NEW YORK, Oct 12 (Reuters Health) -- The pharmaceutical company Schering-Plough has halted further enrollment in some of its p53 gene therapy trials at the request of the US Food and Drug Administration (FDA).
The federal agency made the request in the wake of the death of an 18-year-old man involved in a gene therapy study at the University of Pennsylvania. As previously reported by Reuters Health, the patient had a liver disease, and researchers believe that he might have had an exaggerated inflammatory response in his liver to the viral vector used to carry the gene into cells.
Schering-Plough noted that it was not involved in the gene therapy trial at the University of Pennsylvania and that the university's study did not involve p53 gene therapy or treatment of cancer. The company also noted that the university's study used a different viral vector to carry the gene than that used in Schering-Plough's studies.
The FDA has asked Madison, New Jersey-based Schering-Plough not to enroll new patients in its ongoing p53 gene therapy trials that involve injecting the gene into blood vessels in the liver. These trials involve using an adenovirus -- one of the family of viruses that cause the common cold -- to ferry a p53 gene into the liver as a possible treatment for liver cancer. Previous studies "have demonstrated that the introduction of a normal p53 gene into a malignant cell... can suppress the cell's malignant state or result in apoptosis (programmed cell death)," according to a company statement.
The company said that it has provided the FDA with data from the study to demonstrate the safety of the p53 gene therapy product and stressed that it has not observed any adverse events in its program comparable to those reported in the University of Pennsylvania study.
Schering-Plough also said that it would continue providing the gene therapy to the 60 patients currently enrolled in the study, with the concurrence of the FDA, and will continue with other trials involving p53 gene therapy. The company noted that it has treated approximately 200 patients with the p53 gene therapy product in studies.
