末梢静脈投与可能なプリオン病特効薬の治験開始

抄録

Medical chaperone (MC) specifically binds to the normal conformation of the prion protein (PrP^C) and inhibits its conversion to the pathogenic conformation (PrP^Sc). By peripheral intravenous administration, MC penetrates the blood brain barrier, spreads to the brain, and inhibits the prion's pathogenic conversion. MC is removed from the blood within a week, whereas the half–time of MC in the brain is more than one month, thereby enabling the regulation of brain concentration of MC by controlling the concentration and the time schedule of the peripheral administration. The pharmacological effect of MC is only the anti–prion effect and no other function nor side effect has been found. IC50 of MC is about 500 nM for Fukuoka–1 strain (GSS). Prion is completely eradicated once incubated at the concentration of four times of IC50, 2µM, i.e. prion never proliferate even after the removal of MC. Symptom suppression and the life extension effects of MC were proved for the Fukuoka–1 infected mice and for the BSE infected macaques. Furthermore MC suppresses the quaking induced conversion (QuIC) of a prion in vitro. In short, MC has a strain– and host–independent anti–prion effect. Molecular weight of MC is about 500 and is stable for at least ten years when stored in powder form at room temperature. Since preclinical tests of MC have been completed, the clinical trial will start shortly, through the efforts of those who involved.