Dasatinib and Osimertinib (AZD9291) in Advanced Non-Small Cell Lung Cancer With EGFR Mutations

The treatment of patients with advanced non-small cell lung cancer is unsatisfactory. The median survival is approximately 12 months with standard chemotherapy. Epidermal growth factor receptor (EGFR) mutations are one of the most frequent genetic abnormalities observed in non-small cell lung cancer (NSCLC), especially in adenocarcinoma subtype. The most predominant EGFR mutations are in-frame deletions in exon-19 and L858R missense mutation, and patients carrying these mutations are mostly sensitive to the EGFR-targeted tyrosine kinase inhibitors (TKIs). However, a significant proportion of patients carrying these sensitizing mutations do not respond well to the first generation EGFR-TKIs (erlotinib and gefitinib), indicating the existence of intrinsic resistance mechanisms. Moreover, despite initial response to EGFR-TKIs, acquired resistance is inevitable in all patients. Novel treatment strategies need to be developed to overcome resistance to EGFR-TKIs. The investigators have recently shown that Cripto-1 overexpression in EGFR mutant NSCLC contributes to the intrinsic resistance to EGFR-TKIs through SRC activation. They have also shown that a combination of an EGFR-TKI (both erlotinib and AZD9291) and a Src inhibitor are synergistic in vitro and in vivo in Cripto-1 overexpressing tumors. AZD9291 is a third-generation EGFR-TKI, which selectively blocks the activity of EGFR mutants but spares that of wild type. The advantage of using AZD9291 is that it inhibits not only the mutants of exon-19 deletion and L858R, but also the T790M mutant, which is the most common mechanism of acquired resistance. Dasatinib is a potent, orally available ABL1/SRC TKI, approved for the treatment of chronic myeloid leukemia (CML) in first-line and in patients with imatinib-resistant disease or intolerant, and is being actively studied in patients with advanced solid tumors. This is an open-label, non-randomized, prospective phase I/II trial. The phase I portion will follow a standard 3+3 design for the phase I portion and one-sample group sequential multiple testing procedure for the phase II portion.