Final results from a phase III randomized clinical trial show that addition of aprepitant (Emend®) to the anti-nausea drug ondansetron (Zofran®), with or without dexamethasone, is effective for the prevention of chemotherapy-induced nausea and vomiting in pediatric patients. Approximately half of patients in the trial who received both drugs experienced no nausea or related issues in the 5 days following chemotherapy, compared with approximately one-quarter of patients who only received ondansetron.
Lancet Oncology, March 12, 2015 (see the journal abstract).
Chemotherapy-induced nausea and vomiting are frequent and potentially treatment-limiting complications of cancer therapy in both adults and children. The current standard of care for preventing nausea and vomiting following chemotherapy is treatment with a serotonin receptor agonist (such as ondansetron) and the steroid dexamethasone. However, this treatment is less effective in children than adults.
Aprepitant is a neurokinin-1 receptor antagonist that effectively prevents nausea and vomiting in adults receiving chemotherapy, but its efficacy and safety in children were not known.
A total of 307 cancer patients aged 6 months to 17 years who were being treated with a type of chemotherapy associated with at least a moderate risk of vomiting were randomly assigned to receive aprepitant plus ondansetron (aprepitant group) or placebo plus ondansetron (control group). In both groups, use of dexamethasone was left to the discretion of the treating investigator.
All study medications were given orally on the same day as chemotherapy. The trial’s primary endpoint was complete response, which was defined as no vomiting, retching, or use of antiemetic rescue medication—medication to treat vomiting and nausea that would otherwise not be controlled—during the 25–120 hours after chemotherapy was initiated (the delayed phase). Secondary endpoints included safety.
The study was led by Hyoung Jin Kang, M.D., of the Seoul National University College of Medicine in Seoul, South Korea, and was funded by Merck & Co., which manufactures aprepitant.
Fifty-one percent of patients in the aprepitant group (77 of 152) had a complete response during the delayed phase, compared with only 26 percent (39 of 150) of those in the control group.
Adverse events related to chemotherapy were reported by 79 percent of patients in the aprepitant group and 77 percent of patients in the control group. The most common adverse events of any grade were febrile neutropenia, neutropenia, and anemia. The most common serious (grade 3 or higher) adverse events were febrile neutropenia, anemia, and a decrease in neutrophil count. All of these occurred at a similar frequency in the two treatment groups, except for anemia, which was more common in the control group than the aprepitant group.
Although the trial results were consistent regardless of the chemotherapy regimen patients received, “the study was not designed to assess the efficacy of aprepitant for individual chemotherapy regimens,” the authors wrote.
Also, the use of dexamethasone was elective, and it is possible that it was chosen disproportionately for patients who had a history of nausea and vomiting and might be predisposed to poorer outcomes. As a result, the study cannot be used to determine the role of corticosteroids as anti-emetics in children, the authors cautioned.
“This trial represents … perhaps the largest well-designed anti-emetic study yet done in pediatric oncology,” wrote Richard Gralla, M.D., in an accompanying editorial.
“Aprepitant was approved in 2003 for the prevention of nausea and vomiting with highly emetogenic chemotherapy for patients aged 14 and older, but until now pediatric oncologists only had retrospective reports and anecdotes to guide pediatric dosing,” said Melinda Merchant, M.D., Ph.D., clinical director of NCI’s Pediatric Oncology Branch. This trial, she continued, “provides strong evidence for the addition of aprepitant to current pediatric anti-emetic regimens and guidance on the dosing for adolescents and children.”