Learn more about palbociclib/palbociclib: Instructions for use and precautions

1. Applicable groups and indications of palbociclib

Palbociclib , also known as palbociclib, is used to treat patients with certain types of breast cancer. Specifically, it is suitable for adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer (BC). Treatment options are often combined with the following medications:

In combination with an aromatase inhibitor, as a first-of-its-kind endocrine-based treatment;

Or combined with fulvestrant (Fulvestrant) for patients whose disease has progressed after endocrine therapy.

2. Possible side effects of palbociclib

Taking palbociclib may cause a series of side effects, the most common of which include neutropenia, infection, leukopenia, fatigue, nausea, oral mucosal inflammation, anemia, diarrhea, and thrombocytopenia. In addition, adverse events such as interstitial lung disease (ILD)/non-infectious pneumonia and palmar-plantar dysesthesia syndrome (PPES) have been reported post-marketing.

3. How to take palbociclib

1) Recommended dose: It is recommended to take 125 mg of palbociclib capsule orally once a day for 21 consecutive days, followed by a 7-day break, forming a complete 28-day treatment cycle. Should be taken with food. If the patient vomits or misses a dose, there is no need to take a missed dose. The next dose should be taken at your regular time. Capsules should be swallowed whole and should not be chewed, crushed or opened.

2) Combined use: When used in combination with fulvestrant, the recommended dose of fulvestrant is 500 mg, administered on the 1st, 15th, and 29th day of treatment, and then once a month. Dosing of aromatase inhibitors should follow their respective instruction guidelines.

3) Medication in Specific Populations: Premenopausal/perimenopausal women and male patients receiving palbociclib in combination with an aromatase inhibitor or fulvestrant should consider using a luteinizing hormone-releasing hormone (LHRH) agonist in accordance with current clinical practice standards.

4. Storage conditions of palbociclib

Palbociclib should be stored20°C to 25°C (68°F to 77°F), with fluctuations allowed between 15°C and 30°C (59°F to 86°F).

5. The mechanism of action of palbociclib

Palbociclib is an inhibitor of cyclin-dependent kinase (CDK) 4 and 6. It reduces the proliferation of estrogen receptor (ER)-positive breast cancer cells by blocking cells from entering the S phase from G1 phase. It is more effective at inhibiting cancer cell growth when used in combination with anti-estrogen drugs.

6. Risk of overdose of palbociclib

The reported oral LD50 is100 mg/kg. Overdose may cause clastogenic activity and harm to the fetus. At high doses, it may also increase the incidence of microglial tumors of the central nervous system. General supportive measures should be taken after overdose.