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

Long-term management of atopic dermatitis in infants with topical pimecrolimus, a nonsteroid anti-inflammatory drug

BACKGROUND

Pimecrolimus cream 1% (Elidel, SDZ ASM 981), a nonsteroid selective inhibitor of inflammatory cytokines, is effective in the treatment of atopic dermatitis (AD). In this study we compared early intervention with pimecrolimus cream with treatment with a vehicle control.

OBJECTIVE

The purpose of this investigation was to assess whether early treatment in infants of AD signs/symptoms with pimecrolimus could influence long-term outcome by preventing disease flares.

METHODS

In this 1-year, double-blind controlled study, 251 infants aged 3 to 23 months with AD were randomized 4:1 to a pimecrolimus-based regimen (n = 204) or a conventional treatment regimen (n = 47). Both groups used emollients for dry skin. Early AD signs and symptoms were treated either with pimecrolimus cream to prevent flares or, in the control group, with vehicle. Vehicle was used to maintain blinding conditions. In the event of flares, moderately potent corticosteroid was permitted in both groups. The primary efficacy end point was the incidence of flares at 6 months.

RESULTS

Pimecrolimus significantly reduced the incidence of flares compared with control treatment (P <.001), with 67.6% versus 30.4% of patients completing 6 months with no flare and 56.9% versus 28.3% completing 12 months with no flare. Overall corticosteroid use was substantially lower in the pimecrolimus group: 63.7% versus 34.8% of patients did not use corticosteroids at all during the study. Pimecrolimus was also more effective than control treatment in the long-term control of pruritus and the signs of AD. There were no clinically significant differences in incidence of adverse events between the 2 treatment groups.

CONCLUSIONS

Treatment with pimecrolimus of early signs and symptoms significantly modified the disease course in infants by reducing the incidence of flares and improving overall control of AD. Pimecrolimus was safe and well tolerated.

Efficacy and safety of pimecrolimus cream in the long-term management of atopic dermatitis in children

OBJECTIVE

Pimecrolimus cream (SDZ ASM 981), a nonsteroid inhibitor of inflammatory cytokines, is effective in atopic dermatitis (AD). We assessed whether early treatment of AD signs/symptoms with pimecrolimus could influence long-term outcome by preventing disease flares.

METHODS

Early intervention with pimecrolimus was compared with a conventional AD treatment strategy (ie, emollients and topical corticosteroids). In this 1-year, controlled, double-blind study, 713 AD patients (2-17 years) were randomized 2:1 to a pimecrolimus-based or conventional regimen. Both groups used emollients for dry skin. Early AD signs/symptoms were treated with pimecrolimus cream or, in the conventional treatment group, vehicle to prevent progression to flares. If flares occurred, moderately potent topical corticosteroids were mandated. The primary efficacy endpoint was ranked flares at 6 months. Safety was monitored clinically, and a skin recall-antigen test was performed at study completion.

RESULTS

BASELINE CHARACTERISTICS OF THE PATIENTS: The mean age for both groups was approximately 8 years, and the majority of patients had moderate disease at baseline. PATIENT FOLLOW-UP AND EXPOSURE TO STUDY MEDICATION: The mean duration of follow-up (+/-standard error) was 303.7 (+/-5.30) days in the pimecrolimus group and 235.2 (+/-9.40) days in the control group. The discontinuation rate was significantly higher in the control group than in the pimecrolimus group (51.5% vs 31.6% at 12 months), and proportionately more patients with severe or very severe disease discontinued in the control group. The main reason for the higher discontinuation rate in the control group was unsatisfactory therapeutic effect (30.4% vs 12.4%). This resulted in a substantially higher mean number of study medication treatment days in the pimecrolimus group compared with the control group: 211.9 (69.8% of study days) versus 156.0 (66.3% of study days). Of those patients who completed 12 months on study, 14.2% and 7.0% of patients in the pimecrolimus and vehicle groups, respectively, used study medication continuously.

