Phase III study to evaluate patient's preference of subcutaneous versus intravenous trastuzumab in HER2-positive metastatic breast cancer patients: Results from the ChangHER study (GEICAM/2012-07).

Objective: We compared patients' preferences for intravenous (IV-t) versus subcutaneous (SC-t) trastuzumab administration.

Methods: Phase III, open-label, multicentre study in HER2-positive metastatic breast cancer. Patients were receiving IV-t for at least 4 months without progression. Randomisation was 1:1 to administer 2 cycles of SC-t with vial followed by 2 cycles with single injection device (SID) or the reverse sequence (600mg SC-t every 3 weeks for 4 cycles).

Primary Objective: patients' preference for IV-t versus SC-t; secondary objectives: patients' preference for vial versus SID, healthcare professional (HCP) preference and safety.

Results: We randomised 166 patients in 26 sites. Median number of previous lines of chemotherapy and/or endocrine therapy was 1 (1-7). Median duration of prior IV-t was 1.8 years (0.3-14). Of the159 patients completing the questionnaires, 86.2% preferred SC-t, 6.9% preferred IV-t, and 6.9% had no preference. Patients preferred SID (59.2%) over vial (26.3%). Most (87.2%) HCP preferred SC-t of whom 51.3% and 28.2% preferred SID and vial respectively. Related adverse events included G1-2 injection site reactions in 18 patients (10.8%), G1 pain in 8 (4.8%), G1-2 allergic reaction in 2 (1.2%), one G3 heart failure and 1 G2 ejection fraction decrease.

Conclusions: SC-t is preferred with no safety impact.