Declining to approve Genzyme Corp's marketing application for its new drug - Lumizyme - for the treatment of Pompe disease, the Food and Drug Administration has, in a response letter, asked the biotechnology company to address certain 'remaining items.'

More unexpectedly, Genzyme received a warning letter, along with the complete response letter, addressing shortcomings observed during an FDA inspection of Genzyme's Allston Landing manufacturing facility in September and October 2008.

The company felt the warning letter was uncalled-for since, in its February 23 substantial progress update, it had validated that the requisite remedial actions had either been completed or would be completed on schedule by the March 31, 2009 commitment date.

The FDA rejection of Genzyme's Lumizyme application has impeded the drugmaker's plans of marketing the drug. The six months or so delay in approval is bound to crimp the company's earnings this year, largely because the company is incurring the cost of providing the drug free for empathetic use in nearly 170 patients of Pompe disease.

The disease, a rare and often-fatal hereditary disorder caused by the lack of an enzyme which helps breakdown nutrients, leads to progressive muscle degeneration and severe damage to the heart, liver, and other organs. Genzyme's already-selling Myozyme, and the proposed Lumizyme, combat the disorder by supplying patients with the missing enzyme.