By Julie Steenhuysen
CHICAGO, June 1 (Reuters) - U.S. researchers are finalizing plans to test two immunotherapy drugs made by Bristol-Myers Squibb Co on patients newly diagnosed with the most common form of deadly brain tumors in adults.
Dr. Mark Gilbert, a leading brain tumor researcher at University of Texas MD Anderson Cancer Center in Houston, said he got approval last Tuesday from the National Cancer Institute (NCI) to start designing the trial, likely to begin this fall, with the melanoma drug Yervoy and an experimental drug called nivolumab.
The trial will be run through the nonprofit NRG Oncology, an NCI sponsored cooperative group of cancer researchers.
"We're really excited about them," said Gilbert, who spoke in an interview at the American Society of Clinical Oncology meeting in Chicago.
The hope, he said, is that the drugs, which ramp up the immune system to fight cancer, will prove effective in treating the brain tumors known as glioblastomas.
Researchers are already testing Bristol's nivolumab in patients with a glioblastoma that has come back after standard treatment, which involves surgery followed by radiation and chemotherapy.
Michael Giordano, head of development for oncology and immunology at Bristol-Myers, said the company's trial in recurrent glioblastoma is part of its push to test the potential of immunotherpies in a broad range of cancers.
Gilbert said he has met with company officials, who still need to give written approval for their drugs to be used in the government-backed study.
Initially, the trial in newly diagnosed patients will test the safety of the drugs in some 42 patients, Gilbert said. One concern is that bolstering the immune system in the brain could trigger an autoimmune reaction known as encephalitis, causing swelling and worsening patients' symptoms.
But so far, the studies in patients with recurrent tumors have not shown that to be a major issue, Gilbert said.
"We have to take it slow. We want to understand what we're doing," he said.
What is challenging about brain tumors is getting active treatments through a protective membrane called the blood-brain barrier. A major study led by Gilbert, reported at last year's American Society of Clinical Oncology meeting, showed Roche's antibody drug Avastin failed to prolong life in patients with newly diagnosed disease.
But early studies of immunotherapy in melanoma showed the treatments did shrink tumors in patients whose cancer has spread to the brain, suggesting that immune system cells were reaching their target in the brain and raising hope for immunotherapy treatments.
Gilbert acknowledged that research on brain tumors has lagged some other fields, especially with new immune system therapies, but he sees that changing.
Glioblastomas are the most common and most deadly form of brain and nervous system tumors, which affect an estimated 240,000 adults globally per year. With standard treatments, average survival is 15 to 17 months. (Reporting by Julie Steenhuysen; Editing by Tom Brown)