Like other topical corticosteroids, clobetasol propionate foam has anti-inflammatory,
antipruritic, and vasoconstrictive properties. The precise mechanism of the
anti-inflammatory activity of topical steroids in the treatment of steroid-responsive
dermatoses, in general, is uncertain. However, corticosteroids are thought to
act by the induction of phospholipase A2 inhibitory proteins, collectively called
lipocortins. It is postulated that these proteins control the biosynthesis of
potent mediators of inflammation such as prostaglandins and leukotrienes by
inhibiting the release of their common precursor arachidonic acid. Arachidonic
acid is released from membrane phospholipids by phospholipase A2.
Pharmacokinetics
Topical corticosteroids can be absorbed from intact healthy skin. The extent
of percutaneous absorption of topical corticosteroids is determined by many
factors, including the vehicle and the integrity of the epidermal barrier. Occlusion,
inflammation and/or other disease processes in the skin may also increase percutaneous
absorption.
Once absorbed through the skin, topical corticosteroids are handled through
pharmacokinetic pathways similar to systemically administered corticosteroids.
Due to the fact that circulating levels are well below the level of detection,
the use of pharmacodynamic endpoints for assessing the systemic exposure of
topical corticosteroids is necessary. They are metabolized, primarily in the
liver, and are then excreted by the kidneys. In addition, some corticosteroids
and their metabolites are also excreted in the bile.
Clinical Studies
A well-controlled clinical study evaluated 188 subjects with moderate to severe
scalp psoriasis. Subjects were treated twice daily for 2 weeks with one of four
treatments: OLUX Foam, Vehicle foam, a commercially available clobetasol propionate
solution (Temovate® Scalp Application), or Vehicle solution. The efficacy
of OLUX (clobetasol propionate) Foam in treating scalp psoriasis at the end of the 2 weeks' treatment
was superior to that of Vehicle (foam and solution), and was comparable to that
of Temovate Scalp Application. See Table 1 below.
Table 1: Efficacy results from a controlled clinical trial
in scalp psoriasis
| |
OLUX Foam
n (%) |
Vehicle Foam
n (%) |
| Total number of subjects |
62 |
31 |
| Subjects with Treatment Success* |
39 (63) |
1 (3) |
| Subjects with Parameter Clear at End point (Scalp Psoriasis) |
| Scaling-Clear at End point |
42 (68) |
3 (10) |
| Erythema-Clear at End point |
27 (44) |
2 (6) |
| Plaque Thickness-Clear at End point |
41 (66) |
3 (10) |
| *Defined as a composite of an Investigator's
Global Assessment of “completely clear” or “almost clear,”
a plaque thickness score of 0, an erythema score of 0 or 1, and a scaling
score of 0 or 1 at Endpoint, scored on a severity scale of 0-4. |
Another well-controlled clinical study evaluated 279 subjects with mild to
moderate plaque-type psoriasis (mean Body Surface Area at baseline was 6.7%
with a range from 1% to 20%) of non-scalp regions. Subjects were treated twice
daily for 2 weeks with OLUX (clobetasol propionate) Foam or Vehicle foam. The face and intertriginous
areas were excluded from treatment. The efficacy of OLUX (clobetasol propionate) Foam in treating non-scalp
psoriasis at the end of 2 weeks' treatment was superior to that of Vehicle foam.
See Table 2 below.
Table 2: Efficacy results from a controlled clinical trial
in non-scalp psoriasis Plaque Thickness - Clear at Endpoint 41 (66) 3 (10)
| |
OLUX Foam
n (%) |
Vehicle Foam
n (%) |
| Total number of subjects |
139 |
140 |
| Subjects with Treatment Success* |
39 (28) |
4 (3) |
| Physician's Static Global Assessment-Clear or |
94 (68) |
30 (21) |
| Almost Clear at Endpoint |
|
|
| Scaling-Clear or Almost Clear at Endpoint |
101 (73) |
42 (30) |
| Erythema-Clear or Almost Clear at Endpoint |
88 (63) |
35 (25) |
| Plaque Thickness-Clear at Endpoint |
44 (32) |
5 (4) |
| *Defined as a composite of a Physician's
Static Global Assessment score of 0 or 1, scaling score of 0 or 1, an
erythema score of 0 or 1 and a plaque thickness score of 0, based on a
severity scale of 0-5 at Endpoint. |
Last reviewed on RxList: 5/23/2008
This monograph has been modified to include the generic and brand name in many instances.