Purpose: To investigate the anti-tumor activity and toxicity of the epidermal growth factor receptor (EGFR) inhibitor gefitinib (ZD1839 or Iressa; AstraZeneca Pharmaceuticals, Wilmington, DE), in patients with advanced non-small cell lung cancer (NSCLC).
Methods: This was an open label, expanded access program (EAP) of oral gefitinib administered at 250 mg per day continuously until evidence of undue toxicity or disease progression.
Results: Two hundred consecutive patients with advanced NSCLC were enrolled in this study. The median number of prior chemotherapy regimens was 2 (range 0-6). One hundred seventy-two patients were treated with gefitinib; 23 expired from disease progression prior to treatment and 5 withdrew their consent. One hundred fifty-four patients are evaluable for toxicity; 8 (5.2%) experienced grade 3/4 toxicity; 2 patients discontinued therapy for grade 3 rash and one for grade 3 nausea. Of 172 patients evaluable for efficacy, 7 (4.1%; 95% CI; 1.7-8.2%) experienced a partial response (PR); 60 patients (34.9%) had stable disease (SD) as their best response. Median survival for all patients was 4.5 months (95% CI; 4.1-4.9 months). One-year survival was 29%. Significant independent prognostic factors associated with improved survival were female gender, good performance status (0/1), and adenocarcinoma histology.
Conclusion: Gefitinib has anti-tumor activity, in a heterogeneous population of NSCLC patients treated on the EAP study. Treatment with gefitinib in this population is associated with a longer survival in women, those with good performance status and in patients with adenocarcinomas. These findings need to be further validated in additional clinical studies.