Efficacy and safety of pimecrolimus cream 1% in adult patients with vitiligo: Results of a randomized, double-blind, vehicle-controlled study

BACKGROUND

Vitiligo is an acquired, pigmentary skin disorder which is disfiguring and difficult to treat. In an earlier open label study in adult patients with vitiligo, pimecrolimus cream 1% was reported to have similar efficacy as clobetasol propionate 0.05%. We performed a double-blind, intrapatient comparison of pimecrolimus cream 1% with placebo cream.

PATIENTS AND METHODS

Twenty adult Caucasians with symmetrical vitiligo (predominantly on extremities, none in the face) were treated b.i.d. for 6 months left/right with pimecrolimus/vehicle (N = 10) or vehicle/pimecrolimus (N = 10), respectively. Primary efficacy endpoint was the size of the target lesion at month 6 and secondary efficacy endpoint was re-pigmentation.

RESULTS

Treatment with pimecrolimus cream 1% or vehicle resulted in no significant change in mean target lesion size. Modest repigmentation (1-25%) was noted with pimecrolimus at month 2 in 12 of 17 patients (vehicle: 9 of 17 patients). Afterwards, the number of patients who experienced an improvement of pigmentation steadily decreased (3 of 14 patients with pimecrolimus and 2 of 14 with placebo at month 6). Treatment was well tolerated. There were no treatment-related adverse events, no induction of skin atrophy nor any other application site side effects.

CONCLUSION

In this group of adult patients with symmetrical vitiligo, treatment of body lesions (except face) with pimecrolimus cream 1% could not be shown to be effective.

Discovery of Topical Calcineurin Inhibitors and Pharmacological Profile of Pimecrolimus

Using a newly developed model of allergic contact dermatitis in pigs, calcineurin inhibitors of the tacrolimus and ascomycin type were shown to have a highly anti-inflammatory action after topical application. These findings provided the first pharmacological evidence of the efficacy of this novel class of topical agents in the treatment of inflammatory skin diseases, and, thus, their potential to become the first alternative to corticosteroids in more than 40 years. As a result of a large research program into ascomycins, pimecrolimus (Elidel(R), SDZ ASM 981) was selected for development due to its favorable pharmacology and safety profile, alongside tacrolimus (Protopic(R), FK 506). In vitro, pimecrolimus inhibits the transcription and release of pro-inflammatory cytokines in T cells. Similar to the corticosteroids, betamethasone-17-valerate and dexamethasone, pimecrolimus is effective at nanomolar concentrations. Targeting mainly T cells, pimecrolimus has, however, a more specific mode of action. Moreover, in contrast to corticosteroids, pimecrolimus has no effect on Langerhans' cells, the professional antigen- presenting dendritic cells of the skin that are crucial for local immunosurveillance. When applied topically, pimecrolimus exerts a high and selective anti-inflammatory activity in the skin, shows minimal percutaneous absorption, and has a low potential to affect systemic immunoreactions. Pimecrolimus cream 1% has proven to be well tolerated, safe, and highly effective in clinical studies in patients with atopic dermatitis.

Novel cyclosporin derivatives featuring enhanced skin penetration despite increased molecular weight

Topical cyclosporin A (CsA, 1) is not effective in the treatment of skin diseases, due to its low skin penetration. Following a prodrug strategy, a series of novel derivatives of 1 and of 2-[O-(2-hydroxyethyl)-d-Ser(8)]-CsA (SDZ IMM 125, 5) with potentially enhanced skin penetration properties were synthesized, in order to achieve higher levels of the active parent drugs in the skin. Permeation through skin and prodrug/drug levels in the skin were measured in vitro using rat and human skin. Introduction of a polar side chain, either in the form of a positively charged quaternary amine, a negatively charged phosphate or sulfate, or an amphiphilic phosphocholine moiety, generally increased permeability. Maximal increase in permeability through skin relative to CsA was up to 300-fold with rat skin, and up to 16-fold with human skin. Penetration into skin, as evaluated by measurement of prodrug/drug concentrations in the skin after 48 h, could be enhanced up to 14-fold (rat and human skin). Increases of permeation rates and skin concentrations showed no strict correlation. Using the phosphate 10 as prodrug, a 2.5-fold higher concentration of the active parent compound (5) could be achieved in rat skin as when administering 5 itself. The results demonstrate that in contrast with the '500 Dalton rule', which postulates poor skin penetration of molecules larger than 500 Da, high skin permeation can be achieved also with compounds of a molecular weight in the range between 1200 and 1600 Da. Results also indicate that in principle higher skin levels of active drug can be attained with a prodrug strategy in this class of compounds.

