efficacious than vehicle gel based on the 1-grade improvement
on CEA and PSA on days 1 and 15, in addition to day 29 (all
P<.001). Therefore, no tachyphylaxis or loss of efficacy was observed
during the 4-week treatment period of either study.
Photos of two representative subjects prior to application of BT
gel 0.5%, and at various time points after the application are illustrated
in Figures 5 and 6. A 2-grade improvement on both
CEA and PSA was achieved at 30 minutes, 3 hours, and 6 hours
after drug application in one subject (Figure 5), and at 3 hours,
6 hours, and 9 hours after drug application in the other subject
(Figure 6). Marked and clinically meaningful improvement (eg
1-grade improvement on both CEA and PSA) compared to baseline
was observed at the 9 hour and 12 hour time points in Figure
5 and at the 30 minute and 12 hour time points in Figure 6.
Rebound was defined as worsening of erythema compared
to baseline after treatment cessation. There was no clinically
meaningful aggravation of facial erythema observed during
the follow-up phase, in comparison to the baseline assessments.
In both studies, the mean scores of CEA and PSA
during the visits of follow-up phase were similar to or lower
than the mean scores of CEA and PSA during the visits of
treatment phase prior to drug application. Few subjects in the
group of BT 0.5% showed worsening in scores in the followup
phase relative to baseline: In study A, 4.0% for CEA and
2.4% for PSA at week 6, and 4.7% for CEA and 1.6% for PSA at
week 8; In study B, 3.6% for CEA and 4.3% for PSA at week 6,
and 2.1% each for CEA and PSA at week 8. Furthermore, similar
incidence of worsening was observed in the vehicle group
in both studies.