EFFICACY

Patients in the pimecrolimus group experienced significantly fewer AD flares than those in the control group, according to the primary efficacy analysis on ranked flares of AD (Van Elteren test). The proportion of patients who completed 6 or 12 months with no flares was approximately twice as high in the pimecrolimus group compared with control (61.0% vs 34.2% at 6 months; 50.8% vs 28.3% at 12 months). Fewer flares were observed in the pimecrolimus group regardless of baseline disease severity, so even severe patients derived benefit from the treatment. The analysis of time to first flare showed that treatment with pimecrolimus was associated with a significantly longer flare-free period (log- rank test). Covariate analysis indicated a statistically significant effect on time to first flare of baseline Eczema Area and Severity Index score, and whether patients had "severe" or "very severe" disease at baseline according to the Investigators' Global Assessment, although patients in all baseline disease severity subgroups benefited from treatment. Age had no significant effect. Fewer patients in the pimecrolimus group required topical corticosteroid therapy compared with control (35.0% vs 62.9% at 6 months; 42.6% vs 68.4% at 12 months), and patients in the pimecrolimus group spent fewer days on topical corticosteroid therapy (57.4% vs 31.6% [pimecrolimus vs control, respectively] spent 0 days on topical corticosteroid therapy, 17.1% vs 27.5% 1-14 days, and 25.5% vs 41.0% >14 days over the 12 months of the study). This steroid-sparing effect of pimecrolimus was evident despite pimecrolimus-treated patients being on study longer than patients in the control group. The average proportion of study days spent on second-line corticosteroids was 4.08% in the pimecrolimus group and 9.10% in the control group. Analysis of Eczema Area and Severity Index over time showed significantly lower median scores, thus indicating better disease control in the pimecrolimus group compared with the control group. Similar results were obtained from analysis of the Investigators' Global Assessment (not shown). The treatment groups were well balanced with respect to the number of patients using antihistamines during the study (57.2% vs 62.9%, pimecrolimus vs control, respectively).

SAFETY

There were no appreciable differences between treatment groups in the overall incidence of adverse events. The most frequent adverse events were common childhood infections and ailments, including nasopharyngitis, headache, and cough. The incidence of suspected drug-related adverse events was not significantly different in the pimecrolimus group (24.7% vs 18.7%--pimecrolimus vs control), and the incidence of serious adverse events was low (8.3% vs 5.2%--pimecrolimus vs control). Life-table analysis of incidence of adverse events revealed no significant differences between the treatment groups, except for cough. Local tolerability was good in both treatment groups. The most common application site reaction reported was sensation of burning (10.5% vs 9.3%--pimecrolimus vs control). There were no major differences between treatment groups in the duration or severity of application site reactions, most of which were mild-to-moderate and transient, occurring within the first week of treatment. Skin infections were reported in both groups. There were no between-group differences in the life-table analysis of time to first occurrence of bacterial skin infections nor in the adjusted incidence of bacterial skin infections. Although there were no significant differences between treatment groups in the incidence of individual viral skin infections, the incidence of grouped viral skin infections (12.4% vs 6.3%--pimecrolimus vs control) showed a slightly higher incidence in the pimecrolimus group. Laboratory values and vital signs showed no significant between-group differences. There were no significant differences between treatment groups in response to recall antigens in those patients who remained on study for 12 months.

CONCLUSIONS

Treatment of early AD signs/symptoms with pimecrolimus was effective in preventing progression to flares in more than half the patients, reducing or eliminating the need for topical corticosteroids. The benefits were consistently seen at 6 months across important disease severity subgroups and with respect to the various predefined efficacy endpoints. Furthermore, these benefits were sustained for 12 months, providing evidence that long-term treatment with pimecrolimus leads to better control of AD. Treatment with pimecrolimus was well tolerated and was not associated with clinically relevant adverse events compared with the conventional treatment group. The results reported here offer the prospect of effective long-term management of AD with reduced need for topical corticosteroids.

