What is Abemaciclib?
Abemaciclib (pronounced ab-em-a-SYE-klib), marketed as Verzenio, is a targeted therapy used to treat:
- Hormone receptor-positive (HR+), HER2-negative breast cancer
- Locally advanced or metastatic breast cancer
- Early-stage breast cancer with high recurrence risk
It is typically combined with hormone therapy (fulvestrant or an aromatase inhibitor).
How Does Abemaciclib Work?
Abemaciclib is a CDK4/6 inhibitor, meaning it blocks proteins (cyclin-dependent kinases 4 & 6) that help cancer cells grow and divide. By inhibiting these proteins, it slows or stops cancer progression.
How is Abemaciclib Taken?
Dosage & Administration
- Form: Oral tablets
- Frequency: Twice daily (morning & evening, ~12 hours apart)
- With or Without Food? Can be taken with or without food
- Duration:
- Metastatic/advanced cancer: Taken as long as effective
- Early-stage cancer: Usually up to 2 years
Important Instructions
✔ Swallow tablets whole (do not crush, chew, or split).
✔ Take the exact prescribed dose—do not skip or adjust without medical advice.
✔ Missed a dose? Skip if next dose is due soon; do not double-dose.
Common Side Effects & Management
| Side Effect | How to Manage |
|---|---|
| Diarrhea | Stay hydrated; use anti-diarrheal meds if prescribed. |
| Fatigue | Rest when needed; light exercise may help. |
| Low blood cell counts (infection risk, anemia, bruising) | Monitor for fever (≥37.5°C); report unusual bleeding. |
| Nausea | Take anti-sickness meds; eat small, frequent meals. |
| Hair thinning | Usually temporary; regrows after treatment. |
| Liver changes | Regular blood tests monitor liver function. |
Serious Side Effects (Seek Immediate Help)
⚠ Severe diarrhea (≥6 loose stools/day)
⚠ Signs of infection (fever, chills, cough)
⚠ Shortness of breath (possible lung inflammation)
⚠ Blood clots (leg swelling, chest pain, sudden breathlessness)
Precautions & Important Considerations
Before Starting Treatment
✔ Blood tests (check liver, kidney function, blood counts)
✔ Heart monitoring (if at risk for cardiovascular issues)
Drug & Food Interactions
- Avoid grapefruit/grapefruit juice (increases drug levels).
- Inform your doctor about all medications, including supplements.
Pregnancy & Fertility
- Contraception required (for women during & 3 weeks after treatment).
- Fertility effects unknown—discuss preservation options before starting.
Vaccinations
🚫 No live vaccines (MMR, BCG, yellow fever) during & 12 months post-treatment.
✅ Safe vaccines: Flu shot, COVID-19 vaccine (may be less effective).
Long-Term Monitoring
- Regular blood tests (check blood cells, liver function).
- Watch for late effects (blood clots, secondary cancers).
Where to Find More Information
- Patient Leaflet: UK eMC Website
- Side Effect Reporting: MHRA Yellow Card Scheme
Final Thoughts
Abemaciclib is an effective targeted therapy for HR+ breast cancer, but requires careful monitoring for side effects. Always follow your oncology team’s guidance for the best outcomes.
Have questions about abemaciclib? Ask your healthcare provider for personalized advice.
Disclaimer: This guide is for educational purposes only and does not replace professional medical advice.