Real-world second- and third-line progression-free survival after progression on first-line CDK4/6 inhibitors in HR+/HER2- metastatic breast cancer by PAM50 intrinsic subtype: the SOLTI-1801 CDK-PREDI
5 hours ago
- #metastatic breast cancer
- #PAM50 intrinsic subtypes
- #CDK4/6 inhibitors
- Study evaluates real-world progression-free survival (rwPFS) in HR+/HER2- metastatic breast cancer (MBC) after first-line CDK4/6 inhibitors (CDK4/6i) plus endocrine therapy (ET).
- PAM50 intrinsic subtypes (IS) were analyzed to assess their prognostic role, with Luminal A/B being most common and Basal-like (BL) showing the poorest outcomes.
- Median rwPFS-2L was 7.2 months for luminal IS vs. 6.1 months for non-luminal, with BL subtype having significantly shorter rwPFS-2L (HR 3.82).
- High CCNE1 expression was associated with shorter rwPFS-2L (HR 1.22).
- Targeted agents were frequently used in second-line (51%), while capecitabine was common in third-line (36%). Endocrine monotherapy yielded the poorest rwPFS.
- The study supports the role of PAM50 IS in guiding post-progression treatment decisions.