By Jen Christensen, CNN
(CNN) — A drug used in people in the early stage of the most common kind of breast cancer – HR+/HER2- breast cancer – significantly reduced the risk of the cancer returning after treatment, according to a new study.
The US Food and Drug Administration approved the Novartis drug ribociclib, marketed under the brand name Kisqali, in 2017 for people with cancer that has spread to other parts of the body, helping them live longer by slowing the disease’s growth and spread. The results of a late-stage trial in people with early-stage cancer were presented Friday at the American Society of Clinical Oncology conference in Chicago. The drug is not yet indicated for this patient population.
“Having seen that benefit, it made perfect sense to assess whether the same benefit can now be extended to a group of patients with breast cancer who are at a much earlier stage of their disease,” Novartis’ Dr. Shreeram Aradhye, president for global development and the company’s chief medical officer, said at a news conference Friday. “Breast cancer is often diagnosed at an earlier stage, but because it is picked up early, as in stage two or three, before it has spread, does not necessarily mean that those patients are not at risk of a potential recurrence.”
Oncologists say there is a need for well-tolerated treatments that can keep patients cancer-free over the long term. Studies show that even after successful treatment for an initial cancer, some people have a high risk of recurrence that can last decades.
Typically, after initial treatment, doctors use endocrine therapy to reduce the risk that the cancer will come back. Also known as hormone therapy, it slows or stops the growth of hormone-sensitive cancer cells.
Endocrine therapy generally works well, but for patients with HR+ or HER- breast cancer, there’s still a 10% to 40% chance that the cancer will come back, some studies show. HR+/HER2- breast cancer has tested positive for progesterone and estrogen receptors and negative for HER2.
Some people may see benefits from a drug called Verzenio, but it’s not used in those who meet certain conditions, such those who don’t have lymph node involvement.
The new trial found that when Kisqali is added to endocrine therapy, it reduces the risk of recurrence by 25% across a broad population of patients with early breast cancer.
Drugmaker Novartis’ trial was a randomized, controlled trial, the gold standard of research, of 5,100 patients at 425 sites in 21 countries. The participants were pre- and post-menopausal women and men who were followed for three years.
Kisqali improved the percentage of people with invasive disease-free survival to 90.4% at three years, compared with 87.1% without it, in patients with early HR+/HER2- breast cancer, the study found.
Side effects included elevated liver enzymes, diarrhea and neutropenia, a condition in which the body has too few neutrophils, a type of white blood cell that helps fight infections.
The drug’s cost may be tricky for some patients. It is priced up to $15,000 a month, according to a recent analysis that suggested it was not a cost-effective treatment, even in its current use in people with advanced cancer.
But a large number of people stand to benefit from such a drug. About 90% of patients who have breast cancer are diagnosed in the early stages.
“These landmark results will fundamentally change how we treat patients with stage II and III HR+/HER2- early breast cancer who are in need of new, well-tolerated options that prevent their cancer from coming back,” said the trial’s lead investigator, Dr. Dennis J. Slamon, director of clinical and translational research at the UCLA Jonsson Comprehensive Cancer Center and chairman and executive director of Translational Research In Oncology. “Addressing this unmet need across such a broad patient population could help streamline treatment decisions for healthcare providers and keep many more at-risk patients cancer-free without disrupting their daily lives.”
Doctors say it’s “some of the most exciting” news presented at this year’s conference, according to Dr. Sara Tolaney, a breast medical oncologist at Dana-Farber Cancer Institute who was not involved in the trial but is also presenting research at the event.
“I think we should definitely pay attention to this,” Tolaney said. A 25% relative risk reduction is substantial, she said, and she hopes for longer-term data on these patients. She believes that as more are followed for longer, the benefit will appear even larger.
“I think it really does suggest that we can do better for our patients,” Tolaney said.
“I think this is a very important addition to our quest toward trying to cure more patients with breast cancer,” said Goel, who was not involved in the research.
“I think that this is a huge help in this space because we do have these high-risk patients who are at very high risk for disease recurrence. Our cure rate is not 100%,” she said, but a drug like this could get them there. “I think this is going to change the landscape for a lot of patients.”
Dr. Alberto Montero, director of the breast cancer program at UH Seidman Cancer Center in Ohio and a professor at the Case Western Reserve University School of Medicine, said it is a “significant advance” with “very significant results,” but “most progress in oncology – and especially in breast cancer – is really incremental, and that’s OK.”
Montero said the new findings could mean asking patients to take another medicine for three years, which can have potential side effects.
“I think you always have to weigh that with ‘what is the risk to the individual patient, and then what is the benefit to them?’ Because as an oncologist, we have to sort of be thoughtful about the toxicities of everything that we do and think about ‘is this going to improve the outcomes in a meaningful way for a patient?’ ” he said.
Generally speaking, Montero said, advances like this are important in the development of better cancer treatments.
“You have incremental advances, and those are quite meaningful.”
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