878
Two patients treated for chronic myeloid leukemia with high doses of CCNU (1100 mg/m2 and 1240 mg/m2, respectively) developed a fatal pulmonary fibrosis.
 adverse event: developed 
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:
 adverse event: developed 