Aldarazalf - Imiquimod is veilig en hoog significant effectief voor AK - Actinic Keratosis, een beginnende vorm van niet melanome huidkanker, aldus twee grote placebo gecontroleerde fase III studies.

21 april: bron: Medscape en Arch Dermatol. 2005;141:467-473

Aldara - Imiquimod is een zalf op natuurlijke basis die opnieuw in twee grote fase III studies bewijst hoogsignificant een effectieve zalf tegen actinicic-keratosis (sorry kan geen goed Nederlands woord hiervoor vinden), algemeen aangenomen als een voorstadium van niet-melanome huidkanker. Zalf met 5% Imiquimod (Aldara) en 16 weken lang aangebracht op de aangetaste huidplaatsen gaf een verschil met placebo te zien van 86.6% tegenover 14.3% effectiviteit in het verdwijnen van de aangetaste huidplekken.
,br> April 19, 2005 — Imiquimod (Aldara) is safe and effective for actinic keratosis (AK), according to the results of two randomized, double-blind trials published in the April issue of the Archives of Dermatology.

"The only treatment for AK that works by enhancing the immune response against dysplastic cells is 5% imiquimod cream," write Neil Korman, MD, PhD, from Case Western Reserve University in Cleveland, Ohio, and colleagues. "Since imiquimod works through an immunological mechanism, regimens with infrequent dosing for an extended duration have been evaluated to minimize potentially intolerable adverse effects."

These two phase 3, parallel-group trials took place at 26 ambulatory care offices, including dermatologists in private practice or research centers. Of 654 patients who were 18 years and older and were screened, 162 patients were ineligible. The remaining 492 patients each had four to eight AK lesions in a 25-cm2 treatment area on the face or the balding scalp, and they were randomized to receive an application of 5% imiquimod or vehicle cream to the treatment area once daily, three times per week, for 16 weeks, followed by an eight-week posttreatment period.

Complete clearance rate, which was defined as the proportion of patients at the eight-week posttreatment visit with no clinically visible AK lesions in the treatment area, was statistically significantly higher with imiquimod (48.3%) than with vehicle (7.2%). Partial clearance rate or the proportion of patients at the eight-week posttreatment visit with at least a 75% reduction in the number of baseline AK lesions in the treatment area was 64.0% vs 13.6%.

The median percentage reduction of baseline lesions was 86.6% vs 14.3%, respectively. Overall efficacy was higher for dosing three times per week than for twice weekly, but the rate of local skin reactions was also higher.

"The 5% imiquimod cream dosed three times weekly for 16 weeks is safe and effective for the treatment of AK," the authors write. "An additional benefit from imiquimod treatment appears to be improved skin quality compared with vehicle treatment."

One of the limitations of this study was incomplete blinding because of local skin reactions in the active treatment group, which may have biased the investigators' assessments. "Because imiquimod works by enhancing the innate and adaptive immune responses, individual patient responses will vary depending on many intrinsic and extrinsic factors, such as the number and responsiveness of Langerhans cells and extent of solar damage," the authors conclude. "These results, in addition to results from previously published studies, suggest that many different dosing regimens are effective and that dosing could be tailored to minimize drug exposure and adverse effects."

Seven of the authors report financial arrangements with 3M Pharmaceuticals, the maker of imiquimod, which helped support this study. Three of the authors have received funding from companies with competing products.

Arch Dermatol. 2005;141:467-473