<qa>  What is a cytotoxic agent that may have been administered sequentially?- Treatment with at least one prior cytotoxic agent which must have included at least one of the following: cisplatin, carboplatin, paclitaxel, docetaxel, or gemcitabine, administered in the perioperative or metastatic setting and may have been administered sequentially e.g., first-line treatment followed by second-line treatment at time of progression or as part of a single regimen. 