DESCRIPTION AND STATUS
PRTX-100, a natural compound, has been used in various FDA-approved extracorporeal immunoadsorption systems for both idiopathic thrombocytopenic purpura and rheumatoid arthritis.
The compound aims to restore normal immune system function by binding directly to the surface of monocytes (white blood cells responsible for phagocytosis [ingestion] of foreign substances in the body) and a subset of B-cells that are potentially involved in the development and progression of certain autoimmune diseases, including idiopathic thrombocytopenic purpura. This mechanism of action allows PRTX-100 to modulate the function of these cells and restore balance back to the patient’s immune system. The ability of PRTX-100 to inhibit phagocytosis of platelets in patients suffering from idiopathic thrombocytopenic purpura, therefore, makes this a potentially important new therapy.
When tested in autoimmune disease models, PRTX-100 was able to reverse the pathologic process, resulting in restoration and maintenance of normal, healthy tissue. Specifically, PRTX-100 has proven effective in clinical standard mouse autoimmune models, including:
BXSB Mice
These animals are genetically predisposed to autoimmune diseases. This model is therefore used to evaluate drugs for autoimmune diseases such as lupus, Crohn’s disease and others. This genetic model more closely approximates the human condition in that it is complex, multi-factorial and usually treated by multiple drug regimens. In these studies, mice were treated with PRTX-100 and sacrificed at regular intervals. Their organs were weighed and sectioned for histological analysis and their spleens were used for immunological assays. Spleen enlargement, or splenomegaly, was significantly reduced in treated animals compared with the controls at almost every time point, demonstrating the ability of PRTX-100 to delay the onset and severity of this disease. Treatment with PRTX-100 also reduced non-specific immunoglobulin production and specific autoantibody production and restored the number and function of immune cells (T and B cells). These results represent improvement in the context of an animal setting in this complex disease syndrome.
Additional studies in non-human primates to determine the pharmacokinetics of PRTX-100 have indicated more favorable dosing schedules. Since non-human primates are more closely related to humans, Protalex performed additional toxicology studies in monkeys to establish the toxicity and starting doses in humans.