Immune therapy shows wider promise on breast cancer

Drugmakers are honing in on which cancer patients will benefit from new immune therapies — and finding many more than skeptics had thought.

For the first time, a clinical trial showed that a treatment with one of the new generation of drugs designed to unleash the body’s own immune system against tumors can help some women with the most aggressive type of breast cancer live longer. The study was unveiled by Roche Holding at Europe’s biggest cancer conference.

These medicines, led by Merck & Co.’s blockbuster Keytruda, are sold for more than a dozen different cancers, and pharmaceutical companies are obsessively working to expand their applications with newer versions and treatment cocktails. There are some 1,300 immune-based treatments in human studies, according to the Cancer Research Institute, largely financed by drugmakers angling for a chunk of a market forecast to exceed $100 billion annually by 2024.

“This is just the tip of the iceberg,” said Axel Hoos, oncology research and development chief at U.K. pharma giant GlaxoSmithKline, which is trying to break back into oncology after selling its existing products to Novartis AG in 2015. “There’s a little bit of hype, but there’s a lot of substance.”

At the European Society for Medical Oncology’s meeting over the weekend, Roche disclosed the results of a study that showed one group of patients whose breast tumors tested positive for a protein called PD-L1 lived an average of 25 months when they got an immune therapy called Tecentriq — about 10 months longer than others who got only chemotherapy.

Immune therapies exploded onto the scene about eight years ago when Bristol-Myers Squibb’s Yervoy became the first medicine of its kind to extend the lives of people with melanoma, a lethal skin cancer. Successes in kidney and lung cancers followed shortly thereafter. When immune therapies work, the effect can last for years, one of the reasons they’re regarded as revolutionary. But in most patients, nothing helpful happens — even in skin and lung tumors where some of the most dramatic effects have been seen.

“There are some cancers where the immune system just can’t recognize it,” said Mace Rothenberg, chief development officer for oncology at U.S. pharma giant Pfizer Inc. Flying under the body’s protective radar, scientists refer to them as “cold tumors.”

Companies are starting to rethink their strategy for the toughest cases, said Dan O’Day, Roche’s pharma chief. Testing patients’ tumors for specific proteins and genes will help identify those most likely to benefit, he said.

“We want to get away from this concept of giving cancer immunotherapy to 80 percent of the patients and only half of them respond,” he said in an interview. “Let’s find the other treatment options for the other patient types.”

Roche’s breast cancer study helped support the idea that there are ways for doctors to identify more cancers that will submit to immune therapy. The drug used in the study, Tecentriq, blocks the protein called PD-L1 that hampers the immune system’s attack on cancers, and only women whose tumors had high levels of the protein were helped.