Transkaryotic Therapies Inc has received fast track designation from the US FDA for iduronate-2- sulfatase (I2S) to treat Hunter Syndrome (MPS II), a company release said.

TKT commenced a pivotal study with I2S in September 2003. The study, referred to as AIM (Assessment of Iduronate-2-sulfatase in MPS II) is a twelve-month, randomized, double-blind, placebo-controlled trial evaluating I2S in 96 patients. TKT expects top-line results from the AIM study in the second quarter of 2005 and, if positive, the company expects to submit applications for marketing approval in both the United States and Europe in the second half of 2005.

"We are pleased that the FDA has given I2S this important designation," said Michael J Astrue, president and CEO of TKT. "We are committed to bringing this treatment to patients as quickly as possible," he added.

Under the FDA Modernization Act of 1997, fast track regulations are designed to facilitate the development of products to treat serious or life- threatening diseases where an unmet medical need exists. Fast track regulations are also designed to expedite the review process for designated products, including the potential for companies to submit marketing applications on a rolling basis.

I2S is a human iduronate-2-sulfatase produced by genetic engineering technology intended for long-term treatment of Hunter syndrome. The rationale for the therapy is that I2S would replace enzyme that is deficient in patients with Hunter syndrome and either stop or reverse disease progression.

Hunter syndrome is a genetic disorder, also referred to as MPS II. This hereditary disorder is characterized by the body's inability to produce the enzyme iduronate-2-sulfatase, which is essential in the continuous process of replacing and breaking down glycosaminoglycans (GAG). As a result, GAG remains stored in cells in the body causing progressive damage. There are up to 2,000 patients worldwide afflicted with Hunter syndrome in jurisdictions where reimbursement may be possible, the release says.

Transkaryotic Therapies Inc is a biopharmaceutical company primarily focused on researching, developing and commercializing treatments for rare diseases caused by protein deficiencies.