Safety and Efficacy Study of Vintafolide and Vintafolide Plus Paclitaxel Compared to Paclitaxel Alone in Participants With Triple Negative Breast Cancer (TNBC) (MK-8109-004)

The purpose of this study is to assess the efficacy and safety of vintafolide alone compared to vintafolide plus paclitaxel and paclitaxel alone in participants with with 100% positive folate receptor (FR) triple negative breast cancer (TNBC). The primary hypothesis of this study is the vintafolide alone and/or vintafolide + paclitaxel will improve progression free survival (PFS) in participants with FR (100%) TNBC compared to paclitaxel alone.