A novel anti-inflammatory drug, SDZ ASM 981, for the treatment of skin diseases: in vitro pharmacology

Role of topical therapies in the management of cutaneous disease

Within the last decade, healthcare providers have had a larger selection of effective novel topical immunomodulatory agents to treat many dermatologic conditions. Novel mechanisms of action of newer topical agents have facilitated differentiation from well-established topical agents such as corticosteroids and 5-fluorouracil. Further, because of a growing understanding of the immune mechanisms within the skin, the opportunity has arisen to use the body's immune system to effectively treat many dermatologic conditions, such as condyloma acuminata, actinic keratosis, basal cell carcinoma, and atopic dermatitis, while maintaining a favorable safety profile. Imiquimod 5% cream, an immune response modifier, is safe and effective in the treatment of condyloma acuminata, actinic keratosis, and primary superficial basal cell carcinoma (sBCC). Pimecrolimus cream 1% and tacrolimus ointment (0.1% and 0.03%) are safe and effective in the treatment of atopic dermatitis. This review highlights newer data on approved and investigational indications for these topical immunomodulatory agents.

Long-term control of atopic dermatitis with pimecrolimus cream 1% in infants and young children: a two-year study

OBJECTIVE AND METHODS

The safety and efficacy of treatment with pimecrolimus cream 1% was evaluated for up to 2 years in infants and young children with atopic dermatitis. Ninety-one patients participated in a 1-year, open-label extension to a 1-year double-blind study. Of these, 76 received pimecrolimus for 2 years. Pimecrolimus was applied twice daily at the first signs or symptoms of the disease until clearance. Outcome measures included the incidence of adverse events and the Eczema Area and Severity Index (EASI).

RESULTS

No patient discontinued because of adverse events. The incidence of systemic and skin infections did not increase over time. Over the 2-year period, 2 patients experienced an episode of clinically diagnosed eczema herpeticum. In patients receiving pimecrolimus for 2 years, the mean decrease in EASI score from baseline was 68.7% at 3 months and 70.8% at 24 months.

CONCLUSION

Treatment with pimecrolimus cream 1% for up to 2 years was well tolerated and resulted in a marked and sustained improvement of atopic dermatitis.

Pimecrolimus 1% cream for the treatment of discoid lupus erythematosus

OBJECTIVES

To determine the safety and efficacy of pimecrolimus cream on lesions of discoid lupus erythematosus.

METHODS

In an open-label phase II trial, patients with discoid lupus were treated with pimecrolimus 1% cream twice daily for 8 weeks. We assessed skin involvement with a clinical severity score, quality of life, patient improvement and toxicity. The changes were documented by skin biopsy at baseline and at the end of treatment.

RESULTS

Ten patients with a mean age of 34 +/- 17 yr and disease duration of 3 yr (range 1-8) were studied; 90% were female and 40% had received prior topical or systemic therapy without response. In all patients, improvement of skin damage was observed after therapy. A significant decrease of 52% was observed in the mean +/- s.d. clinical severity score, from 6.1 +/- 1.4 before treatment to 2.9 +/- 1.5 after treatment (P = 0.005). Quality of life score (0 = no effect, 100 = maximum effect on quality of life) showed a mean improvement of 46%, from 42.8 +/- 23.1 before to 23 +/- 16.5 after treatment (P = 0.008). According to the patients' assessment of the response to treatment, 50% qualified as marked improvement, 40% moderate and 10% slight improvement. The treatment was well tolerated; adverse reactions consisted of minimal erythema and pruritus, which resolved without any further action.

CONCLUSIONS

Our data suggest that pimecrolimus cream for discoid lupus erythematosus seems to be a safe and clinically effective option. However, this was an open and uncontrolled study, and double-blind, placebo-controlled studies are needed.

Psoriasis: a fresh look

Psoriasis is a disease characterized by scaly skin lesions secondary to keratinocyte hyperplasia. The presence of active T cells in the lesions, experimental observations on disease transfer, and therapeutic efficacy of specific immunosuppressive drugs have led to the identification of the activated T lymphocyte as the primary factor for keratinocyte stimulation. Understanding the pathways of pathogenesis is fundamental in evolving therapies for intervention at different points in the pathogenic model and for curtailing the process. Advances in biotechnological methods have helped to create designer molecules and proteins that specifically recognize target receptors and chemicals that modify their actions. These drugs, termed "biologic response modifiers," are now being studied as specific immunosuppressive agents producing different T-cell and cytokine effects in psoriasis.

Treatment of infants with atopic eczema with pimecrolimus cream 1% improves parents' quality of life: a multicenter, randomized trial

Atopic eczema begins primarily in infancy or early childhood, and sleep loss due to night-time pruritus can have a considerable impact on patients' and parents' quality of life (QoL). In this study, infants (n = 196) with mild to severe atopic eczema were randomized 2:1, double-blind, to receive either pimecrolimus cream 1% (Elidel, Novartis Pharma, Nürnberg, Germany) or the corresponding vehicle bid for 4 wk, followed by a 12 wk, open-label phase and a 4 wk, treatment-free, follow-up period. The parents' QoL was measured at baseline and at the end of the double-blind phase, using the questionnaire 'QoL in Parents of Children with Atopic Dermatitis' (PQoL-AD), thus data presented here refer to the initial 4-wk treatment phase only. After 4 wk of double-blind treatment, an increase in the mean percentage change from baseline in eczema area and severity index of 71.5% was observed with pimecrolimus, compared with 19.4% with vehicle. The increase in efficacy was paralleled by the following mean percentage changes from baseline in the five domains of the questionnaire in pimecrolimus and vehicle, respectively: psychosomatic well-being: 14.6% vs. 6.2%; effects on social life: 6.7% vs. 2.3%; confidence in medical treatment: 10.0% vs. 3.7%; emotional coping: 16.1% vs. 6.5%; acceptance of disease: 19.6% vs. 7.0%. Analysis (ancova) of the dependent variable difference from baseline and the covariate baseline value revealed values of p < 0.05 for all five domains, despite the very short duration of the study. It is concluded that improvements in atopic eczema in infants achieved by treatment with pimecrolimus have a significant beneficial effect on the QoL of parents.

Low systemic absorption and good tolerability of pimecrolimus, administered as 1% cream (Elidel) in infants with atopic dermatitis--a multicenter, 3-week, open-label study

Pimecrolimus cream 1%, a nonsteroid inhibitor of inflammatory cytokines, offers an alternative to corticosteroids in the treatment of atopic dermatitis. Here we evaluate pimecrolimus blood concentrations and tolerability to pimecrolimus cream 1% in 22 infants below 2 years of age with atopic dermatitis (10-92% body surface area affected at baseline). Efficacy was assessed as a secondary objective. Pimecrolimus cream 1% was applied twice daily for 3 weeks. Blood concentrations were low, typically (96% of total 100 concentrations measured) below 2 ng/mL, the majority (71%) remaining below 0.5 ng/mL. The highest concentration observed was 2.26 ng/mL. At steady state, there was no indication of accumulation. Pimecrolimus was well tolerated locally and systemically, with no serious adverse events recorded. Most adverse events recorded (35 in 17/22 patients) were typical of the young pediatric population studied, of mild to moderate severity, and not considered to be study-medication related, with the exception of four local adverse effects limited to the site of cream application. No clinically relevant change was observed in physical examination, vital signs, or laboratory safety parameters. A rapid onset of therapeutic effect was observed within the first four days of treatment. Pimecrolimus cream 1% is well tolerated in infants 3 to 23 months of age treated for 3 weeks, and results in minimal systemic exposure.

