Phase 1 study to determine the feasibility of the combination of the proteasome inhibitor bortezomib (PS-341, Velcade) with trastuzumab (Herceptin) given either weekly or 3-weekly.~Additionally, hints about efficacy of the combination will be looked upon.
The main objective of this study is to determine the feasibility of the combination of the proteasome inhibitor bortezomib (PS-341, Velcade) with trastuzumab (Herceptin) and to determine the best dose of bortezomib to combine with two trastuzumab schedules, weekly and 3-weekly.