The primary objective of this study was to demonstrate pharmacokinetic similarity of Mylan trastuzumab (Hercules) versus EU-approved Herceptin® and US-licensed Herceptin® and pharmacokinetic similarity of EU-approved Herceptin® versus US-licensed Herceptin® after 8 mg/kg as single dose administered as intravenous infusion over 90 minutes in healthy male subjects based on the equivalence criterion that AUC0-∞, AUC0-last, and Cmax least square mean ratios are bounded within the 90% confidence intervals, 80.00% - 125.00%. Three similarity assessments were performed, 1) Hercules vs. EU-approved Herceptin®, 2) Hercules vs. US-licensed Herceptin® and 3) EU-approved Herceptin® vs. US-licensed Herceptin®. Secondary objectives included further pharmacokinetic assessment of similarity of Hercules, EU-approved Herceptin® and US-licensed Herceptin® λz, tmax and t1/2 along with assessment of safety (including immunogenicity) and local tolerance.