FDA Okays Gilead Sciences Inc's Zydelig for Blood Cancers

The U.S. Food and Drug Administration said Wednesday that it has okayed Gilead Sciences Inc's Zydelig for treatment of three types of blood cancers.

Zydelig can be used to treat relapsed chronic lymphocytic leukemia (CLL), relapsed follicular B-cell non-Hodgkin lymphoma (FL) and relapsed small lymphocytic lymphoma (SLL).

In patients with CLL, Zydelig is to be used in combination with Rituxan (rituximab). The drug has received breakthrough therapy designation by the FDA.

"In less than a year, we have seen considerable progress in the availability of treatments for chronic lymphocytic leukemia," said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA's Center for Drug Evaluation and Research. "Zydelig's approval to treat CLL reflects the promise of the breakthrough therapy designation program and represents the FDA's commitment to working cooperatively with companies to expedite a drug's development, review and approval."

The drug's safety and efficacy to treat relapsed CLL were established after researchers conducted a trial that included 220 patients. The participants either received Zydelig plus Rituxan or placebo plus Rituxan. Researchers found that people on the test drug had the possibility of living for at least 10.7 months without a relapse, whereas progression-free survival for patients who were treated with placebo and Rituxan was 5.5 months, according to a news release.

One hundred and twenty three participants were involved in the trial that tested safety and efficacy of the drug in patients suffering from relapsed FL and relapsed SLL. All patients were given the Zydelig. Researchers then assessed the partial or complete disappearance of the cancer after treatment. Over 50 percent of participants with FL and SLL responded to the treatment.

"Zydelig is a much needed new treatment option for appropriate patients with CLL and these indolent lymphomas who have experienced relapses and have limited, if any, treatment options," said Bruce Cheson, MD, Professor of Medicine, a principal investigator on the Zydelig pivotal Phase 3 trial in CLL, in a news release.

Diarrhea, fever (pyrexia), fatigue, nausea, cough, abdominal pain, pneumonia and rash are some of the common side-effects of using the drug, FDA said. Zydelig carries Boxed warning to inform patients and doctors about potential life-threatening effects of the drug. Patients using the drug might suffer from several types of toxicities including liver toxicity, lung inflammation, colon inflammation etc.

Shares of Gilead increased 0.4 percent to close $89.66 in afternoon trading, Reuters reported. Pharmacyclics Inc, which makes another drug for CLL called Imbruvica saw its shares rise 8.8 percent to $105.05. Imbruvica doesn't carry a box warning.