19204
To date , results of four large , randomized , double - blind , placebo - controlled , multicentre trials with FTC / TDF as pre - exposure prophylaxis have been published .
 Chemical: FTC; Chemical: TDF
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: FTC, TDF 
Answer:
 Chemical: FTC; Chemical: TDF