Dose-comparative monotherapy trials of ZD1839 in previously treated non-small cell lung cancer patients

Abstract

Patients with non-small cell lung cancer (NSCLC) frequently present, or relapse, with unresectable disease that is resistant to standard chemotherapy. There is, therefore, an urgent need for new treatments for NSCLC and other solid tumors. ZD1839 (Iressa; AstraZeneca Pharmaceuticals LP, Wilmington, DE), an orally active, selective epidermal growth factor receptor-tyrosine kinase inhibitor, has shown promising antitumor responses in phase I clinical trials in heavily pretreated patients with advanced NSCLC and other solid tumors. Randomized, multicenter global and US-based clinical trials were conducted to investigate two doses of ZD1839 as second- or third-line monotherapy in patients with advanced NSCLC. The global trial, Iressa Dose Evaluation in Advanced Lung Cancer (IDEAL)-1, was a double-blind, randomized, dose-comparative study that enrolled 210 patients with NSCLC at centers in Europe, Japan, South Africa, and Australia. This trial included patients with advanced unresectable stage III or IV NSCLC who had recurrent or progressive disease following one or two chemotherapy regimens, at least one of which was platinum based. IDEAL-1 showed that once-daily oral treatment with ZD1839 at 250 or 500 mg/day resulted in tumor response rates of 18% and 19%, respectively. Disease control rates, which included both tumor responses and stable disease, were 54% and 51%, respectively. Median progression-free survival was 83 days in the 250 mg/day group and 85 days in the 500 mg/day group. Rapid improvements in NSCLC-related symptoms were seen in the subpopulation of patients who were symptomatic and had completed a Lung Cancer Subscale questionnaire at baseline. Both the 250 mg/day and 500 mg/day doses of ZD1839 were well tolerated by patients in this trial. The majority of adverse events were grades 1 or 2 skin rash and diarrhea, which were readily manageable and reversible, and withdrawals were rare. The US monotherapy study in NSCLC, IDEAL-2, comprised 30 trial centers and enrolled 221 patients with NSCLC for third-line or greater therapy; 216 patients received treatment and were evaluable. This trial included patients with advanced stage III or IV NSCLC who had received two or more chemotherapy regimens that contained platinum and docetaxel, either concurrently or in separate regimens, with most patients having received more than two prior regimens. Although the IDEAL-1 and IDEAL-2 trials were similar in study design, patients in IDEAL-2 were sicker, as evidenced by a higher percentage of patients with a performance status of 2, metastatic disease, and disease-related symptoms. Because measuring the symptom improvement rate was a primary objective in IDEAL-2, all patients were symptomatic and were required to have a Lung Cancer Subscale score of 24 or less at trial entry. Objective tumor response rates (all partial responses) were 12% for the 250 mg/day group and 9% for the 500 mg/day group. Symptom improvement rates (increase of at least two points on the Lung Cancer Subscale) were 43% and 35%, respectively. Both doses of ZD1839 were well tolerated in this trial. The results of IDEAL-1 and IDEAL-2 indicate that ZD1839 monotherapy may offer a single-agent alternative for patients with advanced solid tumors who have received and progressed on prior chemotherapy, many of whom have exhausted their therapy options.