Drug Combo Extends Survival in Advanced Breast Cancer
Benefit seen for addition of CDK4/6 inhibitor after progression of disease on endocrine therapy
FRIDAY, Oct. 4, 2019 (HealthDay News) -- The addition of abemaciclib to fulvestrant provides a statistically significant and clinically meaningful gain in median overall survival, regardless of menopausal status, for women with hormone receptor (HR)-positive, erb-b2 receptor tyrosine kinase 2 (ERBB2 [formerly human epidermal growth factor receptor 2])-negative advanced breast cancer that progressed during endocrine therapy, according to a study published online Sept. 29 in JAMA Oncology. The research was published to coincide with the European Society of Medical Oncology Congress 2019, held from Sept. 27 to Oct. 1 in Barcelona, Spain.
George W. Sledge Jr., M.D., from the Stanford University School of Medicine in California, and colleagues randomly assigned patients (premenopausal or perimenopausal with ovarian suppression, postmenopausal) with HR-positive, ERBB2-negative advanced breast cancer that progressed during endocrine therapy (2:1) to receive either abemaciclib (446 patients) or placebo (223 patients), 150 mg every 12 hours on a continuous schedule plus fulvestrant, 500 mg, per label.
At the prespecified interim period, the researchers found 338 deaths (77 percent of the planned 441 at the final analysis) in the intent-to-treat population, with a median overall survival of 46.7 months for abemaciclib plus fulvestrant and 37.3 months for placebo plus fulvestrant (hazard ratio [HR], 0.757; 95 percent confidence interval [CI], 0.606 to 0.945; P = 0.01). Findings were consistent across all stratifications. More pronounced effects were seen in patients with visceral disease (HR, 0.675; 95 percent CI, 0.511 to 0.891) and primary resistance to prior endocrine therapy (HR, 0.686; 95 percent CI, 0.451 to 1.043). There were significant improvements in time to second disease progression, time to chemotherapy, and chemotherapy-free survival in the abemaciclib arm versus the placebo arm.
"We still haven't cured metastatic breast cancer. But this is a drug that increases survival and reduces the need for chemotherapy," Sledge said in a statement. "Women can live longer and have a relatively good quality of life and more time with their families, their children, and their loved ones."
The study was funded by Eli Lilly, the manufacturer of abemaciclib.