Randomized, Placebo-Controlled, Phase III Trial of Fosaprepitant, Ondansetron, Dexamethasone (FOND) Versus FOND Plus Olanzapine (FOND-O) for the Prevention of Chemotherapy-Induced Nausea and Vomiting in Patients with Hematologic Malignancies Receiving Highly Emetogenic Chemotherapy and Hematopoietic Cell Transplantation Regimens: The FOND-O Trial.

Evidence supports olanzapine for prophylaxis of chemotherapy-induced nausea/vomiting (CINV) for highly emetogenic chemotherapy; however, most studies focus on solid malignancies and single-day regimens. A randomized, double-blinded, placebo-controlled trial was conducted to compare the addition of olanzapine to triplet therapy (fosaprepitant, ondansetron, dexamethasone [FOND-O]) versus triplet therapy alone (FOND) in preventing CINV in hematology patients receiving single-day and multiple-day highly emetogenic chemotherapy and hematopoietic cell transplant (HCT) regimens (NCT02635984). The primary objective of this study was to compare complete response (CR; no emesis and minimal nausea, <25 mm on a 100-mm visual analog scale) during the overall assessment period (chemotherapy days plus 5 days after). Secondary objectives were the number of emesis, number of rescue medications, percent achieving minimal nausea, and percent achieving complete protection (CP; no emesis, rescue antiemetic, or significant nausea), all of which are reported as acute (chemotherapy days), delayed (5 days after chemotherapy), and overall phases. Olanzapine 10 mg or matching placebo were given on each chemotherapy day and 3 days after. Adults with hematologic malignancy receiving HCT regimens of melphalan, BEAM (carmustine, etoposide, cytarabine, melphalan), busulfan (Bu)/cyclophosphamide (Cy), Bu/fludarabine (Flu), Bu/melphalan, FluCy, FluCy-total body irradiation (TBI), etoposide-TBI, and ICE (ifosfamide, carboplatin, etoposide) or 7+3 chemotherapy regimens were included. An estimated 98 patients were required using alpha = .05 and 80% power. No significant differences existed in baseline characteristics between FOND-O (n = 51) and FOND (n = 50) arms. Mean duration of olanzapine was 7.7 days (range, 4 to 11). Discontinuation for possible adverse events occurred in 3 placebo and 0 olanzapine patients. CR was significantly higher for FOND-O in overall (55% versus 26%, P = .003) and delayed (60.8% versus 30%, P = .001) but not acute (P = .13) phases. Significantly more patients receiving FOND-O achieved no more than minimal nausea in overall (P = .001) and delayed phases (P = .0002), as well as fewer overall mean emesis counts (P = .005). CP rates were not different in any assessment phase (P ≥ .05 each). Within the HCT subgroup (n = 64), the CR, CP, and no significant nausea rates were significantly better for FONDO-O in overall and delayed phases (all P < .05). Analysis within the HCT subgroup revealed significant improvement in outcomes in delayed and overall phases with FOND-O in the autologous but not allogeneic cohort. Addition of olanzapine to an NK-1-based triplet antiemetic regimen significantly improved clinically relevant outcomes in the HCT population.