Safety and efficacy of topical calcineurin inhibitors in the treatment of childhood atopic dermatitis

Approximately 10-20% of infants in industrialized countries experience atopic dermatitis. In recent decades topical corticosteroids have been the first-choice therapy for treatment of flares. However, this form of therapy may induce skin atrophy, especially after application to facial lesions or with long-term use. Thus, development of new anti-inflammatory topical agents for the treatment of childhood atopic dermatitis was needed. The topical calcineurin inhibitors tacrolimus and pimecrolimus have an effect on various cells of the cutaneous immune system, specifically on T cells, by inhibiting the phosphatase calcineurin and preventing the transcription of proinflammatory cytokines. In several clinical studies of children and adults with atopic dermatitis, topical calcineurin inhibitors were found to be effective both on the face and the trunk and extremities, in both short- and long-term treatment regimens. Tachyphylaxis or rebound were not observed. In most patients an improvement of their eczema occurred during the first week of treatment, as measured by subjective and objective clinical signs of atopic dermatitis. Treatment significantly reduced the incidence of flares and the need for corticosteroids in children and adults. Treatment success, commonly defined as 'excellent improvement' or 'clearing of all lesions', was observed in more than one-third of all children treated with 0.03% or 0.1% tacrolimus or 1% pimecrolimus. Topical application of pimecrolimus and tacrolimus does not lead to significant blood concentrations of these agents in the majority of children with atopic dermatitis, and any increase in blood concentrations decreases after a few days of therapy. No changes in laboratory parameters were observed in short- and long-term studies in patients with atopic dermatitis. The most common adverse effect following the application of topical calcineurin inhibitors is mild to moderate symptoms of irritation such as burning, erythema and pruritus, which occurred in up to 20% of all children treated with tacrolimus and 10% of children treated with pimecrolimus, and usually faded after a few days. In contrast to topical corticosteroids, calcineurin inhibitors do not induce skin atrophy, even after long-term use. Topical calcineurin inhibitors have been proven to be effective and have a good safety profile during short-term and long-term use for up to 1 year with pimecrolimus and up to 4 years with tacrolimus. Given the lack of extensive experience with use of topical calcineurin inhibitors over longer periods, regular use of these agents, particularly in children, should be undertaken only after careful consideration of individual cases. Sun protection should also be advised.

Inflammatory cell numbers and cytokine expression in atopic dermatitis after topical pimecrolimus treatment

BACKGROUND

In several clinical trials the topical application of pimecrolimus was shown to be effective in the treatment of atopic dermatitis (AD). By targeting calcineurin-dependent signaling pathways, pimecrolimus controls cytokine gene expression. The purpose of this study was to investigate the effect of pimecrolimus on the inflammatory infiltrate and cytokine expression pattern in AD upon topical therapy.

METHODS

From 10 patients with acute AD, skin biopsies as well as immunophenotype and cytokine production of peripheral blood mononuclear cells (PBMC) were examined before and 3 weeks after therapy.

RESULTS

The clinical improvement was associated with a marked regression of histopathological features. In particular, the density of the inflammatory infiltrate mostly containing lymphocytes and eosinophils declined. By double immunofluorescent staining, a reduced expression of the T helper (Th) 2 cytokines interleukin (IL)-5, IL-10, and IL-13 in both CD4+ and CD8+ T cells was demonstrated after therapy. Pimecrolimus therapy was also associated with a reduced expression of the Th1 cytokine interferon (IFN)-gamma. Interestingly, the numbers of epidermal CD1a+ dendritic cells increased following treatment. In the peripheral blood, a decrease of lymphocytes and eosinophils was noticed, but the distribution of lymphocyte subpopulations and their capacity of cytokine production did not change.

CONCLUSIONS

Topical pimecrolimus exhibits anti-inflammatory effects in AD by reducing the inflammatory cell infiltrate and cytokine expression in the dermis.

Efficacy and tolerability of three different doses of oral pimecrolimus in the treatment of moderate to severe atopic dermatitis: a randomized controlled trial

BACKGROUND

Adult atopic dermatitis (AD) can seriously affect quality of life of patients and their families, and patients' disease is frequently not satisfactorily controlled with topical therapy. There is a need for alternatives to topical treatment in patients with moderate to severe AD.

OBJECTIVES

To investigate the efficacy and safety of oral pimecrolimus, and to determine the response to three different doses in the treatment of AD.

METHODS

In a double-blind, placebo-controlled, parallel-group, dose-finding study, patients with moderate to severe AD were randomized to receive either placebo, or oral pimecrolimus 10, 20 or 30 mg twice daily. The study consisted of a pretreatment phase, a 12-week double-blind treatment phase, and a 12-week post-treatment phase.

RESULTS

In total, 103 patients were randomized. A clear, dose-dependent therapeutic effect of pimecrolimus treatment was observed, with a statistically significant onset of efficacy at week 2 and the greatest reduction from baseline of the Eczema Area and Severity Index of 66.6% at week 7 in the 30 mg twice daily dose group. Oral pimecrolimus was well tolerated and there were no signs of nephrotoxicity or the induction of hypertension.

CONCLUSIONS

These data demonstrate the clinically relevant efficacy and short-term safety of oral pimecrolimus in adults with moderate to severe AD. Longer-term studies in larger cohorts are now required.

Oral pimecrolimus in the treatment of moderate to severe chronic plaque-type psoriasis: a double-blind, multicentre, randomized, dose-finding trial

BACKGROUND

There is a need for safe and effective alternative treatments for patients with moderate to severe psoriasis.

OBJECTIVES

Pimecrolimus is a calcineurin inhibitor that is being investigated in oral form for the treatment of psoriasis.

PATIENTS AND METHODS

A double-blind, randomized, parallel-group, dose-finding study was performed. Healthy adult outpatients with moderate to severe chronic plaque-type psoriasis (n = 143) were randomized to receive oral placebo or pimecrolimus 10 mg, 20 mg or 30 mg twice daily (b.d.) for 12 weeks.

MAIN OUTCOME MEASURES

The Psoriasis Area and Severity Index (PASI) was used to assess clinical severity of psoriasis. Results were analysed at weeks 7 (primary endpoint) and 13. Safety was assessed by monitoring all adverse events, laboratory investigations (blood chemistry, urinalysis, haematology) and physical examinations.

RESULTS

The change from baseline in PASI at week 7 showed a dose-dependent effect. The differences between each of the two higher doses of pimecrolimus and placebo were statistically significant (P < 0.001; ANOVA). The mean percentage decreases from baseline in PASI in the placebo group and pimecrolimus 10 mg, 20 mg and 30 mg b.d. groups at week 7 were 3.1%, 22.2%, 51.3% and 54.0%, respectively. Most adverse events were of mild or moderate severity. The only adverse event to show a dose-response relationship was a transient feeling of warmth. No clinically relevant effects on laboratory parameters were observed, and no increase in skin infection with pimecrolimus was seen.

CONCLUSIONS

Oral pimecrolimus produces a dose-dependent reduction in psoriasis severity, with doses of 20 mg and 30 mg b.d. being the most effective and well tolerated.

Long-term treatment of atopic dermatitis with pimecrolimus cream 1% in infants does not interfere with the development of protective antibodies after vaccination

OBJECTIVE

We investigated whether treatment of atopic dermatitis with pimecrolimus cream 1% in infants affects the development of a normal antibody response to vaccinations.

METHODS

In all, 91 patients participated in a 1-year, open-label extension to a 1-year double-blind study: 76 used pimecrolimus twice daily at the first signs or symptoms of the disease until clearance for 2 years and 15 only in the second year. Serum concentrations of antibodies against tetanus, diphtheria, measles, and rubella were measured at months 18 and 24.

