A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Efficacy and Safety of Idelalisib (GS-1101) in Combination with Rituximab for Patients with Previously Treated Chronic Lymphocytic Leukemia

Study Status

Open to Enrollment

Study Description

This is a clinical trial for people with previously treated chronic lymphocytic leukemia (CLL). The purpose of this study is to evaluate the effectiveness of the experimental drug Idelalisib (also called GS-1101, and formerly called CAL-101) combined with rituximab in treating CLL.

GS-1101 (CAL-101) is a pill designed to block some of the cell functions that cause CLL to grow and survive and may help control the disease. Rituximab is FDA-approved as a treatment for CLL. It is possible that giving rituximab together with GS-1101 may have more activity against the CLL disease process than giving rituximab alone.

Study participants will be randomly assigned to one of two treatment groups:

  • Group A: rituximab and GS-1101
  • Group B: rituximab and placebo (an inactive pill that looks like GS-1101 but contains no medicine)

After 24 weeks of therapy with rituximab and GS-1101 or placebo, participants will continue on GS-1101 or placebo as long as their CLL is controlled. If their CLL gets worse, participants may be able to take part in a separate extension study where they receive GS-1101 at a higher or lower dose. Thus, everyone who is treated in this study has an opportunity to receive active GS-1101, either in the main study or the extension study.

Disease Status and/or Stage

Previously Treated Chronic Lymphocytic Leukemia (CLL)


Gilead Sciences, Inc.

Key Eligibility

  • Men and women age 18 and older
  • Diagnosis of B-cell Chronic Lymphocytic Leukemia (CLL)
  • Previously treated for CLL
  • Detailed eligibility reviewed when you contact the study team

Principal Investigator

Richard Furman, MD


Protocol ID


Healthy Volunteers


As a healthy volunteer in a clinical trial you may make a significant contribution to the discovery of medical knowledge and new treatments that could impact people around the world.
Click here for studies seeking healthy volunteers.

Contact Us

For general inquiries, or if you need assistance finding a study, please contact:

Robert Hagerty
Subject Recruitment Manager
Tel: (646) 962-9340
[email protected]

Top of page