Reports of Severe Blood Disorder ITP In 3 Campath – MS Study Patients

On November 30, 2005 the FDA issued a public health advisory warning against the use of Campath in patients with multiple sclerosis (MS).  This FDA warning about Campath and MS is a bit unusual because Campath is not approved to treat MS.  It seems that the FDA issued the Campath warning due to a concern that some doctors may be prescribing Campath "off-label" as an MS treatment.

Campath is co-marketed by Genzyme Corp. and Berlex Inc., a unit of German-based Schering AG.  Campath is currently FDA-approved to treat B-cell chronic lymphocytic leukemia (B-CLL), a blood cancer.  The drug companies had been conducting clinical studies to see if Campath is a viable treatment for MS.  In the course of that Campath – MS clinical study, however, three patients developed severe idiopathic thrombocytopenic purpura (ITP), a severe blood disorder, one of which died from ITP.

The drug companies reportedly informed the FDA of the ITP side-effect events in September 2005, and put the Campath – MS trial on hold. Why the FDA decided to issue this Campath warning now is not altogether clear.

According to a November 30, 2005 Reuters report, Genzyme spokesman Dan Quinn said that, while he was not sure why the FDA issued the Campath alert at this time, he thought it may be directed at some doctors who have been engaged in the off-label prescribing of Campath for MS.  Mr. Quinn said the Genzyme did not know how many MS patients may be using Campath, and added "We hope there are none".

The three patients from the Campath – MS study whose cases were reported to the FDA in September had developed idiopathic thrombocytopenic purpura (ITP), a blood disorder that causes one’s body to attack its own blood platelets.  The current package insert, or label, for Campath already mentions ITP, and contains a "black-box" warning regarding the possibility of developing serious blood problems as a side effect of Campath use.

In the suspended clinical study, Campath was being studied as a drug that could be administered once annually for MS.  According to a December 1, 2005 article in The Wall Street Journal (WSJ):

• "The FDA said patients in the MS study are no longer receiving Campath but are still being monitored. The agency said two of the three patients who developed the serious blood disorder, also known as ITP, received cumulative doses of Campath that were higher than recommended amounts for treating leukemia. Of the three patients who developed ITP, one died of bleeding in the brain."
• "The FDA said the patient who died received a five-day course of Campath and one year later received a three-day course of the drug. About seven months after the second treatment, the patient died from an intracranial hemorrhage. Another patient developed ITP 11 months after finishing the second round of Campath treatment, and the third patient developed ITP after the third treatment — which was 24 months after the first treatment."

Dan Quinn, the Genzyme spokesman, told Reuters that he was not aware of any additional efforts being undertaken by the drug company to inform doctors about the ITP cases nor the FDA warning about Campath use by MS patients.

In its alert, the FDA said patients should talk the their doctor if they are concerned about taking Campath.

(Posted by: Tom Lamb)