RESULTS

The seropositivity rates of 93.6% for tetanus, 88.6% for diphtheria, 88.5% for measles, and 84.4% for rubella were comparable with those reported in literature. Seropositivity was not significantly affected by the use of pimecrolimus at the time of vaccinations (+/- 28 days).

CONCLUSIONS

Treatment of atopic dermatitis with pimecrolimus cream 1% in early childhood does not appear to interfere with the development of a normal immune response to vaccinations.

The effect of topical pimecrolimus on keratoconjunctivitis sicca and chronic superficial keratitis in dogs: results from an exploratory study

OBJECTIVE

Pimecrolimus is an ascomycin derivative that interferes selectively with the activation of T cells and mast cells and inhibits the production of inflammatory cytokines. This study evaluated the efficacy of an experimental ophthalmic formulation of pimecrolimus in treating keratoconjunctivitis sicca (KCS) and chronic superficial keratitis (CSK) in dogs. ANIMALS AND PROCEDURES: Eight dogs with KCS and six with CSK were included. The dogs were of various breeds, suffered from chronic conditions, and had been pretreated unsuccessfully. The affected eyes were treated with 1 drop of an experimental, corn oil-based pimecrolimus 1% formulation three times a day. Parameters evaluated included Schirmer tear test (STT), ocular discharge, conjunctival inflammation, corneal inflammatory cell infiltrate and scarring, and comfort level.

RESULTS

The effect of pimecrolimus 1% was pronounced (increase in STT values to higher than 4 mm/min, no signs of inflammation) or moderate (increase in STT values of 3-4 mm/min, mild signs of corneal/conjunctival inflammation) in a total of 6/8 animals with KCS. In 4/6 animals with CSK, the effect was either pronounced (total regression of fibrovascular infiltration into the cornea, no corneal scarring) or moderate (distinct regression of pannus, mild corneal scarring). The response to treatment was unsatisfactory in four of 14 animals.

CONCLUSION

Results of this exploratory study suggest that topical 1% pimecrolimus may be a new effective treatment for keratoconjunctivitis sicca and chronic superficial keratitis in dogs.

Use of pimecrolimus cream 1% (ElidelR) in the treatment of atopic dermatitis in infants and children: the effects of ethnic origin and baseline disease severity on treatment outcome

BACKGROUND

Pimecrolimus cream 1%, a cell-selective inhibitor of inflammatory cytokines, has been shown to be effective in treating atopic dermatitis (AD). This report examines the effect of ethnic origin and baseline disease severity on treatment outcomes in pediatric patients with AD treated with pimecrolimus cream 1%.

METHODS

The analysis included 589 patients aged 3 months to 17 years from three 6-week, randomized, multicenter studies of similar design. Patients were treated with pimecrolimus cream 1% or vehicle twice daily. Efficacy, safety and tolerability in Caucasian and non-Caucasian groups were compared. In addition, the effect of baseline disease severity on treatment outcome was investigated.

RESULTS

A total of 321 Caucasian and 268 non-Caucasian patients [Blacks, Asians and others (including Hispanics)] with mild, moderate or severe disease at baseline were included. Baseline characteristics were comparable between the pimecrolimus and vehicle control groups and between Caucasian and non-Caucasian groups. Significantly higher efficacy [measured by Investigators' Global Assessment and Eczema Area and Severity Index (EASI) scores] was achieved in the pimecrolimus-treated group, compared with the vehicle group, irrespective of ethnic origin. Baseline disease severity had no effect on treatment outcome: patients with both mild and moderate AD responded well to pimecrolimus (absolute change from baseline in EASI score -2.60 and -5.48, respectively; both P < 0.001). Pimecrolimus cream 1% was safe and well tolerated in all ethnic groups and at all levels of disease severity.

CONCLUSIONS

Ethnic origin and baseline disease severity had no effect on treatment outcome with pimecrolimus cream 1% in patients with AD.

Influence of Pimecrolimus Cream 1% on Different Morphological Signs of Eczema in Infants with Atopic Dermatitis

BACKGROUND

In the published studies on the efficacy of the topical immunomodulator pimecrolimus, different eczema scores were used, and the impact on morphological key signs of eczema was not analysed.

OBJECTIVE

To compare the influence of pimecrolimus cream 1% on different standard eczema scores in infants with atopic dermatitis and to analyse the impact of treatment on the individual morphological key signs of eczema.

METHODS

Pimecrolimus cream 1% (n = 129) or double-blind vehicle control (n = 66) was administered for 4 weeks. The Eczema Area and Severity Index (EASI), Investigators' Global Assessment (IGA) and Scoring Atopic Dermatitis Index (SCORAD) were determined and were correlated with each other.

RESULTS

Following treatment with pimecrolimus, the EASI, IGA and SCORAD were significantly reduced on day 29 as compared with the vehicle group (p < 0.001, p < 0.001, p = 0.002, respectively). There was a close correlation between EASI, IGA and SCORAD. The single parameters of the EASI were already significantly decreased by day 4 in the pimecrolimus group as compared to vehicle (each p < 0.001).

CONCLUSION

Treatment with pimecrolimus 1% cream leads to a rapid improvement of all morphological signs of eczema. The close correlation of different scores was shown for the first time.

Pimecrolimus - an anti-inflammatory drug targeting the skin

Pimecrolimus is the most recent member of calcineurin inhibitors available for the therapy for inflammatory skin diseases. It targets T-cells and mast cells and inhibits the production and release of cytokines and other inflammatory mediators, as well as the expression of signals essential for the activation of inflammatory T-lymphocytes. Pimecrolimus has a cell-selective mode of action. In contrast to corticosteroids, it does not affect, e.g., Langerhans'cells/dendritic cells (LC/DC), as demonstrated in vitro with human monocyte-derived DC and in vivo with epidermal LC in mice, nor human primary fibroblasts. As shown in vitro with human skin and by comparison of clinical pharmacokinetic data from patients with atopic dermatitis, pimecrolimus permeates less through skin than tacrolimus and much less than corticosteroids. It, thus, has a lower potential for transcutaneous resorption after topical administration, resulting in a lower risk of systemic effects. Pimecrolimus has high anti-inflammatory activity in animal models of skin inflammation, including a model reflecting neurogenic inflammation, but a more favourable balance of anti-inflammatory vs. immunosuppressive activity than tacrolimus. Pimecrolimus does not affect sensitization in a murine model of allergic contact dermatitis and has a lower potency in various models of immunosuppression after systemic administration, compared to tacrolimus. In conclusion, the results of preclinical studies show that pimecrolimus has a selective pharmacological profile, suited for effective and safe treatment for inflammatory skin diseases.

The role of topical calcineurin inhibitors in atopic dermatitis:

For more than five decades, topical corticosteroids and emollients have been the mainstay of therapy for atopic dermatitis. However, the potential for side-effects limits the clinical utility of corticosteroids in providing long-term disease control. With a unique mode of action that differs from that of corticosteroids, the steroid-free topical calcineurin inhibitors (TCIs), tacrolimus ointment and pimecrolimus cream, provide skin-selective treatment that targets key factors involved in the pathogenesis of this chronic disease. An extensive series of clinical trials involving more than 16,000 patients with predominantly moderate to severe atopic dermatitis in tacrolimus studies and over 2000 patients with primarily mild to moderate disease in pimecrolimus studies has shown that both TCIs provide effective and well-tolerated treatment for atopic dermatitis. Randomized controlled trials have demonstrated that tacrolimus is superior to conventional hydrocortisone-based regimens and does not cause skin atrophy or other steroidal side-effects. Both tacrolimus and pimecrolimus prevent disease flares and provide progressive and sustained disease improvement with long-term therapy. These and other clinical benefits of TCIs are discussed, together with the safety profiles of tacrolimus and pimecrolimus and their use in clinical practice. In addition, this review summarizes findings from the many trials carried out with these agents and outlines how TCIs can provide long-term treatment and control of a chronic skin disease that may persist for years.

