The death of a patient in Targeted Genetics’ trial of its injectable anti-arthritis drug, tgAAC94, this summer was unlikely to have been caused by the drug, the company reports. The Phase I/II trial of the gene therapy treatment was put on hold by the Food and Drug Administration in July after the company reported a serious adverse event, which was closely followed by the patient’s death (see earlier reports).
Data presented at the US National Institutes of Health’s Recombinant DNA Advisory Committee (RAC) public hearing on September 17th indicated that histoplasmosis - a fungal infection prevalent in the eastern and central US - played a significant role in the death. Trial subjects, including the patient who died, were taking a number of immunosuppressant drugs which would have predisposed them to infection or worsened the symptoms.
Initial tests show there was no replication of the adeno-associated virus vector used by tgAAC94 and only trace amounts of vector DNA in tissues outside the injected joints. "While additional tests are needed to draw final conclusions, we believe the results to date are consistent with preclinical and clinical findings that indicate the level of vector that is present outside the locally treated area is insufficient to have further exacerbated an infection," said Targeted Genetics’ president and CEO, H Stewart Parker.
The investigation is continuing, with molecular tests being conducted in remaining tissues.
