Erlotinib is a drug which targets non small cell lung cancer with a genetic change (mutation) in the epidermal growth factor receptor (EGFR). This drug has been used in other cancer research studies and information from those studies suggests that Erlotinib can control the growth of these cancer cells.

PRIMARY OBJECTIVE

-To prospectively assess the frequency of different genetic mechanisms of secondary resistance in patients' tumors during treatment with erlotinib (e.g., T790M mutations, MET amplification).

• Correlate these genetic changes with patient demographic data and clinical outcomes (time to progression, survival, sites of recurrence/progression).
• Search for novel mechanisms of acquired resistance to erlotinib.
• Identify whether these genetic changes are present at low levels in initial pretreatment tumor specimens.

SECONDARY OBJECTIVE(S)

1. To measure the steady-state plasma concentrations of erlotinib during the course of patients' treatment.

   • Determine if the development and/or resolution of skin toxicity is related to plasma erlotinib concentrations.
   • Determine if the development of disease progression while on erlotinib is correlated with declines in plasma erlotinib concentrations.
   • Assess the plasma levels in patients whose smoking status has been biochemically verified to determine if smoking is associated with lower erlotinib plasma concentration.

2. To analyze from both free plasma DNA and DNA from circulating tumor cells of erlotinib-treated patients for the original sensitizing EGFR mutations and genetic changes associated with secondary resistance.

3. To measure clinical outcomes in patients with known sensitizing mutations in their tumor EGFR when treated with first-line erlotinib.

   • Response rate
   • Time to progression
   • Median overall survival

Inclusion Criteria:

• Histologically or cytologically confirmed non-small cell lung cancer, stage IV or IIIB with a malignant pleural or pericardial effusion. Patients with stage I or II non-small cell lung cancer who have undergone surgical resection but who subsequently relapse with metastatic disease or a malignant pleural effusion are also eligible.
• Documentation of a sensitizing mutation of the epidermal growth factor receptor. In addition, there must be a sufficient tissue for analysis of KRAS (the oncogene from the Kirsten rat sarcoma virus) mutations and MET amplification.
• At least one measurable or evaluable site of disease as defined by revised RECIST (version 1.1) criteria.
• 18 years of age or older
• No more than one prior systemic therapy regimen for advanced non-small cell lung cancer. Chemotherapy delivered as part of concurrent chemoradiation will also count as a prior systemic therapy regimen. Adjuvant therapy for resected NSCLC will not count towards this total as long as it was completed at least 6 months prior to enrollment and did not include therapy with an EGFR-targeted agent. Adjuvant therapy completed less than 6 months prior to the time of screening will count as a prior regimen.
• 3 or more weeks since prior major surgery
• 2 or more weeks since prior radiation
• ECOG performance status 0-1
• Life expectancy > 8 weeks
• Adequate hematologic, renal, and hepatic function
• Willingness to undergo repeat tumor biopsy at the time of disease progression.

Exclusion Criteria:

• Untreated and/or uncontrolled central nervous system metastases. Patients with prior brain metastases must have had definitive treatment (radiation or surgery) and must be clinically stable off steroids for at least 1 week prior to enrollment.
• More than one prior systemic chemotherapy for advanced non-small cell lung cancer. , Chemotherapy delivered as part of concurrent chemoradiation will also count as a prior systemic therapy regimen. Adjuvant therapy for resected NSCLC willnot count towards this total as long as it was completed at least 6 months prior to enrollment and did not include therapy with an EGFR-targeted agent. Adjuvant therapy completed less than 6 months prior to the time of screening will count as a prior regimen.
• Prior exposure to erlotinib or other treatments targeting the HER family axis.
• Active malignancies within the past 3 years, except for adequately treated carcinoma of the cervix or basal or squamous cell carcinomas of the skin.
• Any process that compromises the ability to swallow and/or absorb oral medication.
• Incomplete healing from previous surgery
• A history of any of the following autoimmune skin disorders: Sjogren's syndrome, scleroderma, dermatomyositis, and systemic lupus erythematosus.
• Significant medical history or unstable medical conditions.
• Concurrent use of warfarin. Patients must be off warfarin for at least one week prior to initiation of erlotinib. Other non-warfarin anticoagulants are permitted.
• Patients who require ongoing concomitant use of one of the strong inhibitors/inducers of CYP3A4.
• Pregnant or breastfeeding. Women of child-bearing potential must agree to use adequate contraception prior to study entry and for the duration of study participation.

The analysis data is comprised of all treated patients

Assessed each cycle on treatment up to day 30 post-treatment. Median (range) treatment duration for this study cohort was 10 months (1-62 months).

Serious adverse events (AEs) per protocol are reported. For Other AEs, maximum grade toxicity by type (based on CTCAEv3 which includes coding events as 'Other') for a patient over time including only events with treatment-attribution of possibly, probably or definitely was calculated. A patient appears only once for a given type of toxicity. Patients with reports of multiple toxicities of different types are reported multiple times under the relevant toxicity categories.