PRT062607 (BIIB-057; P 50515 PRT-2607; PRT062607) is a highly specific and potent inhibitor of spleen tyrosine kinase (Syk). PRT062607 (BIIB-057) has a desirable pharmacokinetics profile and is capable of safely, potently, and selectively suppressing SYK kinase function in humans following once-daily oral dosing. The compound is being evaluated for the treatment of chronic inflammatory diseases; including rheumatoid arthritis, systemic lupus erythematosus, non-Hodgkin's lymphoma and chronic lymphocytic leukaemia. Phase I development is underway in the US and the UK for the treatment of patients with inflammation and cancer. Phase I development is also being conducted in rheumatoid arthritis and systemic lupus erythematosus, presumably in the US.

Anisomycin (2-p-methoxyphenylmethyl-3-acetoxy-4-hydroxypyrrolidine) is an antibiotic isolated from cultures of various Streptomyces. Anisomycin is a potent, structurally specific, and reversible inhibitor of protein biosynthesis in certain yeast and mammalian cells. The inhibition occurs subsequent to the formation of aminoacyl transfer ribonucleic acid but prior to the release of polypeptides from the polyribosome. Anisomycin has unspecified effects that can produce temporary amnesia for a reactivated memory and they also could be responsible for any permanent effects that anisomycin produces. Anisomycin is known to cause apoptosis by activation of MAPK cascade.