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.

Initial study of arthropod succession on pig carrion in a central European urban habitat

We conducted a carrion succession study within a restricted urban backyard in the city of Vienna, Austria (16 degrees 22'E, 48 degrees 12'N) from May to November 2001 to analyze sequence and composition of the local carrion visiting fauna. Two medium sized clothed domestic pig carcasses (Sus scrofa Linnaeus), were used as surrogate human models. In total, 42 arthropod species from the families Calliphoridae, Sarcophagidae, Sepsidae, Piophilidae, Muscidae, Fanniidae, Sphaeroceridae, Phoridae, Drosophilidae, Anthomyiidae, and Lauxaniidae (Diptera), Formicidae, Braconidae, Pteromalidae, and Vespidae (Hymenoptera), Silphidae, Staphylinidae, Histeridae, Cleridae, and Dermestidae (Coleoptera), as well as species from the orders Isopoda and Acari were collected during the decomposition of these carcasses. A significant feature in this study was the high abundance of Calliphora vomitoria (L.) and Chrysomya albiceps (Wiedemann). In the experiment conducted May to June, larvae and adults of C. vomitoria outnumbered all other blow fly species, followed by Protophormia terraenovae (Robineau-Desvoidy), C. vicina Robineau-Desvoidy, and Lucilia sericata (Meigen). C. vomitoria is generally considered to be rural in distribution, where it prefers shaded locations. The presence of this species in rural as well as in urban habitats in Austria precludes this species as biogeographic indicator. In the study beginning in August large numbers of female adults of the nonindigeous blow fly C. albiceps began oviposition at day 3 after placement of the cadaver. The predatory second and third instars of C. albiceps larvae subsequently almost monopolized the cadaver. C. albiceps is generally described as tropical and subtropical species. The observed northward expansion of its range beyond southern Europe obviously decreases the value of C. albiceps in estimating place of death, in that it is no longer exclusive to southern regions. Our results clearly show, that caution must be used when drawing conclusions from succession data generated in different geographic areas. Moreover, this study demonstrates, that arthropod mediated decomposition of a 44 kg exposed pig carcass in a central European urban habitat can be completed within 3 wk.

Temperature-related development of the parasitoid wasp Nasonia vitripennis as forensic indicator

Development times of the forensically significant parasitic wasp Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae) from oviposition to pupation, and from oviposition to adult emergence, were studied in the laboratory at temperatures of 15-35 degrees C using host pupae of the blowfly Protophormia terraenovae (Robineau-Desvoidy) (Diptera: Calliphoridae). Total developmental time of N. vitripennis from oviposition to adult emergence (mean+/-SD) was 43.5+/-2.4, 22.5+/-1.1, 14.8+/-1.7 and 11.3+/-0.9 days when reared at 15, 20, 25 and 30 degrees C, respectively. At 35 degrees C, N. vitripennis did not develop successfully. The rate of total immature development (1/days) increased with temperature. From linear regression of development rates, it was determined that the minimum threshold (tL) for total immature development was 9.8 degrees C (approximately 10 degrees C). Above this threshold, the overall thermal constant (K) for N. vitripennis was found to be 224.3+/-1.7 degree-days.

[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.

