An evaluation of palbociclib as a breast cancer treatment option: a current update

Introduction Patients with hormone receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancer have benefitted from treatment with palbociclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor capable of selectively targeting mechanisms of cell cycle progression that contribute to tumor cell proliferation. Palbociclib use in this setting demonstrates improved progression-free survival when given in combination with aromatase inhibitors or fulvestrant. Areas covered The authors describe the current state of research surrounding palbociclib use in breast cancer, present evidence supporting a role for palbociclib in additional subtypes of metastatic breast cancer such as HER2-positive (HER2+) and triple-negative, report ongoing clinical trials aimed at expanding the scope of use for palbociclib, and discuss expected clinical results that will better inform decisions on including palbociclib as a part of breast cancer treatment strategies. Expert opinion Preclinical and clinical studies have shown promising evidence for palbociclib use in metastatic HER2+ and androgen receptor-expressing triple-negative breast cancer but mixed results in the adjuvant/neoadjuvant setting, where differences may only be detectable in high-risk disease. Palbociclib combinations may constitute viable replacements for chemotherapy in the neoadjuvant setting as part of de-escalation strategies. Investigation into synergy of palbociclib with immunotherapies is also ongoing based on non-canonical effects of CDK4/6 inhibition on the tumor immune microenvironment.

Automated summary

Palbociclib shows promise in metastatic HER2+ and androgen receptor-expressing triple-negative breast cancer, with potential as an alternative to chemotherapy in the neoadjuvant setting. Ongoing research also explores the synergy of palbociclib with immunotherapies based on its effects on the tumor immune microenvironment.