The percentage of subjects achieving a 1-grade improvement in both CEA and PSA was significantly increased at 30 minutes post-dosing with BT 0.5 % gel compared to vehicle gel on visit days ( day 1 : 27.9 vs 6.9 % , P < 0.001 ; day 15 : 55.9 vs 21.1 % , P < 0.001 ; Day 29 : 58.3 vs 32.0 % , P < 0.001 for BT 0.5 % gel vs vehicle ) in study A. Similar results were shown for study B.