A new therapeutic strategy is followed by the monoclonal antibody BT-061 from Biotest, which is currently in clinical development. Current knowledge suggests that BT-061 has an influence on superimposed regulatory mechanisms. The antibody attaches to an important immunological control center, the regulatory T cells (Tregs) (see illustration), whose control function malfunctions in autoimmune diseases.
Current data from preclinical and clinical development lead Biotest to speculate that the antibody binds to a structure on the surface of the dysfunctional Treg, thus reconstituting its natural efficacy. After activation, the Tregs apparently are able to contain autoreactive T cells, the actual initiators of autoimmune diseases, and to prevent their destructive attacks on the joints. In other words: BT-061 presumably has the effect, through the targeted activation of Tregs, that previously dysfunctional natural control mechanisms are reactivated, so that the body is able to counteract the dangerous autoreactive T cells by itself.
As presumably only natural regulatory mechanisms are activated and deleterious immune reactions are reduced, based on current knowledge, the immune system as a whole remains functional to fight infections.
As BT-061 presumably only supports natural control routes and does not impose non-physiological reactions on the immune system, scientists at Biotest assume that the effects of this antibody are particularly efficient and safe. The high degree of tolerability and safety of the drug has already been confirmed in preclinical and initial clinical studies.
Based on 2 former concluded clinical trials first positive results on efficacy has been observed. Efficacy over 12 weeks is currently being examined in a repeated dose, placebo controlled phase IIb trial on a broader basis. In this study including 176 patients with inadequate response to Methotrexat (MTX), BT-061 will be administered subcutaneously in combination with MTX. Patient recruitment is in progress.
If these expectations are fulfilled, Biotest will realize the further clinical development together with a strategic partner. Due to the increased medical need and the expected natural mode of action of BT-061, Biotest currently anticipates a high degree of market acceptance. Since the target cells of BT-061, the regulatory T cells (Tregs) are also dysfunctional in the case of other autoimmune diseases as well as some allergies, Biotest may assume that the scope of indications of the Biotest antibody will be extended further in the future.
