Genzyme cut its earnings forecast after the federal regulators delayed the approval process to sell Myozyme, the only treatment for Pompe disease. The Massachusetts-based company expects 2008 net earnings of approximately $3.90 per diluted share, compared with previous guidance of $4.00 per diluted share. Reflecting the delay in the approval of 2000L production of the drug, Myozyme sales will be $275 million to $285 million, down $45 million from the last estimate.

According to an FDA report, Myozyme (alglucosidase alfa) produced at the 160L bioreactor scale and Myozyme produced at the 2000L scale should be classified as two different products because of differences in the carbohydrate structures of the molecules. Genzyme has US approval to sell Myozyme manufactured at the 160L scale, and the company has been seeking clearance from the FDA for Myozyme produced at the 2000L scale. Production at this larger scale has already been approved in more than 40 countries.

Based on the global clinical experience of nearly 900 patients of all ages currently receiving Myozyme produced at the larger scale, including patients who participated in the Late-Onset Treatment Study (LOTS), Genzyme believes that Myozyme produced at both the 160L and 2000L scales is clinically effective and safe. Myozyme is the only treatment for Pompe disease-a severe, progressively debilitating and life-threatening inherited disorder affecting a very small number of people throughout the world.

The FDA will require Genzyme to submit a separate biologics license application (BLA) to gain approval for Myozyme produced at the 2000L scale. The agency proposed that Genzyme initiate a rolling BLA review process by submitting results from the LOTS study. Genzyme expects the FDA to give the BLA priority review and to act on the application by the end of this year. The LOTS study, which met its co-primary efficacy endpoints, was undertaken to evaluate the safety and efficacy of Myozyme in juvenile and adult patients with Pompe disease. Genzyme had already been preparing to submit results from this study to the FDA to fulfill a post-marketing commitment. Genzyme anticipates that this process will culminate in the availability of two commercial versions of Myozyme in the United States - one produced at the 160L scale and the other produced at the 2000L scale. The company expects to begin providing US patients with commercial 2000L Myozyme during the first quarter of 2009.

To ensure that severely affected adults with Pompe disease in the United States have access to treatment, Genzyme, in collaboration with the FDA, created the Myozyme Temporary Access Programme (MTAP) in May 2007. Through this programme the company is currently providing Myozyme produced at the 2000L scale free of charge to approximately 140 patients. Infants and children with Pompe disease in the United States continue to receive commercially approved Myozyme produced at the 160L scale.

"We are extremely disappointed in the FDA's decision because it will further delay broad patient access to Myozyme, which is not possible under the MTAP programme," said Henri A. Termeer, chairman and chief executive officer, Genzyme.