Novel therapies for psoriasis

The T cell-driven immunopathogenesis of psoriasis has been well recognized since cyclosporine first revolutionized the treatment of psoriasis 20 years ago. Almost all investigative and clinical research subsequently, has concentrated on elucidating the specifics of antigen presentation, T cell interaction and the production of specific cytokines. The role of the keratinocyte, previously thought to be the primary target cell in psoriasis pathogenesis, has been relegated to a secondary role and the mechanism of action of systemic methotrexate in psoriasis has been challenged, the primary role of the T lymphocyte is now well known. While psoriasis has traditionally been treated "ab initio" with topical medications (corticosteroids, vitamin D(3), and retinoid derivatives), either singly, in combination, or with ultraviolet B (UVB) or psoralens and ultraviolet A (PUVA) therapy, the role of systemic medications has assumed greater prominence. Thus, three systemic medications currently are approved worldwide for the treatment of moderate to severe forms of psoriasis, namely cyclosporine, methotrexate and acitretin. The first two are likely to give significant clearing (greater than 75%) in the majority of cases, whereas acitretin is significantly less effective as monotherapy, but may approach methotrexate and cyclosporine in efficacy, if combined with PUVA or UVB phototherapy. The main limitations of these three drugs remain organ toxicity, especially hepatic toxicity with methotrexate, hypertension and nephrotoxicity with cyclosporine, and teratogenicity and mucocutaneous toxicity with acitretin. Thus, the need for more specific systemic therapy, targeting the T lymphocyte. This has become the major area of clinical research interest over the past 5 years, with the promise of longer-term disease control (improved remissions) and less organ toxicities. Currently, there are over 15 of these "biologic" drugs in various stages of development and clinical trials, either by the subcutaneous, intramuscular or intravenous route. The three main variables are the rapidity of onset, percentages of improvement and remission rates. Without exception, these new systemic agents appear to be remarkably free of systemic organ toxicities (liver, renal, bone-marrow, etc.), with adverse effects being limited to mild flu-like symptoms with the anticipated increase in infections (e.g., herpes simplex) being either equal to placebo or only marginally increased. Not all these agents under evaluation give clinical responses equal to methotrexate or cyclosporine (75% or greater clearing in 75% of cases). In addition, response rates may be slower with some therapies versus others. However, the need for intermittent administration even by the injectable route, longer remissions, lack of systemic organ toxicities and the potential for safer usage in females of child-bearing age, make a compelling argument for widespread acceptance by both patients and the dermatological community. Other modalities under clinical evaluation include vitamin D and retinoid drugs, topically and systemically, with effects on nuclear receptors, as well as more specific wavelengths (308 to 311 nm) of UVB phototherapy with application for more localized forms of psoriasis. For the 2 to 3% of the worldwide population of patients with psoriasis the future has never looked brighter.

Topical pimecrolimus: a review of its clinical potential in the management of 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 paediatric 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 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 1.0% cream has shown no potential for skin atrophy, a problem commonly associated with treatment with topical corticosteroids. Pimecrolimus 1.0% cream provides a promising and well tolerated treatment option in the management of infants, children and adults with mild to moderate atopic dermatitis.

[New horizons in the treatment of atopic dermatitis]