Effect of pimecrolimus cream 1% on the long-term course of pediatric atopic dermatitis

BACKGROUND

This report investigates the effect of pimecrolimus cream 1% (Elidel, Novartis pharma AG, Basel, Switzerland), a nonsteroid, cell-selective, cytokine inhibitor on the course of atopic dermatitis (AD), as assessed by changes in body surface involvement and pattern of drug use over time.

METHODS

Data from 961 patients in two 1-year double-blind, multicenter, pediatric studies of similar design were analyzed: 250 infants (aged 3-23 months) were randomized 4 : 1 and 711 children (aged 2-17 years) were randomized 2 : 1 to receive pimecrolimus cream 1% or vehicle, respectively. Emollients were used by all patients to alleviate dry skin and, at the first signs or symptoms of AD, pimecrolimus or vehicle was applied twice daily to prevent progression to flares. If flares occurred in either group, moderately potent topical corticosteroids were mandated.

RESULTS

Pimecrolimus was applied for 68.4% (infants) and 53.8% (children) of study days, and frequency of use of pimecrolimus decreased over time, reflecting improvement in disease control. The mean total body surface area affected decreased continuously over time. Significantly more patients in the pimecrolimus than control groups were maintained without corticosteroid therapy (infants: 63.7% vs. 34.8%, P < 0.001; children: 57.4% vs. 31.6%, P < 0.001, respectively).

CONCLUSION

The need for pimecrolimus therapy decreases over time as the patients' disease improves. Hence, once long-term management of AD with pimecrolimus is established, the burden of disease for both the patient and the caregiver decreases significantly and disease-free periods become more frequent.

Current concepts and review of pimecrolimus in the treatment of psoriasis

The ascomycine macrolactam derivative pimecrolimus has a gene profile of broad anti-inflammatory activity without evidence of toxicity. It exhibits excellent clinical tolerability after 4 weeks and 12 weeks, respectively, of oral treatment, and it is highly effective in a concentration-dependent manner in patients with moderate to severe plaque psoriasis. Although not yet approved, oral pimecrolimus promises to be a novel, highly effective, and well-tolerated drug in the systemic treatment of psoriasis and other T-cell-mediated skin diseases.

Pimecrolimus 1% cream for cutaneous lupus erythematosus

Topical treatment of cutaneous lupus erythematosus usually includes potent glucocorticosteroids. However, prolonged use causes adverse side effects including skin atrophy as the foremost concern. In contrast to glucocorticosteroids, the anti-inflammatory and immunosuppressive macrolactam pimecrolimus has no atrophogenic potential. Affected areas of 11 patients with different forms of lupus erythematosus were treated with pimecrolimus 1% cream under semiocclusive conditions twice daily for 3 weeks. Skin involvement before and after therapy was assessed by means of a clinical score. In all patients, significant regression of skin lesions was observed after therapy (P <.001). This was an open and uncontrolled study on a limited number of cases. We suggest that pimecrolimus 1% cream could be an efficacious and safe treatment option for cutaneous lupus erythematosus.

Therapeutic options for chronic hand dermatitis

Hand dermatitis is a common skin condition that often has a chronic and/or relapsing clinical course. Several clinical forms of hand dermatitis have been described, including contact (i.e., allergic and irritant), hyperkeratotic (i.e., psoriasiform or tylotic), frictional, nummular, atopic, pompholyx (i.e., dyshidrosis), and chronic vesicular hand dermatitis. In the present review, therapeutic options for these types of hand dermatitis are discussed in detail, focusing on treatments for recalcitrant hand dermatitis.

Psoriasis: immunopathogenesis and evolving immunomodulators and systemic therapies; U.S. experiences

BACKGROUND

Psoriasis is a chronic inflammatory skin disorder that is presently without a permanent cure. Up to 40% of patients with psoriasis also develop psoriatic arthritis. The mainstay armamentarium to treat psoriasis systemically includes methotrexate, cyclosporin and oral retinoids, all with significant potential for toxicity and the need for close laboratory supervision. The although the exact mechanism of psoriasis is still unclear, the involvement of T-cell-mediated cytokine expression in the aetiology of psoriasis is becoming clearer. The goal of modern treatment is to target such immune responses that lead to the formation of psoriatic plaques and psoriatic arthritis using selective immunomodulating pharmacotherapy. The advantages of these biological agents are less toxic systemic side-effect profiles that will improve the quality of life in psoriatic patients.

OBJECTIVES

This review article describes current and emerging selective immunotherapies and systemic therapies for the treatment of psoriasis, and will briefly discuss disease immunopathogenesis.

METHODS

Literature review.

RESULTS AND CONCLUSIONS

Given the role of the inflammatory immune responses in the pathogenesis of psoriasis, the goal of modern medicine and pharmacotherapy lies in the design and use of specific targets in cell-mediated immune reactions and the modulation of the expression of various inflammatory cytokines. The clinical evidence of efficacy of some of these new biological immunomodulatory agents from several U.S.-based research studies and clinical experiences is convincing.

Corticosteroids But Not Pimecrolimus Affect Viability, Maturation and Immune Function of Murine Epidermal Langerhans Cells

Given the importance of dendritic cells in the immune response, we investigated the effect of corticosteroids (CS) on the integrity, survival, and function of murine Langerhans cells (LC) in comparison with pimecrolimus, a novel anti-inflammatory drug for the topical treatment of atopic dermatitis. BALB/c mice were treated twice on one day with ethanolic solutions of the compounds. At 24-72 h after the last application, we observed fragmented DNA, caspase-3 activity, and an upregulation of CD95 expression in LC from mice treated with CS but not in LC of pimecrolimus- or vehicle-treated animals. CS-epidermal cell (EC) supernatants but not pimecrolimus-EC supernatants contained significantly lower amounts of soluble factors (GM-CSF, TNF-alpha, IL-1alpha) required for LC survival and maturation than EC supernatants from vehicle-treated mice. With regard to LC maturation, CS but not pimecrolimus inhibited the expression of CD25, CD205, and costimulatory molecules. In line with this, LC from pimecrolimus-treated mice were similar to LC from vehicle-treated mice in their capacity to stimulate antigen-presenting function and migration, whereas LC from CS-treated mice were greatly impaired in these abilities. In summary, our data show for the first time that CS but not pimecrolimus induce apoptosis in LC in situ, implying that the prolonged use of CS could have adverse effects on the skin immune system.

Topical pimecrolimus in the treatment of human allergic contact dermatitis

BACKGROUND

Contact dermatitis is a common clinical problem, with prevalent sensitizers being cosmetics, metals, medicines, and plants. Plants of the Toxicodendron species cause allergic contact dermatitis (ACD) in 50% to 70% of the population. Pimecrolimus is an ascomycin macrolactam developed for the treatment of inflammatory skin diseases and approved by the US Food and Drug Administration for atopic dermatitis. There are studies supporting the effectiveness of macrolactams when administered before antigen challenge, but there are no studies describing the effectiveness of these drugs in the treatment of established human ACD.

OBJECTIVE

To investigate the effect of topical pimecrolimus in the treatment of Toxicodendron-induced ACD once rash is evident.

