Pharmacotherapeutic group: Anti-acne preparations for topical use, D10AD Retinoids for topical use in acne;
ATC code: D10AD53
Mechanism of action and Pharmacodynamic effects
Adawell combines two active substances, which act through different, but complementary, mechanisms of action.
- Adapalene: Adapalene is a chemically stable, naphthoic acid derivative with retinoid-like activity. Biochemical and pharmacological profile studies have demonstrated that adapalene acts in the pathology of Acne vulgaris: it is a potent modulator of cellular differentiation and keratinisation and it has anti-inflammatory properties. Mechanistically, adapalene binds to specific retinoic acid nuclear receptors. Current evidence suggests that topical adapalene normalizes the differentiation of follicular epithelial cells resulting in decreased microcomedone formation. Adapalene inhibits the chemotactic (directional) and chemokinetic (random) responses of human polymorphonuclear leucocytes in in vitro assay models; it also inhibits the metabolism of arachidonic acid to inflammatory mediators. In vitro studies have shown inhibition of the AP-1 factors and the inhibition of the expression of toll like receptors 2. This profile suggests that the cell mediated inflammatory component of acne is reduced by adapalene.
- Benzoyl peroxide: Benzoyl peroxide has been shown to have antimicrobial activity; particularly against Cutibacterium acnes, which is abnormally present in the acne-affected pilosebaceous unit. The mechanism of action of Benzoyl peroxide has been explained by its highly lipophilic activity, enabling its penetration through the epidermis into bacterial and keratinocyte cell membranes of the pilosebaceous unit. Benzoyl peroxide is recognized as a very effective broad-spectrum antibacterial agent in the treatment of acne vulgaris. It has been demonstrated to exert bactericidal effect by generating free radicals that oxidize proteins and other essential cellular components in the bacterium wall. The minimum inhibitory concentration of benzoyl peroxide is bactericidal and has demonstrated effectiveness on antibiotic-sensitive and antibiotic-resistant C. acnes strains. Additionally, benzoyl peroxide has demonstrated exfoliative and keratolytic activities.
Clinical efficacy of Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel in patients aged 12 years and older
The safety and efficacy of Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel applied once daily for the treatment of acne vulgaris were assessed in two 12-week, multicenter, controlled clinical studies of similar design, comparing Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel to its individual active components, adapalene and benzoyl peroxide, and to the gel vehicle in acne patients. A total of 2185 patients were enrolled in Study 1 and Study 2. The distribution of patients in the two studies was approximately 49% male and 51% female, 12 years of age or older (mean age: 18.3 years; range 12 – 50), presenting 20 to 50 inflammatory lesions and 30 to 100 noninflammatory lesions at baseline. The patients treated the face and other acne affected areas as needed once daily in the evening.
The efficacy criteria were:
(1) Success rate, percentage of patients rated 'Clear' and 'Almost Clear' at Week 12 based on the Investigator's Global Assessment (IGA);
(2) Change and Percent Change from baseline at Week 12 in
• Inflammatory lesion counts
• Non-inflammatory lesion counts
• Total lesion count
The efficacy results are presented for each study in Table 1 and combined results in Table 2. Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel was shown to be more effective compared to its monads and gel vehicle in both studies. Overall, the net beneficial effect (active minus vehicle) obtained from Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel was greater than the sum of the net benefits obtained from the individual components, thus indicating a potentiation of the therapeutic activities of these substances when used in a fixed-dose combination. An early treatment effect of Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel was consistently observed in Study 1 and Study 2 for Inflammatory Lesions at Week 1 of treatment. Noninflammatory lesions (open and closed comedones) noticeably responded between the first and fourth week of treatment. The benefit on nodules in acne has not been established.
