Gene Test Predicts Whether Cancer Drugs Will Work Against Type of Lymphoma

A gene-based test can predict how patients will respond to treatment for a type of cancer called non-Hodgkin’s lymphoma, a study found.

The research identified specific genetic patterns that could predict how long patients with large-B-cell lymphoma would live when treated with a standard combination-drug therapy that included Genentech Inc.’s cancer drug Rituxan, according to a study published in the New England Journal of Medicine. Lymphoma is a cancer that starts in the lymph system, the disease-fighting network of the body.

The results give scientists a “new perspective” in developing genetically targeted therapies, especially for the roughly half of patients who don’t respond well to standard treatment, the study’s authors wrote.

The findings “give us some real food for thought about new therapeutic strategies” tailored to patients’ genetic profiles, said Louis Staudt, deputy chief at the National Cancer Institute’s Center for Cancer Research in Bethesda, Maryland, and a study co-author. For patients with this kind of lymphoma, he said, “What we hope, and what we are working on, is that there will be a day when this information will be a part of diagnosis.”

Large-B-cell lymphoma is one of the most common types of non-Hodgkin’s lymphoma, accounting for about one in three cases, according to the American Cancer Society Web site. The aggressive disease can be cured with combination-drug chemotherapy.

Scientists are trying to determine why only about half of patients with the disease are cured, said Staudt.

Genetic Signatures

The researchers identified genetic “signatures” by profiling the activity of genes in cancer biopsy samples from 414 patients from 10 places in North America and Europe. Data from another 177 patients from an earlier study also were analyzed, the researchers reported.

Some of the patients received the standard treatment of four chemotherapy drugs. Another group was given that combination plus Rituxan, which was approved in the U.S. for treating large B-cell lymphoma in 2006.

The scientists used a model in which patients were divided into four subgroups based on their genetic signatures. Patients whose disease had not progressed after three years ranged from a high of 89 percent in one group to a low of 33 percent in another.

Scientists determined the genetic signature that helps predict how patients will respond held true even after Rituxan was added to the standard chemotherapy, Stephen Kelsey, vice president for clinical hematology oncology at Genentech, said in Nov. 24 interview. Kelsey wasn’t involved in the study.

Targeting Therapy

The findings “provide a new perspective on current and future clinical trials” for large-B-cell lymphoma, the authors said. The findings suggest, for example, that only a few patients would benefit from Genentech’s and Roche Holding AG’s cancer drug Avastin, a monoclonal antibody. Avastin works by stopping a process called angiogenesis that forms blood vessels to feed tumors, the study said. Several mid- to late-stage clinical trials are testing Avastin in patients with this type of lymphoma.

An accompanying editorial in the journal written by Charis Eng, director of the Genomic Medicine Institute for the Cleveland Clinic Foundation, said the study provided clarity, unlike other studies of genomic profiling that have “often resulted in confusion and, at times, disappointment.” The new study identifies genetic fingerprints that “differentiated the best prognosis from the worst prognosis,” Eng wrote.

Source: Bloomberg