METHODS

Poison ivy tincture was applied to the bilateral anterior forearms of 12 subjects with Finn Chambers (Allerderm Diagnostic Products, Petaluma, CA). After dermatitis was evident, volunteers treated each arm twice daily with either 1% topical pimecrolimus cream or placebo in a blinded fashion. Outcomes measured were a dermatitis grading score and time to rash and itch resolution.

RESULTS

The median +/- SEM time for rash resolution was 16.55 +/- 1.59 days in the treatment group and 16.27 +/- 1.82 days in the placebo group (P = 0.601). The median time for itch resolution was 4.73 +/- 1.56 days in the treatment group and 4.91 +/- 1.59 days in the placebo group (P = 0.167). The average dermatitis score was 2.26 +/- 0.17 in the treatment group and 2.32 +/- 0.15 in the placebo group (P = 0.62).

CONCLUSIONS

The application of topical pimecrolimus is ineffective in the treatment of ongoing Toxicodendron-induced ACD.

Recent Advances in Treatment Strategies for Atopic Dermatitis

A wide range of different therapeutic regimens are used for atopic dermatitis. Although many treatment modalities are well established worldwide among clinicians, only the minority of these therapy recommendations are based on results of randomised controlled trials (RCTs). To close the gap between such 'generally' recommended therapies and therapies that are based on data from controlled trials, this review focuses not only on the pharmacological and clinical aspects of the currently proven agents, but also on the advantages and disadvantages of therapies that have not yet been completely tested.A review of the available literature concerning the pharmacological profile and also the level of evidence of therapeutic efficacy of all currently known topical and systemic agents for the treatment of atopic dermatitis reveals a large gap between the knowledge concerning the pharmacological action in vitro and the evidence of clinical efficacy in many cases. We agree with the conclusion of previous reviews that numerous therapies for atopic dermatitis urgently require more independent RCTs and especially comparative trials (e.g. corticosteroids vs calcineurin inhibitors). These are required in order to facilitate the choice of therapeutic strategy for the individual treatment of atopic dermatitis, with its broad spectrum of clinical manifestations and potential complications in adult patients and, particularly, in children.Finally, we also review preclinical trials with several new drugs. Immunomodulators appear to promise a new dimension for the future of therapy for atopic dermatitis, especially for severe and otherwise refractory forms or as alternatives to corticosteroids, that is, to treat facial atopic eczema without the risk of adverse effects.

Pimecrolimus: a review of its use in atopic dermatitis

Pimecrolimus (Elidel) is a topically active, nonsteroid, calcineurin inhibitor that has shown efficacy in controlling symptoms of atopic dermatitis in adult and pediatric patients. Topical pimecrolimus 1% cream is approved in the US for the short-term and intermittent long-term treatment of mild-to-moderate atopic dermatitis in non-immunocompromised patients aged >/=2 years who do not respond well to, or may have adverse effects with, conventional treatments. Pimecrolimus 1% cream is an effective and well tolerated treatment for atopic dermatitis in infants, children, adolescents, and adults. Pimecrolimus is effective at reducing the incidence of disease flares and, thus, the need for rescue treatment with topical corticosteroids. The drug also improves the health-related quality of life (HR-QOL) of children and adolescents, and improves the QOL of parents of children with atopic dermatitis. Furthermore, pimecrolimus does not cause skin atrophy, a problem commonly associated with topical corticosteroids, and is not associated with clinically relevant systemic adverse events. Thus, topical pimecrolimus 1% cream is an effective treatment option for the management of mild-to-moderate atopic dermatitis.

Percutaneous absorption of drugs used in atopic eczema: pimecrolimus permeates less through skin than corticosteroids and tacrolimus

For treatment of skin diseases with topical drugs, penetration of the agents into the relevant layers of the skin is required. Permeation through the skin should, however, be kept to a minimum, in order to avoid the risk of systemic side effects. Here we compared the in vitro skin penetration and permeation of two novel drugs used in the therapy of atopic eczema (pimecrolimus and tacrolimus) and three representative corticosteroids (betamethasone-17-valerate, clobetasol-17-propionate, and diflucortolon-21-valerate). Drug concentrations of pimecrolimus and corticosteroids in human skin were found to be in the same order of magnitude. Permeation of pimecrolimus through human skin was, however, lower by factors of 70-110 as compared to the steroids. When pimecrolimus was compared with tacrolimus in human, pig, or rat skin, similar concentrations of the two compounds were measured in the skin, whereas permeation of pimecrolimus through skin was consistently lower by factors of 9-10. Lipophilicity was found to be highest for pimecrolimus, its octanol-water distribution coefficient being higher by factors of 8 and 25-450 than that of tacrolimus and the corticosteroids, respectively. The low permeation of pimecrolimus may be explained by its higher lipophilicity (compared to tacrolimus and the corticosteroids) and higher molecular weight (compared to steroids). In conclusion, pimecrolimus appears to have a favourable skin penetration/permeation profile, featuring a low degree of percutaneous absorption.

Systemic exposure, tolerability, and efficacy of pimecrolimus cream 1% in atopic dermatitis patients

AIMS

To measure pimecrolimus blood concentrations and to evaluate tolerability and efficacy in children and infants treated topically for atopic dermatitis with pimecrolimus cream 1% for three weeks.

METHODS

Three open label, non-controlled, multiple topical dose studies were conducted in children aged 8-14 years (study A, ten patients), and in infants aged 8-30 months (study B, eight patients) and 4-11 months (study C, eight patients). Pimecrolimus blood concentrations were determined on days 4 and 22 of treatment, and at end of study. Efficacy was assessed using the Eczema Area and Severity Index (EASI).

RESULTS

Pimecrolimus blood concentrations were consistently low, typically (81%) below 1 ng/ml, with more than half of the measurements below the assay limit of quantitation (0.5 ng/ml) in studies A and B. The highest blood concentration measured throughout the three studies was 2.6 ng/ml. The cream was well tolerated, locally and systemically. The most common adverse event suspected to be related to study medication was a transient mild to moderate stinging sensation at the application site in 5/26 patients. There was no indication of any systemic adverse effect. The patients responded well to therapy with a rapid onset of action, usually within four days. Median reductions of EASI from baseline at day 22 were 55% (study A), 63% (study B), and 83% (study C).

CONCLUSION

Three weeks treatment of children and infants with extensive atopic dermatitis, using pimecrolimus cream 1% twice daily, is well tolerated and results in minimal systemic exposure, at which no systemic effect is expected.

Small molecule integrin antagonists that bind to the beta2 subunit I-like domain and activate signals in one direction and block them in the other

Leukocyte integrins contain an inserted (I) domain in their alpha subunits and an I-like domain in their beta(2) subunit, which directly bind ligand and regulate ligand binding, respectively. We describe a novel mechanistic class of integrin inhibitors that bind to the metal ion-dependent adhesion site of the beta(2) I-like domain and prevent its interaction with and activation of the alpha(L) I domain. The inhibitors do not bind to the alpha(L) I domain but stabilize alpha/beta subunit association and can show selectivity for alpha(L)beta(2) compared to alpha(M)beta(2). The inhibitors reveal a crucial intersection for relaying conformational signals within integrin extracellular domains. While blocking signals in one direction to the I domain, the antagonists induce the active conformation of the I-like domain and stalk domains, and thus transmit conformational signals in the other direction toward the transmembrane domains.

