Although the ex vivo approach did prove safe and was able to confer gene expression within arthritic joints, the authors contend that it also was tedious, time-consuming and expensive. At this point they would advocate a more direct in vivo approach ?introducing the gene directly to affected tissue ?using as the vector an adeno-associated virus (AAV) instead of the vector used in the trial reported in PNAS. AAV appears to have a good safety profile and, in animals, facilitates more extended gene expression. The investigators hope to conduct additional clinical trials in both osteoarthritis and rheumatoid arthritis using AAV to transport the gene.
In addition to Drs. Evans and Robbins, other authors are James H. Herndon, M.D., also now at Harvard; Steven C. Ghivizzani, Ph.D., now at the University of Florida; Mary Chester Wasko, M.D., Molly Vogt, Ph.D., Theresa L. Whiteside, Ph.D., Elaine Elder, Ph.D., and Simon C. Watkins, Ph.D., all of the University of Pittsburgh; Matthew M. Tomaino, M.D., now at University of Rochester Medical School; and Richard Kang, M.D., and Thomas A. Muzzonigro, M.D., who are both now in private practice.