paclitaxel + trastuzumab + vorinostat

This is a combination regimen consisting of paclitaxel, trastuzumab, and vorinostat. Paclitaxel is a microtubule-stabilizing chemotherapeutic agent that inhibits cell division. Trastuzumab is a monoclonal antibody targeting the receptor tyrosine-protein kinase erbB-2 (HER2), used in HER2-positive breast cancer. Vorinostat is a small molecule pan-histone deacetylase (HDAC) inhibitor that modulates chromatin structure and gene expression, sensitizing tumor cells to taxanes and trastuzumab by suppressing HDAC6 and Hsp90 client proteins. This combination has been studied primarily in locally advanced or HER2-positive breast cancer, where it demonstrated increased pathologic complete response rates compared to historical controls[1][3]. The regimen leverages synergistic effects between the agents for enhanced antitumor activity.