According to your FDA:
The number of subjects usually ranges from 
several hundred to about 
3,000 people. If the FDA agrees that the trial results are positive, it will approve the experimental drug or device. A Phase IV trial for drugs or devices takes place after the FDA approves their use.
	
	
		
			
				
			
			
				
				Interested in clinical research? Learn about the phases of clinical trials, why older and diverse participants are needed, and what to ask before participating.
				
					
						
							
						
					
					www.nia.nih.gov
				
 
			 
		 
	 
Where is it in writing that says you have to have 
200 million people in a trial?????????