FDA issues warning on Schering’s cancer drug

The three patients in the multiple sclerosis (MS) trial developed severe idiopathic thrombocytopenic purpura (ITP). One of these individuals died from an intracranial hemorrhage, and dosing with Campath in this study has been suspended. The company’s shares fell by over 1% after the label change was announced.

Campath is approved for treating B-cell chronic lymphocytic leukemia (CLL) and not MS. The Campath package insert currently includes a boxed warning about serious and rare hematologic toxicities, including autoimmune ITP, and carries a caution stating the maximum dose patients can expect to safely tolerate.

In the MS clinical study, two of the cases with ITP, including the patient who died, had received cumulative doses of Campath that exceeded the recommended cumulative weekly dosing limit in the boxed warning.

Although the FDA has not reached a final conclusion and intends to update recommendations when additional information becomes available, so far the authority advises that complete blood counts and platelet counts be obtained at weekly intervals during Campath therapy and more frequently if adverse events are observed, and that Campath should be discontinued in any patient with evidence of autoimmune hematologic toxicity or for severe hematologic toxicity.