A cocktail of three breast cancer drugs buys patients an extra 16 months of life — a good news story so unusual, doctors have rushed to make it standard therapy, researchers said Wednesday.
The combination includes two so-called magic bullet drugs plus standard chemotherapy. It helps patients with advanced HER-2 positive breast cancer — a hard-to-treat type that's more often than not a death sentence.
"I can't think of something that improves survival by this much. Often, we debate over changing practice for something that extends survival by a few months, so 15.7 months that is so impressive. And really that's exactly what I see in the clinic," says Dr. Jennifer Keating Litton of the University of Texas MD Anderson Cancer Center. She was not involved in the trial.
"Quite frankly, this is even becoming standard of care in the early cancers," Litton told NBC News.
The cocktail includes two drugs made to go together by California-based Genentech. They are monoclonal antibodies — lab-engineered antibodies that home in on tumor cells. One is Herceptin, originally made to fight HER-2 breast tumors, which account for about 20 percent of breast cancer cases. The second is called pertuzumab, brand name Perjeta, and it was designed to complement Herceptin.
The third drug in the combination is the standard chemotherapy drug docetaxel.
A study of about 800 patients with advanced breast cancer, meaning the disease had spread, showed that the drug combination slowed the tumors and kept the women alive longer — on average 16 months longer — than Herceptin and docetaxel alone. The women lived on average for 56 months — nearly five years — compared to the usual lifespan of two to three years.
"We've never seen results like this before in HER2-positive metastatic breast cancer," said Dr. Sandra Swain of MedStar Washington Hospital Center, who led the trial. "This unprecedented data gives patients with an aggressive disease hope to live a longer, better life."
The combination is approved for women with advanced breast cancer, and Swain says a trial is now going on to see if it works women with earlier-stage breast cancer, right after surgery to remove the tumor. "It is our hope it would actually cure patients in that setting," Swain told NBC News.
There are reasons to be cautious. The regimen costs about $10,000 a month and Perjeta adds to the side-effects. "You do have an increase of diarrhea and rash, and it's expensive," Swain said.
The findings were reported at a European cancer conference last year and are published this week in the New England Journal of Medicine.
One patient who got the combination is Darlene Gant of Tampa Bay. In 2012, she was dying from stage III/IV breast cancer and posted a video on YouTube complaining about her plight.
"This was pretty much a death sentence. I was given less than a 15 percent chance for survival with all the treatment they could offer," Gant wrote in a blog post.
She was writing birthday cards to her then 11-year-old son for his father to give him after she died. She wasn't eligible for the clinical trial and begged to be given Perjeta, which had not yet been approved by the U.S. Food and Drug Administration.
"I have to plan what I am going to have to do for my son so he'll remember me," Gant said in the video.
Genentech gave Gant the drug and she chronicled a remarkable recovery. "Today I am still under treatment of Pertuzumab and Herceptin and doing well, miraculous some would say," she wrote in September 2012.
In February 2014, the drugs stopped working for Gant. She switched to another drug called Kadcyla, which combines Herceptin with a cancer-killing toxin. "I am now on it 1 year and it we have had to lower the dose 3 times and now pushing it out to 4 weeks (fingers crossed)," Gant writes in a Facebook post dated Feb. 11.
"I will have scans in Feb 2015 and see Onc (oncologist) March 2015. God knows this drug has been one of the worst for me to tolerate but I think it is helping and is suppose(d) to be less toxic (not that it feels that way). Will update when I get results - prayers please! Blessings."
Genentech says it can help people pay for the drugs. "We provide a number of services to help people having trouble accessing our medicines, including providing free medicine to people who do not have insurance, are underinsured, or are rendered uninsured due to payer denial. We also provide assistance with co-pays," spokeswoman Susan Wilson said by email.
Breast cancer is the second-biggest cancer killer of American women, after lung cancer. The American Cancer Society says more than 232,000 cases will be diagnosed this year, and more than 39,000 people will die of it.