Prospective Study of Gefitinib Readministration After Chemotherapy in Patients With Advanced Non–Small-Cell Lung Cancer Who Previously Responded to Gefitinib

IntroductionSalvage treatment for acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitor in patients with non–small-cell lung cancer is a matter of clinical concern. Several retrospective reports have indicated the usefulness of epidermal growth factor receptor tyrosine kinase inhibitor readministration; however, there have been few prospective studies.Materials and MethodsThis study was designed to prospectively evaluate the clinical efficacy of gefitinib readministration in patients with advanced or metastatic non–small-cell lung cancer who responded well to initial gefitinib treatment. The subjects received at least 1 regimen of cytotoxic chemotherapy after progressive disease with the initial gefitinib therapy. Gefitinib administration (250 mg/d, orally) was started after progressive disease with the previous chemotherapeutic regimen. The primary endpoint in the present study was the response rate.ResultsTwenty patients were enrolled between April 2007 and May 2011. Three patients achieved partial response, and 6 showed stable disease. Thus, the overall response rate and disease control rate of gefitinib readministration were 15% (95% CI, 3.21-37.9) and 45% (95% CI, 23.1-68.5), respectively. Median progression-free survival and overall survival from the start of gefitinib readministration were 2.0 months (95% CI, 0.9-3.1 months) and 12.0 months (95% CI, 8.0-16.0 months), respectively.ConclusionThese results suggest that gefitinib readministration may be an option, albeit with a low response rate and short progression-free survival, for patients who responded well to initial gefitinib followed by systemic chemotherapy. These findings provide valuable information for the management of previous gefitinib responders.