PMX 205 Trifluoroacetate is a potent complement antagonist of C5a receptor.

PMX205, which is an antagonist, gave more effects towards the cell as compared with the treatment of EP54.

oral delivery of a cyclic hexapeptide C5a receptor antagonist (PMX205) for 2-3 mo resulted in substantial reduction of pathological markers such as fibrillar amyloid deposits (49-62%) and activated glia (42-68%) in two mouse models of AD. The reduction in pathology was correlated with improvements in a passive avoidance behavioral task in Tg2576 mice. In 3xTg mice, PMX205 also significantly reduced hyperphosphorylated tau (69%). These data provide the first evidence that inhibition of a proinflammatory receptor-mediated function of the complement cascade (i.e., C5aR) can interfere with neuroinflammation and neurodegeneration in AD rodent models, suggesting a novel therapeutic target for reducing pathology and improving cognitive function in human AD patients[3].