1873
In developing an vivo drug - interception therapy to treat cocaine abuse and hinder relapse into drug seeking provoked by re - encounter with cocaine , two promising agents are : ( 1 ) a cocaine hydrolase enzyme ( CocH ) derived from human butyrylcholinesterase and delivered by gene transfer ; ( 2 ) an anti - cocaine antibody elicited by vaccination .
 Chemical: cocaine; Chemical: cocaine; Chemical: cocaine; Chemical: cocaine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: cocaine; Chemical: cocaine; Chemical: cocaine; Chemical: cocaine