329PComparative effectiveness of palbociclib plus letrozole vs letrozole for metastatic breast cancer in US real-world clinical practices

ConclusionsThe first comparative analysis of a CDK4/6 inhibitor in combination with endocrine therapy compared to endocrine therapy alone provides real-world evidence confirming the findings of PFS benefit demonstrated in clinical trial data for palbociclib in diverse clinical practices. Table:329P Patient characteristics and real-world progressionfree survival (rwPFS)VariablePB+LE (N  = 453)LE alone (N = 453) Median age (years)68.068.0 White (%)69.870.6 Median number of metastatic sites (n)2.02.0 Bone only disease (%)26.932.2 Visceral disease (%)49.749.7 Median rwPFS, months (95%CI)24.5 (20.7—32.7)17.1 (13.7—19.8) rwPFS rate at 6 months (%)82.874.5 rw PFS rate at 12 months (%)72.158.9 rwPFS rate at 18 months (%)60.148.4 rwPFS rate at 24 months (%)50.239.1 Median follow-up, months (IQR)16.8(8.1—27.1)16.8(6.9—26.9)PB+LE = Palbociclib plus letrozole; LE = Letrozole alone; IQR = Interquartile RangeLegal entity responsible for the studyPfizer Inc.FundingPfizer Inc.DisclosureR.M. Layman: Research grant / Funding (institution): Pfizer Inc. X. Liu: Shareholder / Stockholder / Stock options, Full / Part-time employment: Pfizer Inc. J. Mardekian: Shareholder / Stockholder / Stock options, Full / Part-time employment: Pfizer Inc. L. McRoy: Shareholder / Stockholder / Stock options, Full / Part-time employment: Pfizer Inc.
Source: Annals of Oncology - Category: Cancer & Oncology Source Type: research