of those agents ª Incyte’s ruxolitinib which leads over a dozen JAK inhibitors in development for a range of indications (TABLE 1) ª is up for regulatory approval In August the US Food and Drug Administration began reviewing the New Drug Application for HER2 Inhibitors ruxolitinib (also known as INCB18424 or INC424) against myelofibrosis and a decision is expected by 3 December Novartis which licensed the rights to ruxolitinib for sale outside the United States has similarly filed the drug for approval with the European Medicines Agency and other regulatory bodies around the world If approved analysts say the oral drug could fetch global sales approaching US$1 billion by 2015 .

The market is substantial says Ren Benjamin of the investment bank Rodman & Renshaw °In this indication there really is nothing else out there that’s helping to better the MDV3100 symptoms If the product gets approved for polycythaemia vera as well for which Phase III trials are ongoing °then I think the story of it becoming a blockbuster candidate is possible adds Andrew Weiss an analyst with Vontobel Yet despite the excitement ª and the widespread expectation that the drug will be approved before the end of the year owing to its two positive pivotal trials ª ruxolitinib does not seem to stop myelofibrosis progression in the way scientists had hoped In fact no investigational JAK inhibitors do °At first there was a thought ª and in retrospect it was a bit of an unrealistic thought ª that they would lead to complete remissions like we see [with imatinib] in CML says .

Ruben Mesa a haematologist at the Mayo Clinic in Scottsdale Arizona USA who has been involved in testing several of the drugs Yet although they do not stop cancer growth JAK inhibitors do block the inflammatory cytokine signalling associated with various symptoms of disease such as enlarged spleens and severe itching °We seem to have effectively shut down the JAK2 dysregulation pathway and also to have reined in the overactivation of the pro-inflammatory cytokine pathway says Paul Friedman CEO of Incyte °They’re not  bandages perfect drugs by any stretch of the imagination admits Jerry Spivak a haematologist at Johns Hopkins School of Medicine in Baltimore Maryland USA who hasn’t consulted with any companies developing .