366P - Activity of T-DM1 in Her2-positive breast cancer brain metastases

Date 27 September 2014
Event ESMO 2014
Session Poster Display session
Topics Anti-Cancer Agents & Biologic Therapy
Biomarkers
Breast Cancer, Metastatic
Presenter Rupert Bartsch
Citation Annals of Oncology (2014) 25 (suppl_4): iv116-iv136. 10.1093/annonc/mdu329
Authors R. Bartsch1, A.S. Berghoff1, U. Vogl2, M. Rudas3, E. Bergen1, M. Gnant4, K. Dieckmann5, K. Pinker-Domenig6, L. Oehler2, C. Zielinski7, G.G. Steger8, M. Preusser7
  • 1Department Of Medicine I, Clinical Division Of Medical Oncology, Medical University of Vienna, 1090 - Vienna/AT
  • 2Department Of Medicine, St. Joseph's Hospital, Vienna/AT
  • 3Pathology, Medical University of Vienna, 1090 - Vienna/AT
  • 4Deparment Of Surgery, Medical University of Vienna, 1090 - Vienna/AT
  • 5Radiation Oncology, Medical University of Vienna, Vienna/AT
  • 6Department Of Radiology, Medical University of Vienna, 1090 - Vienna/AT
  • 7Department Of Medicine I, Medical University of Vienna, 1090 - Vienna/AT
  • 8Department Of Medicine I/oncology, Medical University of Vienna, AT-1090 - Vienna/AT

Abstract

Aim

Local treatment options such as radiotherapy or neurosurgery are the mainstay of brain metastases (BM) management. Whole brain radiotherapy (WBRT), however, is associated with severe late-toxicity. The LANDSCAPE trial established lapatinib plus capecitabine (LapCap) as primary systemic treatment in oligosymptomatic patients (pts) with multiple Her2-positive BM. Limited evidence exists regarding the activity of antibodies in BM. T-DM1 is an antibody-drug conjugate covalently linking trastuzumab (T) to an anti-microtubule agent (emtansine) with higher activity and lower toxicity as compared to LapCap. Therefore, we evaluated the activity of T-DM1 in newly diagnosed BM or BM progressing after local initial treatment.

Methods

Nine pts (median age 55 years) with Her2-positive BM treated at two Austrian centres were included. All pts had received prior treatment with T, five pts (55.6%) had already received lapatinib, and two pts (22.2%) pertuzumab as well. In two asymptomatic pts, T-DM1 was administered as primary therapy, while seven pts had documented CNS progression upon prior local treatment. T-DM1 was administered every three weeks at a dose of 3.6 mg/kg.

Results

Median follow-up was 6 months and median brain metastases-free survival 11 months. Seven pts (two with primary treatment and five receiving T-DM1 upon CNS progression) are currently assessable for CNS response. 3/7 pts (42.9%) had a partial remission, one patient progressing upon prior local therapy had stable disease lasting for fifteen cycles, and one patient had stable disease for 5 month. Two pts with prior WBRT had CNS progression after three treatment cycles.

Conclusions

This prospective case series again indicates relevant clinical activity of systemic treatment in Her2-positive BM. LapCap remains the standard of care but results of this analysis warrants further investigation of T-DM1 in BM in the context of prospective clinical studies.

Disclosure

R. Bartsch: has received lecture honoraria, research grants and travel support from Roche Austria. R. Bartsch has received lecture honoraria from GSK Austria; M. Preusser: has received lecture honoraria and research support from Roche Austria.All other authors have declared no conflicts of interest.