New treatment options are here for people with breast cancer that has spread elsewhere in the body, a process known as metastasis.
A novel class of drugs called PARP inhibitors, which interfere with proteins that repair DNA damage, can help women with inherited BRCA gene mutations that raise the risk of breast and ovarian cancer.
In January, the Food and Drug Administration (FDA) approved Lynparza (olaparib) for people with HER2-negative metastatic breast cancer—including those with hard-to-treat triple-negative cancer—who previously used chemotherapy.
In the OlympiAD trial, Lynparza delayed disease progression and shrank tumors twice as much as chemotherapy. New data presented at the recent American Association for Cancer Research annual meeting showed that Lynparza may also improve overall survival—especially for people who didn’t receive prior chemotherapy, suggesting it may work best as first-line treatment.
The EMBRACA trial, presented at the 2017 San Antonio Breast Cancer Symposium, showed that metastatic breast cancer patients treated with the experimental PARP inhibitor talazoparib were half as likely to experience disease progression or death as those treated with chemotherapy.
Another type of targeted therapy, CDK4/CDK6 inhibitors, has also shown good results. These drugs block two cyclindependent kinase proteins that regulate cell division.
In February, the FDA approved Verzenio (abemaciclib) as a first-line option with hormone therapy for postmenopausal women with HER2-negative advanced or metastatic breast cancer. The MONARCH 3 trial showed that Verzenio plus an aromatase inhibitor nearly doubled progression-free survival, from 15 months to 28 months.
Kisqali (ribociclib), another CDK4/CDK6 inhibitor, was already approved for first-line treatment of postmenopausal women with this type of breast cancer. The MONALEESA-7 trial showed that Kisqali plus hormone therapy also extends progression-free survival for younger premenopausal and perimenopausal women.
Together, these findings suggest that new therapies like PARP inhibitors and CDK4/CDK6 inhibitors could replace traditional chemotherapy—with its notoriously challenging side effects—for first-time treatment of advanced breast cancer.