The most frequent grade 3 and 4 adverse events were thrombocytopenia ( 9.6 % [ TSU-68 + SOX ] vs. 26.4 % [ SOX ] ) , neutropenia ( 13.5 % [ TSU-68 + SOX ] vs. 15.1 % [ SOX ] ) , and anemia ( 3.8 % [ TSU-68 + SOX ] vs. 13.2 % [ SOX ] ) .