A phase II study of gefitinib as a dirst-line therapy of advanced or metastatic adenocarcinoma of the lung in lifetime non-smokers

Abstract

7072 Background: The analyses gefitinib trials suggested that gefitinib induced more responses in patients (pts) with adenocarcinoma of the lung who never smoked cigarettes. We conducted this study to evaluate the efficacy of gefitinib as a first-line therapy for this particular subgroup of pts. Methods: Eligible pts had stage IIIB or IV adenocarcinoma, ECOG PS of 0–2, adequate organ functions, measurable lesions and no smoking history. No pts received prior chemotherapy or radiotherapy to measurable disease. Treatment consisted of gefitinib 250 mg p.o daily x 28 days till disease progression, unacceptable toxicity or patient’s refusal. Objective tumor responses were assessed every 2 cycles. Results: Between 8/2003 and 8/2004, 55 pts were enrolled (median age: 55 years; M/F 4/51; ECOG PS 0/1/2 19/33/3; stage IIIB/IV 5/50); 54 were evaluable for response. The overall response rate was 61.1% (PR 57.4% & CR 3.7%) with SD in 11.1% and PD in 27.8% of pts. The response rate in female pts was 62.0% (31/50) but 50% (2/4) in male pts. There were 20 pts with evaluable brain metastases, 12 of whom had responses in both intracranial and extracranial lesions, and one had SD in intracranial metastases while extracranial lesions showed dramatic response. After a median follow-up of 36 weeks, the median progression-free survival was 26 weeks with 1-year survival rate of 78.5%. The median response duration for 33 responders was 30 weeks. Common toxicities were skin rash (95%), diarrhea (58%), and elevated liver enzyme (44%), and there was no significant hematologic toxicity. Significant toxicities included; G3 skin rash (2), G3 elevated liver enzyme (3), and G3 asthenia, vomiting, and neuropathy in one each. Conclusions: Gefitinib showed very promising antitumor activity and good toxicity profile for patients with advanced or metastatic adenocarcinoma of the lung and no smoking history. A further study is warranted in comparison with chemotherapy as a first-line therapy. (Supported in part by NCC grant 0210140) No significant financial relationships to disclose.