Trying to beat PPAR
Since entering the market in 1999, the PPAR gamma agonists Avandia rosiglitazone from GlaxoSmithKline plc and Actos pioglitazone from Eli Lilly and Co. and Takeda Chemical Industries Ltd. have created a blockbuster class of diabetes therapeutics - even though both are known to cause serious side effects. Thus, with their eyes on a roughly $3 billion market occupied by two compounds whose clinical profiles leave room for improvement, a large number of biotech and pharma companies are racing to bring out the next generation of PPAR modulators.
Peroxisome proliferation activated receptors are ligand-activated transcription factors that regulate cellular and physiological metabolism. PPAR gamma is the target of the marketed glitazones, which lower blood glucose and are used to treat Type II diabetes. Another subtype, PPAR alpha, is the target of marketed fibrate drugs, which are used to lower triglycerides and raise HDL cholesterol. A third subtype, PPAR delta, is believed to play a role in cholesterol transport and in raising HDL cholesterol (see "PPAR Comparison," A2).
Both Avandia and Actos are insulin sensitizers that belong to the thiazolidinedione class of PPAR gamma full agonists. In 2003, GlaxoSmithKline (LSE:GSK; GSK, London, U.K.) reported $1.6 billion in total sales for Avandia and Avandamet, which is a combination of Avandia and metformin. U.S. sales of Avandia and