Nearly fifty years after their introduction, corticoids continue to be one of the main pillars of dermatological therapy in general and in atopic dermatitis in particular. However, their use is limited by local and systemic adverse effects.There is enormous demand for anti-inflammatory agents not belonging to the corticoid group that would be useful in the different inflammatory dermatoses.In the last few years the therapeutic arsenal for atopic dermatitis has increased with two distinct groups of drugs: topical immunomodulators and leukotriene inhibitors. Both groups of drugs are new and new compounds belonging to these types of drugs will probably appear in the next few years.Among the alternatives to corticoids are the immunomodulators and the most promising of these are macrolide antibiotics. Tacrolimus (FK 506) and pimecrolimus (ASM 981) belong to this group of substances with a high capacity to inhibit T lymphocyte activation. Although they also act on other cells playing a role in atopic dermatitis (mastocytes, Langerhans' cells, B lymphocytes) their action on T lymphocytes seems to be the most important. In T lymphocytes, these drugs act by inhibiting the action of calmodulin, a vital enzyme in the activation chain of these cells that ends in the production of interleukin 2 and other proinflammatory cytokines.The accumulated evidence of the various publications seems to indicate that tacrolimus is a safe and effective treatment of atopic dermatitis in patients aged 2 years or more. The drug was approved for clinical use 3 years ago in Japan and more than 1 year ago in the United States. The number of randomized clinical trials comparing this drug with placebo or various corticoids demonstrate that its action is overwhelming. Its anti-inflammatory action is similar to that of high-potency topical corticoids. Two doses daily are required and the drug has been tested in patients with moderate-to-severe atopic dermatitis. Published data from more than 10,000 patients guarantee its safety. The most frequent short-term adverse effect is a burning sensation in the site of application lasting a few minutes.Pimecrolimus has not yet been commercialized in any country and is currently undergoing phase III clinical investigations. It has been tested in three clinical trials in patients aged more than 3 months old with mild-moderate atopic dermatitis. Its safety profile is good and similar to that of tacrolimus.The number and quality of the data provided by studies of treatment with leukotriene inhibitors (zafirlukast, montelukast and zileuton) is much lower but these substances seem to warrant further investigation. Only five small series undergoing treatment with these products have been published.

Safety and efficacy of pimecrolimus (ASM 981) cream 1% in the treatment of mild and moderate atopic dermatitis in children and adolescents

BACKGROUND

The ascomycin derivative pimecrolimus (ASM 981) is a cell-selective cytokine inhibitor, specifically developed for the treatment of inflammatory skin diseases.

OBJECTIVE

When applied topically, pimecrolimus cream 1% has shown promise as a treatment for inflammatory skin conditions, including atopic dermatitis (AD) in children and adults, allergic contact dermatitis, and chronic contact irritant hand dermatitis in adults.

METHODS

In two independent 6-week, randomized, multicenter studies of identical design, the efficacy and safety of pimecrolimus cream 1% in children with predominantly moderate AD were compared with vehicle. Pooled data from a total of 403 patients were used in the analysis. The primary efficacy parameter was the Investigator's Global Assessment (IGA) score. Secondary parameters included Eczema Area and Severity Index (EASI) and severity of pruritus scores. Subjects were also asked to assess their disease control as uncontrolled, limited, good, or complete.

RESULTS

Significant therapeutic benefits relative to vehicle were observed in the pimecrolimus-treated group at the first efficacy assessment, 8 days after initial application of the study medication (eg, relief of pruritus). At each subsequent postbaseline visit, pimecrolimus-treated patients showed significant improvement relative to controls in all efficacy measures. The medication was well tolerated.

CONCLUSION

Pimecrolimus cream 1% appears to be a safe and effective alternative to currently used therapies for AD.

New and established topical corticosteroids in dermatology: clinical pharmacology and therapeutic use

Currently, topical glucocorticosteroids are the most frequently used drugs in dermatologic practice. Over the years, research has focused on strategies to optimize potency and, in particular, the anti-inflammatory and immunosuppressive capacity of these drugs, while minimizing adverse effects. However, 'ideal' topical corticosteroids have not yet been synthesized. They should be able to permeate the stratum corneum and reach adequate concentrations in the skin without reaching high serum concentrations. Such characteristics can be obtained by increasing the natural lipophilicity of corticosteroids, e.g. by esterification. In the past, many structural modifications have been made to improve the efficacy of topical corticosteroids to produce drugs with greater potency, although this has often been associated with a higher likelihood of adverse effects. Betamethasone dipropionate and clobetasol propionate, known as fifth-generation corticosteroids, are a typical example of potent molecules that can control specific dermatoses very rapidly, but which are associated with a high risk of topical and systemic adverse effects. Recently, steroid components have been synthesized that aim to have adequate anti-inflammatory effects and minimal adverse effects. The newest topical corticosteroids used for the treatment of different dermatoses and allergic reactions of the respiratory tract (in particular asthma) are budesonide, mometasone furoate, prednicarbate, the di-esters 17,21-hydrocortisone aceponate and hydrocortisone-17-butyrate-21-propionate, methylprednisolone aceponate, alclometasone dipropionate, and carbothioates such as fluticasone propionate. These new topical corticosteroids are evaluated in the current review, which compares the risk/benefit ratio of each molecule with established agents. The new molecules, compared with the well known and established corticosteroids, generally have a higher anti-inflammatory effect, good compliance among patients (only a once-daily application is needed), rarely induce cross-sensitivity reactions and have weak atrophogenicity.

