Mesoblast eyes human trials of stem cell treatment for rheumatoid arthritis

Mesoblast (ASX:MSB) is continuing to expand the applications for its off-the-shelf stem cell technology by pushing forward to conduct a phase II trial for rheumatoid arthritis (RA).

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.

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.

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.

Following the release of the results, Bell Potter Securities affirmed its $16 target for Mesoblast shares – which is close to three times the current trading price, which has recently hovered around $6.

In a research note, Bell Potter said the plan to conduct a phase II RA trial “adds another high-value, un-partnered programme to Mesoblast, given the high prevalence of RA globally, the US$12 billion global market for existing RA drugs, and the drawbacks of those drugs.”

Mesoblast is also investigating the use of MPCs to treat Type 2 diabetes, and entered the phase II trial stage for this project at the start of the year.

Mesoblast (ASX:MSB) shares grew 0.85% in Wednesday's trading to $5.950.