2439
Replicate brain magnetic resonance imaging examinations after six weeks and 11 months of penicillamine therapy documented the development of new brain lesions during this period, while liver biopsy specimen data disclosed that excellent hepatic decoppering had occurred.
 adverse event: development 
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: development 