BioCryst Pharmaceuticals, Inc. and Roche initiated the first Phase II study to evaluate BCX-4208/R3421 in patients with moderate to severe plaque psoriasis. BCX-4208 is an inhibitor of purine nucleoside phosphorylase (PNP), an enzyme essential for the proliferation of activated T cells. With its mechanism of action, BCX-4208 has the potential to address a range of autoimmune diseases as well as transplant rejection. The Phase II double-blind, placebo-controlled trial is comprised of three a...