New Cancer Drugs That Enable the Body’s Immune System To Attack Cancer Cells

Research on new cancer medicine presented Saturday at the American Society of Clinical Oncology offers hope for mesothelioma treatment of patients with advanced non-small cell lung cancer. Exposure to asbestos causes one type of non-small cell lung cancer called adenocarcinoma, as well as mesothelioma, an aggressive cancer of the lining of the lungs.

Two clinical trials led by cancer researchers at Johns Hopkins Kimmel Cancer Center reported promising early results in tests of experimental drugs designed to restore the immune system’s ability to spot and attack cancer. Investigators observed positive responses to the therapies in patients with advanced non-small lung cancer, melanoma and kidney cancer, according to Johns Hopkins press release. The results were published online in the New England Journal of Medicine.

Rather than killing the cancer cells directly, the experimental drugs made by Bristol-Myers Squibb make cancer cells more vulnerable to attack by the immune system. They do so by blocking proteins that create a biochemical shield to protect tumor cells from being destroyed.

One of the two drugs was tested in 296 patients with various advanced cancers that had not responded to traditional cancer treatments. Approximately one out of four to one out of five of the patients saw significant shrinkage of tumors. Among the patients with advanced lung cancer, 14 of 76 patients (18 percent) had significant shrinkage of malignant tumors.

“The level of response in patients with advanced lung cancer, which is typically not responsive to immune-based therapies, was unexpected and notable,” Dr. Julie Brahmer, associate professor of oncology at Johns Hopkins said in a press release.

Dr. Suzanne Topalian, professor of surgery and oncology at Johns Hopkins, said the positive response to both drugs indicates that the biochemical shield that protects tumors is a good target for cancer investigators. Among the patients who responded to the immune therapy treatments, more than two-thirds controlled the cancer for more than a year in one trial and half the patients managed the cancer for a year or longer in the second trial. Sustained control of cancer is considered remarkable with advanced cancer.

“We have just scratched the surface of laboratory and clinical research on these drugs,” Topalian said in a press release.

The researchers said the results merit followup clinical trials to test the drugs further.

According to the Agency for Toxic Substances and Disease Registry, a federal agency, an estimated 4 to 12 percent of lung cancers are related to workplace exposure to asbestos. Lung cancer related to asbestos exposure typically develops 20 years to 40 years after exposure. Most patients with adenocarinomas have advanced cancer before it is diagnosed, making it more difficult to treat.