Gefitinib as a last treatment option for non-small-cell lung cancer: durable disease control in a subset of patients

Background: We describe 16 months' single-institution experience with gefitinib ('Iressa', ZD1839) used as 'ultimum refugium' for pretreated non-small-cell lung cancer (NSCLC) patients. Patients and methods: Toxicity, response and survival data of NSCLC patients participating in a compassionate-use program with gefitinib were reviewed. Documented disease progression and confirmation of the absence of other treatment options were requested. Oral gefitinib at a dose of 250 mg/day was given until disease progression, unacceptable toxicity or death. Cox's proportional hazards model was used to analyze relationships between factors and probability of survival. Results: Rapid disease precluded treatment in eight cases. Of 92 evaluable patients, one-third had a baseline performance status (PS) of greater than or equal to2. The main side-effects of gefitinib were grade 1-2 diarrhea and skin rash. A disease control rate of 46% (objective response rate 8.7%) and 1-year survival of 29% were documented. Histology (adenocarcinoma) and a 'never-smoking' history were predictive of response. Number of previous chemotherapy regimens, gender, time since diagnosis and time since last chemotherapy lacked such an association. Radiotherapy during gefitinib treatment was well tolerated and was associated with prolonged survival in a patient with multiple brain metastases. Multivariate analyses revealed a significant impact of PS on survival. A 'never-smoking' history, adenocarcinoma/bronchoalveolar-cell carcinoma and female gender showed a trend towards better survival outcomes. Conclusion: Gefitinib's single-agent activity in a group consisting of pretreated NSCLC patients is confirmed. Side-effects of gefitinib were mild. Prolonged survival was associated with good PS and less significantly with a never-smoking history, female gender and histology. Additional studies on mechanisms of tumor control and selection of target populations for this remarkable new drug are warranted.