Resumen de Safety and efficacy of trastuzumab emtansine in patients with advanced her2-positive breast cancer

Beatriz Sánchez Sanz, Susana Cortijo Cascajares, M. P. Goyache-Goñi, Iván González Barrios, José Miguel Ferrari Piquero

• Objective. Trastuzumab-emtamsine (TDM-1) is a therapeutic option for patients with HER+ Overexpression and locally unresectable or metastatic breast cancer following therapy with taxane/trastuzumab or less than six months of adjuvant therapy. The aim of this study was to assess its efficacy and safety in an unselected representative population.

  Method. A single-center, retrospective observational study including patients who had received two or more cycles of TDM-1 between February 2014 and February 2020. Hematologic, hepatic and cardiac adverse events (AEs), progres- sion-free survival (PFS) and overall survival (OS) were assessed.

  Results. Of the 37 assessed patients with a median age of 61 years (42-91) (32.4% with age >65 years), 33 patients (86.5%) had some AE. In 26 patients (78.8%) they were mild (grade 1-2) and in seven (18.9%), five of them over 65 years, severe (grade ≥3) the most recurrent were thrombocytopenia (37.8%), as- thenia (43.2%) and anemia (24.3%). Bleeding was reported in 57.1% of the pa- tients with thrombocytopenia. Six patients (16.2%) had mild hepatic toxicity and in no case a decline in LVEF more than 50%. The median PFS obtained was eight months (CI95: 5.32-10.69) and the median OS was 20 months (CI95: 17.58-22.41).

  Conclusion. The toxicity observed in our study was consistent with that of reference trials, featuring a higher number of interruptions in our population. Thrombocytopenia was the most recurrent and severe AE. No major toxicity was described in older patients. Survival of our patients was lower than that reported in clinical trials