1. Comparative biomarker analysis of PALOMA-2/3 trials for palbociclib
- Author
-
Zhu, Z, Turner, NC, Loi, S, Andre, F, Martin, M, Dieras, V, Gelmon, KA, Harbeck, N, Zhang, C, Cao, JQ, Yan, Z, Lu, DR, Wei, P, VanArsdale, TL, Rejto, PA, Huang, X, Rugo, HS, Loibl, S, Cristofanilli, M, Finn, RS, Liu, Y, Zhu, Z, Turner, NC, Loi, S, Andre, F, Martin, M, Dieras, V, Gelmon, KA, Harbeck, N, Zhang, C, Cao, JQ, Yan, Z, Lu, DR, Wei, P, VanArsdale, TL, Rejto, PA, Huang, X, Rugo, HS, Loibl, S, Cristofanilli, M, Finn, RS, and Liu, Y
- Abstract
While cyclin-dependent kinase 4/6 (CDK4/6) inhibitors, including palbociclib, combined with endocrine therapy (ET), are becoming the standard-of-care for hormone receptor-positive/human epidermal growth factor receptor 2‒negative metastatic breast cancer, further mechanistic insights are needed to maximize benefit from the treatment regimen. Herein, we conducted a systematic comparative analysis of gene expression/progression-free survival relationship from two phase 3 trials (PALOMA-2 [first-line] and PALOMA-3 [≥second-line]). In the ET-only arm, there was no inter-therapy line correlation. However, adding palbociclib resulted in concordant biomarkers independent of initial ET responsiveness, with shared sensitivity genes enriched in estrogen response and resistance genes over-represented by mTORC1 signaling and G2/M checkpoint. Biomarker patterns from the combination arm resembled patterns observed in ET in advanced treatment-naive patients, especially patients likely to be endocrine-responsive. Our findings suggest palbociclib may recondition endocrine-resistant tumors to ET, and may guide optimal therapeutic sequencing by partnering CDK4/6 inhibitors with different ETs. Pfizer (NCT01740427; NCT01942135).
- Published
- 2022