Pimecrolimus (Elidel, SDZ ASM 981)--preclinical pharmacologic profile and skin selectivity

The ascomycin macrolactam derivative pimecrolimus (Elidel, SDZ ASM 981; Novartis Pharma AG, Basel Switzerland) is a cell-selective inhibitor of inflammatory cytokines specifically developed for the treatment of inflammatory skin diseases, such as atopic dermatitis, allergic contact dermatitis, irritant contact dermatitis, and plaque-type psoriasis. It inhibits the production of inflammatory cytokines in T cells and mast cells and prevents the release of preformed inflammatory mediators from mast cells. Topically administered pimecrolimus is as effective as the high-potency corticosteroid clobetasol-17-propionate in a pig model of allergic contact dermatitis (ACD). Unlike clobetasol, however, it does not cause skin atrophy. Given orally, pimecrolimus is as potent or superior to tacrolimus (FK 506) in treating ACD in mice and rats. Pimecrolimus also effectively reduces skin inflammation and pruritus in hypomagnesemic hairless rats, a model that mimics acute signs of atopic dermatitis. Pimecrolimus shows only a low potential to impair systemic immune responses when compared with tacrolimus as shown in rats in (1) the localized graft-versus-host reaction, (2) the antibody formation to sheep red blood cells, and (3) kidney transplantation. Pimecrolimus permeates through pig skin in vitro at a 10-times lower rate than tacrolimus, indicating a lower potential for percutaneous absorption in vivo. The data suggest that pimecrolimus combines high anti-inflammatory activity in the skin with a low potential to impair systemic immune reactions.

The ascomycin macrolactam pimecrolimus (Elidel, SDZ ASM 981) is a potent inhibitor of mediator release from human dermal mast cells and peripheral blood basophils

BACKGROUND

The ascomycin macrolactam pimecrolimus (Elidel, SDZ ASM 981) has recently been developed as a novel and cell-selective inhibitor of inflammatory cytokine secretion; it has fewer adverse effects than currently available drugs.

OBJECTIVE

In this study, we investigated the capacity of pimecrolimus to directly inhibit in vitro mediator release from human skin mast cells and basophils.

METHODS

Purified cutaneous mast cells or basophil-containing peripheral blood leukocytes were obtained from healthy human donors and preincubated with pimecrolimus (0.1 nmol/L to 1 micromol/L) in the absence or presence of its specific antagonist (rapamycin), cyclosporin A (100 nmol/L to 1 micromol/L), or dexamethasone (1 micromol/L) and then stimulated with anti-IgE or with calcium ionophore A23187 plus phorbol myristate acetate. Cell supernatants were kept for analysis of histamine, tryptase, LTC4, and TNF-alpha.

RESULTS

Pimecrolimus caused a strong and dose-dependent inhibition of anti-IgE--induced release of histamine from mast cells and basophils (maximally 73% and 82%, respectively, at 500 nmol/L pimecrolimus) and of mast cell tryptase (maximally 75%) and a less pronounced inhibition of LTC4 (maximally 32%) and of calcium ionophore plus phorbol myristate acetate--induced mast cell TNF-alpha release (90% maximum at 100 nmol/L pimecrolimus). In contrast, inhibition achieved during mast cell histamine release was maximally 60% with cyclosporin A and only 28% with dexamethasone.

CONCLUSION

These data demonstrate a marked inhibitory capacity of pimecrolimus on mediator release from human mast cells and basophils with a potency exceeding that of cyclosporin A and dexamethasone. Pimecrolimus might thus be expected to be effective in the treatment of mast cell-- and basophil-dependent diseases.

