On June 20, 2005, Transkaryotic Therapies, Inc. (TKT) announced the results of its Phase III clinical trial evaluating its drug iduronate-2-sulfatase (I2S) in the treatment of Hunter syndrome, also known as mucopolysaccharidosis II. I2S replaces an enzyme deficient in Hunter syndrome. In the trial, patients who received I2S on a weekly basis showed statistically significant improvement in a lung function test and in a six-minute walk test compared to patients receiving a placebo. TKT expects to file for regulatory approval of I2S in both the United States and Europe in the fourth quarter of 2005.