The use of olanzapine versus metoclopramide for the treatment of breakthrough chemotherapy-induced nausea and vomiting (CINV) in patients receiving highly emetogenic chemotherapy.
9064 Background: Olanzapine (OLN) has been shown to be a safe and effective agent for the prevention of CINV. OLN may also be an effective rescue medication for patients who develop breakthrough CINV despite having received guideline directed CINV prophylaxis. Methods: A double blind, randomized phase III trial was performed for the treatment of breakthrough CINV in chemotherapy naïve patients receiving highly emetogenic chemotherapy (HEC) (cisplatin, >70 mg/m2, or doxorubicin, >50 mg/m2 and cyclophosphamide, > 600mg/m2 ) comparing OLN to Metoclopramide (METO). Patients who developed breakthrough emesis or nausea despite prophylactic dexamethasone (12 mg IV), palonosetron (0.25 mg IV), and fosaprepitant (150 mg IV) pre chemotherapy and dexamethasone (8 mg p.o. daily, days 2-4) post chemotherapy were randomized to receive OLN, 10 mg orally daily for three days or METO, 10 mg orally TID for three days. Patients were monitored for emesis and nausea for the 72 hours after taking OLN or METO. Eighty patients (median age 56 yrs, range 38-79; 43 females; ECOG PS 0,1) consented to the protocol and all were evaluable. Results: During the 72 hour observation period, 30 of 42 (71%) patients receiving OLN had no emesis compared to 12 of 38 (32%) patients with no emesis for patients receiving METO (p<0.01). Patients without nausea (0, scale 0-10, M.D. Anderson Symptom Inventory) during the 72 hour observation period was: OLN: 67% (28 of 42); METO 24% (9 of 38) (p<0.01). There were no Grade 3 or 4 toxicities. Conclusions: OLN was significantly better than METO in the control of breakthrough emesis and nausea in patients receiving HEC.