Pharmacotherapeutic group: Anti-Acne Preparations for Topical Use; clindamycin, combinations
ATC code:
D10AF51
Treclin combines two active substances, which act through different mechanisms of action (see below).
Clindamycin:
Clindamycin is a semisynthetic derivative of the parent compound lincomycin that is produced by Streptomyces lincolnensis and is predominantly bacteriostatic. Clindamycin binds to the 50S ribosomal subunits of susceptible bacteria and prevents elongation of peptide chains by interfering with peptidyl transfer, thereby suppressing bacterial protein synthesis. Although clindamycin phosphate is inactive in-vitro, rapid in-vivo hydrolysis converts this compound to the antibacterial active clindamycin.
Clindamycin has been shown to have in vitro activity against Cutibacterium acnes, one pathophysiological factor that influence the development of acne vulgaris. Clindamycin also exerts an anti-inflammatory effect on the acne vulgaris lesions.
Treclin has only a local antibacterial action. MIC (minimum inhibitory concentration) interpretive criteria for susceptibility testing of Cutibacterium acnes established by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) do not apply.
Tretinoin:
Topical tretinoin has both comedolytic and anti-inflammatory effects. Tretinoin decreases cohesiveness of follicular epithelial cells resulting in decreased microcomedone formation. Additionally, tretinoin stimulates mitotic activity and increased turnover of follicular epithelial cells, causing extrusion of the comedones. The comedolytic activity is related to a normalisation of the desquamation of the follicular epithelium. Tretinoin exerts anti-inflammatory effect via suppression of toll-like receptors (TLRs).
A combination therapy of clindamycin and tretinoin, as in Treclin Gel, not only combines the individual actions of both active agents but also complements their certain actions. There is also evidence in the literature to show that when applied together, tretinoin increases the penetration of clindamycin. Thus, this combination therapy targets multiple pathogenic factors: abnormal follicular keratinization, C.acnes proliferation, inflammation and increased sebum production.
Clinical efficacy of Treclin
Three randomised double-blind clinical studies, including a total of 4550 patients with acne vulgaris with both inflammatory and non-inflammatory lesions were performed. Of these 1853 patients were treated with Treclin Gel, 846 with tretinoin, 1428 with clindamycin phosphate and 423 with Treclin Gel vehicle.
Patients with 20-50 facial acne inflammatory lesions (papules and pustules), 20-100 facial acne non-inflammatory lesions (open and closed comedones), two or fewer nodules (defined as an inflammatory lesion greater than or equal to 5 mm in diameter) and without cysts were included. Lesions were counted at baseline and at weeks 2, 4, 8 and 12.
Primary measurements of efficacy for studies 7001.G2HP-06-02 and 7001.G2HP-07-02 were (1) mean percent change from baseline at Week 12 in inflammatory lesion counts, (2) mean percent change from baseline at Week 12 in non inflammatory lesion counts, (3) mean percent change from baseline at Week 12 in total lesion counts, and (4) the percent of subjects who were clear or almost clear, at Week 12 as judged by an Evaluator's Global Severity Score (EGSS). Superiority vs. monotherapies was concluded if two of three lesion count variables and dichotomized EGSS were significant.
Treatment was applied once daily for 12 weeks and patients were evaluated and lesions counted at week 12.
Studies 7001.G2HP-06-02 and 7001.G2HP-07-02 compared Treclin to both mono treatments (clindamycin phosphate 1.2% gel and tretinoin 0.025% gel) and vehicle using a double-blind treatment regimen. The third clinical study (MP1501-02) was conducted to compare Treclin to clindamycin alone.
