Gene therapy for rheumatoid arthritis: recent advances

The treatment of rheumatoid arthritis (RA) in the last decade has made enormous advances with the use of biological therapies. However, these therapies have serious limitations such as the expense, side-effects, and the requirement for repeated injections, each of which can potentially be obviated by gene therapy. A gene therapy approach for the treatment of RA has the potential to stably deliver a gene product or multiple products in a target-specific, disease-inducible manner. There are many studies investigating gene therapy in RA, the majority of which have been designed to test proof-of-principle in an animal model. With an abundance of animal studies that have established much promise, the field is now at the early stage of moving towards human trials, where patient benefit needs to overshadow associated risks, especially since RA is publicly perceived as a non-life-threatening disease. Here, we provide an overview that focuses on advances in the application of gene therapy to RA over the last five years, including: novel targets and approaches; the viral and non-viral applications most likely to succeed in the clinic; advances in our understanding of the contralateral effect; the latest successes with anti-inflammatory cytokines; and a review of advancements towards clinical trials.