FDA Approves Idelalisib (Zydelig) for Leukemia and Lymphoma

People with certain types of leukemia and lymphoma that has returned after treatment now have a new drug therapy to try. The U.S. Food and Drug Administration (FDA) has approved idelalisib (Zydelig) for people with relapsed chronic lymphocytic leukemia (CLL), relapsed follicular B-cell non-Hodgkin lymphoma, and relapsed small lymphocytic lymphoma (another type of non-Hodgkin lymphoma).

Zydelig is a pill taken twice a day. It targets a protein found in the cells of several types of blood cancer that helps the cancer cells develop, grow, and spread.

In a clinical trial of 220 CLL patients, those who received Zydelig in combination with rituximab (Rituxan) went nearly 11 months without their cancer getting worse, compared to about 6 months for people given rituximab and a placebo. Now, CLL patients who would be eligible to be treated with rituximab alone can instead choose combination therapy with Zydelig.

Zydelig now is also approved to treat people with 2 types of slow-growing lymphoma who have had at least 2 other treatments. The drug is used alone in these patients.  In a clinical trial of 123 patients who all took Zydelig, more than half saw their cancer disappear partially or entirely. The FDA granted the drug accelerated approval for these lymphomas because of this result. That means patients can get it now, but the manufacturer must conduct more studies to make sure it is still as effective over the long term.

Zydelig can have serious side effects that can sometimes be fatal. These include liver problems, diarrhea and colon inflammation, lung inflammation, serious skin problems, and intestinal perforation. The drug carries a boxed warning about these possible problems, and the FDA has set up a plan to assure doctors who are likely to prescribe it are aware of these risks.

The drug’s more common side effects include diarrhea, fever, fatigue, nausea, cough, pneumonia, abdominal pain, chills, and rash. It may also cause low levels of white blood cells, high blood sugar and triglycerides, and high levels of liver enzymes.

Zydelig is manufactured by Gilead Sciences, Inc.

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