Treatment Regimen, Drug Administration, and Dose
Escalation
Palbociclib was supplied by Pfizer as 75, 100, and 125 mg capsules,
taken orally once a day for 21 days followed by a 7-day rest. One course
was equivalent to 28 days. Patients were encouraged to take palbociclib
with food at the same time each day. The pediatric equivalent dosage of
the adult MTD (125 mg daily on this same schedule)6,7was approximately 75 mg/m2. The starting dosage for
Stratum I was 50 mg/m2 with planned dose escalations
to 75 mg/m2 and 95 mg/m2. The
planned starting dosage for Stratum II was one dosage level below the
MTD for Stratum I. Dosage escalation was governed by the Rolling-6
statistical design separately in each of the two
strata.16 Therapy was allowed to continue for up to
two years (26 courses) in the absence of disease progression or
unacceptable toxicity.