FOSTER CITY, Calif.--(BUSINESS WIRE)--Gilead Sciences, Inc. (Nasdaq: GILD) today announced that the first patient has been dosed in a Phase 3 clinical trial evaluating the efficacy and safety of GS-1101 (formerly CAL-101). GS-1101 is an investigational, first-in-class specific inhibitor of the phosphoinositide-3 kinase (PI3K) delta isoform and is being evaluated in combination with rituximab in previously treated chronic lymphocytic leukemia (CLL) patients. The Phase 3 trial (Study 116) will enroll 160 patients at approximately 70 sites in the United States and Europe.