Phase I trials in oncology usually enrolling patients with advanced disease who have failed standard treatment options. The primary endpoint of these studies is to establish the recommended dose and/or schedule of new drugs or drug combinations for phase II trials. The guiding principle for dose escalation in phase I trials is to avoid unnecessary exposure of patients to sub-therapeutic doses of an agent. The mission of phase I clinical trials is to accelerate the development of new anticancer drugs with the purpose of improving quality of life and survival for patients with cancer.