Employment of Substandard Antiemetic Prophylaxis in Recent Trials of Chemotherapy-Induced Nausea and Vomiting

OBJECTIVE: To determine the prevalence of substandard antiemetic therapy among recently published trials conducted in patients with cancer who received emetogenic chemotherapy. DATA SOURCES: A MEDLINE search was conducted (2000-July 2004) using the key words 5-HT(3) antagonists, ondansetron, granisetron, dolasetron, tropisetron, ramosetron, palonosetron, NK-1 antagonists, and aprepitant. STUDY SELECTION AND DATA EXTRACTION: All antiemetic trials in patients receiving chemotherapy that were published from January 2000 to July 2004 were evaluated. Standard prophylactic antiemetic therapy was derived from contemporary antiemetic guidelines published by oncology professional organizations and expert panels. The number of patients and studies in which patients received standard and substandard antiemetic therapy was determined for both the acute and delayed phases of chemotherapy-induced nausea and vomiting (CINV). Separate determinations were made for severely and moderately emetogenic chemotherapy. The annual percentage of studies in which substandard antiemetic prophylaxis was given and the percentage of patients who received substandard prophylaxis also were determined. DATA SYNTHESIS: Fifty-six studies were reviewed, which included a total of 10 274 patients and 125 study arms. The percentage of patients who received substandard antiemetic prophylaxis was 30% (n = 3063) for acute CINV and 33% (n = 3413) for delayed CINV. The average annual percentage of studies that employed substandard prophylaxis during this time period was 54%. CONCLUSIONS: In recent antiemetic trials for CINV, the employment of substandard antiemetic therapy is common. These results raise important ethical questions regarding contemporary antiemetic trial design.