Immune system therapy is more promising against cancer

ATLANTA: A treatment that helps the immune system fight deadly blood cancers shows promising signs against some solid tumors, giving hope that this approach could be extended to more common cancers in the future.

The treatment, called CAR-T therapy, involves genetically modifying some of a patient's cells to help them recognize and fight cancer. Richard Carlstrand of Long Key, Florida, had it more than a year ago for mesothelioma, an aggressive cancer of the lining of the lungs.

"We were going to unknown territories" to try this, he said, but now he shows no signs of cancer and "I could not be happier."

The findings regarding his case and other cases were discussed Sunday at a conference of the American Cancer Association in Atlanta.

The first CAR-T therapies were approved in 2017 for certain leukemias and lymphomas. After being modified in the laboratory, the modified immune system cells are returned to the patient intravenously, placing them exactly where the cancer is – in the blood.

But this approach does not work well if cells have to travel a great distance in the blood to get to tumors of the lungs, bad, colon or other places.

"Solid tumors are notorious for not letting immune cells enter," and not enough could do to have an effect, said Dr. Prasad Adusumilli of the Memorial Sloan Kettering Cancer Center in New York.

A bigger concern is that the solid tumor cell proteins that these therapies also aim for are found in normal cells at lower levels, so the therapy could also be harmful to them.

Adusumilli helped design a new CAR-T to try to avoid these problems and tested it on 19 patients with mesothelioma and two others with lung cancer and one with bad cancer, respectively, which had spread to the chest wall. Each year, approximately 150,000 patients in the United States are faced with this situation.

The modified cells were injected directly into the chest where the tumors were located. A genetic safety switch has been added so that a drug can be administered to destroy the cells if they cause damage.

After the therapy, a patient was able to undergo surgery and radiation therapy and is doing well 20 months later without further treatment. Fifteen others were doing well enough to start taking a medication that strengthens the immune system differently.

Eleven of the 15 were studied long enough to report on the results. Two had signs of cancer disappeared for about a year, but one relapsed later. Six saw their tumors contract. Three have seen their cancer worsen.

There were no serious side effects although some patients had temporarily low blood counts and fatigue.

Grants from the federal government and foundations have funded the work and a larger study is planned. Sloan Kettering has licensed the treatment to Atara Biotherapeutics and could get it, just like Adusumilli.

A second study tested a different CAR-T treatment in 10 children and adults with advanced sarcomas – cancers from various soft tissues or bones. Unlike other DAS-Ts, which are usually given only once, it has been administered several times, up to 15 in the case of a patient, if there were signs that it was helping. .

"From a simple blood test, we make a large amount of T-Cells and then freeze them," and we administer an intravenous as needed, said Dr. Shoba Navai of Baylor College of Medicine in Houston. .

Two of the 10 patients with all the signs of cancer have disappeared, one for 17 months and the other for almost three years, until now. Three others had their disease stabilized. Five worsened despite treatment.

The side effects were similar to those of the other study. The therapy seems safe "and we have early signs that this treatment approach can help," Navai said.

Many foundations and charities paid for the work.

"These studies show that solid tumors can progress" with CAR-T therapies, said Dr. Louis Weiner, director of the Georgetown Lombardi Cancer Treatment Center and one of the conference leaders. This could be promising for some cancers of the stomach, bad, colon, lung and other regions, he said.

Cost is a big problem – current CAR-T treatments cost about $ 400,000 but can be obtained at a price well below that of research centers. Doctors hope that the cost will decrease as new products come on the market and achieve wider use.

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