Mesenchymal Stem Cells Prove Effective in Animal Trials for Rheumatoid Arthritis Treatment
Animal trials of Mesoblast's mesenchymal stem cells in rheumatoid arthritis (RA) have encouraged the company press on with an FDA application for a phase II trial. This follows encouraging results from preclinical trials of its adult stem cells in animal models of RA.
The company revealed that a single injection of its mesenchymal precursor cells (MPCs) was able to simultaneously inhibit multiple cytokines responsible for driving RA. The MPCs concomitantly affected T cells, monocytes and synoviocytes to shut down TNF-alpha, IL-6 and IL-I7 cytokine pathways in sheep with collagen-induced arthritis.
Treatments that shut down any of these pathways alone are only moderately effective at treating RA, and often need to be administered chronically.
During the pilot study, significant numbers of allogenic MPCs were detected in involved joints or lymph nodes of the arthritic sheep, but not in normal sheep. This suggests the MPCs selectively migrate to sites of immune-mediated inflammation.
Sheep were injected with three different quantities of MPCs. Joint tissue from sheep receiving the largest dose showed an 88% mean reduction in IL-6 levels, an 83% reduction in TNF-alpha levels and a 52% reduction in IL-I7 levels. MPC-treated animals had a 31% mean reduction in histopathology severity scores compared to the control group.
Based on the promising results, Mesoblast has arranged a meeting with the US FDA to discuss organising a phase II trial. Subject to receiving approval, the company plans to conduct a randomised, placebo-controlled phase II trial in the fourth quarter of 2012.