Targeted Genetics Corporation, of Seattle, Washington, released clinical data from a small multicenter Phase I study showing that tgAAC94, a recombinant adeno-associated virus (AAV) vector, is well tolerated and can be administered directly into the joints of patients with inflammatory arthritis.

Fifteen patients with inflammatory arthritis not taking concomitant systemic tumor necrosis factor-alpha (TNF-α) antagonist therapy were randomly assigned to receive a intra-articular injection of either one of two escalating dose levels of tgAAC94 (11 patients) or placebo (four patients). 

The investigational therapy was found to be well tolerated, and in nine of 11 patients who were followed for 4 weeks post-treatment, there was an indication of sustained improvement in joint swelling and tenderness in the injected joint.  Seven of the nine responders evaluated through week 8 following treatment continued to experience sustained improvement in arthritic signs and symptoms, versus two of the four patients receiving placebo. According to Targeted Genetics, patients will continue to be followed for 24 weeks post-treatment. 

tgAAC94, an AAV vector that contains a gene that encodes for the soluble TNF-α receptor, is being developed as a potential supplement to systemic anti-TNF-α antagonist therapy for use in patients with inflammatory arthritis, where one or more joints remain affected.  In addition, Targeted Genetics says that a locally administered anti-TNF-α therapy might be useful in patients with a limited number of affected joints who are at high risk for progressive joint damage, but who may not require systemic therapy.   

--Nicholas K. Zittell