- Potential New Treatment Paradigm, PTC124 -

CAMBRIDGE, Mass. and SOUTH PLAINFIELD, N.J., July 17 /PRNewswire- FirstCall/ -- Genzyme Corporation (Nasdaq: GENZ) and PTC Therapeutics, Inc. (PTC) today announced an exclusive global collaboration to develop and commercialize PTC124, PTC's novel oral therapy in late-stage development for the treatment of genetic disorders due to nonsense mutations.

Under the terms of the agreement, PTC will commercialize PTC124 in the United States and Canada, and Genzyme will commercialize the treatment in all other countries. Genzyme will make an up-front payment of $100 million to PTC, plus potential milestone and royalty payments. PTC will be financially responsible for one ongoing and three additional clinical trials of PTC124, which is potentially applicable to hundreds of genetic diseases.

PTC124 is currently being evaluated in a phase 2b trial for Duchenne muscular dystrophy (DMD), and a phase 2b trial in cystic fibrosis (CF) is expected to begin by the end of this year. In its collaboration with PTC, Genzyme will draw on its expertise in genetic disorders and its strong regulatory, manufacturing and marketing infrastructure outside of the United States. Genzyme has extensive experience with cystic fibrosis, having conducted more than six clinical trials among CF patients. In the field of DMD, Genzyme's experience with Myozyme(R) (alglucosidase alfa), for the treatment of the genetic disorder Pompe disease, will be directly applicable as patients with both diseases are treated by the same specialist physicians.

'Over the past two decades, Genzyme has successfully developed four therapies for patients with severe genetic diseases. PTC124 is a powerful new approach that holds great potential to help CF and DMD patients, and many others with a variety of devastating diseases,' stated Henri A. Termeer, Genzyme's chairman and chief executive officer. 'This collaboration is an excellent strategic fit for Genzyme and will be managed within the company's stated financial guidance.'

'One of PTC's earliest scientific insights was that targeting nonsense mutations represented a novel approach to treating a large number of genetic disorders. The translation of that insight through the discovery and rapid development of PTC124 has been very gratifying,' commented Stuart W. Peltz, Ph.D., PTC's president and chief executive officer. 'This collaboration supports PTC's business strategy of establishing a fully integrated biopharmaceutical company by retaining commercial rights in the United States and Canada while engaging an experienced and capable partner to swiftly address additional markets.'

PTC initiated the clinical development of PTC124 in 2004. Based on phase 2a clinical proof of concept in both DMD and CF, further development in each of these indications is being pursued in international, multicenter trials. A phase 2b trial of PTC124 in DMD is currently enrolling, and is expected to include 165 patients. A phase 2b trial of PTC124 in CF is planned to begin by the end of this year. With demonstration of clinical benefit, these two trials are expected to serve as the basis for registration of PTC124 in these indications. Further development of PTC124 will include clinical trials in multiple additional genetic disorders.

In the United States, there are an estimated 10,000 DMD patients, approximately 13 percent of which have nonsense mutations. Of the more than 30,000 U.S. patients with CF, about 10 percent have nonsense mutations. There is a significant unmet medical need for new treatments for these diseases. In addition to DMD and CF, the companies plan to explore PTC124's potential to make a difference for patients with other types of severe and debilitating genetic diseases.

'We are impressed by the quality of the preliminary PTC124 data, which suggest broad applicability to a large number of genetic disorders,' said Geoff McDonough, M.D., Genzyme's senior vice president and general manager of LSD Therapeutics.