The assessment of FDG-PET response was performed by a central reading site. PET response was based on the maximum standard uptake value (SUVmax) of up to 5 regions of interest (ROI). The tumor ROIs were identified for each patient on pretreatment FDG-PET scans and corresponded to a subset of the target lesions identified for Response Evaluation Criteria for Solid Tumors (RECIST) analysis. Specifically, the SUVmax of each ROI on the on-treatment scans was compared with the SUVmax on the corresponding pretreatment scan and the percent change was calculated. When there was more than 1 ROI, the overall percent change in SUVmax was the arithmetic mean of the percent changes in SUVmax for each of the ROIs (mSUVmax). An PET response is defined as a decrease of ≥ 20% in mSUVmax. EGFR mutation status was assessed in tumor tissue samples taken from each patient.

All 41 patients treated with pertuzumab and erlotinib were evaluable for analysis. Patients with a missing Day 56 assessment were deemed non-responders. Tumor tissue samples were only available for 32 patients for EGFR mutation status analysis.

PFS was defined as the time from the first dosing with pertuzumab and erlotinib to the first occurrence of disease progression (PD), as determined by the investigator and based on computed tomography using Response Evaluation Criteria in Solid Tumors (RECIST), or death from any cause, whichever comes first. PD was defined as ≥ 20% increase in the sum of the longest diameter of target lesions (TL), taking as reference the smallest sum longest diameter recorded since treatment started, the unequivocal progression of existing non-target lesions (non-TL), or the appearance of 1 or more new lesions. TLs were selected on the basis of their size (those with the longest diameter) and their suitability for accurate repeated measurements by imaging techniques or clinically. All measurable lesions up to a maximum of 5 lesions per organ and 10 lesions in total, representative of all involved organs, were identified as TLs. All other lesions (or sites of disease) were identified as non-TLs.

All 41 patients treated with erlotinib and pertuzumab. Patients who had not progressed or died at the time of analysis for PFS were censored at the date of their last tumor assessment.

Overall survival was defined as the time from the date of first dosing with pertuzumab and erlotinib until the date of patient death from any cause.

All 41 patients treated with erlotinib and pertuzumab. Patients who had not died at the time of analysis for OS were censored at the date of last contact.

OR was defined as a complete response (CR) or a partial response (PR) as determined by the investigator and based on computed tomography (CT) using Response Evaluation Criteria in Solid Tumors (RECIST) on 2 consecutive occasions at least 4 weeks apart. A complete response was defined as the disappearance of all target and non-target lesions and normalization of tumor marker level. A partial response was defined as ≥ 30% decrease in the sum of the longest diameter of target lesions, taking as reference the baseline sum longest diameter, or the persistence of 1 or more non-target lesions and/or the maintenance of a tumor marker level above the normal limits.

All 41 patients treated with erlotinib and pertuzumab.

DC was defined as a CR, a PR, or stable disease (SD) as determined by the investigator and based on CT using RECIST. A CR was defined as the disappearance of all target (TL) and non-target lesions (nTL). A PR was defined as ≥ 30% decrease in the sum of the longest diameter (SLD) of TLs, taking as reference the baseline sum longest diameter, or the persistence of 1 or more nTLs and/or maintenance of a tumor marker level (TML) above normal limits. For TLs, SD was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD), taking as reference the smallest sum longest diameter (SSLD) since treatment started. For nTLs, SD was defined as the persistence of 1 or more lesions and/or maintenance of a TML above normal limits. PD was defined as ≥ 20% increase in the SLD of TLs, taking as reference the SSLD recorded since treatment started, the appearance of 1 or more new lesions, or the unequivocal progression of existing nTLs.

All 41 patients treated with erlotinib and pertuzumab.