RESUMO
BACKGROUND: Dupilumab [a monoclonal antibody blocking the shared receptor subunit for interleukin (IL)-4 and IL-13] is approved for patients aged ≥ 12 years with inadequately controlled, moderate-to-severe atopic dermatitis (AD). Dupilumab trials of up to 52 weeks demonstrated efficacy and a favourable safety profile in patients with moderate-to-severe AD inadequately controlled with topical medications. OBJECTIVES: To further characterize the safety of dupilumab by evaluating clinical laboratory findings from three randomized, double-blinded, placebo-controlled phase III trials (LIBERTY AD SOLO 1 & 2 and LIBERTY AD CHRONOS). METHODS: Patients were randomized 1 : 1 : 1 (SOLO 1 & 2) or 3 : 1 : 3 (CHRONOS) for 16 and 52 weeks, respectively, to dupilumab weekly, every 2 weeks or placebo. CHRONOS patients received a standardized concomitant topical corticosteroid regimen. Laboratory outcomes were summarized descriptively in 1376 patients from SOLO 1 & 2 and 740 from CHRONOS. RESULTS: Treatment groups had similar results in baseline laboratory parameters. Platelets and neutrophils showed mild decreases from baseline in dupilumab vs. placebo groups. Some dupilumab-treated patients had small transient increases in eosinophils. Grade 3 eosinophilia was reported in < 1% of dupilumab-treated and placebo-treated patients; no adverse events were associated with eosinophilia. Lactate dehydrogenase levels decreased from baseline during dupilumab treatment in all trials. No clinically meaningful changes were observed between treatment groups in other haematology, chemistry or urinalysis parameters. CONCLUSIONS: There were no clinically important changes in routine laboratory parameters that could be attributed to dupilumab. This study supports the use of dupilumab as a systemic treatment for moderate-to-severe AD that does not require laboratory monitoring. What's already known about this topic? Long-term treatment of atopic dermatitis (AD) with conventional immunosuppressive agents is limited by the risk of significant side-effects and a need for repeated tests to monitor haematological and/or organ (e.g. liver, kidney) toxicities. Dupilumab [a monoclonal antibody blocking the shared receptor subunit for interleukin (IL)-4 and IL-13] is approved for the treatment of patients with inadequately controlled, moderate-to-severe AD. In 16-week and 52-week studies, dupilumab demonstrated a positive risk/benefit profile in moderate-to-severe AD. What does this study add? This study is the first comprehensive analysis of dupilumab laboratory safety data of the 16-week SOLO 1 & 2 (pooled N = 1376) and 52-week CHRONOS (N = 740) trials, demonstrating an absence of clinically important changes in haematology, serum chemistry and urinalysis parameters in patients with moderate-to-severe AD treated with dupilumab. Our data support the use of dupilumab as a systemic treatment for the long-term management of moderate-to-severe AD without routine laboratory monitoring in clinical practice.
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Dermatite Atópica , Idoso , Anticorpos Monoclonais Humanizados , Dermatite Atópica/tratamento farmacológico , Método Duplo-Cego , Humanos , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
Atopic dermatitis (also known as AD or eczema) is a common skin disease that can cause intense and persistent itching and rashes. Skin creams or ointments are not suitable or effective for some patients with moderate-to-severe AD. In these patients, oral (taken by mouth) or injected medications may be required. Some of those oral or injected treatments could be toxic and often have unwanted side effects, especially when used for a longer period of time, so patients must be regularly tested to see whether those treatments are harming their blood or organs. Dupilumab is a newer injectable drug for treating moderate-to-severe AD. Dupilumab specifically targets key molecules in the body that cause AD. Dupilumab has been tested for up to one year in more than 2000 patients enroled in placebo-controlled clinical trials. During those trials, patients provided blood and urine samples for laboratory testing while they were being treated with dupilumab or placebo (dummy drug). In this paper, the authors from Germany and the U.S.A, analysed how blood cells, blood chemistry, and urine chemistry changed during treatment, to check whether dupilumab is safe to use without the need for regular laboratory tests. After performing many routine laboratory tests on patients' blood and urine, they found that there were no clinically important changes in test results that could be linked to dupilumab. They concluded that patients using dupilumab for moderate-to-severe AD do not need routine laboratory testing. This is a summary of the study: Laboratory safety of dupilumab in moderate-to-severe atopic dermatitis: results from three phase III trials (LIBERTY AD SOLO 1, LIBERTY AD SOLO 2, LIBERTY AD CHRONOS).
