Datopotamab deruxtecan (Dato-DXd) in combination with durvalumab as first-line treatment for unresectable locally advanced or metastatic triple-negative breast cancer: results from arms 7 and 8 of the phase Ib/II BEGONIA study
Published report from the BEGONIA trial registered as NCT03742102, in Annals of Oncology (2026), chosen as the most cited paper whose own text cites the registry id.
Overview
Background: BEGONIA (NCT03742102) is a phase Ib/II, Simon's 2-stage, open-label, platform study evaluating the safety and efficacy of durvalumab, an anti-programmed death ligand-1 (PD-L1) antibody, combined with novel therapies, as first-line treatment for patients with unresectable locally advanced or metastatic triple-negative breast cancer (TNBC). Arms 7 and 8 of BEGONIA assessed the combination of datopotamab deruxtecan (Dato-DXd), a TROP2-directed antibody-drug conjugate, with durvalumab.
Patients and methods: Arm 7 included patients regardless of tumor PD-L1 expression level. Arm 8 then enrolled patients with PD-L1-high tumors, as determined by local immunohistochemistry-based testing. In Arms 7 and 8, patients received Dato-DXd 6 mg/kg intravenously plus durvalumab 1120 mg intravenously every 3 weeks. Primary endpoints were safety and tolerability, and investigator-assessed confirmed objective response rate (cORR). Secondary endpoints included cORR (Part 1), duration of response (DoR), progression-free survival (PFS) per RECIST 1.1 and overall survival (OS).
Results: Overall, 62 and 33 patients had received Dato-DXd and durvalumab in Arms 7 and 8, respectively. At data cutoff (29 November 2024), median study follow-up was 35.0 and 10.7 months in Arms 7 and 8, respectively. In Arm 7, cORR was 79.0% [95% confidence interval (CI) 66.8-88.3], median DoR was 17.6 months (95% CI 10.5-27.3), median PFS was 14.0 months (11.0-21.1) and median OS was not reached. In Arm 8, cORR was 81.8% (95% CI 64.5-93.0). The median DoR and median PFS for Arm 8 were immature given the short median follow-up (8.3 months in censored patients). The safety profile of the combination was manageable, with no new safety signals versus prior studies.
Conclusions: First-line Dato-DXd plus durvalumab demonstrated substantial and durable antitumor activity in locally advanced unresectable or metastatic TNBC, regardless of PD-L1 status.
Indexed on Europe PMC as PubMed record 42167437 (DOI 10.1016/j.annonc.2026.05.693). Its abstract cites the registry id NCT03742102, 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 NCT03742102 with the most citations, so it is the natural first reading for anyone following the BEGONIA 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.