Innohep Death Risk for Elderly Leads to New Warning

Celgene Corp. sent a letter last week to healthcare providers warning that their blood thinner Innohep may increase the risk of death in elderly patients with kidney problems, recommending that alternative treatments be considered for these 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 (PE) and deep vein thrombosis (DVT).

Since it was first introduced in Europe in 1991, over 30 million people in 60 countries have received Innohep injections.

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%), compared with only 9 out of 174 patients treated with UFH (5%).

Celgene Corp., which sells Innohep in the United States, 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.

A new letter sent to healthcare providers was posted by the FDA on December 31, 2008, where Celegene now recommends that physicians consider Innohep alternatives when treating deep vein thrombosis (DVT), 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 overall results of the IRIS study.

As of October 15, 2008, the FDA has received 383 reports worldwide of Innohep side effects and complications, including at least 96 Innohep deaths.

In early December 2008, the FDA indicated that they expect to receive the final IRIS study report this month, and plan to complete their review of the Innohep death risk soon thereafter. The FDA has indicated that they will consider whether additional regulatory action is appropriate after a review of all applicable data from the manufacturer of Innohep.