A phase II randomized double-blind placebo-controlled study of 6-gingerol as an anti-emetic in solid tumor patients receiving moderately to highly emetogenic chemotherapy.

6-Gingerol is a natural compound extracted from ginger. Preclinical studies demonstrated that 6-gingerol has an anti-emetic activity by inhibiting neurokinin-1, serotonin, and dopamine receptors. Several clinical trials examined crude ginger powder for preventing chemotherapy-induced nausea and vomiting (CINV), but none of them was conducted with a standardized bioactive compound. Patients who received moderately to highly emetogenic adjuvant chemotherapy were randomized to receive 6-gingerol 10 mg or placebo orally twice daily for 12 weeks. Ondansetron, metoclopramide, and dexamethasone were given to all patients. The primary endpoint was complete response (CR) rate defined as no emesis or rescue treatment at any time. Eighty-eight patients were randomized to receive 6-gingerol (N = 42) or placebo (N = 46). Most patients received highly emetogenic chemotherapy (93%). Overall CR rate was significantly higher in 6-gingerol group as compared with that of the placebo (77 vs. 32%; P < 0.001). The difference in means of appetite score was significant (P = 0.001) and more noticeable over time. Mean FACT-G score indicating quality of life was significantly higher (86.21) in 6-gingerol group at 64 days as compared with that of placebo group (72.36) (P < 0.001). No toxicity related to 6-gingerol was observed. Patients treated with 6-gingerol reported significantly less grade 3 fatigue (2 vs. 20%; P = 0.020). 6-Gingerol significantly improved overall CR rate in CINV, appetite and quality of life in cancer patients receiving adjuvant chemotherapy. A phase III randomized study of 6-gingerol is warranted to confirm these results.