Immunotherapy to fight leukemia: Some impressive results

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Cancer is a group of diseases, all involving uncontrolled cell growth. The site of the cancer and cell type make all the difference in the prognosis. For example, thyroid cancer and basal cell carcinoma could be looked at as marginal cancers at worst, since they rarely spread and thus are rarely fatal.

On the other hand, the prognoses for cancers of the pancreas, brain and lung are usually quite poor.

Leukemias, depending on the cell type, lie somewhere in the middle probably closer to the worst cancers. But research in the area of cancer immunotherapy probably the hottest approach in current research has uncovered a potentially huge breakthrough against a form of leukemia called acute lymphoblastic leukemia (ALL).

ALL is caused by the bone marrow producing huge numbers of immature white blood cells, two types of which are called lymphocytes (which are usually normal progenitors of blood lymphocytes) and lymphoblasts (which are immature and should be present only in small numbers, normally). When the production of immature lymphoblasts goes out of control, it is at the expense of other critical cells, such as red blood cells, platelets (required for clotting), and other white blood cells that fight infection.

The survival and cure statistics for ALL can be a bit misleading.

Children are more likely to develop this condition than adults, but are easier to cure. While about 80 percent of adults will respond to ALL chemotherapy, half of them will relapse, and there is very little that can be done. The prognosis for these patients, as well as the 20 percent with refractory ALL (didn t respond to initial treatment) is quite poor. Stem cell transplants have been used with limited success.

But a collaboration between researchers at the University of Pennsylvania's Perelman School of Medicine and the pharmaceutical giant Novartis has the potential to change this.

Novartis experimental therapy called CTL019 was tested against the worst possible types of ALL refractory and those that reoccured. Based on a small phase I/II study, the drug was granted fast-track status, meaning that it will get an accelerated review from the FDA.

CTL019 is a personalized treatment that is based on immunotherapy the modification of the immune system so that it attacks the cancer cells. In this case, researchers isolated T-cells (another type of white blood cell) from the patients and reprogrammed them so they would attack the cancerous cells, and reinjected them back into the patient. The early results are quite promising. Keep in mind that these trials were done on patients who either didn t respond to, or relapsed following treatment. These are the worst case scenarios.

In 22 children who had failed initial therapy, 19 out of 22 achieved complete remission (although five of them later relapsed). In adults, seven out of 32 people achieved remission, and 15 had a partial response.

ACSH s Dr. Josh Bloom comments, Although it is way too early to call this a miracle therapy, Novartis and the University of Pennsylvania seem to have taken a pretty big step in cancer immunotherapy. Many oncology researchers are convinced that immunotherapy, not chemotherapy, will be the standard treatment for many cancers in the future. This is certainly worth keeping an eye on.