Preliminary results of a phase I trial of sorafenib combined with cisplatin/etoposide (CE) or carboplatin/pemetrexed (CbP) in solid tumor patients (pts)

Abstract

e13521 Background: Sorafenib had demonstrated single agent activity in non-small cell and small cell lung cancer. Methods: A non-comparative, two arm phase I trial escalating sorafenib in combination with fixed doses of CE or CbP was performed. A 3-patient cohort design was utilized to determine the maximum tolerated dose (MTD) and dose limiting toxicities (DLT). Dose level 0 for all pts was a sorafenib dose of 200 mg po BID continuously. Pts on arm A received C (60 mg/m2) on day 1 and E 120 mg/m2 on days 1,2,3 every 3 weeks with escalating doses of sorafenib. On arm B, pts received treatment with Cb (AUC=6) and P 500 mg/m2 every 3 weeks with escalating doses of sorafenib. However, excessive toxicity was observed on arm B, therefore the trial was amended such that Cb dose was lowered to AUC=5 (arm C). DLT were assessed in the 1st cycle and defined as grade (gr.) 4 anemia or thrombocytopenia, gr. 4 neutropenia lasting > 7 days, gr. ≥ 3 non-hematologic toxicity (except nausea, vomiting, and alopecia) and > 2 week dose delay. Response was assessed every 2 cycles according to RECIST, and best response was recorded. Results: Between 9/2007 and 9/2008, 20 pts were treated on the trial; median age 62 (range 47–73), male/female: 12/8, PS of 0/1: 6/14, and median number of prior therapies 2 (range 1–4). The most common tumor types were NSCLC (n=8), SCLC (n=4) and head/neck (n=2). At dose level 0 arm A (200 mg BID), 2 of 4 patients experienced DLT (gr.4 thrombocytopenia, gr.3 fatigue, febrile neutropenia and gr.4 neutropenia for > 7 days, gr.3 febrile neutropenia, diarrhea, hypokalemia, hyponatremia); 2 pts have been enrolled at dose level -1 (200 mg po QD) without DLT. Two of 3 patients enrolled on arm B at dose level 0 had gr.4 thrombocytopenia. On arm C at dose level 0 (200 mg po BID), 1/6 pts experienced DLT (gr.3 hyponatremia, dehydration, hypoglycemia). Enrollment continued at dose level 1 (400 mg po BID), but 2/5 pts experienced a DLT (both gr. 3 fatigue/anorexia). Responses observed were: PR (n=3) (all arm C), and SD (n=6). Conclusions: The MTD of sorafenib in combination with carboplatin (AUC=5) and pemetrexed 500 mg every 3 weeks is 200 mg po BID. The MTD of sorafenib in combination with cisplatin/etoposide has yet to be determined and is currently accruing at dose level -1. [Table: see text]