Assuntos
Dermatite Atópica , Eczema , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Dermatite Atópica/tratamento farmacológico , Método Duplo-Cego , Alemanha , Humanos , Injeções Subcutâneas , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
BACKGROUND: In the U.S.A., an Investigator's Global Assessment (IGA) score of ≤ 1 (clear or almost clear skin) has been the standard measure in regulatory outcomes for registration clinical trials in atopic dermatitis (AD), including those supporting the recent approval of dupilumab. OBJECTIVES: To evaluate the treatment effect of dupilumab in patients with IGA > 1 at the end of treatment, using other validated outcome measures for AD signs, symptoms and quality of life. METHODS: LIBERTY AD SOLO 1 and 2 were two 16-week, randomized, double-blind trials enrolling adult patients with moderate-to-severe AD (IGA ≥ 3) inadequately controlled with topical treatment. We performed a post hoc analysis in patients receiving dupilumab 300 mg every 2 weeks (q2w) or placebo. Outcome measures in patients with IGA > 1 included Eczema Area and Severity Index (EASI), pruritus numerical rating scale (NRS), affected body surface area (BSA), Patient-Oriented Eczema Measure (POEM) and Dermatology Life Quality Index (DLQI). The trials were registered at ClinicalTrials.gov: NCT02277743 and NCT02277769. RESULTS: At week 16, 278 of 449 dupilumab q2w-treated patients (median age 36·0 years) and 396 of 443 placebo-treated patients had IGA > 1. Among patients with IGA > 1 at week 16, dupilumab significantly improved several outcome measures compared with placebo: EASI (-48·9% vs. -11·3%, P < 0·001), pruritus NRS (-35·2% vs. -9·1%, P < 0·001), affected BSA (-23·1% vs. -4·5%, P < 0·001), POEM score ≥ 4-point improvement (57·4% vs. 21·0%, P < 0·001) and DLQI score ≥ 4-point improvement (59·3% vs. 24·4%, P < 0·001). CONCLUSIONS: In patients with IGA > 1 at week 16, dupilumab induced statistically significant benefits in multiple validated outcome measures compared with placebo. The IGA ≤ 1 end point significantly underestimates clinically relevant dupilumab treatment effects.
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Anticorpos Monoclonais Humanizados/administração & dosagem , Dermatite Atópica/tratamento farmacológico , Qualidade de Vida , Adulto , Dermatite Atópica/complicações , Dermatite Atópica/diagnóstico , Método Duplo-Cego , Feminino , Humanos , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Placebos/administração & dosagem , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
BACKGROUND: Dupilumab blocks the shared receptor component for interleukin (IL)-4 and IL-13. It is approved in the U.S.A. for patients aged ≥ 12 years with moderate-to-severe atopic dermatitis (AD) uncontrolled by topical prescription medicines or who cannot use topical medicines, for patients in Japan whose AD is uncontrolled with existing therapies, for patients with moderate-to-severe AD in Europe who are candidates for systemic therapy and for patients aged ≥ 12 years for maintenance treatment of moderate-to-severe asthma uncontrolled with their current medicines. AD trials have reported increased incidence of conjunctivitis for dupilumab vs. placebo. OBJECTIVES: To characterize further the occurrence and risk factors of conjunctivitis in dupilumab clinical trials. METHODS: We evaluated randomized placebo-controlled trials of dupilumab in AD (n = 2629), asthma (n = 2876), chronic rhinosinusitis with nasal polyps (CRSwNP) (n = 60) and eosinophilic oesophagitis (EoE) (n = 47). RESULTS: In most AD trials, dupilumab-treated patients had higher conjunctivitis incidence than placebo controls. Higher baseline AD severity and previous history of conjunctivitis were associated with increased conjunctivitis incidence. Conjunctivitis was mostly mild to moderate. Most cases recovered or resolved during the treatment period; two patients permanently discontinued dupilumab due to conjunctivitis or keratitis. Common treatments included ophthalmic corticosteroids, antibiotics, and antihistamines or mast cell stabilizers. Most cases were diagnosed by the investigators. In asthma and CRSwNP trials, the incidence of conjunctivitis was lower for both dupilumab and placebo than in AD trials; dupilumab did not increase the incidence compared with placebo. In the EoE trial, no patients