Verzenio (abemaciclib)

P2, N=19, Completed, Dana-Farber Cancer Institute | Active, not recruiting --> Completed | Trial completion date: Apr 2026 --> Nov 2025

P2, N=60, Recruiting, University of Texas Southwestern Medical Center | Trial primary completion date: Apr 2026 --> Apr 2027

P1/2, N=1132, Recruiting, Hoffmann-La Roche | N=792 --> 1132

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, such as abemaciclib, ribociclib, and palbociclib, are used in combination with ET as a standard of care first-line option in HR+, HER2- advanced disease to improve survival outcomes...Abemaciclib has also been shown to be effective when combined with a variety of ET options, including aromatase inhibitors, tamoxifen, fulvestrant, imlunestrant, or as monotherapy, and has shown efficacy regardless of prior CDK4/6 inhibitor exposure, ESR1 or PI3K pathway mutational status, menopausal status, and in both endocrine-sensitive and endocrine-resistant breast cancer. Importantly, the safety profile of abemaciclib has been consistent across trials and allows the administration of the drug over long periods of time when needed, particularly if dose-reduction strategies are employed. Together, the data summarized in this publication help inform clinical decision making regarding the role of abemaciclib in the treatment of patients with both early and metastatic HR+, HER2- breast cancer.

P1/2, N=435, Active, not recruiting, Stemline Therapeutics, Inc. | Recruiting --> Active, not recruiting

P1, N=45, Recruiting, National Cancer Institute (NCI) | Trial completion date: Jun 2026 --> Jun 2027 | Trial primary completion date: Jun 2026 --> Jun 2027

Patients were divided into three groups: Group A (n=69, palbociclib 125 mg orally, 3 weeks on/1 week off, plus fulvestrant), Group B (n=72, ribociclib 600 mg orally, 3 weeks on/1 week off, plus fulvestrant), Group C (n=99, abemaciclib 150 mg orally, twice daily, plus fulvestrant). However, neither drug exhibits comprehensive superiority across all endpoints. Therefore, clinical treatment decisions should take consideration of multiple factors based on individualized medicine protocol.

This case represents a rare report of surgical resection for breast cancer liver metastasis after CDK4/6 inhibitor-based therapy. It suggests that local treatment may be effective even in cases with suspected endocrine-resistant disease and provides practical insight into patient selection and treatment strategies, as the case fulfilled previously reported criteria for local therapy.

This study demonstrates that adjuvant abemaciclib+ET is being used at the labeled dosage in most Japanese patients. Furthermore, 2-year completion rates in patients with 2-year follow-up were comparable to the clinical trial data from monarchE (69%).

The majority of patients (72%) were treated in the first-line setting; 11 received ribociclib, 15 received palbociclib, and 3 received abemaciclib. Whether this translates into deferring disease progression requires randomized studies with larger treatment groups. To our knowledge, this study represents the first analysis evaluating 18F-FDG-PET/CT-guided SBRT in combination with CDK4/6 inhibitor-based therapy in patients with metastatic breast cancer.

P2, N=33, Active, not recruiting, Memorial Sloan Kettering Cancer Center | Trial completion date: Jul 2026 --> Jul 2027 | Trial primary completion date: Jul 2026 --> Jul 2027

Palbociclib, ribociclib, and abemaciclib, which are FDA-approved CDK4/6 inhibitors, constitute the standard first-line treatment for advanced hormone receptor-positive (HR+) breast cancers. Collectively, this study deepens the understanding of shared and drug-specific molecular characteristics and mechanisms of CDK4/6 inhibitors at multi-omic levels. Moreover, it provides an experimental basis and potential directions for customizing combination therapies based on pathway vulnerabilities, as well as exploration of novel therapeutic modes and drugs.