Table 1 Clinical efficacy in two comparative trials
| Study 1 |
| Study 1 Week 12 LOCF; ITT | Adapalene+BPO N=149 | Adapalene N=148 | BPO N=149 | Vehicle N=71 |
| Success (Clear, Almost Clear) | 41 (27.5%) | 23 (15.5%) p=0.008 | 23 (15.4%) p=0.003 | 7 (9.9%) p=0.002 |
| Median Reduction (% Reduction) in | | | | |
| Inflammatory Lesion Count | 17 (62.8 %) | 13 (45.7 %) p<0.001 | 13 (43.6 %) p<0.001 | 11 (37.8 %) p<0.001 |
| Noninflammatory Lesion Count | 22 (51.2 %) | 17 (33.3 %) p<0.001 | 16 (36.4 %) p<0.001 | 14 (37.5 %) p<0.001 |
| Total lesion Count | 40 (51.0 %) | 29 (35.4 %) p<0.001 | 27 (35.6 %) p<0.001 | 26 (31.0 %) p<0.001 |
| Study 2 |
| Study 2 Week 12 LOCF; ITT | Adapalene+BPO N=415 | Adapalene N=420 | BPO N=415 | Vehicle N=418 |
| Success (Clear, Almost Clear) | 125 (30.1%) | 83 (19.8%) p<0.001 | 92 (22.2%) p=0.006 | 47 (11.3%) p<0.001 |
| Median Reduction (% Reduction) in | |
| Inflammatory Lesion Count | 16 (62.1 %) | 14 (50.0 %) p<0.001 | 16 (55.6 %) p=0.068 | 10 (34.3 %) p<0.001 |
| Noninflammatory Lesion Count | 24 (53.8 %) | 22 (49.1 %) p=0.048 | 20 (44.1 %) p<0.001 | 14 (29.5 %) p<0.001 |
| Total Lesion Count | 45 (56.3 %) | 39 (46.9 %) p=0.002 | 38 (48.1 %) p<0.001 | 24 (28.0 %) p<0.001 |
Table 2 Clinical efficacy in combined comparative trials
| | Adapalene+BPO N=564 | Adapalene N=568 | BPO N=564 | Gel Vehicle N=489 |
| Success (Clear, Almost Clear) | 166 (29.4%) | 106 (18.7%) | 115 (20.4%) | 54 (11.1%) |
| Median Reduction (% Reduction) in | |
| Inflammatory Lesion Count | 16.0 (62.1) | 14.0 (50.0) | 15.0(54.0) | 10.0 (35.0) |
| Noninflammatory Lesion Count | 23.5 (52.8) | 21.0 (45.0) | 19.0 (42.5) | 14.0 (30.7) |
| Total Lesion Count | 41.0 (54.8) | 34.0 (44.0) | 33.0 (44.9) | 23.0 (29.1) |
Clinical efficacy of Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel in children 9 to 11 years old
During a paediatric clinical trial, 285 children with acne vulgaris, aged 9 – 11 years (53% of the subjects were 11 years old, 33% were 10 years old and 14% were 9 years old) with a score of 3 (moderate) on the IGA scale and a minimum of 20 but not more than 100 total lesions (Noninflammatory and/or Inflammatory) on the face (including the nose) at baseline were treated with Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel once daily for 12 weeks. The study concludes that the efficacy and safety profiles of Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel in the treatment of facial acne in this specific younger age group are consistent with results of other pivotal studies in subjects with acne vulgaris aged 12 years and older showing significant efficacy with an acceptable tolerability. A sustained early treatment effect of Adapalene/Benzoyl Peroxide 0.1%/2.5% Gel compared to Gel Vehicle was consistently observed for all Lesions (Inflammatory, Non-Inflammatory, and Total) at Week 1 and continuing to Week 12.
| Study 3 |
| Week 12 LOCF; ITT | Adapalene+BPO N=142 | Vehicle Gel N=143 |
| Success (Clear, Almost Clear) | 67 (47.2%) | 22 (15.4%) |
| Median Reduction (% Reduction) in | |
| Inflammatory Lesion Count | 6 (62.5%) | 1 (11.5%) |
| Noninflammatory Lesion Count | 19 (67.6%) | 5 (13.2%) |
| Total Lesion Count | 26 (66.9%) | 8 (18.4%) |