With personalized approach, new drugs on the horizon for leukemia patients

Drugs used to shrink tumors in ovarian and skin cancer might be enlisted soon to treat chronic lymphocytic leukemia or CLL.

Through sequencing, researchers at the University of Pennsylvania have found that leukemia cells share a surprising number of genetic defects with other tumors.

“We found mutations that are thought of in other cancers, but not routinely thought of in patients with CLL,” said Penn hematologist Anthony Mato.

In work presented at this year’s annual American Society of Hematology meeting in Orlando, Florida, the team identified 35 such mutations in 87 patients. About 15 percent of patients had mutations in ATM, which codes for a critical DNA repair protein. Others included changes in a splicing-factor gene and the classic tumor suppressor gene, TP53.

Further research is needed, Mato said, but more than 20 of those mutations are already targeted by existing drugs.

The findings are the latest to suggest that it is more beneficial to understand each tumor’s underlying genetic flaws rather than its cell type or tissue of origin.

“A colon cancer may have a BRAF mutation present, as may a breast cancer and a lymphoma,” said Mato. “What they have in common is that particular activating mutation, and that’s how therapies may be selected in the future.”

Right now, precision medicine isn’t far enough along for most CLL patients to change treatments based on genetic testing. But the information is already valuable for prognosis. In Mato’s survey, mutations were markers of more aggressive cancers and worse outcomes. And eventually, if an already approved drug targets the defect, patients with certain mutations might be the lucky ones.