Sanglifehrin A, a novel cyclophilin-binding compound showing immunosuppressive activity with a new mechanism of action

We report here on the characterization of the novel immunosuppressant Sanglifehrin A (SFA). SFA is a representative of a class of macrolides produced by actinomycetes that bind to cyclophilin A (CypA), the binding protein of the fungal cyclic peptide cyclosporin A (CsA). SFA interacts with high affinity with the CsA binding side of CypA and inhibits its peptidyl-prolyl isomerase activity. The mode of action of SFA is different from known immunosuppressive drugs. It has no effect on the phosphatase activity of calcineurin, the target of the immunosuppressants CsA and FK506 when complexed to their binding proteins CypA and FK binding protein, respectively. Moreover, its effects are independent of binding of cyclophilin. SFA inhibits alloantigen-stimulated T cell proliferation but acts at a later stage than CsA and FK506. In contrast to these drugs, SFA does not affect IL-2 transcription or secretion. However, it blocks IL-2-dependent proliferation and cytokine production of T cells, in this respect resembling rapamycin. SFA inhibits the proliferation of mitogen-activated B cells, but, unlike rapamycin, it has no effect on CD154/IL-4-induced Ab synthesis. The activity of SFA is also different from that of other known late-acting immunosuppressants, e.g., mycophenolate mofetil or brequinar, as it does not affect de novo purine and pyrimidine biosynthesis. In summary, we have identified a novel immunosuppressant, which represents, in addition to CsA, FK506 and rapamycin, a fourth class of immunophilin-binding metabolites with a new, yet undefined mechanism of action.

SDZ ASM 981: an emerging safe and effective treatment for atopic dermatitis

BACKGROUND

SDZ ASM 981 is a selective inhibitor of the production of pro-inflammatory cytokines from T cells and mast cells in vitro. It is the first ascomycin macrolactam derivative under development for the treatment of inflammatory skin diseases.

OBJECTIVES

This study was designed to determine the safety and efficacy of SDZ ASM 981 cream at concentrations of 0.05%, 0.2%, 0.6% and 1.0% in the treatment of patients with atopic dermatitis and to select the concentration to be used in phase III studies.

METHODS

This was a double-blind, randomized, parallel-group, multicentre dose-finding study. A total of 260 patients were randomly assigned to treatment with SDZ ASM 981 cream at concentrations of 0.05%, 0.2%, 0.6%, or 1.0%, matching vehicle cream, or the internal control 0.1% betamethasone-17-valerate cream (BMV). Treatment was given twice daily for up to 3 weeks.

RESULTS

A clear dose-response relationship for SDZ ASM 981 was evident, with 0.2%, 0.6% and 1.0% SDZ ASM 981 creams all being significantly more effective than vehicle (P = 0.041, 0.001 and 0.008, respectively) in terms of baseline to end-point changes in the Eczema Area Severity Index (EASI) and pruritus score. The 1.0% cream was the most effective SDZ ASM 981 concentration. BMV was more effective than the SDZ ASM 981 creams tested in this study. It appears that the efficacy plateau was not reached with the SDZ ASM 981 creams within 3 weeks treatment. SDZ ASM 981 was well tolerated. Burning or a feeling of warmth were the only adverse events reported more frequently in the 0.6% and 1.0% SDZ ASM 981 treatment groups than in the vehicle treatment group (42.9%, 48.9% and 34.9%, respectively). Few systemic adverse events were reported during the study (headache was the most frequent systemic event reported by 15 of 252 patients) and none was considered to be related to treatment. The local tolerability profile of the 1.0% cream was similar to that of the lower concentrations.

CONCLUSIONS

1.0% SDZ ASM 981 cream, which was shown to be safe, well tolerated and the most effective concentration in this study, was selected as the concentration to be further developed in phase III studies.

First experience of topical SDZ ASM 981 in children with atopic dermatitis

BACKGROUND

SDZ ASM 981 is a selective inhibitor of inflammatory cytokine release under development for the topical treatment of atopic dermatitis.

