Updated mipomersen safety data

Genzyme Corp. (NASDAQ:GENZ) and partner Isis Pharmaceuticals Inc. (NASDAQ:ISIS) reported additional data from the Phase III RADICHOL II trial to treat heterozygous familial hypercholesterolemia (heFH), including updated safety data. Six of 83 patients treated with mipomersen had persistent elevations in liver alanine transaminase (ALT) levels -- defined as consecutive elevations at least one week apart -- that were three times the upper limit of normal. Furthermore, mipomersen-treated patients had a median increase in liver fat from baseline of 4.9% vs. a 0.4% increase for placebo. No patients had changes in other laboratory tests that would indicate hepatic dysfunction. Nine patients discontinued the study due to adverse events, including three cases of ALT elevations, two cases of injection-site reactions, two cases of non-cardiac chest pain, one case of injection-site reactions and flu-like symptoms, and one case of constipation. The double-blind, North American trial enrolled 124 patients. Data were presented at the European Society of Cardiology meeting in Stockholm.

In February, the partners reported that mipomersen met the primary endpoint of significantly reducing LDL-C from baseline to week 26 vs. placebo in the trial. Data reported at this time showed that 12 of 83 patients treated with mipomersen had at least one weekly evaluation at which ALT levels were three times the upper limit of normal, with three patients reaching levels that were more than 5 times the upper limit of normal. ...