A phase I trial of sorafenib combined with cisplatin/etoposide or carboplatin/pemetrexed in refractory solid tumor patients.

Introduction: Sorafenib has demonstrated single agent activity in non-small cell (NSCLC) and small cell lung cancer (SCLC). Carboplatin/pemetrexed (CbP) and cisplatin/etoposide (PE) are commonly used in the treatment of these diseases.

Methods: A phase I trial escalating doses of sorafenib in combination with fixed doses of PE (Arm A) or CbP (Arm B) was performed using a 3-patient cohort design to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT); DLT were assessed in the first cycle. The trial was subsequently amended with closure of Arm B and to include Arm C with a reduced dose of carboplatin.

Results: Between 9/2007 and 9/2008, 20 pts were treated on the trial; median age 62 (range 42-73), male/female ratio 12/8, PS 0/1 ratio 6/14, and median number of prior therapies 2 (range 1-4). The most common tumor types were NSCLC and SCLC. On Arm A at dose level 0 (sorafenib 200 mg BID), 2 of 4 patients experienced DLT; 2 patients were enrolled at dose level -1 (sorafenib 200 mg QD) without DLT, but this arm was closed due to slow accrual. On Arm B, 2 of 3 patients experienced DLT at dose level 0 (sorafenib 200 mg BID). On Arm C at dose level 0 (sorafenib 200 mg BID), 1 of 6 patients experienced DLT, and at dose level +1 (sorafenib 400 mg BID) 2 of 5 patients experienced a DLT.

Conclusions: The MTD of sorafenib was 200 mg BID continuously in combination with carboplatin (AUC of 5) and pemetrexed 500 mg/m² every 3 weeks. However, only 6 patients were treated at this dose level, and the results should be interpreted cautiously.