High-risk, HR+, HER2-, early-stage BC patients continue to benefit from abemaciclib

December 09, 2020

SAN ANTONIO - Extended follow-up data from the phase III monarchE trial showed that adding the cyclin-dependent kinase (CDK) inhibitor abemaciclib (Verzenio) to standard adjuvant endocrine therapy continued to improve invasive disease-free survival (IDFS) among patients with high-risk, node-positive, early-stage, HR-positive, HER2-negative breast cancer, according to data presented at the 2020 San Antonio Breast Cancer Symposium, held Dec. 8-11.

"While many patients with HR-positive early breast cancer will not experience recurrence on endocrine therapy alone, approximately 20 percent may experience disease recurrence in the first 10 years, often in the form of incurable metastatic breast cancer," said Priya Rastogi, MD, associate professor at the University of Pittsburgh Department of Medicine and medical director of the National Surgical Adjuvant Breast and Bowel Project (NSABP) Foundation.

"The risk of recurrence is higher among patients whose cancer has certain clinical and/or pathological risk factors such as a high number of positive lymph nodes, large tumor size, or a high cellular proliferation as measured by tumor grade or biomarkers," Rastogi continued. "There is a significant unmet need for this patient population, and research must be done to find new treatment options to help prevent early breast cancer from returning for these patients."

Earlier results from an interim analysis of the monarchE trial, which is comparing abemaciclib plus adjuvant endocrine therapy with endocrine therapy alone in 5,637 patients with high-risk, node-positive, early-stage, HR-positive, HER2-negative breast cancer, have been previously reported. After a median follow-up of 15.5 months and 323 invasive disease-free events, it was found that the addition of abemaciclib to endocrine therapy reduced the risk of invasive disease by 25 percent. The two-year IDFS rates in the combination arm and the endocrine therapy alone arm were 92.2 percent and 88.7 percent, respectively.

The current study describes an extended follow-up of this trial, capturing results from 395 invasive disease-free events with a median follow-up time of 19 months.

Following surgery, and radiotherapy and/or chemotherapy as indicated, patients were randomly assigned to receive standard of care adjuvant endocrine therapy with or without abemaciclib (150 mg twice per day for two years). Eligibility criteria included having at least four positive nodes, or having one to three positive nodes in combination with either grade 3 disease, a tumor of at least 5 cm, or centrally assessed high Ki-67 status (where "high" is defined as at least 20 percent positivity in tumor cells). Higher levels of Ki-67 protein are indicative of a fast-growing, aggressive tumor with increased probability of recurrence.

At the time of this analysis, 1,437 patients (25.5 percent) had completed the two-year treatment period and 3,281 patients (58.2 percent) were in the two-year treatment period. Compared with patients who received endocrine therapy alone, those who also received abemaciclib had a 28.7 percent reduced risk of invasive disease. The two-year IDFS rate in the combination arm and the endocrine therapy alone arm was 92.3 percent and 89.3 percent, respectively. Further, the researchers observed an improvement in the two-year distant relapse-free survival (DRFS) rate among patients who received the combinatorial treatment compared with those who received endocrine therapy alone (93.8 percent versus 90.8 percent, respectively).

The researchers also evaluated outcomes among 2,498 patients with centrally assessed high Ki-67 status. Among patients in this cohort, those who received the combination treatment had a 30.9 percent decreased risk of invasive disease compared with those who received endocrine therapy alone. The two-year IDFS rates in the combination arm and the endocrine therapy alone arm were 91.6 percent and 87.1 percent, respectively.

"Across the spectrum of data for abemaciclib, we have observed a consistent benefit, in all subgroups," said Rastogi. Safety data from this trial were consistent with the known safety profile of abemaciclib and no new safety signals were observed.

"These results may mark a notable treatment advance in the last two decades for people living with high-risk, node-positive, HR-positive, HER2-negative early breast cancer," Rastogi continued. "These clinically meaningful results have the potential to change how high-risk, HR-positive, HER2-negative early breast cancer is treated."

Rastogi noted that overall survival data are immature at this time, and additional follow-up is warranted.
This study was sponsored by Eli Lilly and Co.

Rastogi has received reimbursement for travel and accommodation expenses from AstraZeneca, Genentech/Roche, and Eli Lilly and Co.

About the San Antonio Breast Cancer Symposium

Since 1977, the San Antonio Breast Cancer Symposium® (SABCS®) has been the leading scientific conference for basic scientists, physician-scientists, clinical investigators and breast care providers, and advocates seeking an exchange of new information in experimental biology, etiology, prevention, diagnosis, and therapy of premalignant breast disease and breast cancer. Founded, owned, and operated by UT Health San Antonio, the symposium has grown to a five-day event attended by an international audience of academic investigators and private physicians from over 80 countries to attain information through abstract presentations, panel discussions, research findings, and state-of-the-art educational sessions. UT Health San Antonio, with co-sponsors the Dan L Duncan Comprehensive Cancer Center at Baylor College of Medicine and the American Association for Cancer Research, supports SABCS, which provides education and accessibility to the latest information regarding the prevention, diagnosis, and treatment of premalignant breast cancer and breast disease. For more information on SABCS, visit http://www.sabcs.org.

To interview Priya Rastogi, please contact Julia Gunther at julia.gunther@aacr.org or 770-403-7690.

American Association for Cancer Research

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.