had conjunctivitis. CONCLUSIONS: Conjunctivitis was more frequent with dupilumab treatment in most AD trials. In dupilumab trials in other type 2 diseases, incidence of conjunctivitis was overall very low, and was similar for dupilumab and placebo. In AD, the incidence of conjunctivitis was associated with AD severity and prior history of conjunctivitis. The aetiology and treatment of conjunctivitis in dupilumab-treated patients require further study. What's already known about this topic? Ocular disorders, including allergic conjunctivitis, are common in patients with atopic dermatitis (AD). In most dupilumab AD trials, dupilumab-treated patients had higher conjunctivitis incidence than those receiving placebo. Most cases were mild to moderate and recovered or were recovering during study treatment; study treatment discontinuation due to conjunctivitis was rare. Conjunctivitis incidence was very low and similar for dupilumab and placebo in clinical trials in asthma, chronic rhinosinusitis with nasal polyps and eosinophilic oesophagitis. What does this study add? This analysis confirms and extends the results of the individual clinical trials. Baseline disease-related factors, including AD severity, prior conjunctivitis history and certain biomarkers (thymus and activation-regulated chemokine, IgE, eosinophils), were associated with increased incidence of conjunctivitis. Patients who responded well to dupilumab had reduced incidence of conjunctivitis. Further study is needed to elucidate the aetiology and treatment of conjunctivitis in dupilumab-treated patients with AD.
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Anticorpos Monoclonais Humanizados/efeitos adversos , Conjuntivite/epidemiologia , Dermatite Atópica/tratamento farmacológico , Adulto , Asma/tratamento farmacológico , Asma/imunologia , Conjuntivite/induzido quimicamente , Conjuntivite/diagnóstico , Conjuntivite/imunologia , Dermatite Atópica/diagnóstico , Dermatite Atópica/imunologia , Esofagite Eosinofílica/tratamento farmacológico , Esofagite Eosinofílica/imunologia , Humanos , Incidência , Subunidade alfa de Receptor de Interleucina-4/antagonistas & inibidores , Subunidade alfa de Receptor de Interleucina-4/imunologia , Pólipos Nasais/complicações , Pólipos Nasais/tratamento farmacológico , Pólipos Nasais/imunologia , Placebos/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Rinite/complicações , Rinite/tratamento farmacológico , Rinite/imunologia , Fatores de Risco , Índice de Gravidade de Doença , Sinusite/complicações , Sinusite/tratamento farmacológico , Sinusite/imunologia , Adulto JovemRESUMO
BACKGROUND: There are limited long-term, 'real-world' data on ustekinumab, or the effect of dose adjustment in suboptimal responders. OBJECTIVES: We describe 52-week data from TRANSIT, which initiated ustekinumab by licensed regimen and investigated exploratory dose adjustment. METHODS: Patients with moderate-to-severe psoriasis and inadequate methotrexate response received ustekinumab, with immediate or gradual methotrexate withdrawal. Outcomes were similar between treatment arms at week 12 (primary endpoint), so week 52 data were pooled. Patients weighing ≤ 100 kg or > 100 kg were administered ustekinumab 45 or 90 mg, respectively. Patients weighing ≤ 100 kg without 75% improvement in Psoriasis Area and Severity Index (PASI 75) response at weeks 28 or 40 received a dose adjustment to 90 mg. The primary analysis used observed data. RESULTS: Overall, 391 and 98 patients received ustekinumab 45 and 90 mg, respectively. Forty-four patients (9%) discontinued before week 52 (0·4% due to adverse events). At week 52 (in the overall population), 369 patients (83%) achieved a PASI score ≤ 5, and 341 patients (77%) achieved PASI 75; the median PASI score decreased from 15 at baseline to 1·8. At weeks 28 and 40, 84 and 31 patients, respectively, did not achieve PASI 75 and received a dose adjustment; by week 52, 35/82 (43%) and 15/31 (48%) of these patients, respectively, achieved PASI 75 (two discontinued between weeks 28 and 40). CONCLUSIONS: Ustekinumab showed sustained 1-year efficacy and was well tolerated when initially administered according to label. Adjusting the ustekinumab dose to 90 mg may result in clinically meaningful improvement in response in patients weighing ≤ 100 kg with suboptimal initial response.
