Rosacea Study Results

A Comparison of 15% Azelaic Acid Gel and 0.75% Metronidazole Gel in the
Topical Treatment of Papulopustular Rosacea: Results of a Randomized Trial
Elewski BE, Fleischer AB, Pariser DM
Archives of Dermatology. 2003;139(11):1444-1450

In this randomized clinical trial, Elewski and colleagues compared the
efficacy and tolerability of 15% azelaic acid gel (Finacea) with the
standard topical preparation of 0.75% metronidazole gel (MetroGel) for the
treatment of papulopustular (stage 2) rosacea. This multicenter US study
enrolled 251 patients with papulopustular rosacea to receive 15 weeks of
topical monotherapy (n = 127 in the metronidazole gel twice-daily group vs n
= 124 in the azelaic acid gel twice-daily group). Outcome measures included
change in inflammatory lesion count, change in erythema and telangiectasia
severity, and global-assessment scores (investigator and patient ratings).

Both treatment groups showed comparable demographics and rosacea severity. A
majority of patients were white (93%-94%) and female (66%-68%). After 15
weeks of treatment, patients in the azelaic acid group showed a greater
percentage decrease in inflammatory lesions (-72.7% vs -55.8%, respectively;
P < .001), and erythema severity (56% improved vs 42% improved,
respectively; P < .02). Both the investigator's global assessment and
overall assessment of improvement (investigator and patient) showed superior
results in the azelaic acid gel group. Not surprisingly, telangiectatic
vessels failed to improve in either group. Of interest, improvement
(erythema and lesion count variables) reached a plateau in the metronidazole
gel group after 8 weeks of treatment but continued to improve throughout the
15-week treatment period in the azelaic acid group.

Both gels were well tolerated, with no significant adverse effects reported.
Nevertheless, most patients reported some degree of local skin irritation
(ie, burning, stinging, itching, dry skin) in the azelaic acid and
metronidazole treatment groups (85% and 95%, respectively). Both gels showed
comparable "cosmetic acceptability."

Comment
This randomized, controlled comparison trial showed slightly superior
results in patients receiving 15% azelaic acid gel monotherapy vs 0.75%
metronidazole gel. Perhaps the most impressive feature of azelaic acid gel
is that it seems to yield progressive improvement for at least 15 weeks, in
contrast to metronidazole, whose efficacy appeared (in this study) to
plateau at 8 weeks. As with all rosacea therapies, the mechanism of action
of azelaic acid is unclear. This dicarboxylic acid compound is thought to
exert anti-inflammatory effects, and shows modest comedolytic and
antibacterial activity in the treatment of acne vulgaris. Since rosacea
features no comedones and has not been linked to any bacterial pathogens,
azelaic acid may improve papulopustular rosacea mainly through its
anti-inflammatory actions.

Finacea is formulated in a gel vehicle in order to optimize bioavailability
of the active agent (azelaic acid). Nevertheless, it should be kept in mind
that some individuals with rosacea may not tolerate this formulation -- a
drawback hinted at by the high rate of local skin irritation seen in the
above study with both Finacea and MetroGel. Azelaic acid is also available
in a cream vehicle (Azelex or Finevin cream), and these formulations may be
better tolerated in patients with sensitive skin.


Abstract

--