Scientists, companies rush to expand gene-therapy use

Blood-cancer therapies could work for tumors.

The approval of gene therapy for leukemia, expected in the next few months, will open the door to a radically new class of cancer treatments.

Companies and universities are racing to develop these new therapies, which re-engineer and turbocharge millions of a patient’s own immune cells, turning them into cancer killers that researchers call a “living drug.”

One of the big goals is to get them to work for many other cancers, including those of the breast, prostate, ovary, lung and pancreas.

“This has been utterly transformative in blood cancers,” said Dr. Stephan Grupp, director of the cancer immunotherapy program at the Children’s Hospital of Philadelphia and a professor of pediatrics at the University of Pennsylvania. “If it can start to work in solid tumors, it will be utterly transformative for the whole field.”

But that will take time, he said, estimating five years or more.

The products closest to approval have a limited focus — to treat blood cancers like leukemia (for which an FDA advisory panel recommended approval of the first treatment last week) and lymphoma, as opposed to the solid tumors that form in organs like the breasts and lungs.

The new treatments are expected to cost hundreds of thousands of dollars, and they come with risks. Patients in the earliest studies nearly died from side effects like raging fever, low blood pressure and lung congestion. Doctors have learned how to control those reactions, but experts also have concerns about possible longterm effects.

The new leukemia treatment involves removing millions of white blood cells called T-cells from the patient’s bloodstream, genetically engineering them to recognize and kill cancer, multiplying them and then infusing them back into the patient.

Solid tumors are less amenable to T-cell treatment, or CAR-T, but studies at various centers are trying to find ways to use it against mesothelioma and cancers of the ovary, breast, prostate, pancreas and lung.

“These solid tumors are like Fort Knox,” Grupp said. “They don’t want to let the T cells in. We need combination approaches, CAR-T plus something else, but until the something else is defined we’re not doing to see the same kind of responses.”