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Anticorpos Monoclonais Humanizados/administração & dosagem , Fármacos Dermatológicos/administração & dosagem , Metotrexato/administração & dosagem , Psoríase/tratamento farmacológico , Anticorpos Monoclonais Humanizados/efeitos adversos , Fármacos Dermatológicos/efeitos adversos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Substituição de Medicamentos , Feminino , Humanos , Masculino , Metotrexato/efeitos adversos , Pessoa de Meia-Idade , Resultado do Tratamento , UstekinumabRESUMO
BACKGROUND: Limited data exist on transitioning patients with psoriasis from conventional systemic agents to biologics. OBJECTIVES: The TRANSIT study aimed to assess the efficacy and safety of two methotrexate-to-ustekinumab transition strategies. METHODS: Patients with moderate-to-severe psoriasis and inadequate methotrexate response were randomized 1 : 1 to receive ustekinumab with immediate (arm 1) or 4-week gradual (arm 2) methotrexate withdrawal. Patients weighing ≤ 100 kg or > 100 kg received ustekinumab 45 mg or 90 mg, respectively. The primary endpoint was the frequency of adverse events (AEs) at week 12. Secondary endpoints included additional safety, efficacy and patient-reported outcomes. We report the 12-week efficacy and safety results. RESULTS: Overall, 244 patients in arm 1 and 245 in arm 2 were randomized and received ustekinumab. Four patients per arm discontinued the trial by week 12. At week 12 in arms 1 and 2, respectively, 61% and 65% of patients experienced an AE, 2·9% and 2·4% had a serious AE, and 1·2% and 0·4% had an AE leading to ustekinumab discontinuation. In arms 1 and 2, respectively, median Psoriasis Area and Severity Index (PASI) score decreased from 15·2 and 15·4 at baseline to 2·9 and 2·8 at week 12; 58% and 62% of patients achieved a 75% reduction from baseline in PASI score (PASI 75) at week 12; median baseline Dermatology Life Quality Index fell from 8 and 9 at baseline to 1 (both arms) at week 16. CONCLUSIONS: Ustekinumab was well tolerated and effective in patients who had an inadequate response to methotrexate. Both transition strategies resulted in similar week 12 safety and efficacy outcomes.
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Anticorpos Monoclonais Humanizados/administração & dosagem , Fármacos Dermatológicos/administração & dosagem , Metotrexato/administração & dosagem , Psoríase/tratamento farmacológico , Anticorpos Monoclonais Humanizados/efeitos adversos , Fármacos Dermatológicos/efeitos adversos , Relação Dose-Resposta a Droga , Substituição de Medicamentos , Feminino , Humanos , Masculino , Metotrexato/efeitos adversos , Pessoa de Meia-Idade , Resultado do Tratamento , UstekinumabRESUMO
Vitamin D analogues are widely used for the treatment of psoriasis. A new topical formulation of calcitriol (3 microg/g ointment) has been shown to be effective in the treatment of stable plaque-type psoriasis. This paper reports the results of four separate studies designed to evaluate specific local-safety parameters: cumulative irritancy, cutaneous contact sensitization, potential photoallergic contact sensitization and phototoxicity. Calcitriol 3 microg/g ointment was classified as non-irritant when compared to calcipotriol, tacalcitol and white petrolatum. Petrolatum and tacalcitol were slightly irritant and calcipotriol moderately irritant. No sensitization was observed with calcitriol 3 microg/g ointment. With regard to phototoxic potential, sites treated with calcitriol 3 microg/g ointment or vehicle ointment were less irritated than those treated with white petrolatum or those that were untreated. Using standard photoallergenicity testing methodology, there were no skin reactions of a photoallergic nature to the study material. These studies showed that calcitriol 3 microg/g ointment is a well-tolerated treatment for stable plaque-type psoriasis.
