FDA Approves Zydelig To Treat Pateints With Three Types of Blood Cancers

The U.S. Food and Drug Administration approved Zydelig to treat patients with three types of blood cancers.

In a latest announcement, the FDA approved Gilead Sciences' Zydelig to treat patients whose chronic lymphocytic leukemia (CLL) has returned. The drug is to be used in combination with Rituxan to treat those for whom Rituxan alone was not an appropriate therapy due to other existing medical conditions.

Zydelig is the fifth new drug with breakthrough therapy designation sanctioned by the FDA and the third drug approved with this designation to treat CLL. Apart from this, the regulators also granted Zydelig accelerated approval to treat patients with relapsed follicular B-cell non-Hodgkin lymphoma (FL) and relapsed small lymphocytic lymphoma (SLL) which is another type of non-Hodgkin lymphoma.

The drug can be used only by those patients who received at least prior systemic therapies.

"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."

Prior to Zydelig, the FDA approved Gazyva (2013), Imbruvica (2014) and Arzerra (2014) to treat CLL. The two drugs Gazyva and Arzerra received breakthrough therapy designation for this indication. Similar to the other two drugs, Zydelig also received orphan product designation as it is meant to cure a rare disease.

Using a clinical trial, the team established the safety and effectiveness to treat relapsed CLL. The trial included 200 participants who were randomly given Zydelig and Rituxan or placebo and Rituxan. The trail was stopped for efficacy following the first pre-specified interim analysis point that showed those receiving Zydelig and Rituxan had the possibility of surviving for 10.7 months without any progression in the disease when compared to those 5.5 months of those who received placebo and Rituxan.

The second interim analysis also showed a significant improvement for Zydelig and Riituxan.

To check the efficacy of the drug to treat relapsed FL and relapsed SLL, the team conducted a clinical trial that included 123 participants with slow-growing non-Hodgkin lymphomas. The participants were treated with Zydelig and were evaluated for complete or partial disappearance of their cancer after treatment. It was seen that 54 percent of participants with relapsed FL and 58 percent of participants with SLL experienced objective response rate.

The newly approved product carries a Boxed Warming to caution patients and health care professionals of fatal and serious toxicities including liver toxicity, diarrhea and colon inflammation, lung inflammation and intestinal perforation.

The common side effects include diarrhea, fever, fatigue, nausea, cough, pneumonia, abdominal pain, chills and rashes. Common lab abnormalities included low levels of white blood cells, high levels of triglycerides in the blood, high blood sugar and high levels of liver enzymes.