Abemaciclib
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Abemaciclib: From Breast Cancer to Rheumatoid Arthritis
One-Sentence Summary
Abemaciclib is an oral CDK4/6 inhibitor marketed in Singapore as an anticancer drug. The Singapore licence records compiled for this report do not state an approved indication, but the published literature consistently describes its use in HR+/HER2- breast cancer. The TxGNN model predicts it may be effective for rheumatoid arthritis, but there are 0 clinical trials and only 2 publications (one observational, one preclinical), so evidence is limited to a research-question level.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not stated in the Singapore licence records (literature describes HR+/HER2- breast cancer) |
| Predicted New Indication | Rheumatoid arthritis |
| TxGNN Prediction Score | 97.32% |
| Evidence Level | L4 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 6 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available in the data compiled for this report. Based on known information, abemaciclib is a CDK4/6 inhibitor that blocks cell-cycle progression. Its efficacy in HR+/HER2- breast cancer is established in the literature.
Rheumatoid arthritis is driven partly by overproliferation and defective apoptosis of fibroblast-like synoviocytes (FLSs). Inhibiting CDK4/6 could plausibly reduce this proliferation and modulate immune cell activity. A preclinical nanoplatform study loaded with abemaciclib reported inducing cell-cycle arrest and apoptosis in FLSs.
However, the direction of effect in humans is unclear. An observational study in breast cancer patients on CDK4/6 inhibitors looked at pre-existing and newly emerging immune-mediated diseases. These may include both new onset and flares, so it cannot show that the drug treats autoimmune disease. CDK4/6 inhibitors may also trigger autoimmune reactions.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 40504547 | 2025 | Cohort | The Oncologist | Studied the prevalence of autoimmune diseases in HR+/HER2- breast cancer patients on CDK4/6 inhibitors plus endocrine therapy; CDK4/6 inhibitors may enhance antitumour immunity but also trigger autoimmune reactions |
| 42289719 | 2026 | Preclinical | Journal of Nanobiotechnology | A pH-responsive abemaciclib-loaded nanoplatform (Mn/Si-Abe@BSA) induced cell-cycle arrest and apoptosis in fibroblast-like synoviocytes for RA |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN15788P | Verzenio 50 mg | Film-coated tablet | Not stated in the records |
| SIN15789P | Verzenio 100 mg | Film-coated tablet | Not stated in the records |
| SIN15790P | Verzenio 150 mg | Film-coated tablet | Not stated in the records |
| SIN16574P | Yulareb 50 mg | Film-coated tablet | Not stated in the records |
| SIN16575P | Yulareb 100 mg | Film-coated tablet | Not stated in the records |
A sixth licence, SIN16576P (Yulareb 150 mg film-coated tablet), is also valid. All six are single-ingredient products.
Cytotoxicity
| Item | Content |
|---|---|
| Cytotoxicity Classification | Targeted therapy (CDK4/6 kinase inhibitor), not a conventional cytotoxic |
| Myelosuppression Risk | Please refer to the package insert warnings and precautions |
| Emetogenicity Classification | Please refer to the package insert warnings and precautions |
| Monitoring Items | Please refer to the package insert; blood counts and liver function are typically monitored for this class |
| Handling Protection | Please refer to the package insert warnings and precautions |
Safety Considerations
- Drug Interactions: 100 interactions were identified in total. Examples at Major level include clarithromycin, cobicistat, deferiprone, samarium (153Sm) lexidronam and lumacaftor. Examples at Moderate level include aprepitant, dexamethasone, metformin, fluconazole, erythromycin, ticagrelor and roflumilast.
- Class-related cardiovascular signals (from literature compiled for another predicted indication): QTc prolongation, atrial arrhythmia, and thromboembolic events, including a case of coronary plaque erosion after abemaciclib onset. Kidney injury reports have also appeared in pharmacovigilance data.
Please refer to the package insert for warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: The high TxGNN score is supported only by one observational report with an unclear direction of effect and one preclinical nanoplatform study. No clinical trials exist, and the evidence level is L4. Autoimmune reactions are also a possible concern with this drug class. This is best treated as a research question rather than a candidate for clinical development.
To proceed, the following is needed:
- Mechanism of action data (MOA) and a clearer mechanistic link to RA
- Package insert warnings and contraindications from the HSA
- In vivo efficacy data in RA animal models, using abemaciclib itself rather than a nanoplatform formulation
- Analysis of whether CDK4/6 inhibitor exposure triggers or worsens autoimmune disease
- A safety plan covering cardiovascular risk, drug interactions, and long-term tolerability in a non-oncology population
Other predicted indications (not evaluated in detail): The data also include amyotrophic lateral sclerosis, which has preclinical evidence that abemaciclib reduces TDP-43 accumulation and is a "Research Question" at L4. Heart disease is not supported, since the literature describes cardiotoxicity rather than benefit. Hyperthyroidism, multiple endocrine neoplasia, and several rare syndromes have little or no supporting evidence and are rated Hold.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.