Abemaciclib Indication Expands to Include HR+, HER2–, Node+, High-Risk, Early Breast Cancer

The FDA has approved an expanded indication for abemaciclib (Verzenio), which now gives the CDK4/6 inhibitor approval for the adjuvant treatment of adult patients with hormone receptor (HR)–positive, HER2-negative, node-positive, early breast cancer who are at a high risk of recurrence.¹

High-risk patients can be identified based off nodal status, tumor size, and tumor grade (4+ positive nodes, or 1-3 positive nodes and at least one of the following: tumors that are ≥5 cm or grade 3). The expanded indication removed the Ki-67 score requirement for patient selection. The expanded indication removes the Ki-67 score requirement for patient selection.

Four-year data from the phase 3 monarchE trial (NCT03155997) supported the approval. Findings from this trial demonstrated superior invasive-disease free survival (iDFS) following 2-years of adjuvant treatment with abemaciclib. This randomized, open-label, 2-cohort trial included patients who with HR+, HER2-, node-positive, resected, early disease. Patients also needed to have features demonstrable of high-risk of disease recurrence.

At 48 months of follow-up, the recurrence-free rate in patients who received abemaciclib (n = 2555) was 85.5% (95% CI, 83.8-87.0) compared with 78.6% (95% CI, 76.6-80.4) with endocrine therapy alone (n 1565). This came out to an absolute difference in iDFS of 6.9%. Further, at 2- and 3- years posttreatment, the absolute differences were 3.1% and 5.0%, respectively. The addition of abemaciclib reduced the risk of recurrence by 35% over endocrine therapy alone (HR, 0.653; 95% CI, 0.567-0.753). According to the monarchE investigators, there were no new safety findings and the agents’ overall profile was consistent with previous reports.²

"Our goal in intensifying treatment for early breast cancer is to maintain remission and prevent the recurrence of cancer. The magnitude of benefit seen in the 4-year data from the monarchE study reinforces my confidence in adjuvant [abemaciclib] as the standard-of-care for high-risk patients in this setting," Erika P. Hamilton, MD, medical oncologist, director of Breast and Gynecologic Cancer Research at Sarah Cannon Research Institute, and a study investigator, said in a press release. "The initial [abemaciclib] FDA approval in early breast cancer was practice-changing and now, through this indication expansion, we have the potential to reduce the risk of breast cancer recurrence for many more patients, relying solely on commonly utilized clinicopathologic features to identify them."

Abemaciclib is a CDK4/6 inhibitor and a nonchemotherapy oral anticancer agent. It is also indicated in combination with an aromatase inhibitor as initial endocrine based therapy for patients with HR-positive, HER2-negative, advanced metastatic breast cancer; in combination with fulvestrant for adult patients with HR-positive, HER2-negative advanced or metastatic breast cancer with disease progression following endocrine therapy; and as a monotherapy for patients with HR+, HER2-,advanced or metastatic breast cancer with disease progression following endocrine therapy and prior chemotherapy in the metastatic setting. It is available in tablets of 5-mg, 100-mg, 150-mg, and 200-mg doses.

Abemaciclib prescribing label comes with warnings and precautions for diarrhea, neutropenia, interstitial lung disease, hepatotoxicity, venous thromboembolism, and embryo-fetal toxicity.

Patients should be taught to begin antidiarrheal therapy, increase oral fluids, and notify their health care team at the first sign of loose stools. Before starting patients on abemaciclib, their complete blood counts and liver function should be assessed. These assessments should continue every 2 weeks for the first 2 months of treatment. If these assessments come back abnormal, dose modifications may be warranted. Patients will also need to be monitored for signs and symptoms of thrombosis and pulmonary embolism and treated as medically appropriate.

"This expanded approval for [abemaciclib] is welcome news for our community," added Jean Sachs, chief executive officer of Living Beyond Breast Cancer in the press release. "A significant number of women and men have HR-positive, HER2-negative early breast cancer at high risk of returning. Making effective treatment options available is crucial to allowing people to make the best care decisions for themselves, together with their health care providers. We're pleased [abemaciclib] will now be available to more people with this type of early breast cancer."

References

1. U.S. FDA broadens indication for Verzenio® (abemaciclib) in HR+, HER2-, node-positive, high risk early breast cancer. News release. Eli Lilly and Company. March 3, 2023. Accessed March 3, 2023. http://bit.ly/3Ypwzsd
2. Verzenio. Prescribing label. Lilly USA; 2023. Accessed March 3, 2023. https://pi.lilly.com/us/verzenio-uspi.pdf