番茄社区

SAN ANTONIO – Young women with advanced breast cancer significantly improve their progression-free survival (PFS) if they received treatment with ribociclib (Kisqali) instead of placebo along with tamoxifen/aromatase inhibitors and goserelin to suppress ovarian function, researchers reported here.

PFS was 23.8 months among pre-menopausal women on the ribociclib regimen compared with 13.0 months among women on the placebo regimen (P=0.0000000983), said Debu Tripathy, MD, of the University of Texas MD Anderson Cancer Center, Houston.

"The treatment benefit was consistent across patient subgroups and regardless of the endocrine partner treatment," Tripathy said in his oral at the annual San Antonio Breast Cancer Symposium. "A clinically meaningful improvement in time to deterioration of quality of life and improvement in pain score were observed in patient's in the ribociclib arm."

A benefit of at least 10% in quality of life global health status from the EORTC QLC-C30 instrument was observed among patients on ribociclib compared with placebo, he reported. The median time to deterioration in the placebo arm was 21.2 months but the median time to deterioration for the ribociclib patients has not yet been reached, Tripathy said.

"Ribociclib combined with tamoxifen/non-steroidal aromatase inhibitor plus goserelin is a potential new treatment option for pre-menopausal women with hormone receptor-positive, HRER2-negative advanced breast cancer, regardless of disease free interval or endocrine partner," he said.

Tripathy said that PFS with tamoxifen was similar to that with aromatase inhibitors. He said he was encouraged that both tamoxifen and aromatase inhibitor use has similar outcomes which would give patients an option if there were intolerable side effects with the aromatase inhibitors.

"Based on this study, I would feel very comfortable giving a woman an aromatase inhibitor and goserelin and ribociclib or another similar CDK4/6 inhibitor," said Virginia Kaklamani, MD, of UT Health at San Antonio, who was not involved with the study.

"The benefit we see from these drugs is pretty similar. We are adding another line of chemotherapy with really good response rates," she told 番茄社区. "Instead of giving a breast cancer patient with liver metastases chemotherapy, I will be giving her these drugs and so delay chemotherapy for years."

In the study, Tripathy and colleagues administered ribociclib to 335 women; placebo was administered to 337 women. Tumor assessments were performed every 8 weeks for 18 months, then every 12 weeks thereafter. The women were enrolled from December 2014 to August 2016 when 318 events had occurred. Median time from randomization to data cutoff was 19.2 months, Tripathy said.

MONALEESA-7 enrolled pre- and perimenopausal women with hormone-receptor positive, HER2-negative advanced breast cancer who had no more than one previous line of therapy – and that line of therapy could not have included endocrine therapy. Patients were required to be in ECOG performance status 0-1 to be eligible for the trial. About 40% of the women in the study had de novo metastatic breast cancer, Tripathy said.

Participants averaged 43 years old and about 55% were Caucasian; about 30% were Asian, as this was an international trial that included women from Hong Kong, India, Korea, Malaysia, Saudi Arabia, Taiwan, Thailand, and the United Arab Emirates. Patients were also recruited from the United States, Canada, Western and Eastern Europe, Australia, and South America.

Ribociclib dosing was 600 mg/day for 3 weeks followed by a 1-week holiday. They also received goserelin at dose of 3.6 mg every 28 days to suppress ovarian function – effectively making the women post-menopausal. That allowed the endocrine therapy to function optimally, the researchers explained.

Tripathy said about one-fourth of the patients in each arm were treated with tamoxifen, while the other women received non-steroidal aromatase inhibitors. Dose interruptions occurred in 75% of the ribociclib patients and 35% of ribociclib patients required dose reduction.