Drug products: IBRANCE
ATC code: L01XE33
At present, studies concerning differences in effect and safety of palbociclib between men and women are limited as the approved indication only includes women. There are studies indicating lower absolute neutrophil count in women but the clinical relevance is unclear.
Palbociclib is an oral, cyclin-dependent kinase inhibitor that prevents the deactivation of the retinoblastoma susceptibility gene protein, thereby interfering with tumor cell progression . It is used in postmenopausal women with a HR-positive, HER2-negative metastatic breast cancer [1-2].
The producer reports that sex did not affect exposure of palbociclib (50 men, 133 women) and no dose adjustment based on sex is thus recommended .
No studies with a clinically relevant sex analysis regarding effect of palbociclib have been found
Neutropenia is a dose limiting adverse effect of palbociclib . In a pooled analysis of three studies (50 men, 135 women) the baseline absolute neutrophile count was 34% higher in men .
Palbociklib should be avoided during pregnancy. Human data is lacking but animal data suggest a teratogenic risk. Therefore, both women and men using palbociclib should us effective contraception [1,2]. Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).
Date of litterature search: 2018-12-17
Reviewed by: Karin Schenck-Gustafsson
Approved by: Karin Schenck-Gustafsson