The US Food and Drug Administration (FDA) has approved Merck's Emend (aprepitant) for use with other antiemetic medicines for the prevention of nausea and vomiting associated with initial and repeat courses of moderately emetogenic chemotherapy, which are likely to cause nausea and vomiting. Emend, in combination with other antiemetics, is also approved for the prevention of nausea and vomiting caused by initial and repeat courses of highly emetogenic chemotherapy treatments, which are highly likely to cause nausea and vomiting, including high dose cisplatin.

The FDA approval for Emend is based on the findings of a study published in April 2005 in the Journal of Clinical Oncology (JCO) that enrolled 866 breast cancer patients, of whom 99.5 per cent were women. The study compared a regimen including Emend (Emend in combination with ondansetron, a 5-HT3 receptor antagonist, and dexamethasone, a corticosteroid, on day 1 followed by Emend on day 2 and 3) and a standard regimen.

According to the company release, results from this study of breast cancer patients who received moderately emetogenic chemotherapy treatments, which are likely to cause nausea and vomiting, showed that a significantly higher proportion of patients treated with the regimen including Emend in Cycle 1 reported a complete response (defined as no vomiting and no use of other therapies for nausea or vomiting) in the five days after initiation of chemotherapy compared to a standard regimen (51% vs. 42%, p=0.015). The difference between treatment groups was primarily driven by the "No Emesis Endpoint", a principal component of this composite primary endpoint. In addition, a higher proportion of patients receiving the regimen including Emend in Cycle 1 had a complete response during the acute (0-24 hours) and delayed (25-120 hours) phases compared with patients receiving the standard regimen; however, the treatment group differences failed to reach statistical significance after multiplicity adjustments.

"Patients with cancer are not only facing a serious illness, they also face the possibility of distressing side effects such as nausea and vomiting from their chemotherapy, and breast cancer patients are particularly susceptible to these side effects," said Kelly Pendergrass, clinical investigator and medical oncologist at the Kansas City Cancer Centre.

The study also showed that more patients receiving Emend reported minimal or no impact of nausea and vomiting on their daily life (64% vs. 56%). This difference between treatment groups was primarily driven by the "No Vomiting Domain" of this composite endpoint. Patients were permitted to continue into a multiple-cycle extension of the study for up to three additional cycles of chemotherapy. Results showed that antiemetic effectiveness for the patients receiving the regimen including Emend was maintained during all cycles.