Multinational phase 3 study of oral paclitaxel plus encequidar versus intravenous paclitaxel for metastatic breast cancer

Intravenous paclitaxel (IVPac) is complicated by neuropathy and requires premedication to prevent hypersensitivity-type reactions. Oral paclitaxel (oPac) is poorly absorbed; encequidar (E), a novel P-glycoprotein pump inhibitor, allows oral absorption. A multinational phase 3 study in Latin America compared oPac + E versus IVPac for metastatic breast cancer. Confirmed response was 36% with oPac + E versus 23% with IVPac (p=0,01). There were trends for better PFS and OS with oPac + E versus IVPac. Neuropathy was less frequent and severe with oPac + E, while serious infections were increased.