Phase II study of gefitinib readministration in patients with advanced non-small cell lung cancer and previous response to gefitinib.

OBJECTIVE Salvage treatment for acquired resistance to gefitinib has yet to be developed. We conducted the first prospective phase II study of gefitinib readministration in previous gefitinib responders. METHODS Gefitinib (250 mg/day) was readministered to patients with advanced/metastatic non-small cell lung cancer who had achieved objective response to initial gefitinib and subsequently received cytotoxic chemotherapy after disease progression with initial gefitinib. The primary endpoint was the objective response rate with gefitinib readministration. Secondary endpoints were disease control rate, progression-free survival (PFS), overall survival (OS), quality of life, and toxicity. Changes in lung cancer-related symptoms were evaluated using the seven-item lung cancer subscale of the questionnaire. RESULTS Sixteen patients were enrolled between February 2005 and January 2008. Most had received ≥3 regimens of chemotherapy. Response and disease-control rates for all patients were 0 and 44%. Median PFS and OS were 2.5 and 14.7 months, respectively. Four of 7 patients with stable disease experienced a long duration (≥6 months) of disease control without severe toxicity. Symptom improvement was observed in 2 of 12 patients (17%) for whom quality of life was evaluable. CONCLUSION Gefitinib represents a useful therapeutic option for selected previous gefitinib responders.