Technology evaluation: MFG-IRAP, University of Pittsburgh

The University of Pittsburgh is developing MFG-IRAP, a retroviral vector carrying the human interleukin-1 receptor antagonist protein (IRAP) cDNA for potential treatment of arthritis. MFG-IRAP gene therapy was effective in local gene delivery to synovial lining of joints and systemically to hematopoietic stem cells, in preclinical studies. Intra-articular expression of IRAP, although transient (4 to 6 weeks), was efficacious in several animal models of arthritis. On the other hand, systemic transgene expression was prolonged (15 months), but was relatively less efficacious. Clinical data on the safety of MFG-IRAP therapy per se are limited, however, recombinant IRAP studies in humans have not resulted in any serious adverse effects. Phase II studies, including a trial in arthritis patients should provide the much anticipated MFG-IRAP efficacy data.