Grade 4 selleck kinase inhibitor toxicity of any kind required consultation with study chair to determine dose reductions and consideration for withdrawal from study. Supportive medications were allowed at the discretion of the investigator including antiemetics, anti-anxiolytics and anti-diarrheals. Statistical analysis The statistical design for this study is based on the primary endpoint of tumor response (RECIST) within the first 18 weeks of

treatment with this regimen. Patients whose tumors showed complete response (CR) or partial response (PR) were classified as a response to treatment. All patients meeting the eligibility criteria who signed a consent form and began treatment were followed for Inhibitors,research,lifescience,medical one year or Inhibitors,research,lifescience,medical until death. The study used a two-stage Simon-Optimal study design permitting early termination for poor results. The design assumed that 0.05 success rate would be considered as unacceptably low and that a success rate of at least 0.2 would be considered promising. The design (with the null hypothesis that the true success rate is at most 5%) had a one-sided significance level of 5% and 85% power to detect a success probability of 20%. The maximum Inhibitors,research,lifescience,medical sample size was thus 39 [with an additional 4 (~10%) patients accrued to protect against ineligiblilities, cancellations, major violations, etc.]. The first stage enrolled

18 patients and required 2 or more objective responses to continue on to the second stage. Accrual was not suspended after the first 18 patients to evaluate for disease progression. The study was designed to be terminated if there were 0 or 1 responses in the first stage. If >1 response was seen, Stage 2 would enroll 21 additional patients. If there were 4 or less responses of the 39 patients then no further

studies would be recommended. Inhibitors,research,lifescience,medical Primary endpoint was overall response Inhibitors,research,lifescience,medical rate (ORR). Secondary outcomes included overall survival (OS), progression-free survival (PFS) and toxicity. The survival function for OS was estimated using Kaplan-Meier method. Though not planned in the original protocol, subgroup analysis was performed with respect to prior use of EGFR monoclonal of antibody (cetuximab and panitumumab) and k-ras mutational status. Comparison of overall survival between those with and without prior EGFR monoclonal antibody use was performed with the log-rank test. The study was approved by the institutional review board at each institution that participated and conducted with adherence to good clinical practices (GCP). Results Demographics The first patient was enrolled in June 2008, with the last patient enrolled in April 2009, for an average enrollment rate of 2.6 patients per month. The patient population was primarily Caucasian (97%) and 55% male (see Table 1). The majority of patients did not have K-ras mutational analysis done. Most patients (72%) were ECOG PS 1. Twenty patients had prior EGFR monoclonal antibody use.