NEW YORK (CBSNewYork) – There’s exciting news for women with an extremely hard to treat  type of breast cancer called triple negative.

For the first time, immunotherapy is extending the lives of these women.

CBS2’s Dr. Max Gomez says this could change the way patients are treated.

Three years ago, at age 39, Maribel Ramos was diagnosed with advanced breast cancer. The type was triple negative.

“I was angry and sad,” Ramos said. “Because I know that the triple negative is a type of cancer that is really hard to treat.”

Ten to 20 percent of breast cancers are called triple negative because they don’t have receptors, such as ones for estrogen, that can be targeted by certain medications. Treatment options are limited, and these cancers tend to be more aggressive, with worse outcomes.

In 2016, Ramos entered a trial to test the immunotherapy drug Tecentriq on patients with advanced triple negative breast cancer.

The drug works by targeting proteins found on immune cells and some cancer cells. It’s approved for bladder and one type of lung cancer.

Dr. Sylvia Adams of NYU Langone Health was one of the trial investigators. She says the new drug helps the immune system recognize the cancer.

“So there are killer cells already in the cancer present and ready to fight, except that this cancer shields itself from the from the immune attack,” Adams said. “So this drug is now able to take the shield down and basically paves the way for your own immune response to kill the tumor.”

The trial, conducted at hundreds of sites in 41 countries, followed 902 patients and found the combination of immunotherapy and chemotherapy improved overall survival by nearly four month and nearly 10 months for those patients whose tumors tested positive for the targeted protein.

Dr. Adams examined a recent scan and said it showed Ramos is still completely without any evidence of the disease.

Three years ago, Ramos worried she wouldn’t see her oldest daughter graduate. Last June, she did.

This could change the way triple negative breast cancer is treated, especially for women whose tumors are positive for the protein this drug targets.