Immunotherapy found effective against 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.

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.

The findings may lead to the first approval by the Food and Drug Administration or an immunotherapy drug to treat breast 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,” said Dr. Ingrid Mayer, a breast cancer specialist at Vanderbilt University. “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 of South San Francisco, which is the maker of the immunotherapy drug (brand name Tecentriq) in the study and paid for the research.

The findings were published Saturday in the New England Journal of 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.

The women in the study had triple-negative breast cancer that had been newly diagnosed and had become metastatic, meaning it had begun to spread. Once that occurs, the outlook is grim, with many patients surviving 18 months or less.

Half received chemo alone, and half were given chemo plus immunotherapy.

Among those who received the combination, the median survival was 21.3 months, compared with 17.6 months for those who received chemo alone. The difference was not statistically significant.

But when the researchers looked at women who had a marker called PD-L1 on their cancer cells, the results were striking: The median survival was 25 months in the combination group, versus 15.5 months with just chemo.

“This is truly a game changer,” said Dr. Sylvia Adams, an author of the study from New York University Langone Health’s Perlmutter Cancer Center.