Celgene has warned healthcare providers that its blood thinner Innohep may increase the risk of death in elderly patients with kidney problems, recommending that alternative treatments be considered for the patients.
Innohep (tinzaparin) is a low-molecular weight heparin used as a blood thinner or anti-coagulant. It was approved in 2000 by the FDA to treat blood clots in patients with pulmonary embolism and deep vein thrombosis. Since it was first introduced in Europe in 1991, Innohep injections have been administered in more than 30 million people in 60 countries.
Concerns about side effects of Innohep surfaced after preliminary results were released from a clinical study known as IRIS (Innohep in Renal Insufficiency Study), which involved the study of the drug among patients 70 years of age and older who had deep vein thrombosis and failing kidneys.
The study, which was designed to compare the effects of Innohep and unfractionated heparin (UFH), was stopped in February 2008, after early data suggested an apparent increase in all-cause mortality among patients given Innohep.
Out of 176 patients treated with Innohep, 23 died after three months (13 percent), compared with only nine out of 174 patients treated with UFH (5 percent).
Celgene, which sells Innohep in the U.S., sent a letter to doctors in July 2008 advising them of revisions to the drug’s warning label, which indicated that Innohep increases the risk of death in patients 90 years of age and older. However, the drug maker now acknowledges that the Innohep death risk applies to all elderly patients with renal insufficiency.
FDA posted the new letter on Dec. 31, 2008, where Celgene now recommends that physicians consider Innohep alternatives when treating deep vein thrombosis, with or without pulmonary embolism, in elderly patients with renal insufficiencies.
The revised warnings about the risk of death with Innohep were issued after the FDA requested the drug maker update the label to better describe the results of the IRIS study.
As of Oct. 15, 2008, the FDA has received 383 reports worldwide of Innohep side effects and complications, including at least 96 Innohep deaths.