Pimecrolimus: a review

Pimecrolimus (SDZ ASM 981), an ascomycin derivative, is one of the new classes of immunomodulating macrolactams and was specifically developed for the treatment of inflammatory skin diseases. The interest in pimecrolimus has been substantial because of its significant anti-inflammatory activity and immunomodulatory capabilities and its low systemic immunosuppressive potential. The mechanism of action of pimecrolimus is the blockage of T cell activation. Pimecrolimus (like all ascomycins) is an immunophilin ligand, which binds specifically to the cytosolic receptor, immunophilin macrophilin-12. This pimecrolimus-macrophilin complex effectively inhibits the protein phosphatase calcineurin, by preventing calcineurin from dephosphorylating the nuclear factor of activated T cells (NF-AT), a transcription factor. This results in the blockage of signal transduction pathways in T cells and the inhibition of the synthesis of inflammatory cytokines, specifically Th1- and Th2-type cytokines. Pimecrolimus has also been shown to prevent the release of cytokines and pro-inflammatory mediators from mast cells. Several studies have evaluated the effectiveness of pimecrolimus as a treatment for skin diseases. In animal models of allergic contact dermatitis, topical pimecrolimus was found to be effective. In human studies of allergic contact dermatitis pimecrolimus demonstrated significantly more efficacy than the control treatment. As well, the effectiveness of pimecrolimus 0.6% cream was comparable to 0.1% betamethasone-17-valerate; however, pimecrolimus was not associated with any of the side effects characteristic of a topical steroid. Topical application of pimecrolimus is not associated with skin atrophy. Pimecrolimus is effective and safe in both children and adults with atopic dermatitis. When pimecrolimus 1% cream has been applied to adult atopics, improvement has been observed as early as the first week, with a 72% reduction in severity after 3 weeks. Pharmacokinetic studies have shown very low blood levels of pimecrolimus following topical application, with no accumulation after repeated applications. Following application of pimecrolimus cream occasional transient irritation may be experienced at the application site. Similar results have also been found in children aged 3 months and older following application of pimecrolimus 1% cream. Topical pimecrolimus in psoriasis appears to exhibit a dose-dependent therapeutic effect under semi-occlusive conditions. Pimecrolimus has an enormous potential as a new treatment of inflammatory skin diseases. It has been shown to be effective in atopic and allergic contact dermatitis, with a favorable adverse-effects profile, which includes little effect on the systemic immune response.

Pimecrolimus does not affect the differentiation, maturation and function of human monocyte-derived dendritic cells, in contrast to corticosteroids

Clinically, corticosteroids (CS) are among the first line drugs in the therapy of autoimmune and allergic diseases and potently inhibit the activation of immune cells. However, due to their pleiotropic mode of action, the prolonged use of CS is generally associated with a range of undesirable side-effects. In this study, we compared the activity of pimecrolimus, a novel immunomodulatory drug for the treatment of inflammatory skin disorders, and the CS dexamethasone (Dex) and beta-methasone-valerate (beta-MSV) in different in vitro assays addressing the cytokine-induced differentiation and maturation of monocyte-derived dendritic cells (M-DC), the susceptibility of M-DC to drug-induced apoptosis and the potency of differentiated M-DC to induce primary T cell activation. In contrast to pimecrolimus, Dex and beta-MSV strongly induced apoptosis of M-DC precursors if added at the start of the DC differentiation culture. Flow cytometric analysis of surviving cells on day 6 of culture showed that the expression of several DC-specific antigens such as CD1a, CD40 and CD80 was inhibited by 50% to 80% at concentrations between 1 nm and 10 nm of either Dex or beta-MSV. Furthermore, the presence of CS during the final maturation of M-DC inhibited the synthesis of IL-12p70, the expression of critical DC costimulatory molecules, such as CD83 and CD86 and impaired their ability to activate primary CD4+ T cell proliferation. In contrast, pimecrolimus did not inhibit the LPS-induced secretion of IL-12, surface expression of costimulatory molecules or the maturation of M-DC into potent stimulators of T cells. Taken together, these data indicate that pimecrolimus does not interfere with the differentiation and viability of dendritic cells and their precursors or with the function of mature M-DC to prime naïve T lymphocytes, and thus may have a lower potential than CS to interfere with DC-mediated immunosurveillance.

Investigational therapies for psoriasis

As the pathogenesis of psoriasis is better understood, specific targeted therapies are being developed. In addition to alefacept, etanercept, efaluzimab, and infliximab, discussed in separate articles in this issue, numerous other investigational therapies are currently in clinical trials, some of which will likely be approved in the future. We review the most promising of these therapies and their mechanisms of action.

Pimecrolimus inhibits the elicitation phase but does not suppress the sensitization phase in murine contact hypersensitivity, in contrast to tacrolimus and cyclosporine A

Pimecrolimus (SDZ ASM 981, Elidel) is a nonsteroid inflammatory cytokine inhibitor specifically developed for the treatment of inflammatory skin diseases. Its effect on the elicitation and sensitization phases of oxazolone-induced contact hypersensitivity was compared with tacrolimus and cyclosporine A (CyA) in BALB/c mice using the ear swelling assay. The compounds were administered orally. Elicitation was dose-dependently inhibited by all three compounds. The minimal effective doses were 30 mg per kg (pimecrolimus, tacrolimus) and 90 mg per kg (CyA), respectively. There was no impairment of sensitization by pimecrolimus up to the highest dose tested (120 mg per kg), in contrast to CyA (60% inhibition at 60 mg per kg) and tacrolimus (71% inhibition at 30 mg per kg). Weight and cellularity of the draining lymph nodes in mice treated with tacrolimus or CyA during sensitization were reduced. In addition, proliferation of T cells after secondary stimulation was inhibited in cell cultures from lymph nodes of mice treated with tacrolimus or CyA. Thus, in contrast to tacrolimus and CyA, pimecrolimus exerts a more selective immunomodulatory effect. It does not impair the primary immune response (sensitization phase) but effectively inhibits the secondary phase, the elicitation phase that is the clinical manifestation of contact hypersensitivity.

[Development and pre-clinical aspects of pimecrolimus]

Pimecrolimus (SDZ ASM 981), an ascomycin derivative, inhibits the phosphatase calcineurin and blocks the production of inflammatory cytokines in T cells. In contrast to corticosteroids, pimecrolimus has a cell selective mode of action, exerting e.g. no effect on dendritic cells, which have a central function in the skin-associated immune system. Pimecrolimus shows less permeation through skin than corticosteroids and tacrolimus which indicates a lower potential for systemic side effects after topical application. In animal models pimecrolimus has a marked dose-dependent anti-inflammatory activity. However, treatment with pimecrolimus does not induce skin atrophy in contrast to corticosteroids. In contrast to tacrolimus, pimecrolimus does not impair the primary immune reaction in the sensitization phase of allergic contact dermatitis and has generally less effect on systemic immune reactions. In summary, the pharmacological profile of pimecrolimus suggests high clinical efficacy together with excellent safety.

Elidel (pimecrolimus) cream 1%: a nonsteroidal topical agent for the treatment of atopic dermatitis

Elidel is a steroid-free cream containing a 1% strength of the topical immunomodulator pimecrolimus. Elidel was specifically developed as a treatment for atopic dermatitis (AD) and is approved for use in children as young as 2 years of age. The production of inflammatory cytokines by activated T cells in skin is thought to play an important role in the pathogenesis of AD. Elidel potently suppresses cytokine production by dermal T cells without significantly impairing systemic immune responses. Elidel does not cause steroid-associated local effects, such as dermal atrophy, striae, or telangiectasia. In randomized controlled clinical studies, twice-daily application of Elidel was shown to significantly improve the signs and symptoms of AD in infants, children, and adults. The clinical effect of Elidel on pruritus, the most troublesome symptom of AD, can be observed within 1 week of therapy and is maintained for the duration of treatment. Elidel is well tolerated; the risk of application-site reactions, such as itching or burning, is comparable with that of the vehicle. Adverse effects were generally mild in patients receiving Elidel and occurred at rates comparable with those in patients receiving vehicle treatment. In a 1-year study, Elidel significantly reduced the incidence of flares when used at the first signs and symptoms of acute AD. As a result, overall corticosteroid use to treat flares was significantly lower in patients using Elidel for early intervention.

