U.S. regulators have declined to approve Genzyme Corp's new Lumizyme treatment for Pompe disease, a setback the drugmaker said could delay its approval for six months and crimp 2009 earnings. Genzyme, whose shares fell more than 5 percent in after-hours activity, currently sells Myozyme to treat the rare and often-fatal inherited disorder. But because Myozyme is made in relatively small 160-liter batches in the United States, the drug is only commercially available to children and infants. The biotechnology company had asked the U.S. Food and Drug Administration for permission to make Myozyme in 2000-liter batches, in order to ease supply restraints and make the product available to adult patients. It is approved by more than 40 countries from such larger batches.