OBJECTIVES

This first paediatric study was designed to measure the systemic exposure to SDZ ASM 981 in young children with atopic dermatitis treated on extensive skin areas.

METHODS

Children 1-4 years of age referred to a tertiary care centre for their atopic dermatitis were treated twice daily for 3 weeks with 1% SDZ ASM 981 cream. SDZ ASM 981 blood concentrations were measured on day 4 and 22 (last day) of treatment, and 1 week after the last application, using a radioimmunoassay with a limit of quantification of 0.5 ng mL(-1). Efficacy was assessed by the Eczema Area Severity Index (EASI).

RESULTS

The 10 patients included had 23-69% of their body surface area (BSA) affected at baseline. Of the 63 SDZ ASM 981 blood concentrations measured, 63% were < 0.5 ng mL(-1); the maximum value observed was 1.8 ng mL-1. No accumulation was evidenced between days 4 and 22. The first two patients experienced a flare of atopic dermatitis that was not controlled by the study medication. In the other patients, the EASI improved by 8-89% at 3 weeks of treatment.

CONCLUSIONS

In these children 1-4 years of age, blood concentrations of SDZ ASM 981 during topical treatment with the 1% cream were consistently low even in the children with the most extensive areas treated (up to 69% of their BSA).

What are the most promising strategies for the therapeutic immunomodulation of allergic diseases?

Specific immunotherapy and other immunomodulatory strategies have long been a stronghold in the management of allergic diseases. In particular, "immunodeviation-therapy" or "vaccination for allergies", i.e. the redirection of Th2-type immune responses towards a Th1-response pattern, has become an ever more popular concept. The present feature of CONTROVERSIES complements our previous discussion of atopy (Röcken et al., Exp Dermatol 7: 97--104, 1998), and is dedicated to a critical analysis of the general problems and limitations one faces with the main immunomodulatory strategies traditionally considered in this context. We also explore alternative approaches that appear promising in order to achieve both a more effective and/or a more specific immunotherapy of allergic diseases. Given that the mast cell remains a key protagonist in the pathogenesis of allergic diseases finally, this feature examines how innovative, more selectively mast cell-targeted strategies may be developed for the management of allergic diseases.

The new topical ascomycin derivative SDZ ASM 981 does not induce skin atrophy when applied to normal skin for 4 weeks: a randomized, double-blind controlled study

BACKGROUND

SDZ ASM 981 is a selective inhibitor of inflammatory cytokines released from T lymphocytes and mast cells, which has been developed for the treatment of inflammatory skin diseases.

OBJECTIVES

In the present study, the atrophogenic potential of SDZ ASM 981 1% cream in humans was compared with that of medium and highly potent topical steroids, and vehicle.

METHODS

Four different preparations, SDZ ASM 981 1% cream, the corresponding vehicle of SDZ ASM 981 1% cream, betamethasone-17-valerate 0.1% cream and triamcinolone acetonide 0.1% cream, were applied to the volar aspect of the forearms of 16 healthy volunteers, twice daily, 6 days a week, for 4 weeks. Skin thickness was evaluated by ultrasound examination, clinical signs of atrophy by stereomicroscopy, and epidermal thickness was assessed by histology.

RESULTS

Both topical corticosteroids induced a significant reduction in skin thickness, as compared with SDZ ASM 981 1% cream and vehicle, which were shown to be equivalent. The difference in skin thickness (measured by ultrasound examination) between patients treated with SDZ ASM 981 1% cream and those receiving either of the two topical steroids was significant from day 8 onwards. Histological analysis performed at day 29 showed significant epidermal thinning with topical steroids compared with SDZ ASM 981 1% cream or the vehicle. Conclusion The lack of atrophogenic properties of SDZ ASM 981 1% cream in this short-term study demonstrates its potential as long-term treatment for inflammatory skin diseases, thus overcoming a major drawback of topical steroids. This may also be important for the treatment of children, and sensitive areas of skin, such as the face and skin-folds.

