The numbers of new drugs developed for diabetes have been very less in the decade. The proven and effective treatments for Type I diabetes is insulin and the leaders of this therapeutic domain are Novo Nordisk, Sanofi and Elli Lilly. For type II diabetes, the most effective drugs are metformin and its analogues.
Other add on drugs for Type II diabetes with proven efficacy are gliclazide, glimepride, etc to name few. After these followed the " glitazones" namely Pioglitazone and rosiglitazone as further add on drugs to cure diabetes. Although rosiglitazone came to the market along pioglitazone in the pharma world, the same occupied lesser popularity in terms of its efficacy. However that was "subjective" matter and MNC brands like Glaxo's Avandia occupied the forefront of the Type II diabetes market with Avandia.