Psoriasis is a chronic skin disease with as yet no cure that affects approximately 4.5 million people in the U.S. and 5.7 million people in Europe. About 10% of these people develop chronic inflammation of the joints called psoriatic arthritis. In clinical trials testing a drug based on the discovery of Prof. David Wallach of the Weizmann Institute's Biological Chemistry Department, the condition of psoriasis and psoriatic arthritis patients was greatly improved. The treatment had no adverse effects.
The results were reported by the Swiss-based company Serono
that produces this drug in their Israel-based subsidiary Interpharm Laboratories. Interpharm was founded by Serono 25 years ago for the application of Weizmann Institute discoveries for therapy.
The drug, called onercept, or TBPI, caused significant improvement in the patients' Psoriasis Area and Severity Index (PASI) score. PASI is the globally accepted measure of treatment efficacy in this indication. After 12 weeks of therapy, 54% of patients receiving onercept demonstrated 75% or greater PASI score improvement. Only 12% of patients on placebo exhibited the same level of improvement. In addition, 74% of patients treated with onercept achieved 50% or greater PASI score improvement, versus 26% in the placebo group.
Over the 12-week treatment period patients treated with onercept experienced a significant improvement in quality of life, based on the standard measurements of Short Form 36 (SF-36) and Dermatology Life Quality Index (DLQI).
As a result of this positive outcome, Serono plans to initiate Phase III trials in psoriasis with onercept later this year.
The drug works by neutralizing a hormone called "tumor necrosis factor" (TNF), which is produced by the immune system in response to injury or infection. In various inflammatory diseases, TNF production becomes excessive, leading to the destruction of healthy tissue. In search for natural inhibitors of TNF, Wallach’s team at the Weizmann Institute isolated, from urine, two proteins called TBP1 and TBP2 that can bind TNF specifically and thus block its function. One of these proteins, TBP1, is the currently tested drug. The other, TBP2, is the basis for a drug called Enbrel® that is already widely applied by the Amgen, Inc. for the treatment of rheumatoid arthritis. Antibodies against TNF, which were also first generated in the laboratory of Wallach, are applied by a number of companies (such as Centocor, Inc. whose antibody preparation is called Remicade®) for the treatment of rheumatoid arthritis as well as for the treatment of the inflammatory bowel diseases, Crohn’s disease and colitis.
Prof. David Wallach's research is supported by The Joseph and Bessie Feinberg Foundation; Alfred and Ann Goldstein Foundation; Kekst Family Center for Medical Genetics; and David and Fela Shapell Family Center for Genetic Disorders.