New approaches to topical therapy

Despite the rapid and proven efficacy of topical corticosteroids, side-effects can limit their clinical usefulness. Topically active macrolide immunosuppressants such as ascomycin and tacrolimus appear to provide comparable therapeutic potency without significant local or adverse effects. Data from ongoing studies will be crucial in determining the safety of these agents in the long term, and also their place within the current therapeutic armamentarium available for patients with atopic dermatitis. Enzyme inhibitors of PLA(2) and PDE 4 currently in the very early stages of clinical development also show potential promise as additional alternative strategies to topical treatment and may perhaps act as steroid sparing agents. Having been in the therapeutic doldrums for years, topical management of atopic dermatitis is likely to show great changes in the very near future.

Atopic dermatitis: new insights and opportunities for therapeutic intervention

Atopic dermatitis (AD) is a chronic inflammatory skin disease that frequently predates the development of allergic rhinitis or asthma. It is an important skin condition with significant costs and morbidity to patients and their families; the disease affects more than 10% of children. Recent studies have demonstrated the complex interrelationship of genetic, environmental, skin barrier, pharmacologic, psychologic, and immunologic factors that contribute to the development and severity of AD. The current review will examine the cellular and molecular mechanisms that contribute to AD as well as the immunologic triggers involved in its pathogenesis. These insights provide new opportunities for therapeutic intervention in this common skin condition.

Atopic dermatitis-like symptoms in hypomagnesaemic hairless rats are prevented and inhibited by systemic or topical SDZ ASM 981

Magnesium deficiency in hairless rats results in a transient erythematous rash within several days, the pathogenetic mechanisms of which are not yet well defined. However, the extremely pruritic rash closely mimics the acute clinical features of atopic dermatitis. Owing to the similarity of clinical signs between hypomagnesaemic rats and patients with atopic dermatitis, this rodent skin condition holds promise as a model for the in vivo evaluation of new treatment modalities against pruritic inflammatory skin conditions. The efficacy of the new ascomycin macrolactam derivative SDZ ASM 981 was tested in hypomagnesaemic rats by systemic or topical administration using prophylactic or therapeutic treatment regimens. Oral treatment of diseased rats with SDZ ASM 981 (12.5 mg kg-1 daily) inhibited the erythematous pruritic rash within 1 day after the start of treatment. This was associated with a clear reduction in histaminaemia, leucocytosis, eosinophilia and serum nitric oxide levels. The same daily oral dose of SDZ ASM 981 administered before the onset of the rash proved to be an efficacious prophylactic treatment regimen to prevent signs. Topical treatment of the ears with 0.4% SDZ ASM 981 locally inhibited and prevented inflammatory changes in a therapeutic and prophylactic treatment regimen, respectively. The histo- and immunopathological skin changes, as well as the numbers of degranulated mast cells in the dermis, were reversed towards normal after oral and topical administration. The pharmacological activity of SDZ ASM 981 reported here corresponds well to its anti-inflammatory and antipruritic activity observed in atopic dermatitis patients, confirming the usefulness of this rat model in drug evaluations.

Ascomycins: promising agents for the treatment of inflammatory skin diseases

Ascomycin derivatives represent a novel class of anti-inflammatory macrolactams currently under development for the treatment of skin diseases. The main biological effect of ascomycins is an inhibition of the synthesis of both Th1 and Th2-type cytokines in target cells. Several compounds are being developed with SDZ ASM 981 being at the most advanced stage. It has high anti-inflammatory activity in animal models of skin inflammation and does not induce skin atrophy. Topical application of SDZ ASM 981 was shown to be effective in atopic dermatitis (AD), allergic contact dermatitis and also in psoriasis under semi-occlusive conditions. In patients with AD, SDZ ASM 981 cream led to consistently low systemic exposure even when applied on large areas of skin. SDZ ASM 981 overcomes the drawbacks of current topical therapies of inflammatory skin diseases as its safety profile is better than that of topical corticosteroids. Studies continue to investigate its efficacy and safety in the treatment of inflammatory skin diseases.