Isis Experimental Drug Lowers Cholesterol, but Has Damaging Side Effects

By Don Bauder

November 17, 2009

Stock of Carlsbad-based biotech Isis Pharmaceuticals plunged 17.01% today to $11.12 on good/bad news. Isis is developing a drug with Genzyme for reducing cholesterol in an extremely rare genetic disorder in which a gene that should remove cholesterol from the body is missing. A phase III study indicated that the drug, mipomersen, cut levels of "bad" LDL cholesterol by 25% in patients with the disorder. But it also caused elevated liver enzymes in 12% of patients -- a sign the drug may have damaging liver effects. Isis and Genzyme said that none of the patients showed signs of permanent liver damage.