Key clinical point: The combination of ibandronate and endocrine therapy (ET) failed to improve disease-free survival (DFS) compared with ET alone in postmenopausal women with estrogen receptor-positive (ER+) early breast cancer (BC).
Major finding: During a median follow-up of 8.5 years, DFS was not significantly different between the ibandronate+ET and ET treatment arms (hazard ratio [HR] 0.97; log-rank P = .811). Overall, the incidence of adverse events, particularly osteonecrosis ( P = .002) and dyspepsia ( P < .001), was higher in the ibandronate+ET vs. ET treatment arm.
Study details: This phase 3, TEAM-IIB trial included 1116 postmenopausal women with invasive stage I-III ER+ BC who were randomly assigned to receive ET for 5 years with or without 50 mg adjuvant oral ibandronate once daily for 3 years.
Disclosures: This study was supported by grants from Roche Nederland B.V. and Pfizer Nederland B.V. Some authors declared serving as consultants, advisors, or receiving research funding, honoraria, travel support, or accommodation expenses from several sources, including Roche and Pfizer.
Source: Vliek SB, Noordhoek I, et al. Daily oral ibandronate with adjuvant endocrine therapy in postmenopausal women with estrogen receptor–positive breast cancer (BOOG 2006-04): Randomized phase III TEAM-IIB trial. J Clin Oncol. 2022 Apr 20. doi: 10.1200/JCO.21.00311.