FDA statement on gene therapy trial

Jul 27 2007

On July 24, 2007 the U.S. Food and Drug Administration (FDA) was informed by Targeted Genetics Corporation of Seattle about the death of a patient who received an investigational gene therapy product in a clinical trial for the treatment of active inflammatory arthritis.

FDA's condolences go to the patient's family.

FDA is providing this preliminary information in recognition of the public's interest in these types of new therapies.

Targeted Genetics notified FDA earlier that a patient in its trial experienced a serious adverse event. Even though the cause of the illness wasn't known, and is still uncertain, the agency immediately placed the trial on clinical hold--meaning no further product can be administered and no new patients can be enrolled.

The product that was being studied uses a particle called a vector that is designed to deliver treatment genes to target cells. The vector used is a recombinant adeno-associated virus (AAV) derived vector and delivers the gene for Tumor-Necrosis Factor -Receptor, with the intent to inhibit a key mediator of inflammation. In the study, the gene therapy was administered into the joint affected by the disease to reduce inflammation and disease in patients with active inflammatory arthritis.

More than 100 subjects have been enrolled in the trial, according to the company, without known similar serious events. However, the patient's illness was related in time to the receipt of a second injection of the product. Upon being alerted to the adverse event, FDA immediately began its investigation to determine whether the illness was related to the treatment. The investigation into the cause of the patient's illness and subsequent death is intensive and ongoing.

Targeted Genetics is cooperating with FDA's investigation and has agreed to provide the agency with ongoing results from various tests and all other information it is compiling that may help determine the cause of this patient's death. FDA is also coordinating with the National Institutes of Health in an effort to acquire a better understanding of the potential scientific and safety implications of this event. These matters will be discussed at the September meeting of the NIH Recombinant DNA Advisory Committee.

FDA is not aware of similar adverse events occurring in other gene therapy trials either with this specific product or with those that use other genes in AAV vectors. However, as a precaution, the agency is further reviewing all ongoing trials involving any use of AAV.

FDA recognizes the contributions of participants in clinical trials and places a high priority on potential safety issues – volunteers play a critical role in making treatments available that have the potential to help many other patients who need new treatments for serious diseases.
The agency is continuing to obtain and assess additional information to help determine, if possible, the cause of the event, and any potential implications and will take additional steps and provide updates as warranted.