From the Guidelines
Palbociclib should be administered once per day for 21 days every 28 days. This medication is typically taken orally as a capsule or tablet, and the recommended starting dose is 125 mg once daily for 21 consecutive days followed by 7 days off treatment (28-day cycle) 1. It is essential to take palbociclib with food to improve absorption and reduce gastrointestinal side effects. Patients should swallow the capsules or tablets whole and not crush, chew, or open them.
Key Administration Considerations
- Dose adjustments may be necessary based on individual tolerability and side effects, particularly neutropenia, which is commonly monitored through regular blood tests 1.
- Treatment continues until disease progression or unacceptable toxicity occurs.
- Palbociclib works by inhibiting cyclin-dependent kinases 4 and 6, which prevents cell cycle progression from G1 to S phase, thereby blocking cancer cell proliferation.
- This mechanism is particularly effective in hormone receptor-positive, HER2-negative breast cancer when combined with endocrine therapy 1.
Monitoring and Safety
- Blood counts should be monitored every 14 days for the first two 28-day cycles, then at the start of each subsequent cycle, with neutropenia managed by dose delays and reductions 1.
- Patients should be advised to take the medication at approximately the same time each day and to inform their healthcare provider about all other medications they are taking to avoid potential drug interactions.
- The safety profile of palbociclib, including the incidence of hematologic toxicities, has been consistently reported across studies, with no new safety signals observed with extended follow-up 1.
From the FDA Drug Label
The dose of IBRANCE
The information provided in the drug label does not directly answer the question of how palbociclib is administered. The FDA drug label does not answer the question.
From the Research
Administration of Palbociclib
- Palbociclib is administered orally 2, 3, 4
- The typical dosing schedule is 125 mg daily for 3 weeks, followed by 1 week off, in 28-day cycles 3, 4
- It is usually given in combination with an aromatase inhibitor, such as letrozole, or with fulvestrant, as initial endocrine-based therapy or in patients previously treated with endocrine therapy 2, 3, 4
Key Considerations
- Palbociclib is a highly selective inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6) 2, 3, 4
- The most commonly reported adverse event is neutropenia, which can be managed with dose delay, interruption, or reduction 2, 3
- Palbociclib has been shown to significantly prolong progression-free survival (PFS) in patients with HR-positive, HER2-negative advanced or metastatic breast cancer 2, 3, 5, 6, 4