Pimecrolimus: a review of pre-clinical and clinical data

Pimecrolimus (Elidel) is a novel cell-selective inhibitor of inflammatory cytokines that has specifically been developed for the treatment of inflammatory skin diseases due to its favourable skin selective pharmacological profile. Therapeutic efficacy and safety of pimecrolimus cream 1% has been established in the short-term treatment and the long-term management of atopic eczema in clinical studies in adults, children and infants. It rapidly relieves pruritus, and redness and swelling disappear or are only mild in up to 70% of pimecrolimus treated patients during the first three weeks. When applied at the first signs and symptoms of atopic eczema, pimecrolimus has proven to prevent flare progression and to provide superior long-term disease control compared with a conventional treatment, based on reactive use of corticosteroids. Pimecrolimus cream 1% is well tolerated, even on sensitive areas such as the face and neck. Blood concentrations remain low, even when extensive body areas are treated and no clinically significant systemic effects have been observed during short- or long-term clinical studies with pimecrolimus.

Large interarcuate spaces in the cervical vertebral column of the tyrolean mountain sheep

Large interarcual spaces have been described between the arcus vertebrae C5/C6 and C6/C7 in the cervical vertebral column of Nubian goats. This aperture enables direct access to spinal cord and rootlets without the need to perform a hemilaminectomy. The present study was performed in order to determine whether these large interarcual spaces can also be found in the vertebral column of the Tyrolean mountain sheep, as this small ruminant, which is anatomically very similar to the Nubian goat, is frequently used for experimental purposes at the Surgical University Clinic in Austria. The carcasses of 10 sheep (six females, four males; range of age: 2.5-6 years, range of weight: 52-89 kg) were dissected and the vertebral column was exposed. All 10 sheep showed elliptic openings between the fourth cervical and the first thoracal vertebrae. Three sheep had additional openings between the first and the second thoracal vertebrae. All openings were covered solitarily by the ligamentum flavum and under this ligamentum lay the spinal cord without any further osseous or ligamentous protection. These findings are not mentioned in the common textbooks of veterinary anatomy and deserve attention, as they can be a step forward towards non-traumatic experimental surgery on the spinal cord.

[An historical review of the use of maggots in wound therapy]

Since William Baers first publication about the use of fly larvae in the treatment of wounds in the year 1931 more than hundred papers have been published about this topic. However, little is known about the first observations that finally led to the widespread use of this technique. The current paper reviews the historic background of the utilization of blowfly-maggots in wound therapy until its decline with the advent of antibiotic drugs and its revival since the eighties of the 20th century.

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.

Effect of temperature on Lucilia sericata (Diptera: Calliphoridae) development with special reference to the isomegalen- and isomorphen-diagram

Developmental behavior of eggs, larva and pupa of the blowfly species Lucilia sericata (Meigen) were studied under 10 different temperature regimes. Data from these studies were used to construct the isomegalen-diagram. In this diagram, time from hatching to peakfeeding is plotted against temperature, each line representing identical larval length at various temperatures. If the temperature is roughly constant, as is the case with corpses found indoors, the age of the maggot can be read off instantly from its length, provided that the maggot has not entered the migratory phase. Where temperature is variable, an age range can be estimated between the points where the measured larval length cuts the graph at the maximum and minimum temperatures recorded. Equally, the isomorphen-diagram representing all morphological stages from oviposition to eclosion should be used, if maggots in the migratory phase or pupae or puparia are recovered from the scene. The isomegalen- and the isomorphen-diagrams could facilitate a quick and more precise estimate of the postmortem interval even for the inexperienced investigator. In addition, our results vary from those of other investigators, suggesting a different thermal behavior of the holarctic blowfly L. sericata in various zoogeographic regions.

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.

