Figure 1.

Palbociclib/placebo dose modification schema for managing treatment-related toxicities. ^aIf patients still have not returned to grade 2 on day 1 of next cycle. ^bReduce by 2 dose levels. ^cIf uncomplicated grade 3 neutropenia recurs in 2 consecutive cycles, after recovery as per retreatment criteria (ANC≥1,000/mm³ and no fever), treatment may restart at the next lower dose level at investigator’s discretion. ^dIf no further dose reduction is possible (i.e., patient is already receiving 75 mg per day according to schedule 3/1), consider changing the schedule to 75 mg per day, 2 weeks on/2 weeks off, or discontinue palbociclib/placebo and continue with fulvestrant alone.

Abbreviation: ANC, absolute neutrophil count.