SDZ ASM 981 is an anti-inflammatory macrolactam which binds with high affinity to macrophilin-12. The resulting complex inhibits calcineurin, thus blocking the synthesis of inflammatory cytokines. Twice daily application of topical SDZ ASM 981 1% cream was effective in the treatment of atopic dermatitis in adults and children in clinical trials. Summarised results from 260 patients with atopic dermatitis indicate that the efficacy of SDZ ASM 981 is dose dependent. The highest concentration evaluated (1% cream) was not as effective as betamethasone valerate 1% cream in this 3-week trial. The efficacy of SDZ ASM 981 and clobetasol ointments, used under occlusion, did not differ significantly in 10 patients with chronic psoriasis. Likewise, SDZ ASM 981 0.6% and betamethasone valerate 1% creams were similarly effective in 66 patients with allergic contact dermatitis. Concentrations of SDZ ASM 981 in the blood during topical treatment were invariably below 2.1 microg/L. Oral SDZ ASM 981 20mg or 30mg twice daily were effective in a dose dependent manner in the reduction of psoriasis in adults with no evidence of adverse effects. SDZ ASM 981 was well tolerated in the available trials, exhibiting no potential for systemic adverse reactions and no atrophogenic potential, a problem commonly associated with corticosteroid treatment.