Table 1.

Efficacy of palbociclib in ER-positive, HER2-negative advanced breast cancer

Cohort 1 + Cohort 2Cohort 1Cohort 2
P+LLP+LLP+LL
N = 84N = 81N = 34N = 32N = 50N = 49
Number of events (%)41 (48.8%)59 (72.8%)15(44.1%)25 (78.1%)26 (52.0%)34 (69.4%)
Censored (%)43 (51.2%)22 (27.2%)19 (55.9%)7 (21.9%)24 (48.0%)15 (30.6%)
Median PFS (mo)20.210.226.15.718.111.1
95% CI(13.8–27.5)(5.7–12.6)(11.2–NR)(2.6–10.5)(13.1–27.5)(7.1–16.4)
HR0.4880.2990.508
95% CI(0.319–0.748)(0.156–0.572)(0.303–0.853)

Abbreviations: CI, confidence interval Kaplan–Meier estimate; L, letrozole; P, palbociclib.