Biomarker analyses from a phase l study of pertuzumab combined with erlotinib in patients (pts) with non-small cell lung cancer (NSCLC).

7540 Background: Pertuzumab (P) is a fully humanised, murine monoclonal antibody that targets the dimerisation epitope of human epidermal growth factor receptor (HER) 2, preventing dimerisation between HER2 and other HER receptors and inducing antibody-dependent cell-mediated cytotoxicity. P as a single agent is not associated with meaningful activity against NSCLC, though stable disease (SD) has been observed in a phase II study (Herbst et al. Clin Cancer Res 2007;13:6175). Erlotinib (E) inhibits HER1 tyrosine kinase signalling and is widely registered for treatment of relapsed NSCLC. By inhibiting extracellular receptor dimerisation, as well as internal signal transduction through HER1, the combination of E and P would be expected to result in extensive blockade of HER signalling. Preclinical and initial response data seem to confirm this (Felip et al. ESMO 2008, abs 269P). Methods: 15 pts in 2 cohorts were treated in this Phase I, dose-escalating study. There was no evidence of pharmacokinetic interact...