Comment: The proposed indication is for those whose disease has progressed after prior endocrine therapy. This study enrolled patients who had progressed after a single line of therapy in the metastatic setting (but who may have been treated in an earlier setting), but also significant numbers who had been heavily pre-treated with 39.2% and 36.2% in the palbociclib and fulvestrant arm and placebo and fulvestrant arms respectively, having received ≥ 3 prior systemic treatments; and 75.5% and 74.1% having had ≥ 2 prior systemic therapies, respectively. 72.6% in the palbociclib and fulvestrant arm and 79.3% in the placebo and fulvestrant arm had received chemotherapy at the time of their primary diagnosis (although it is not clear whether this initial presentation was with local or metastatic disease), with 32.6% and 36.8% having had chemotherapy for metastatic disease, respectively.
This is considered representative of the target population identified in the proposed indication.
Table 14: Study A5481023 Summary of demographic and baseline characteristics by treatment (ITT population)