Tacrolimus ointment for the treatment of psoriasis on the face and intertriginous areas

The safety and efficacy of 0.1% tacrolimus ointment for the treatment of psoriasis on the face, intertriginous areas, or both were evaluated in an open-label, clinical trial of 21 patients with psoriasis. Patients applied 0.1% tacrolimus ointment twice daily for 8 weeks. Efficacy was assessed through the investigator's evaluation of the individual signs and symptoms of psoriasis, and the physician's global evaluation of change in disease status. Assessments of cutaneous atrophy and other adverse events were made throughout the study to evaluate the safety of tacrolimus ointment. A total of 21 patients were enrolled in the study; 21 patients at least 18 years of age received study medication. Statistically significant improvement in the physician's assessment of the individual signs and symptoms was observed during the study. A total of 81% of patients (17 of 21) experienced complete clearance at day 57 (end of treatment). Only 2 patients reported adverse events, which were limited to itching and the feeling of warmth at the application site. None of the patients had atrophy, telangiectasia, or striae develop during the study. In summary, tacrolimus 0.1% ointment may be a safe and effective treatment option for patients with psoriasis on the face, intertriginous areas, or both.

Calcineurin antagonists differentially affect mediator secretion, p38 mitogen-activated protein kinase and extracellular signal-regulated kinases from immunologically activated human basophils

BACKGROUND

Basophils participate in allergic diseases by invading affected tissues and secreting histamine, leukotriene (LT)C4, IL-4 and IL-13 following FcepsilonRI cross-linking. A reduction of basophil mediator production is therefore of considerable therapeutical interest. Macrolactam derivatives, which inhibit calcineurin activation, may be candidates for antiallergic therapy as they reduce both symptoms of inflammatory skin disease in animal models and mast cell degranulation.

OBJECTIVE

To investigate the effects of the calcineurin antagonists ascomycin and cyclosporin A on IgE-dependent mediator release from human basophils.

METHODS

Basophils were purified by Ficoll density centrifugation, elutriation and negative selection. Histamine release was measured spectrofluorometrically; LTC4, IL-4 and IL-13 secretions were assayed by enzyme-linked immunosorbent assay (ELISA). Lysed cells were subjected to Western blotting using specific antibodies to phospho-p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK)-1 and -2.

RESULTS

Ascomycin (0.01 nm to 1 micro m) and cyclosporin A (0.1 nm to 10 micro m) strikingly inhibited (maximally 100%) anti-IgE-induced histamine and cytokine release from basophils, and these actions were unaffected by IL-3 priming. Ascomycin, however, was less potent at blocking LTC4 secretion, whereas cyclosporin A was unable to block production of this mediator. In immunoblotting studies, ascomycin and cyclosporin A reduced IgE-dependent p38 MAPK activation but were less potent at reducing ERK phosphorylation in basophils.

CONCLUSION

Calcineurin antagonists like ascomycin and cyclosporin A block IgE-dependent basophil degranulation and cytokine synthesis. Calcineurin may target p38 MAPK activation, but seems to have less activity on ERK phosphorylation. This is paralleled by a reduced or even absent effect of calcineurin antagonists on eicosanoid production.

Safety and efficacy of nonsteroid pimecrolimus cream 1% in the treatment of atopic dermatitis in infants

OBJECTIVE

The safety and efficacy of a 1% cream formulation of pimecrolimus, a selective, nonsteroid immunomodulator, was studied in infants with atopic dermatitis (AD).

METHODS

During a 6-week double-blind phase, 186 infants with mild/moderate AD were randomly assigned to twice-daily pimecrolimus cream 1% or vehicle. All patients were subsequently treated with open-label pimecrolimus for 20 weeks.

RESULTS

At the end of the double-blind phase, 54.5% and 23.8% of patients in the pimecrolimus and vehicle groups, respectively, were clear or almost clear of AD (P <.001). Similar improvements were observed in the Eczema Area and Severity Index, pruritus assessment, and the care giver's assessment. By the first return visit, 69.9% and 36.5% of pimecrolimus and vehicle-treated patients, respectively, achieved absent or mild pruritus. Efficacy during the double-blind phase was maintained throughout the open-label phase. Vehicle-treated patients transferring to open-label pimecrolimus rapidly achieved disease control comparable to those receiving continuous pimecrolimus. There were no significant differences between groups in application site reactions or skin infections. Most adverse events were mild or moderate and unrelated to treatment.

CONCLUSIONS

Pimecrolimus was safe in infants with AD, with rapid and sustained efficacy. Pimecrolimus holds promise as a valuable new treatment option for the youngest patients with AD.

Pharmacokinetics of Pimecrolimus, a Novel Nonsteroid Anti-Inflammatory Drug, After Single and Multiple Oral Administration

OBJECTIVE

To investigate the pharmacokinetics and tolerability of the new nonsteroid anti-inflammatory pimecrolimus (SDZ ASM 981, Elidel) after oral administration.

DESIGN

A single-dose, randomised, double-blind, placebo-controlled, dose-rising, parallel-group study in healthy male volunteers, and a multiple-dose, randomised, double-blind, placebo-controlled, dose-rising study in patients with psoriasis.

SETTING

One centre in France (single-dose study) and one centre in Austria (multiple-dose study).

METHODS

The first study investigated the pharmacokinetics and tolerability of ascending single oral doses of pimecrolimus (5-60mg). The 60mg dose was repeated in the same subjects after a fat-rich breakfast. The second study investigated the pharmacokinetics, tolerability, safety and efficacy of rising oral doses administered once daily (5-20mg) or twice daily (20 and 30mg) for 28 days. Only the pharmacokinetic, safety and tolerability data of this study are presented.

OUTCOME MEASURES AND RESULTS

Oral administration of pimecrolimus was well tolerated up to the highest dose (60mg). Pimecrolimus was rapidly absorbed (time to maximum blood concentration 0.7-2 hours). A high-fat meal before drug administration delayed the time to peak concentration. Blood concentrations appear to have a long-terminal half-life (30-40 hours after a single dose in fasted subjects, 50-100 hours after the final dose on day 28 in psoriasis patients). After multiple doses, steady state was attained after 6-13 days. Maximum blood concentrations (C(max)) and exposure (area under the concentration-time curve; AUC) were broadly dose proportional. At the highest dose administered in the multiple-dose study (30mg twice daily), a C(max ) of 54.7 microg/L was measured and an AUC(24) of 589.8 microg.h/L was calculated at steady state (day 13).

CONCLUSION

The results support further evaluation of the therapeutic potential of oral pimecrolimus for the treatment of inflammatory diseases.

