Systemic Cyclosporin in the Treatment of Psoriasis

Cyclosporin was isolated in 1970, by Jean François Borel at Sandoz Laboratories (Basel, Switzerland), from the soil fungus Tolypocladium inflatum (Borel et al., 1995; Amor et al., 2010). The compound was initially identified as a possible antifungal agent, but it was subsequently shown to have limited antifungal activity. However, in 1976, the drug demonstrated potent immunosuppressive properties, and two years later, it was successfully shown to prevent renal allograft rejection in renal transplant recipients. A year later, a pilot study showed that cyclosporin improved psoriasis in patients treated for rheumatoid and psoriatic arthritis. Ultimately, in the early 1990s, cyclosporin was approved in Europe for the treatment of psoriasis and atopic dermatitis. In 1997, the United States Food and Drug Administration approved a microemulsion formulation of cyclosporin (Neoral®; Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA) for the treatment of severe psoriasis in adults. Worldwide, cyclosporin has been used extensively in various dermatological disorders: e.g. pyoderma gangrenosum, and refractory chronic idiopathic urticaria (Amor et al., 2010; Vena et al., 2006).