Exposure-toxicity associations
Associations were explored between palbociclib Cmax and
AUC0-Tlast after single and repeated doses and
hematologic toxicities occurring during course 1 that were at least
possibly attributable to the drug. Toxicities included neutropenia,
thrombocytopenia, lymphopenia, and leukopenia. Patients were classified
into three categories (0/1/2) based on their highest toxicity grade
reported for course 1 for each toxicity: 0 = no toxicity reported, 1 =
grade 1 or 2, and 2 = grade 3 or 4. Ordinal logistic regression models
were built for each hematological toxicity outcome, and explanatory
pharmacokinetic variables were transformed by dividing by 100.
Statistical significance was defined by a p-value P <
0.05.