Topical Minocycline in Rosacea
A similar foam formulation of minocycline (1.5% concentration) has shown benefit in 2 identical phase 3 studies.19 A total of 1522 participants were enrolled in 2 phase 3, randomized, multicenter, double-blind, vehicle-controlled, 2-arm studies in participants 18 years and older with moderate to severe papulopustular rosacea. Participants were randomized (2:1) to either minocycline foam 1.5% or vehicle once daily to the face for 12 weeks.19
Treatment was associated with a statistically significant reduction in counts of inflammatory lesions of rosacea (Study FX2016-11: −17.57 vs −15.65 [P=.003]; Study FX2016-12: −18.54 vs −14.88 [P<.0001]) and a significantly higher rate of IGA treatment success compared to vehicle (Study FX2016-11: 52.1% vs 43.0% [P=.027]; Study FX2016-12: 49.1% vs 39.0% [P=.008]), highlighting the anti-inflammatory action of the topically applied agent.19
The most common TEAE for both studies was upper respiratory tract infection; there were no serious TEAEs. Overall, 9 participants across both studies discontinued because of a TEAE (foam, 7 participants; vehicle, 2 participants).19
Clascoterone: First-in-Class Topical
Clascoterone cream 1% is a new chemical entity under investigation for the treatment of moderate to severe acne in patients 9 years and older. Clascoterone targets androgen receptors in the skin to block the effects of circulating endogenous androgens; chemically, it shares a 4-ring backbone identical to dihydrotestosterone and spironolactone (Figure 2). Clascoterone competes with dihydrotestosterone for binding to the androgen receptor to limit or block transcription of androgen-responsive genes and modify specific gene expression.20
Figure 2. Clascoterone shares a 4-ring backbone identical to dihydrotestosterone and spironolactone.
Androgens are known to promote both sebum production and inflammatory responses within the follicle, contributing to the cycle of acne.21 Antiandrogen therapy would, therefore, inhibit excess sebum production and directly reduce the presence of certain inflammatory mediators in skin. This effect is expected to lead to reduced follicular plugging and a reduction in growth of P acnes and its inflammatory by-products.
Direct and indirect hormonal modulation have been successfully employed to manage acne in women; however, such therapies have not been considered first-line interventions for the disease.22 Although systemic antiandrogens and hormonal modulation are effective for certain women with acne, there may be concerns about systemic exposure23; no hormone-modulating agent has been adopted for use in men with acne.
As an androgen inhibitor, clascoterone is thought to displace androgen hormones from androgen receptors located at the sebaceous gland and hair follicle, thus inhibiting the cycle of physiologic events that leads to acne formation. Clascoterone is applied topically and acts locally on androgen receptors in the skin, with no systemic exposure seen. In phase 2 trials, clascoterone was found to be safe and effective with no systemic exposure and was suggested to have better tolerability than topical tretinoin.
Preliminary individual study analysis of data from 2 phase 3 trials showed that topical clascoterone met its primary end points, achieving statistically significantly greater rates of IGA treatment success (≥2 point reduction in IGA and score of 0 [clear] or 1 [almost clear]) at week 12 (P<.0001).24 Rates of treatment success for actively treated participants were 16.1% and 18.7%, respectively, compared to 7% and 4.7%, respectively, for vehicle. The study population included both males and nonpregnant females 9 years and older who had a baseline IGA score of 3 (moderate) or 4 (severe). At baseline, participants had a mix of inflammatory lesions (≥30, to a maximum of 75) and noninflammatory lesions (≥30, to a maximum of 100).24
Intention-to-treat analysis at week 12 showed a mean total lesion reduction from baseline for active treatment of 37.1% and 37.7%, respectively, compared to 28.5% and 22.2%, respectively, for controls.24 Mean reductions from baseline in noninflammatory lesions for active treatment were 30.7% and 29.3%, respectively, compared to 21.9% and 15.8%, respectively, for controls. Mean reductions from baseline in inflammatory lesions for active treatment were 44.8% and 47%, respectively, compared to 36.6% and 29.8%, respectively, for controls. Similarly low rates of TEAEs were reported in active and placebo groups in both studies. No TEAE suggested systemic antiandrogen exposure.24