 
 <prompt> How trials dey happen? Based on di last question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: For US, new medicine gats get approval from FDA say e dey safe and e dey work well. Dem go submit Investigational New Drug wey get pre-clinical data for human trials. After dem approve IND, dem fit do three phases of human trials wey dey increase. Phase I dey check toxicity with healthy people. Phase II fit include how drug dey work for patients, and Phase III na big study to see if e dey work well for the people wey need am. If Phase III dey successful, dem go submit New Drug Application to FDA. Dem go review the data and if dem see say the drug dey benefit well well, dem go approve am to sell for US. 