Turning Leukemia into a Highly Treatable Disease

Chronic lymphocytic leukemia responded well to rituximab and idelalisib

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Chemotherapy is a standard treatment for the most common form of leukemia — chronic lymphocytic leukemia (CLL). A combination of pills may offer CLL patients new, better and gentler options.

Twice as many CLL patients who received a combination of the standard CLL therapy — Rituxan — and an investigational medication called idelalisib had stable disease at six months, as did patients who received only Rituxan (rituximab).

Compared to patients who received only Rituxan, six times more patients responded to the combination therapy.

"Discuss emerging treatment options for your condition with a doctor."

The lead investigator of this study was Richard R. Furman, the Richard A. Stratton Associate Professor in Hematology and Oncology at Weill Cornell Medical College and a hematologist/oncologist at NewYork-Presbyterian/Weill Cornell Medical Center.

CLL is the most common form of leukemia, a cancer of the white blood cells. Nearly 16,000 Americans will be diagnosed with CLL this year, and about 5,000 die from it.

CLL develops in the B cells — blood cells designed to fight off viruses and other invaders. The blood cancer is normally treated with a combination of chemotherapy medications. The disease ultimately comes back after initially responding to treatment. So more chemotherapy is given until the patient no longer responds or the therapy becomes too toxic for them to handle.

Rituximab is the standard medication used to treat CLL. It’s also used to treat non-Hodgkin lymphoma, rheumatoid arthritis and a rare condition that results in the inflammation of blood vessels.

Dr. Furman and his colleagues conducted a randomized, double-blinded study involving 220 CLL patients from 19 medical centers around the world. In addition to CLL, participants had chemotherapy-related complications such as decreased kidney function or other major co-existing conditions. The patients were no longer able to be treated with chemotherapy.

Participants were randomly assigned to one of two regimens: 1) Rituxan and idelalisib, a medication currently being reviewed by the US Food and Drug Administration (FDA) for approval, or 2) Rituxan and a placebo (sugar pill).

These researchers saw that the combination of idelalisib and Rituxan was more effective:

  • At six months, the CLL in 93 percent of the patients who received the combination therapy had not gotten worse (progression-free survival), compared to 46 percent of patients who received only Rituxan.
  • The median progression-free survival in the placebo group was 5.5 months, while the median progression-free survival in the idelalisib group had not yet been reached.
  • 81 percent of patients responded to the Rituxan plus idelalisib regimen, compared to 13 percent of those who received Rituxan and a placebo.
  • 92 percent of patients on the combination therapy were alive after one year of treatment, as were 80 percent of those on the single therapy.
  • The most common side effects in the idelalisib group were fever, fatigue, nausea, chills and diarrhea. In the placebo group, patients most commonly experienced fatigue, cough, nausea and trouble breathing.

So significant were the findings, the study was halted early so all of the participants could receive the idelalisib treatment.

“We saw incredible responses in patients who used idelalisib. Their cancer quickly melted away," Dr. Furman said in a statement. "These types of responses were even seen in patients who didn't respond to chemotherapy."

“The combination of idelalisib and rituximab, as compared with placebo and rituximab, significantly improved progression-free survival, response rate, and overall survival among patients with relapsed CLL who were less able to undergo chemotherapy,” the researchers wrote.

This study was published in the January 22 issue of the New England Journal of Medicine.

The research was funded by Gilead, the maker of idelalisib. A number of the authors reported financial ties with Gilead and various other pharmaceutical companies.

Review Date: 
January 28, 2014
Last Updated:
January 29, 2014