Efficacy of aprepitant in patients receiving high-dose chemotherapy with hematopoietic stem cell support

This study describes the efficacy of aprepitant in preventing nausea and vomiting associated with high-dose chemotherapy in hematopoietic stem cell transplant (HSCT) patients. Our hypothesis is the addition of aprepitant to 5-HT3 antagonists and dexamethasone would result in a 20% increase in complete response (CR) rates compared to CR rates from published studies evaluating antiemetic regimens without aprepitant.

Adult HSCT patients receiving high-dose chemotherapy and aprepitant as part of their antiemetic regimen were included following written informed consent. CR was defined as no emesis, none to mild nausea, and no breakthrough antiemetic use. Daily patient diaries were used on days 1 through 7 following high-dose chemotherapy to collect severity of nausea, emetic episodes, breakthrough antiemetic use, and any antiemetic related side effects.

We accrued a total of 42 patients. CR rates ranged from 42.9% to 73.8% for the 7 days. The average CR rate for days 1 through 7 was 54%. Fourteen patients (33%) maintained a complete emetic response on each of the 7 days. The average CR rate for published studies in HSCT patients receiving an antiemetic regimen without aprepitant is 57%. Most common adverse effects reported by patients receiving aprepitant were hiccups (33%) and drowsiness (33%).

The addition of aprepitant failed to meet our primary endpoint of increasing CR rates by 20%. The lower than expected CR rate was attributed to use of breakthrough antiemetics. Aprepitant did result in preventing emesis in the majority of patients and was associated with minimal side effects.