Pimecrolimus inhibits up-regulation of OX40 and synthesis of inflammatory cytokines upon secondary T cell activation by allogeneic dendritic cells

Pimecrolimus is a new non-steroidal inhibitor of T cell and mast cell activation. In the present study, we compared the potency of pimecrolimus and cyclosporin A (CyA) to inhibit cytokine synthesis of alloantigen-primed T cells and the expression of CD134 (OX40), an inducible co-receptor molecule thought to be critical for the survival and expansion of inflammation-mediating T cells. To mimic the physiological situation of recurrent antigenic stimulation, we have used dendritic cells (DC) as stimulators of purified CD4+ T cells in the primary and secondary allogeneic mixed lymphocyte culture (allo-MLC). Pimecrolimus inhibited surface expression of OX40 and prevented the up-regulation of CD25 and CD54 with a 10-fold higher potency compared to CyA. Similarly, 50% inhibition of allo-DC-mediated T cell proliferation by pimecrolimus was obtained at 0.55 nm, compared to about 12 nm for CyA. Furthermore, pimecrolimus blocked the increase of OX40 on primed T cells restimulated on day 10 in secondary allo-MLC. Allo-DC-primed T cells showed a restricted cytokine profile characterized by the production of TNF-alpha, IFN-gamma and IL-2 but low to undetectable levels of IL-4 and IL-10. The synthesis of TNF-alpha and IFN-gamma and the up-regulation of OX40 on T cells after secondary allogeneic stimulation were almost entirely blocked by 10 nm pimecrolimus. Taken together, pimecrolimus inhibits T cell proliferation and Th1 cytokine synthesis and also prevents the up-regulation of the OX40 co-receptor on primed T cells indicating its potential in the therapy of chronic inflammation and autoimmunity.

Atopic dermatitis: review of immunopathogenesis and advances in immunosuppressive therapy

This paper reviews the theories of the pathogenesis of atopic dermatitis (AD), with a particular emphasis on its immunopathogenesis. The contribution of predisposing factors, immunopathogenic factors and provoking factors in the pathogenesis of AD are considered. Predisposing factors explored in this article include genetics and the disturbance of skin function. Immunopathogenic factors reviewed include T cell dysfunction, biphasic cytokine expression and the role of immunoglobulin E. Provoking factors considered include microbial factors, psychosomatic interactions, contact allergens and irritants, inhalant allergens, food and climate. Immunosuppressive treatments reviewed include cyclosporin, azathioprine, methotrexate, tacrolimus, interferon-gamma, phosphodiesterase inhibitors and pimecrolimus (SDZ ASM 981).

Topical noncorticosteroid immunomodulation in the treatment of atopic dermatitis

At present, the first-line drugs for treating atopic dermatitis are topical corticosteroids. They are effective when used short-term; however, long-term use of the corticosteroids is associated with suppressive effects on the connective tissue, seen as skin atrophy or resistance to therapy. Currently, two topical noncorticosteroid immunomodulators tacrolimus (FK506) and pimecrolimus (SDZ ASM 981) are under development, or already on the market in some countries for atopic dermatitis. These two compounds show structural similarity. In T lymphocytes they bind to the same cellular receptor, the FK-binding protein (FKBP) or macrophilin-12. Tacrolimus shows a 3-fold greater affinity to FKBP compared with pimecrolimus. The tacrolimus/ pimecrolimus-FKBP complex further binds to calcineurin, an enzyme vital for the early activation of T cells. The consequence of calcineurin binding is a lack of activation of both T helper cell types 1 and 2. Further effects of these compounds have been suggested on other inflammatory cells, such as Langerhans cells and mast cells/basophils. In contrast to corticosteroids, no suppressive effects on connective tissue cells have been observed. Taken together, treatment of inflammation results in healing of the barrier function of the skin. This again results in reduced bioavailability of the drug, as compared with systemic use. Placebo-controlled studies have shown the efficacy of both tacrolimus (at 0.03 and 0.1%) and pimecrolimus (at 0.6 and 1%). The main adverse event in these studies has been a burning sensation and increased pruritus at the site of application. Typically, these adverse events are observed only during the first days of treatment. Long-term safety studies, of up to one year, have not revealed any new adverse events. So far, long-term use of topical noncorticosteroid compounds has not been associated with signs of immune deficiency. Although there is currently no evidence for clinically relevant, prolonged adverse effects, some of these, such as an increased risk of photocarcinogenesis, need to be monitored. There is evidence from tacrolimus studies that monotherapy results in better long-term results when compared with combination therapy with corticosteroids. Tacrolimus and pimecrolimus could replace topical corticosteroids as the first-line treatment of atopic dermatitis.

Spotlight on topical pimecrolimus in atopic dermatitis

Pimecrolimus (SDZ ASM 981), an ascomycin derivative, is a nonsteroid, has anti-inflammatory activity, and has demonstrated efficacy in reducing symptoms of atopic dermatitis in adult and pediatric patients when applied topically. Compared with vehicle, topical pimecrolimus 1.0% cream was significantly more effective at reducing symptoms of atopic dermatitis, as measured by the Eczema Area and Severity Index (EASI), in infants aged 3 to 23 months, children aged 2 to 17 years, and adults. The median reductions from baseline in the total EASI score in adults after treatment with pimecrolimus 1.0% or corresponding vehicle twice daily for 3 weeks were 47 and 0%, respectively. In infants and children, treatment with pimecrolimus 1.0% twice daily for 6 weeks resulted in significant decreases in mean EASI scores compared with vehicle. The severity of pruritus was significantly reduced in patients of all age groups after topical treatment with pimecrolimus 1.0% cream. Compared with vehicle, the incidence of eczematous flares was also reduced by intermittent long-term use of topical pimecrolimus 1.0% in adults, children and infants. Sixty-one percent of children treated with pimecrolimus for 1 year completed the first 6 months of treatment without experiencing a flare, compared with 35% of patients who received vehicle. Furthermore, the use of topical corticosteroids for the treatment of uncontrolled flares in adults, children and infants was lower in the pimecrolimus groups than in the vehicle groups. Topical pimecrolimus 1.0% cream is well tolerated in atopic dermatitis patients of all age groups. There were no clinically relevant systemic adverse events reported from any of the studies in patients with atopic dermatitis. The most frequently reported adverse events pertained to application site reactions, such as burning and a feeling of warmth. In conclusion, topical pimecrolimus 1.0% cream has shown efficacy in the treatment of mild to moderate atopic dermatitis in infants, children and adults. Although tolerability data concerning infants and children have not yet been published in full, the drug appears to be well tolerated in all age groups, and there have been no reports of clinically relevant systemic adverse events. Furthermore, pimecrolimus has shown no potential for skin atrophy, a problem commonly associated with treatment with topical corticosteroids. Topical pimecrolimus 1.0% provides a promising and well tolerated treatment option in the management of infants, children and adults with mild to moderate atopic dermatitis.

Pimecrolimus identifies a common genomic anti-inflammatory profile, is clinically highly effective in psoriasis and is well tolerated

The ascomycin macrolactam pimecrolimus is a novel inflammatory cytokine release inhibitor that so far has not been administered systemically to humans. In this phase I/II randomized double-blind, placebo-controlled, multiple rising dose proof of concept study psoriasis patients were treated with oral pimecrolimus or placebo. Gene profiling identified a common genomic profile with a downregulation of genes associated with inflammation but no changes in gene expression linked to drug-related side-effects. A steady state of pimecrolimus was reached after 5-10 d, Cmax, and area under the curve (0-24) was 54.5 ng per ml and 589.9 ng h per ml, respectively, at steady state at the highest dose. There was clear clinical efficacy in patients receiving 20 mg pimecrolimus twice daily and 30 mg twice daily with a reduction of Psoriasis Area and Severity Index by 60% and 75%, respectively. Histopatho logically and immunopathologically there was a reversion of the psoriatic phenotype towards normal. There were no notable clinical, laboratory, kidney function, or immunologic side-effects. We conclude that pimecrolimus taken orally is highly effective in a concentration-dependent manner in patients with psoriasis and on a short-term basis it is well tolerated and this is confirmed by its pharmacogenomic profile. The latter also indicates that pimecrolimus should be equally effective in other inflammatory skin diseases.