms and signs depend on the growth rate of the tumor, its location in the central nervous system (CNS), and the age of the child. This article describes the presentation, diagnosis and management of these tumors.

Electrocardiographic findings after 5-HT3 receptor antagonists and chemotherapy in children with cancer

BACKGROUND

The antiemetic efficacy of serotonin-type 3 (5-HT3) receptor antagonists has been found to be superior to older antiemetic drugs in cancer patients. Following the administration of these agents, changes in ECG parameters and increased or decreased heart rates have been demonstrated, but there is no sufficient data in children with cancer who are treated with cytotoxic agents. The objective of this study is to evaluate the ECG changes after administration of 5-HT3 receptor antagonists and chemotherapeutic agents in children with cancer.

PROCEDURE

Thirty-eight patients with an age range between 2 and 19 years receiving chemotherapy for solid tumors were included in the study. The patients received 5-HT3 receptor antagonists 30 min before antineoplastic agents in 83 chemotherapy days. Antiemetic therapy consisted of ondansetron in 43 and granisetron in 40 chemotherapy days. Twelve-leads ECGs were obtained four times at the first day of each chemotherapy: just before 30, 90 min, and 24 hr after 5-HT3 receptor antagonists were given. Rate, rhythm, PR interval, QRS duration, ST segment, the shortest (QTca) and the longest (QTcb) QTc intervals with QTc dispersion (QTcd) were all evaluated.

RESULTS

We found a significant shortening of the PR interval and QRS complex durations in the granisetron group at 90th min and at 24th hr, respectively. Also, granisetron infusion caused a significant prolongation of the QTca interval at 90 min.

CONCLUSION

Although we observed minor ECG changes after 5-HT3 receptor antagonists and chemotherapy, neither dangerous rhythm disturbances nor serious ECG changes were seen.

American Society of Clinical Oncology guideline for antiemetics in oncology: update 2006

PURPOSE

To update the 1999 American Society of Clinical Oncology guideline for antiemetics in oncology.

UPDATE METHODOLOGY

The Update Committee completed a review and analysis of data published from 1998 thru February 2006. The literature review focused on published randomized controlled trials, and systematic reviews and meta-analyses of published phase II and phase III randomized controlled trials.

RECOMMENDATIONS

The three-drug combination of a 5-hydroxytryptamine-3 (5-HT(3)) serotonin receptor antagonist, dexamethasone, and aprepitant is recommended before chemotherapy of high emetic risk. For persons receiving chemotherapy of high emetic risk, there is no group of patients for whom agents of lower therapeutic index are appropriate first-choice antiemetics. These agents should be reserved for patients intolerant of or refractory to 5-HT3 serotonin receptor antagonists, neurokinin-1 receptor antagonists, and dexamethasone. The three-drug combination of a 5-HT3 receptor serotonin antagonist, dexamethasone, and aprepitant is recommended for patients receiving an anthracycline and cyclophosphamide. For patients receiving other chemotherapy of moderate emetic risk, the Update Committee continues to recommend the two-drug combination of a 5-HT3 receptor serotonin antagonist and dexamethasone. In all patients receiving cisplatin and all other agents of high emetic risk, the two-drug combination of dexamethasone and aprepitant is recommended for the prevention of delayed emesis. The Update Committee no longer recommends the combination of a 5-HT3 serotonin receptor antagonist and dexamethasone for the prevention of delayed emesis after chemotherapeutic agents of high emetic risk. CONCLUSION The Update Committee recommends that clinicians administer antiemetics while considering patients' emetic risk categories and other characteristics.

Prophylaxis of acute chemotherapy-induced nausea and vomiting in children with cancer: what is the evidence?

BACKGROUND

Nausea and vomiting are preventable side effects of cancer chemotherapy for children. Antiemetics are essential, especially as treatment becomes more intensive. Many drugs are available, but adequate evidence-based recommendations are lacking. We aimed (1) to consider an evidence-based approach for pharmacological prophylaxis of chemotherapy-induced nausea and vomiting (CINV) in children, and (2) to compare this approach with antiemetic prescribing in two paediatric oncology centres.

