Randomized double-blind evaluation of dronabinol for the prevention of chemotherapy-induced nausea

9061 Background: Although great progress has been made in the control of chemotherapy-induced vomiting (CIV), prevention of chemotherapy-induced nausea (CIN) has been less successful. Preliminary data suggests that some families of lesser used antiemetic agents, such as the cannabinoids, may have greater efficacy against nausea than against vomiting. Methods: Adult solid tumor patients (pts) receiving cyclophosphamide ≤ 1500 mg/m2 (C) and/or doxorubicin ≥ 40 mg/m2 (A) were eligible. Pts could have received prior mildly emetogenic chemotherapy (EC). Pts were not eligible who were receiving other moderately or highly EC, were receiving cranial, abdominal or pelvic radiotherapy, had CIV/CIN with previous chemotherapy, had other causes for nausea/vomiting besides chemotherapy, or were scheduled to receive other antiemetics. Pts with habitual cannabinoid use were not eligible. All pts received palonosetron 0.25 mg (PALO) and dexamethasone 10 mg (DXM) IV before chemotherapy. Patients were randomized double-blind to receive dronabinol 5 mg (D) or matching placebo (P) 3 times a day for 5 days. Nausea, vomiting and toxicity data was collected daily for 5 days. Results: 62 pts were entered on study – female/male 61/1, White/Black/Hispanic/Other 45/14/2/1, median age (range) 58 (29-76). No significant difference was noted in CIV-dependent endpoints (including No Vomiting, Complete Response, or Complete Protection) or in rescue medication use. However pts receiving D had a shorter duration of nausea – Mean number of days of nausea (D vs P) 1.86 days vs 3.10 days (p=0.027) – and a trend toward greater frequency of No Nausea (D vs P) 37% vs 17% (p=0.143). Common toxicities included fatigue (D/P 17/11), headache (D/P 16/16), dizziness (D/P 14/7), constipation (D/P 14/11), and diarrhea (D/P 13/6) No pt discontinued therapy due to mood changes. Conclusions: Low-dose D decreased the duration of CIN and increased the frequency of No Nausea in pts receiving C and/or A. Agents to prevent CIV (such as PALO and DXM) and to prevent CIN (such as D) have complementary activity and result in improved overall control when used together.