Palbociclib in metastatic breast cancer: current evidence and real-life data

Area of Science:

• Oncology
• Pharmacology
• Clinical Medicine

Background:

• Advanced breast cancer, particularly hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) subtypes, presents significant treatment challenges.
• Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors represent a novel therapeutic class for HR+/HER2- advanced breast cancer.

Purpose of the Study:

• To review the current evidence for palbociclib, a selective CDK4/6 inhibitor, in advanced breast cancer.
• To discuss unanswered questions regarding palbociclib's clinical practice performance.
• To summarize real-world data and clinical trial findings for palbociclib-based combinations.

Main Methods:

• Review of clinical data from controlled trials and real-life experiences.
• Analysis of palbociclib combinations in HR+/HER2- metastatic breast cancer.
• Inclusion of patient-reported outcomes and subgroup analyses.

Main Results:

• Palbociclib significantly improved progression-free survival (PFS) and clinical benefit rates with letrozole in postmenopausal women.
• Palbociclib plus fulvestrant prolonged PFS and overall survival in patients progressing on prior endocrine therapy.
• The tolerability profile was manageable, with neutropenia as the most common side effect, not impacting quality of life.

Conclusions:

• Palbociclib combined with endocrine therapy is a valuable option for HR+/HER2- advanced or metastatic breast cancer.
• Real-world data support palbociclib's efficacy in unselected, heavily pretreated populations.
• Further research is needed to address palbociclib resistance and optimize treatment sequencing for maximal patient benefit and minimal toxicity.