PHARMACEUTICALS

* The FDA issued a letter to Sepracor Inc. asserting the Marlborough, Mass.-based biotech company had made “unsubstantiated and misleading” safety and efficacy claims about its recently approved asthma drug Xopenex. In a letter dated May 21, a division of the federal agency said the “violative” claims appear in promotional Sepracor materials and “are inconsistent with the approved product labeling of the drug.” It ordered the company to cease immediately distribution of the materials, which it said appeared in advertisements and “Dear Doctor” letters.