The contribution to efficacy of individual components of the vehicle has not
been established.
Mechanism of Action
The mechanism of action of calcitriol in the treatment of psoriasis has not
been established.
Pharmacokinetics
The systemic exposure of calcitriol was assessed in subjects with chronic,
plaque psoriasis. In the pivotal pharmacokinetic/pharmacodynamic study, calcitriol
ointment 3 mcg/g, was applied twice daily for 21 days (for a total dose of 30
g/day) to 35% of the body surface area (psoriatic + surrounding healthy skin)
of subjects with at least 25% of body surface area involvement. At Day 21, the
geometric mean plasma concentration values of Cmax increased by approximately
36% over baseline and the geometric mean value of AUC(0 – 12 hr) increased
by 44%. There was no correlation between the elevated calcitriol levels and
the pharmacodynamic parameters of serum albumin adjusted calcium, serum phosphorus,
urinary calcium and urinary phosphorus.
Clinical Studies
In two, multicenter, double-blind, vehicle-controlled studies, a total of 839
subjects with psoriasis rated “mild” or “moderate” using
an investigator global assessment scale were treated twice daily for 8 weeks.
Subjects were randomized in a 1:1 ratio to receive either VECTICAL (calcitriol ointment) Ointment
or vehicle ointment. The mean age of the subjects was 48 years and 66% were
male; most subjects were rated “moderate” at baseline.
Success was defined as “Clear or Minimal”(up to light red or pink
in coloration, surface dryness with some white coloration, and slight elevation
above normal skin) with at least a 2-grade change from baseline. The success
rates are displayed in the table.
Percentage of Subjects with Clear or Minimal Disease AND
Two Grade Improvement at End of Treatment (8 weeks)
| Study 1 |
Study 2 |
VECTICAL Ointment
(N=209) |
Vehicle Ointment
(N=209) |
VECTICAL Ointment
(N=210) |
Vehicle Ointment
(N=211) |
| 23.4% |
14.4% |
20.5% |
6.6% |
Last reviewed on RxList: 3/10/2009
This monograph has been modified to include the generic and brand name in many instances.