Assuntos
Anti-Inflamatórios/efeitos adversos , Calcitriol/efeitos adversos , Dermatite Alérgica de Contato/etiologia , Dermatite Fotoalérgica/etiologia , Dermatite Fototóxica/etiologia , Fármacos Dermatológicos/efeitos adversos , Di-Hidroxicolecalciferóis/efeitos adversos , Emolientes/efeitos adversos , Vaselina/efeitos adversos , Psoríase/tratamento farmacológico , Administração Tópica , Calcitriol/análogos & derivados , Dermatite Alérgica de Contato/patologia , Dermatite Fotoalérgica/patologia , Dermatite Fototóxica/patologia , Humanos , Pomadas , Segurança , Índice de Gravidade de Doença , Método Simples-Cego , Fatores de TempoRESUMO
OBJECTIVE: To assess the systemic safety of calcitriol 3 microg/g ointment (Silkis) ointment) in relation to body surface area (BSA) affected by chronic plaque psoriasis. METHODS: In this open-label, multicentre study, patients were divided into three parallel groups: 5% to <15% (n=23), 15% to <25% (n=18), 25% to 35% (n=18) based on BSA involvement. Ointment was applied topically twice daily for 12 weeks; patients were followed up for a further 8 weeks. RESULTS: There was no alteration of calcium homeostasis: the mean values of albumin-adjusted serum total calcium, as well as 24-hour urinary calcium and serum calcitriol levels, remained within normal ranges throughout treatment. No changes in calcium or phosphate homeostasis related to the area of psoriasis being treated with calcitriol ointment were detected. CONCLUSIONS: Reductions in the global severity score and BSA involvement, as well as results of the assessment of improvement, attested to the clinical efficacy of calcitriol 3 microg/g ointment in psoriasis. The study confirms the systemic safety of calcitriol 3 microg/g in psoriatic patients with 5-35% BSA involvement.
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Calcitriol/uso terapêutico , Cálcio/metabolismo , Psoríase/tratamento farmacológico , Administração Cutânea , Adolescente , Adulto , Idoso , Calcitriol/administração & dosagem , Calcitriol/efeitos adversos , Calcitriol/sangue , Calcitriol/farmacologia , Cálcio/sangue , Cálcio/urina , Doença Crônica , Esquema de Medicação , Inglaterra , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pomadas , Psoríase/patologia , Albumina Sérica/metabolismo , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
Assessment of improvement in acne lesions following treatment is often based on clinical evaluation and photographs. However, limitations are associated with this sublective evaluation, making it difficult to accurately review individual acne lesions and to observe early response to therapy. Conventional photographs do not allow us to visualize small lesions, and it can be difficult to differentiate inflammatory lesions as papules or small nodules. Our objective was to evaluate a new standardized method for tracking individual acne lesions based on photographs. The effect of adapalene gel 0.1% on both inflammatory and noninflammatory acne lesions was evaluated using this technique. Polarized light photography and videomicroscopy were used to record the evolution of acne lesions over a 16-week period in 5 volunteers with moderate acne vulgaris. During the first 4 weeks before treatment, acne lesions were evaluated on a 3-times weekly basis to establish a pattern of progression and determine the length of time to resolution. Sebum secretion rates were monitored using Sebutape adhesive patches applied to the forehead and both cheeks for 1 hour. After 4 weeks, adapalene gel 0.1% was used once daily at bedtime for 8 weeks; polarized light photography, videomicroscopy, and assessment of sebum production followed treatment response. This treatment period was followed by a further 4-week phase, after which acne lesions and sebum secretion rates were evaluated. Our results showed that the new methodology was appropriate to track acne lesions and allowed an accurate and more oblective evaluation of individual lesions. Using this methodology demonstrated that adapalene gel 0.1% causes rapid resolution of inflammatory and noninflammatory lesions. The probability of clearing inflammatory and noninflamma tory lesions during the treatment period increased, and the probability of new lesions appearing decreased. Sebum secretion rates declined in patients while on study drug, returning to near pretreatment levels following therapy cessation. Using sophisticated photography and videomicroscopy every other day proved to be a valuable, noninvasive, and reliable method of following response to adapalene treatment in patients with moderate acne vulgaris.
