Baseline (BL) characteristics and efficacy endpoints for patients (pts) with node-negative (N0) HR+/HER2− early breast cancer (EBC): NATALEE trial.

• DOI: 10.1200/jco.2024.42.16_suppl.512
• Publication Date: 2024-05-29T16:01:20Z
• Authors: Denise A. Yardley; Michael Untch; Carlos H. Barrios; Aditya Bardia; Kevin Kalinsky; Seock-Ah Im; Stephen K. L. Chia; Alistair E. Ring; Nicholas Patrick ...; Vicente Valero; Manuel Ruiz-Borrego; Rodrigo Fresco; Eleanor Sum; Yogesh Chattar; Sorcha Waters; Nadia Harbeck
• Keywords: 03 medical and health sciences; 0302 clinical medicine

512 Background: NATALEE assessed ribociclib (RIB) + non-steroidal aromatase inhibitor (NSAI) vs NSAI alone in pts with HR+/HER2− EBC at increased risk of recurrence, including N0 disease, and showed a statistically significant invasive disease-free survival (iDFS) benefit. We report BL characteristics, efficacy, safety for the subgroup. Methods: Pts stage II/III were randomized (R) 1:1 to RIB 400 mg/d (3 wk on/1 off 36 mo) (letrozole or anastrozole ≥60 alone. Men premenopausal women received goserelin. could receive any standard (neo)adjuvant endocrine therapy (ET) ≤12 mo before randomization. In intent-to-treat (ITT) population, 78% completed 3y treatment (tx) discontinued early 21% still on tx time this analysis (data cutoff: July 21, 2023; median follow up, 33 mo). The subgroup included T2N0 (stage IIA; grade [G]3, G2 disease Ki-67 ≥20% high genomic [HGR]), T3N0 IIB), T4N0 IIIB); T1N0 was excluded. Results: Of 2549 R 2552 alone, 285 (11%) 328 (13%) had respectively. characteristics balanced across arms. Most (RIB NSAI: 67% alone: 63%). anatomic IIA 74% 73%), IIB (17% 13%), IIIB (9% 12%) (Table). prior chemotherapy 72% 71%); ET by 59% 62% For treated 49% 45% G3 53% (54% 56% T2N0, & > 20%; 13% 23% G2, ≤20%/missing HGR). Consistent ITT improved iDFS (HR, 0.72; 95% CI, 0.41-1.27; rate 93.2% 90.6%), distant disease–free (DDFS; HR, 0.70; 0.38-1.29; rate, 94.3% 91.5%), recurrence–free (DRFS; 0.58; 0.29-1.17; 96.3% 92.5%) high-risk disease. profile consistent population. discontinuation due all adverse events 24% 8% Conclusions: This efficacy benefit manageable NATALEE. iDFS, DDFS, DRFS rates control arm follow-up underscore recurrence These findings support use Clinical trial information: NCT03701334 . [Table: see text]