In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 38, No. 15_suppl ( 2020-05-20), p. 1009-1009
Abstract:
1009 Background: Biomarker analyses have been presented separately for each Phase III ML trial, which tested efficacy and safety of ribociclib (RIB) with different endocrine therapy (ET) combination partners as first- or second-line treatment for hormone receptor–positive, HER2-negative (HR+/HER2−) ABC. Here, using the largest pooled biomarker dataset of a CDK4/6 inhibitor in ABC to date, we identify potential biomarkers of response or resistance to RIB across ML trials. Methods: Baseline ctDNA from 1503 patients (pts) enrolled in ML-2, 3, and 7 was assessed using next-generation sequencing with a targeted panel of 557 genes. Genes with an alteration frequency ≥2% and in ≥15 pts per treatment arm were included (83 genes). Genetic alteration was defined as presence of a mutation, short insertion/deletion, or copy number alteration. Cox proportional hazard model of progression-free survival (PFS) was fit with gene-by-treatment interaction. Genes with interaction P 〈 0.10 and genes of interest were investigated. Results: Pts with alterations in FRS2 and PRKCA (treatment interaction P 〈 0.05) as well as MDM2, ERBB2, AKT1, and BRCA1/2 ( P 〉 0.05 but considered actionable) had a trend for increased PFS benefit of RIB vs PBO (Table). Pts with alterations in CHD4, BCL11B, ATM, or CDKN2A/2B/2C derived little to no added PFS benefit with RIB vs PBO ( P interaction 〈 0.10; hazard ratio [HR] 〉 0.80). Data on genes implicated in the literature as potential mechanisms of resistance to ET and/or CDK4/6 inhibition ( ESR1, PTEN, FAT1, RB1, and NF1) will be presented. Conclusions: Results of this pooled analysis of the ML-2, 3, and 7 trials, the largest biomarker analysis of any CDK4/6 inhibitor in ABC, revealed several potential biomarkers of response ( FRS2, MDM2, PRKCA, ERBB2, AKT1, and BRCA1/2) or resistance ( CHD4, BCL11B, ATM, or CDKN2A/2B/2C) to RIB. Clinical trial information: NCT01958021; NCT02422615; NCT02278120 . [Table: see text]
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2020.38.15_suppl.1009
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2020
detail.hit.zdb_id:
2005181-5
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