Trastuzumab Botidotin Versus Trastuzumab Emtansine in Human Epidermal Growth Factor Receptor 2-Positive Advanced Breast Cancer: A Phase III, Open-Label, Randomized Controlled Trial
Published report from the trial registered as NCT06968585, in Journal of Clinical Oncology (2026), chosen as the most cited paper whose own text cites the registry id.
Overview
Purpose: To evaluate the safety and efficacy of the novel human epidermal growth factor receptor 2 (HER2)-directed antibody-drug conjugate, trastuzumab botidotin, for the treatment of HER2-positive unresectable/metastatic breast cancer (BC).
Methods: In this phase III, open-label, multicenter trial (ClinicalTrials.gov identifier: NCT06968585), conducted at 57 centers in China, adult patients with HER2-positive, unresectable/metastatic BC who had received prior trastuzumab and a taxane were randomly assigned (1:1) to receive trastuzumab botidotin or trastuzumab emtansine. The primary end point was progression-free survival (PFS), assessed by blinded independent central review (BICR), using an intention-to-treat analysis. In a prespecified interim analysis of PFS per BICR, trastuzumab botidotin met the prespecified superiority boundary ( P <.0001). We report here the prespecified final analysis of PFS.
Results: Between July 18, 2023, and April 26, 2024, 365 patients were randomly assigned to trastuzumab botidotin (n = 182) or trastuzumab emtansine (n = 183). At data cutoff (median follow-up, 14.9 months), trastuzumab botidotin resulted in longer PFS than trastuzumab emtansine (median, 11.1 v 4.4 months; hazard ratio [HR], 0.39 [95% CI, 0.30 to 0.51]; nominal P <.0001). Benefit was consistent across subgroups, including those defined by prior lines of anti-HER2 therapy, prior pertuzumab or anti-HER2 tyrosine kinase inhibitors, and visceral metastases. The objective response rate was 76.9% (95% CI, 70.1 to 82.8) with trastuzumab botidotin and 53.0% (95% CI, 45.5 to 60.4) with trastuzumab emtansine. Overall survival data were immature (medians not reached in either group; HR, 0.62 [95% CI, 0.38 to 1.03]). Grade ≥3 treatment-emergent adverse events occurred in 127 (69.8%) and 116 (63.7%) patients in each group, respectively. Ocular treatment-related adverse events had a high incidence with trastuzumab botidotin; however, with a protocol-defined algorithm, most events generally recovered or resolved. Trastuzumab botidotin treatment had low incidences of pulmonary, hematologic, hepatic, and GI toxicities.
Conclusion: Among patients with HER2-positive advanced BC previously treated with trastuzumab and a taxane, trastuzumab botidotin resulted in significantly longer PFS than trastuzumab emtansine, with a distinct safety profile.
Indexed on Europe PMC as PubMed record 42727044 (DOI 10.1200/jco-26-00602). Its abstract cites the registry id NCT06968585, which is how it was matched to this trial; no figure has been checked by an editor.
This is the paper Europe PMC returns for registry id NCT06968585 with the most citations, so it is the natural first reading for anyone following the trial. Read the abstract above alongside the trial page and the registry entry; the record was linked automatically and its figures have not been checked by hand.
- Matched to the trial by the registry id cited in the Europe PMC record; the summary reproduces the record's abstract and no figure has been verified against the full paper.