PROCEDURE

Relevant publications (Medline, Embase, CancerLit:1966-2002) were critically evaluated using pre-defined criteria. Evidence-based statements summarising their findings were formulated, and evidence basis proposed. Current prescribing practice was then compared with this evidence basis in Welsh children under 16 receiving chemotherapy at Llandough Hospital, Cardiff or Alder Hey Children's Hospital, Liverpool between 1 January 2001 and 31 December 2001.

RESULTS

Of 213 studies retrieved, 82 provided evidence. Our evidence basis recommends combination 5HT3-antagonist/corticosteroid for highly emetogenic chemotherapy, 5HT3-antagonist alone for moderate emetogenicity, and no antiemetic for other chemotherapy. Forty-four children in Cardiff (0.6-16.9 yrs) and 14 in Liverpool (0.8-16.2 yrs) were included in the audit. Differences in prescribing practice between the centres were not significant. In 109/159 (69%) of chemotherapy courses (35, 87 and 100% of high, moderate and low emetogenicity, respectively), antiemetics were selected in accordance with evidence basis. Seventy percent of prescribed doses were as evidence basis recommended.

CONCLUSIONS

We present an evidence basis for prescribing prophylactic antiemetics to children undergoing chemotherapy. Prescribing practices in these two centres treating Welsh children were similar. Both differed from the evidence basis we propose. Deviations were greatest for regimens of high emetogenicity, where effective emetic control is most crucial.

Nausea and vomiting associated with cancer chemotherapy: drug management in theory and in practice

The function of cytotoxics is to damage cells, and it makes teleological sense for the body to expel them as soon after ingestion as possible. Ideally, from the body's point of view, they should simply be avoided, and it is not surprising that the experience of chemotherapy induced nausea and vomiting (CINV) is powerfully aversive. Nausea and vomiting were once among the most intractable and unpleasant experiences of a child undergoing treatment for cancer.

Safety, tolerability, antiemetic efficacy, and pharmacokinetics of oral dolasetron mesylate in pediatric cancer patients receiving moderately to highly emetogenic chemotherapy

PURPOSE

The safety, antiemetic efficacy, and pharmacokinetics of single oral doses of dolasetron, a new highly selective 5-HT3 receptor antagonist, were evaluated in children with cancer undergoing treatment with moderately to highly emetogenic chemotherapy.

PATIENTS AND METHODS

A total of 32 children, ages 3 to 18 years, were enrolled in a nonrandomized, multicenter, open-label, dose-escalation study. Three oral dose levels (0.6, 1.2, or 1.8 mg/kg) were studied. Safety, efficacy, and pharmacokinetic parameters were assessed over 24 hours at each dosage level.

RESULTS

The most effective dose was 1.8 mg/kg; 60% of the patients achieved a complete or major response (< or =2 emetic episodes in 24 hours). A complete response was achieved in 3 of 9 patients (33%) who received 0.6 mg/kg, 4 of 13 (31%) patients who received 1.2 mg/kg, and 5 of 10 (50%) patients who received 1.8 mg/kg of dolasetron. Overall, dolasetron was well tolerated. Adverse events were mild and similar to those reported in adults. Peak plasma concentrations (Cmax) of dolasetron's active reduced metabolite, MDL 74,156, were dose proportional and occurred, on the average, within 1 hour of oral administration. The half-life (t1/2) in plasma was approximately 6 hours for all dose levels, and the mean clearance (CLapp) was unrelated to dose.

CONCLUSIONS

Oral dolasetron is safe and effective in reducing chemotherapy-induced nausea and vomiting, particularly at the 1.8-mg/kg dose level. These results support further evaluation of oral dolasetron in larger randomized clinical trials in the pediatric cancer population.