Phase III Double-Blind, Placebo-Controlled Study of Gabapentin
BACKGROUND: Despite targeted antiemetics, data support an unmet need related to the management of delayed nausea and vomit-ing (NV). Promising pilot data informed this phase III trial evaluating gabapentin for delayed NV from highly emetogenic chemother-apy (HEC). METHODS: Participants were randomized to receive prophylactic treatment with 20 mg of dexamethasone and a 5HT3 receptor antagonist (RA) on the day of chemotherapy, followed by gabapentin 300 mg twice a day and dexamethasone (dex) or pla-cebo and dex after HEC. Gabapentin/placebo was started the day of chemotherapy and continued through day 5 for the first chemo-therapy cycle, whereas dex was titrated down on days 2-4. The primary end point was complete response (CR), defined as no emesis and no use of rescue medications on days 2-6, using an NV diary. The percentages of those in each group with a CR were compared by Fisher’s exact test. RESULTS: Four hundred thirty patients were enrolled in this study. Forty-seven percent of patients in the gaba-pentin arm and 41% in the placebo arm had a CR (P 5.23). Mean number of emesis episodes was <0.5 daily, and mean nausea sever-ity was < 2 (mild). In both arms, patient satisfaction with NV control was greater than 8 (with 10 being perfectly satisfied). There were no significant differences in unwanted side effects. CONCLUSIONS: In this study, gabapentin did not significantly improve delayed NV. Patients were satisfied with the control of their nausea and vomiting irrespective of arm. The use of a 5HT3 RA and dexametha-sone provided good control of nausea and vomiting for most patients. Cancer 2014;120:3575-83. CV 2014 American Cancer Society.