525
Gefitinib (IRESSA, ZD1839), an epidermal growth factor receptor tyrosine kinase inhibitor, has been approved in several countries for the treatment of advanced non-small-cell lung cancer.
 potential therapeutic event: treatment 
Please tell me event type and its trigger word from given type options. Output format is "type: trigger".  Option: adverse event, potential therapeutic event 
Text: {0} 
Answer:
 potential therapeutic event: treatment 