Phase 1 Descovy® (TAF/FTC) 25/200 mg once daily for 28 days (DAYS 1-28) Phase 2 Descovy® (TAF/FTC) 25/200 mg once daily plus Rifadin® 600 mg once daily for 28 days (DAYS 29-56) Phase 3 Viread® (TDF) 245 mg once daily for 28 days (DAYS 57-84)