Ibrance (palbociclib)
Pfizer · CDK4/6 Inhibitor
What is Ibrance? Ibrance (palbociclib) is a CDK4/6 inhibitor by Pfizer approved for HR-positive, HER2-negative advanced or metastatic breast cancer in combination with an aromatase inhibitor or fulvestrant. It is the first CDK4/6 inhibitor to receive FDA approval.
About Ibrance
| Brand Name | Ibrance |
| Generic / INN | palbociclib |
| Drug Class | CDK4/6 Inhibitor |
| Manufacturer | Pfizer |
| Administration | Oral capsule |
| FDA Approval | 2015 |
FDA-Approved Uses for Ibrance
Indications are based on FDA approval. Your healthcare provider determines appropriate use based on your specific diagnosis, stage, biomarker status, and overall clinical picture.
- HR+/HER2-negative advanced or metastatic breast cancer — with letrozole or anastrozole as initial endocrine therapy
- HR+/HER2-negative advanced or metastatic breast cancer — with fulvestrant after disease progression on endocrine therapy
How Does Ibrance Work?
Palbociclib inhibits CDK4 and CDK6, cyclin-dependent kinases that promote cell cycle progression from G1 to S phase in HR+ breast cancer cells. By blocking CDK4/6, palbociclib causes G1 cell cycle arrest and prevents tumor cell proliferation. It is given intermittently (21 days on / 7 days off) unlike abemaciclib (continuous dosing).
Dosage & Administration
125 mg orally once daily for 21 consecutive days followed by 7 days off (28-day cycle). Take with food. Capsules should be swallowed whole. Dose reductions to 100 mg or 75 mg for toxicity (primarily neutropenia).
Dosing is individualized by the prescribing clinician. Never adjust your dose without consulting your healthcare provider. This information is educational only and does not replace the official prescribing information.
Warnings, Precautions & Side Effects
General Warning
Neutropenia — very common and dose-limiting. Infections — related to neutropenia. ILD/pneumonitis — rare but serious. Embryo-fetal toxicity.
- Severe neutropenia — monitor CBC; dose interruption often required
- ILD/pneumonitis
- Embryo-fetal toxicity
Common Side Effects
- Neutropenia (very common)
- Infections
- Fatigue
- Nausea
- Alopecia
- Anemia
- Diarrhea
- Decreased appetite
- Thrombocytopenia
This is not a complete list. Always report new or worsening symptoms to your healthcare provider promptly.
Storage & Handling
Store at room temperature 20°C to 25°C (68°F to 77°F).
BiologicHealthPlus provides temperature-monitored cold-chain specialty delivery for medications requiring refrigeration. Never use a medication if its storage conditions have been compromised.
Insurance Coverage, Prior Authorization & Patient Assistance
🛡️ Commercial Insurance
Ibrance is covered by most major commercial insurance plans when medically necessary and prior authorized. Coverage tier and cost-sharing vary by plan.
✅ Prior Authorization
Prior authorization is required by virtually all insurance plans for Ibrance. BiologicHealthPlus handles the complete prior authorization process at no cost to patients or providers.
🏥 Medicare Coverage
Medicare Part D covers this oral specialty medication. Medicaid coverage varies by state.
🆓 Patient Assistance
Manufacturer patient assistance programs may be available for eligible uninsured or underinsured patients. Contact BiologicHealthPlus for a confidential eligibility review.
Prior Authorization Patient Assistance Insurance & Savings Medication Costs
Frequently Asked Questions — Ibrance
Ibrance (palbociclib) is the first CDK4/6 inhibitor approved by the FDA, for HR+/HER2-negative advanced or metastatic breast cancer. It is taken 21 days on and 7 days off each cycle.
Both are CDK4/6 inhibitors for HR+/HER2- breast cancer. Key differences: palbociclib uses a 21/7 intermittent schedule vs abemaciclib continuous daily dosing; abemaciclib has an approval for early breast cancer and as monotherapy; the dominant toxicity differs (neutropenia for palbociclib, diarrhea for abemaciclib).
Neutropenia is the most common serious side effect. CBC should be monitored at the start of each cycle and day 15 of the first 2 cycles.
Ibrance is covered by commercial insurance and Medicare Part D with prior authorization for HR+/HER2- advanced breast cancer.
Related Medications & Conditions
Related Medications
Verzenio (abemaciclib) · Kisqali (ribociclib) · Letrozole (Femara) · Fulvestrant (Faslodex) · Anastrozole (Arimidex)
Related Conditions
HR+/HER2- breast cancer · Advanced breast cancer · Metastatic breast cancer