Abbott Wins FDA Approval for First Companion Diagnostic in LeukemiaAbbott Wins FDA Approval for First Companion Diagnostic in Leukemia

In a first for the disease, there is now an FDA-approved companion diagnostic and drug pairing intended to treat a specific population of leukemia patients.

Some patients with a common type of adult leukemia, B-cell chronic lymphocytic leukemia (CLL), have a deletion of the TP53 gene, also known as the 17p deletion. This deletion is linked to a lower response rate to chemotherapy and is more prevalent in relapsing or refractory CLL patients. 

Now, FDA has approved both a new drug targeted at these patients as well as a companion diagnostic to find them. Abbott Molecular's Vysis CLL fluorescence in situ hybridization (FISH) probe kit and AbbVie's Venclexta received FDA approval this week.

"Abbott and Abbvie have obtained the first FDA approval for a targeted therapy and companion diagnostic in the field of leukemia," Kathryn Becker, PhD, global franchise director for oncology and companion diagnostics in Abbott's Molecular Diagnostics business, wrote in an e-mail to MD+DI.

Venclexta was approved for those CLL patients with the 17p deletion who have received at least one prior therapy. According to an FDA press release about the approval, the drug works against the cancer cell growth-promoting B-cell lymphoma 2 protein.

Becker explained that the Vysis CLL FISH probe kit was used to find eligible patients with the 17p deletion for a global clinical trial of Venclexta. That trial evaluated the efficacy of the drug in CLL patients who had already undergone prior treatment.

"These patients now have a new, targeted therapy that inhibits a protein involved in keeping tumor cells alive," Richard Pazdur, director of the Office of Hematology and Oncology Products in FDA's CDER, said in the release.

According to statistics from the American Cancer Society, there are expected to be approximately 19,000 new cases of CLL in the United States this year, mainly in adults over the age of 55.

Becker pointed out that back in 1998, Abbott put forward one of the the first gene-based diagnostics paired with a drug. That was the company's PathVysion test to detect the HER-2 gene in breast cancer patients, a population that was then eligible for treatment with Herceptin. "PathVysion testing along with Herceptin therapy is one of the first examples of what is recognized as genomic disease management, or personalized medicine," Becker wrote.

The pairing of Abbott's Vysis ALK FISH diagnostic test and Pfizer's XALKORI was the first simultaneous FDA approval of a companion diagnostic and drug, in August 2011, Becker wrote. That companion diagnostic is now considered the "clinical gold standard" in non-small cell lung cancer treatment, she noted.

The Vysis CLL FISH test, used in hospitals and reference labs, is available for doctors to order for their patients now, Becker noted. FISH testing at diagnosis and relapse was included in the recent National Comprehensive Cancer Network's non-Hodgkin's lymphoma guideline update, a category that covers CLL.

[Image courtesy of ABBOTT]