Immunotherapy shows hope for cancer battle

Treatment helped on aggressive form of breast cancer.

Women with an aggressive type of breast cancer lived longer if they received immunotherapy plus chemotherapy, rather than chemo alone, a major study has found.

The results are expected to change the standard of care for women like those in the clinical trial, who had advanced cases of “triple-negative” breast cancer. That form of the disease often resists standard therapies, and survival rates are poor. It is twice as common in African-American women as in white women, and more likely to occur in younger women.

Researchers said the new study was a long-awaited breakthrough for immunotherapy in breast cancer. Until now, most progress had been in other cancers, including lung cancer and melanoma, an aggressive skin cancer.

These findings may lead to the first approval by the Food and Drug Administration for an immunotherapy drug to treat breast cancer. But the approval would likely be limited to a certain type of aggressive cancer.

Although triple-negative tumors occur in only about 15 percent of patients with invasive breast cancer in the United States (or nearly 40,000 each year), they account for a disproportionate share of deaths, as many as 30 percent to 40 percent.

“These women really needed a break,” Dr. Ingrid Mayer, a breast cancer specialist at Vanderbilt University, said in a telephone interview. “Nothing has worked well.”

Mayer, who was not part of the study, called the findings “very significant.” She said she had received consulting fees from seven drug companies, including Genentech, which is the maker of the immunotherapy drug in the study and paid for the research.

The term triple-negative refers to the tumors’ lack of sensitivity to the hormones estrogen and progesterone, and their lack of a protein called HER2, which is a target of treatment.

The immunotherapy in the study was atezolizumab (brand name Tecentriq), which belongs to a class of drugs called checkpoint inhibitors; the chemotherapy was nab-paclitaxel (Abraxane).

The findings were published Saturday in The New England Journal of Medicine, and were to be presented at a meeting of the European Society for Medical Oncology in Munich. The study included 902 patients treated at 246 medical centers in 41 countries. Genentech, which is part of Roche, has already submitted the data to the FDA for approval.

Checkpoint inhibitors like atezolizumab work by helping T-cells — a type of white blood cell that is part of the immune system — recognize cancer and attack it. Research that led to these drugs won this year’s Nobel Prize in medicine.

The drugs generally work for fewer than half of patients but can bring lasting recoveries even to people who were severely ill. Side effects can be dangerous, even life-threatening, and treatment costs more than $100,000 a year.

In other cancers, researchers sometimes describe the tumors as “hot,” meaning they tend to have many mutations — genetic abnormalities that the immune system can recognize as foreign and attack.

But breast cancers tend to be relatively “cold,” with fewer mutations. The immune system is less likely to recognize them as invaders, which may help explain why previous studies of checkpoint inhibitors in breast cancer have been somewhat disappointing, researchers say.

EWA KRAWCZYK / NATIONAL CANCER INSTITUTE VIA AP This fluorescence-colored microscope image made available by the National Institutes of Health in September 2016 shows a culture of human breast cancer cells.