Final outcome analysis from the phase II TUXEDO-1 trial of trastuzumab-deruxtecan in HER2-positive breast cancer patients with active brain metastases
Rupert Bartsch, Anna S. Berghoff, Julia Furtner, Maximilian Marhold, Elisabeth Bergen, Sophie Roider‐Schur, Maximilian J. Mair, Angelika M. Starzer, Heidrun Forstner, Beate Rottenmanner, Marie‐Bernadette Aretin, Karin Dieckmann, Zsuzsanna Bagó-Horváth, Helmuth Haslacher, Georg Widhalm, Aysegül Ilhan‐Mutlu, Christoph Minichsdorfer, Thorsten Fuereder, Thomas Szekeres, Leopold Oehler, Birgit Gruenberger, Georg Pfeiler, Christian F. Singer, Ansgar Weltermann, Luzia Berchtold, Matthias Preusser
Abstract
BACKGROUND: Brain metastases (BM) are a devastating complication of HER2-positive metastatic breast cancer (BC) and treatment strategies providing optimized local and systemic disease control are urgently required. The antibody-drug conjugate trastuzumab deruxtecan (T-DXd) improved progression-free survival (PFS) and overall survival (OS) over trastuzumab emtansine but data regarding intracranial activity is limited. In the primary outcome analysis of TUXEDO-1, a high intracranial response rate (RR) was reported with T-DXd. Here, we report the final PFS and OS results. PATIENTS AND METHODS: TUXEDO-1 accrued adult patients with HER2-positive BC and active BM (newly diagnosed or progressing) without indication for immediate local therapy. The primary endpoint was intracranial RR; secondary endpoints included PFS, OS, safety, quality-of-life (QoL), and neurocognitive function. PFS and OS were estimated with the Kaplan-Meier method and analyzed in the per-protocol population. RESULTS: At 26.5 months median follow-up, median PFS was 21 months (95% CI: 13.3-n.r.) and median OS was not reached (95% CI: 22.2-n.r.). With longer follow-ups, no new safety signals were observed. The most common grade 3 adverse event was fatigue (20%). Grade 2 interstitial lung disease and a grade 3 symptomatic drop of left-ventricular ejection fraction were observed in one patient each. QoL was maintained over the treatment period. CONCLUSIONS: T-DXd yielded prolonged intra- and extracranial disease control in patients with active HER2-positive BC BM in line with results from the pivotal trials. These results support the concept of antibody-drug-conjugates as systemic therapy for active BM.