By Amy Norton
WEDNESDAY, Dec. 6, 2017 (HealthDay News) – Adding a new drug to standard treatment may slow the progression of advanced breast cancer in younger women, a new trial Clinician has found.
The drug, called ribociclib (Kisqali), was approved by the US Food and Drug Administration. UU in March for the treatment of postmenopausal women with advanced breast cancer.
Now, experts say, the drug is equally effective for premenopausal women.
In the trial, the treatment generally doubled the time a woman remained free of cancer progression, from about one year to two years.
That benefit is "surprisingly similar" to what has been seen in postmenopausal women, said Dr. Neil Iyengar, who specializes in treating breast cancer at Memorial Sloan Kettering Cancer Center in New York City .
Breast cancer occurs more frequently in older women and tumors that develop before menopause tend to be more aggressive than Iyengar.
"This is an important study because it addresses the question of whether a treatment is as effective for premenopausal women as it is for postmenopausal women," he said. Iyengar was not involved in the investigation.
Kisqali is one of several new drugs called CDK4 / 6 inhibitors. They work by blocking two proteins that help cancer cells grow and divide.
The drug was specifically approved as a first-line treatment for postmenopausal women with advanced breast cancer who is a positive hormone receptor, which means that estrogen stimulates cancer growth.
It is intended to be used in conjunction with an aromatase inhibitor, a drug that blocks the production of estrogen in postmenopausal women. Aromatase inhibitors can be given to premenopausal women if they are used with drugs that interrupt the production of estrogen in the ovaries.
The new trial included 672 women with advanced breast cancer, 25 to 58 years old, who were premenopausal or in treatment. menopause.
All women were given standard hormone therapy, an aromatase inhibitor or the drug tamoxifen, plus medications that suppress the ovaries. Half were randomly assigned to take Kisqali in addition. The other half took inactive placebo tablets.
The main focus of the trial was "progression free survival": how long a patient lives without the cancer getting worse.
In general, women who took Kisqali typically had no progression for two years, versus 13 months for women with standard treatment only.
The findings offer "clear evidence" that the drug can work just as well for younger women, said the study's principal investigator, Dr. Debu Tripathy. He is a professor of medicine and president of the department of breast medical oncology at the MD Anderson Cancer Center at the University of Texas, Houston.
Tripathy cautioned, however, that Kisqali is not yet approved for premenopausal women.
Last month, Kisqali's maker, Novartis, said it would "start discussions" with drug regulators based on the results of these trials.
Tripathy, paid consultant to Novartis, was scheduled to present the findings on Wednesday at the San Antonio Breast Cancer Symposium. The research presented at the medical meetings should be seen as preliminary until it is published in a peer-reviewed journal.
Kisqali does have problems. For example, it is known that it often causes a decrease in certain white blood cells that help fight infections.
In this study, three-quarters of the women who took Kisqali had a drop in blood cells called neutrophils, although most did not have symptoms, according to Tripathy.
A small number of women had what is called QT prolongation: a change in the electrical activity of the heart that can trigger an abnormal heart rhythm. Novartis says that, as a "precaution," Kisqali patients should monitor their cardiac activity before and during treatment.
The study does not answer the question of whether the drug ultimately extends women's lives, said Tripathy.
But, he Besides, that's a difficult question, because once a woman's cancer progresses, she'll usually try other treatments, like chemotherapy or newer "targeted" drugs.
Iyengar agreed. And, he said, researchers are still trying to discover the best course of treatment once patients progress.
For now, Iyengar said, "This study gives us new and compelling evidence that many doctors and patients will do it." I want to consider "
The cost, and what the insurance will cover, is another problem." Kisqali, like other CDK4 / 6 inhibitors, costs thousands of dollars for a 28-day treatment cycle.