The distribution of percent change in lesion counts was skewed, therefore the median percent change is shown in the following tables.
| Median percent change (decrease) in the number of lesions at week 12 |
| Lesion type | Treatment | Study | Meta-analysis |
| G2HP_06_02 (n=1252) | G2HP_07_02 (n=1288) | MP1501_02 (n=2010) | All studies1 (n=4550) |
| Inflammatory | Treclin | 52.6 | 61.3 | 70.0 | 65.2 |
| Clindamycin | 46.4* | 52.1* | 64.5* | 60.0* |
| Tretinoin | 42.9* | 50.0* | n.a. | 46.4* |
| Vehicle | 25.0* | 38.9* | n.a | 32.3* |
| Non-inflammatory | Treclin | 43.8 | 42.3 | 57.6 | 51.6 |
| Clindamycin | 27.5* | 32.2 | 48.2* | 43.5* |
| Tretinoin | 36.2* | 40.0 | n.a. | 37.3* |
| Vehicle | 23.0* | 24.2* | n.a. | 23.9* |
| Total | Treclin | 46.3 | 48.4 | 62.0 | 54.5 |
| Clindamycin | 33.9* | 40.9* | 53.1* | 48.1* |
| Tretinoin | 39.6* | 39.7* | n.a. | 39.6* |
| Vehicle | 22.2* | 25.0* | n.a. | 22.8* |
| p-values from ranked ANOVA 1 for pairwise comparison vs. Tretinoin and Vehicle data from studies 7001-G2HP-06-02 and 7001-G2HP-07-02 were considered. * p ≤ 0.05 |
Global Severity Score at Week 12 –presented as dichotomised values
| | Treclin | Clindamycin | Tretinoin | Vehicle |
| ITT-clear or almost clear * |
| Success | 85 (20%) | 32 (15%) | 62 (15%) | 18 ( 9% ) |
| Failure | 335 (80%) | 176 (85%) | 355 (85%) | 189 (91%) |
| Total | 420 | 208 | 417 | 207 |
| P-value | | 0.147 | 0.037 | <0.001 |
| ITT-clear or almost clear ** |
| Success | 95 (22%) | 38 (17%) | 60 (14%) | 16 ( 7% ) |
| Failure | 330 (78%) | 180 (83%) | 369 (86%) | 200 (93%) |
| Total | 425 | 218 | 429 | 216 |
| P-value | | 0.122 | 0.001 | <0.001 |
| ITT- clear, almost clear or at least 2-grade improvement*** |
| Success | 381 (38%) | 318 (32%) | | |
| Failure | 627 (62%) | 684 (68%) | | |
| Total | 1008 | 1002 | | |
| P-value | | 0.002 | | |
1 missing values imputed as failures
* Study 7001-G2HP-06-02
** Study 7001-G2HP-07-02
*** Study MP-1501-02
Paediatric Population
The percentage change in the number of lesions at Week 12 for adolescents, between 12 and 17 years, in the individual trials and the metanalysis of these trials are provided below.
| Median percent change (decrease) in the number of lesions at Week 12: Adolescents |
| Lesion type | Treatment | Study | Meta-analysis |
| G2HP_06_02 (n = 800) | G2HP_07_02 (n = 795) | MP1501_02 (n = 1320) | All studies1 (n = 2915) |
| Inflammatory | Treclin | 50.0 | 56.2 | 66.7 | 62.5 |
| Clindamycin | 40.4 | 46.7 | 64.0* | 58.3* |
| Tretinoin | 38.5* | 47.3* | n.a. | 40.7* |
| Vehicle | 16.7* | 25.4* | n.a. | 21.4* |
| Non-inflammatory | Treclin | 43.4 | 40.2 | 55.6 | 50.0 |
| Clindamycin | 23.4* | 26.5* | 48.7* | 42.2* |
| Tretinoin | 30.2* | 36.9 | n.a. | 32.8* |
| Vehicle | 13.5* | 13.7* | n.a. | 13.5* |
| Total | Treclin | 42.0 | 44.8 | 59.4 | 52.5 |
| Clindamycin | 31.3* | 34.2* | 53.0* | 46.4* |
| Tretinoin | 31.9* | 38.1* | n.a. | 35.6* |
| Vehicle | 14.6* | 14.6* | n.a. | 14.6* |
| p-values from ranked ANOVA 1 for pairwise comparison vs. Tretinoin and Vehicle data from studies 7001-G2HP-06-02 and 7001-G2HP-07-02 were considered. * p ≤ 0.05 |
Although the studies were not powered for the subgroups and the results are not as consistent as for the changes in lesion counts, they also provide evidence for superiority of the combination product.