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

SDZ ASM 981, a novel ascomycin macrolactam derivative, has high anti-inflammatory activity in animal models of allergic contact dermatitis and shows clinical efficacy in atopic dermatitis, allergic contact dermatitis and psoriasis, after topical application. Here we report on the in vitro activities of this promising new drug. SDZ ASM 981 inhibits the proliferation of human T cells after antigen-specific or non-specific stimulation. It downregulates the production of Th1 [interleukin (IL)-2, interferon-gamma] and Th2 (IL-4, IL-10) type cytokines after antigen-specific stimulation of a human T-helper cell clone isolated from the skin of an atopic dermatitis patient. SDZ ASM 981 inhibits the phorbol myristate acetate/phytohaemagglutinin-stimulated transcription of a reporter gene coupled to the human IL-2 promoter in the human T-cell line Jurkat and the IgE/antigen-mediated transcription of a reporter gene coupled to the human tumour necrosis factor (TNF)-alpha promoter in the murine mast-cell line CPII. It does not, however, affect the human TNF-alpha promoter controlled transcription of a reporter gene in a murine dendritic cell line (DC18 RGA) after stimulation via the FcgammaRIII receptor. SDZ ASM 981 also prevents the release of preformed pro-inflammatory mediators from mast cells, as shown in the murine cell line CPII after stimulation with IgE/antigen. In summary, these results demonstrate that SDZ ASM 981 is a specific inhibitor of the production of pro-inflammatory cytokines from T cells and mast cells in vitro.

Ascomycin macrolactam derivative SDZ ASM 981 inhibits the release of granule-associated mediators and of newly synthesized cytokines in RBL 2H3 mast cells in an immunophilin-dependent manner

Mast cells play an important role in the pathological development of many inflammatory and allergic diseases and inhibition of mast cell activation is a potential target for therapeutic intervention. Therefore, the effect of the novel ascomycin macrolactam derivative SDZ ASM 981 on Fc epsilonRI-mediated activation of rat basophilic leukemia (RBL) cells, as a model for mast cell activation, was investigated. First, the ability to inhibit different mast cell immunophilins in vitro was tested. Using recombinant macrophilin-12 (FKBP-12), inhibition of rotamase activity with an IC50 of approximately 6 nM was observed. The rotamase activity of cyclophilin A (18 kDa) was not affected. Secondly, the effect of SDZ ASM 981 on Fc epsilonRI-mediated mast cell activation was investigated in the RBL cell model. SDZ ASM 981 inhibited exocytosis of preformed mediators (e.g. serotonin) with an IC50 of approximately 30 nM. Transcription and release of newly synthesized mediators (e.g. TNF-alpha) was inhibited with an IC50 of approximately 100 nM. The inhibitory effect of SDZ ASM 981 was antagonized by rapamycin. We conclude that SDZ ASM 981 is a potent inhibitor of Fc epsilonRI-mediated activation of mast cells in vitro. The mechanism of action involves formation of (calcineurin) inhibitory complexes with macrophilins. We suggest that this inhibitory action on mast cells might contribute to the antiinflammatory effect of SDZ ASM 981 observed in vivo (e.g. in aptopic dermatitis and psoriasis).

A novel anti-inflammatory drug, SDZ ASM 981, for the topical and oral treatment of skin diseases: in vivo pharmacology

There is a need for safe and effective therapies for inflammatory skin diseases. Current topical and systemic treatment of psoriasis is effective but suffers from side-effects or is inconvenient. The therapeutic armamentarium for atopic dermatitis is very limited and far from satisfactory. In vivo preclinical data are presented for SDZ ASM 981, a novel ascomycin macrolactam derivative with high anti-inflammatory activity. Anti-inflammatory activity was observed in mouse, rat and pig models of allergic contact dermatitis. In the pig model, topical SDZ ASM 981 was as effective as the ultrapotent corticosteroid clobetasol-17-propionate, and when compared with a series of commercial topical corticosteroid preparations, 0.1% SDZ ASM 981 had equivalent efficacy to clobetasol-17-propionate (0.05%), the most potent product on the market. Unlike the corticosteroid, however, SDZ ASM 981 did not cause skin atrophy in pigs. SDZ ASM 981 potently inhibited allergic contact dermatitis in mice and rats when given systemically, and oral treatment was more effective than cyclosporin A in rats. Furthermore, SDZ ASM 981 has a low potential for affecting systemic immune responses, as demonstrated in rat models of localized graft vs. host reaction and allogeneic kidney transplantation. Preclinical results suggest that SDZ ASM 981 has the potential to be a well-tolerated and effective drug for topical as well as oral treatment of inflammatory skin diseases.