(BN) Bristol Immune Drug Success in Cancer May Spur Industry Race

Bristol-Myers Immune Drug Puts Deadly Cancers on Hold in Study

An experimental drug from Bristol- (BMY) Myers Squibb Co., designed to unleash the body's own defenses against cancer, shrank lung, kidney and skin tumors in a study that points the way to a new class of immune-boosting therapies.

The drug reduced tumors in roughly 20 percent to 25 percent of patients with these tumors who had failed to respond to other therapies, according to results from the 296-patient trial being presented today at the American Society of Clinical Oncology meeting in Chicago. The drug held cancer at bay in 20 patients for more than a year by keeping the body's immune system on alert to fight the disease.

The findings show that medicines that spur immune cells to attack cancer can work in more patients and tumor types than previously thought, said Antoni Ribas, an oncologist at the University of California, Los Angeles, who wasn't involved in the trial. Lung cancer in particular hasn't been thought of as responsive to immune therapies, he said in an interview.

"We are getting response levels that go beyond what we were seeing before -- and in different types of cancer," said Ribas, who wrote an editorial on the drug in the New England Journal of Medicine, where the trial data is also being published. "It is not common at all" to see results this good.

Drugmakers and scientists have been trying to find ways to boost the immune system against cancer for decades, with little successes until very recently. In 2010, Dendreon Corp. (DNDN)'s Provenge prostate cancer treatment was approved in the U.S. as the first therapy designed to train the body's immune system to attack cancer cells as if they were a virus.

Milestone Achievement

The field achieved a milestone last year with the U.S. approval of Bristol-Myers's Yervoy, the first drug proven to extend the survival of advanced melanoma patients. Yervoy blocks a molecular off-switch on the immune cells that keeps them from attacking cancer. The treatment shrinks melanoma in 10 percent to 15 percent of patients, Ribas said.

The new Bristol-Myers drug, BMS-936558, is an antibody that blocks another off-switch of the immune system, called PD-1. Many types of tumors act to keep the off-switch in place to protect themselves from the immune system.

Results from the company-sponsored trial reported at the cancer conference showed Bristol-Myers's anti-PD-1 drug shrank tumors in 18 percent of lung cancer patients, 27 percent of kidney cancer patients and 28 percent of melanoma patients.

Based on the findings, Bristol-Myers plans to begin a final set of trials of the treatment in lung and kidney cancer this year, and in melanoma by early next year, said Michael Giordano, a Bristol-Myers senior vice president, in a phone interview.

Immune therapy will become "a new paradigm in the way cancers are treated," he said.

Emerging Rivals

Bristol-Myers needs to move fast because other companies, including Merck & Co. (MRK), Roche Holding AG (ROG), Teva Pharmaceutical Industries Ltd. (TEVA) and GlaxoSmithKline Plc (GSK), are in early stages of testing drugs that work by similar mechanisms. Merck is presenting data from an initial trial of its anti-PD-1 drug at the cancer meeting.

The new class of drugs "is definitely a revolution in the making, there is absolutely no doubt," said Keith Flaherty, head of developmental cancer therapeutics for Massachusetts General Hospital in Boston and a co-investigator on the study.

A promising aspect of new immune-boosting therapies is that they may work for long periods of time, said Suzanne Topalian, a professor of surgery and oncology at the Johns Hopkins University School of Medicine in Baltimore and lead author on the study.

Year-Long Response

According to the results, 20 patients on the Bristol-Myers PD-1 drug have tumor responses that have lasted a year or more. This stands in contrast to existing drugs that hit mutated genes on cancer cells. These often stop working in a matter of months as the tumors become resistant, Topalian said in a phone interview before the meeting.

Some patients who responded to BMS-936558 have now gone off therapy without their tumors regrowing, Topalian said.

The immune system "has a memory component that continues to hold to the tumor in check" even after therapy is stopped, she said in the phone interview.

A downside of boosting the immune system against cancer is that it may also attack normal tissue. Three patients in the trial died from lung inflammation linked to the drug, according to the results.

There haven't been any deaths since Bristol started a program to aggressively treat patients who showed signs of the lung inflammation, said Fouad Namouni, the Bristol-Myers vice president who is leading the testing program for BMS-936558, in a phone interview.

In addition to lung, kidney and melanoma patients, the Bristol-Myers drug trial also included people with advanced colon cancer and prostate cancer. None of those patients experienced major tumor shrinkage, for reasons that aren't clear.

To contact the reporter on this story: Robert Langreth in New York at rlangreth@bloomberg.net