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Acne Vulgar/tratamento farmacológico , Anti-Inflamatórios não Esteroides/uso terapêutico , Fármacos Dermatológicos/uso terapêutico , Microscopia de Vídeo/métodos , Naftalenos/uso terapêutico , Fotografação/métodos , Acne Vulgar/diagnóstico , Adapaleno , Adolescente , Adulto , Feminino , Humanos , Luz , Masculino , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
Calcitriol 3 microg g(-1) ointment (Silkis ointment, Galderma Laboratories) is a new treatment for psoriasis. Calcitriol is the biologically active metabolite of vitamin D3. It induces keratinocyte differentiation, inhibits keratinocyte, T-cell and fibroblast proliferation, and inhibits the production of some inflammatory mediators, all contributors to the pathogenesis of psoriasis. Preclinical studies have shown an effect of topical calcitriol on calcium homeostasis at doses higher than those in clinical use. No adverse local events were observed when calcitriol was applied to animal skin. Phase I clinical studies confirmed that calcitriol 3 microg g(-1) ointment is well tolerated in humans. These studies have demonstrated that at the minimal effective concentration of 3 microg g(-1), calcitriol ointment has no discernible photosensitizing or phototoxic potential and no skin irritant or allergic potential in healthy volunteers. Its low systemic absorption through human skin is unlikely to significantly affect calcium homeostasis. This paper summarizes the findings of the preclinical and early clinical studies that provided the foundation of the later Phase II and III clinical trials on efficacy and safety with topical calcitriol 3 microg g(-1) ointment for the treatment of plaque psoriasis.
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Calcitriol/uso terapêutico , Agonistas dos Canais de Cálcio/uso terapêutico , Psoríase/tratamento farmacológico , Administração Cutânea , Animais , Calcitriol/efeitos adversos , Calcitriol/farmacocinética , Agonistas dos Canais de Cálcio/efeitos adversos , Agonistas dos Canais de Cálcio/farmacocinética , Relação Dose-Resposta a Droga , HumanosRESUMO
Clinical evaluation of acne is usually based on direct visual assessment and ordinary flash photography, both of which are compromised by viewer subjectivity. It is difficult to accurately assess individual acne lesions and to observe early response to therapy. Standard flash photography has inherent limitations owing to the physics of light; it does not permit consistent visualization of subtle cutaneous characteristics like erythema or microcomedones, and it tends to blur distinctions between active inflammatory lesions and older hyperpigmented macules. Over the last decade there has been increasing interest in newer techniques aimed at increasing the accuracy and objectivity of acne evaluation. These include parallel-polarized light photography, cross (or perpendicular)-polarized light photography, videomicroscopy, and fluorescence photography. This article will review the advances of the past decade and summarize new techniques to evaluate acne lesions. Moreover, findings of a study that evaluated the course of individual acne lesions and the effects of adapalene gel 0.1% on inflammatory and non-inflammatory acne lesions will be viewed. In this study, the use of parallel-polarized and cross-polarized photography, in combination with videomicroscopy and sebum production measurement, provided objective, detailed information on the evolution of different variable acne lesions and their response to adapalene gel 0.1%. Adapalene treatment produced rapid resolution of inflammatory and non-inflammatory lesions, and inhibited formation of new lesions. Sebum secretion rates also declined during treatment. Use of the new assessment techniques proved to be a valuable, non-invasive and reliable method of assessing acne vulgaris and its response to treatment.
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Acne Vulgar/diagnóstico , Acne Vulgar/tratamento farmacológico , Naftalenos/administração & dosagem , Fotografação/métodos , Adapaleno , Adolescente , Adulto , Feminino , Fluorescência , Humanos , Masculino , Estudos Prospectivos , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
A randomized, investigator masked, intra individual comparative study was conducted in 30 healthy volunteers to compare the cutaneous effects of adapalene 0.1% gel and adapalene 0.1% cream with their respective vehicles, using tretinoin 0.05% cream (n = 21) or tretinoin 0.1% cream (n = 9) and a tretinoin cream vehicle (n = 30) as controls. The products were applied to hip/buttock skin for 4 days under occlusive conditions. Cytosolic retinoic acid binding protein-II (CRABP-II) mRNA levels were measured using the RT-PCR technique in punch biopsies taken from 10 subjects. Epidermal thickness was assessed using image analysis of haematoxylin and eosin stained sections from another 11 subjects. Erythema was assessed in all subjects both by a visual scoring system and by chromameter. Adapalene 0.1% gel and adapalene 0.1% cream produced similar significant increases in CRABP-II mRNA levels compared to their vehicles (P < 0.01). The two tretinoin formulations also resulted in similar significant increases in CRABP-II compared to the cream vehicle (P < 0.001). However, only the two tretinoin formulations resulted in an increase in epidermal thickness and only the tretinoin 0.1% cream resulted in significant erythema. Adapalene 0.1% gel and adapalene 0.1% cream induce RAR-mediated gene expression to a similar degree in this model, without the irritant effects of tretinoin.