A multicenter phase II study of erlotinib and sorafenib in chemotherapy-naive patients with advanced non-small cell lung cancer

PURPOSE

This multicenter, phase II study evaluates the efficacy and safety of erlotinib, an epidermal growth factor receptor (EGFR) inhibitor, plus sorafenib, a multityrosine kinase inhibitor against vascular endothelial growth factor receptors, in patients with previously untreated advanced non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Chemotherapy-naïve patients with stage IIIB/IV NSCLC received erlotinib (150 mg once a day) and sorafenib (400 mg twice a day) until disease progression or unacceptable toxicity. The primary end point was the rate of nonprogression at 6 weeks. Secondary end points included objective response rate (ORR), time to progression, overall survival, and adverse events. Exploratory end points included pretreatment EGFR and KRAS mutation status, pharmacokinetics, and cytochrome P450 polymorphisms.

RESULTS

Fifty patients initiated therapy. The nonprogression rate at 6 weeks was 74%: 12 (24%) partial response and 25 (50%) stable disease. Ultimately, the ORR was 28%. Median time to progression was 5.0 months [95% confidence interval (95% CI), 3.2-6.8 months]. Median overall survival was 10.9 months (95% CI, 3.8-18.1 months). Grade 3/4 adverse events included fatigue (16%), hand-foot skin reaction (16%), rash (16%), diarrhea (14%), and hypophosphatemia (42%). There was one treatment-related fatal pulmonary hemorrhage. Patients with wild-type EGFR had a higher ORR (19%) than previously reported for single-agent erlotinib/sorafenib. Erlotinib levels were lowered. This was associated with CYP3A4 polymorphism and was possibly due to sorafenib.

CONCLUSION

Despite a possible drug interaction, sorafenib plus erlotinib has promising clinical activity in patients with stage IIIB/IV NSCLC and has an acceptable safety profile. Further evaluation of this combination as potential salvage therapy in EGFR mutation-negative patients and the possible drug interaction is warranted.

Phase I combination of sorafenib and erlotinib therapy in solid tumors: safety, pharmacokinetic, and pharmacodynamic evaluation from an expansion cohort

The aims of this study were to further define the safety of sorafenib and erlotinib, given at their full approved monotherapy doses, and to correlate pharmacokinetic and pharmacodynamic markers with clinical outcome. In addition, a novel pharmacodynamic marker based on the real-time measurement of RAF signal transduction capacity (STC) is described. Sorafenib was administered alone for a 1-week run-in period, and then both drugs were given together continuously. RAF STC was assessed in peripheral blood monocytes prior to erlotinib initiation. Epidermal growth factor receptor (EGFR) expression and K-RAS mutations were measured in archival tumor samples. Changes in pERK and CD31 were determined in fresh tumor biopsies obtained pretreatment, prior to erlotinib dosing, and during the administration of both drugs. In addition, positron emission tomography-computed tomography scans and pharmacokinetic assessments were done. Eleven patients received a total of 57 cycles (median, 5; range, 1-10). Only four patients received full doses of both drugs for the entire study course, with elevation of liver enzymes being the main reason for dose reductions and delays. Among 10 patients evaluable for response, 8 experienced tumor stabilization of >or=4 cycles. Pharmacokinetic analysis revealed no significant interaction of erlotinib with sorafenib. Sorafenib-induced decrease in RAF-STC showed statistically significant correlation with time-to-progression in seven patients. Other pharmacodynamic markers did not correlate with clinical outcome. This drug combination resulted in promising clinical activity in solid tumor patients although significant toxicity warrants close monitoring. RAF-STC deserves further study as a predictive marker for sorafenib.