Prolonged survival in graft-versus-host disease study

Regenerative medicine company Cynata Therapeutics (ASX:CYP) has announced positive interim data from a proof-of-concept study of its lead Cymerus mesenchymal stem cell (MSC) product, CYP-001, with the product demonstrating prolonged patient survival.

In the study, a humanised mouse model of severe acute graft-versus-host disease (GvHD) was induced by infusing human peripheral blood mononuclear cells (PBMCs) into mice. Animals were randomly assigned to control or treatment groups; treated animals received either one or two doses of CYP-001, while control animals received only saline.

Animals in the control group had a median survival time of just 25.5 days, compared to a median survival time of at least 54 days — more than double that of the controls — in the CYP-001 treated groups. All control animals succumbed to the disease between 24 and 31 days after induction, while as at the date of the interim review, survival among the CYP-001 treated animals has been 31–68 days with three animals still alive. Further analysis will be performed once these last three animals have completed the study.

“We are delighted with these initial results, which are consistent with the substantial body of evidence we have generated from in vitro laboratory testing of our product,’’ said Cynata Vice President of Product Development Dr Kilian Kelly. “Collectively, these data show that Cynata’s proprietary Cymerus MSCs exert pronounced immunomodulatory effects.

“The results are also consistent with the successful study of Cymerus MSCs in a model of critical limb ischemia (CLI), which was recently published in Cytotherapy. This augurs well for our initial planned clinical trial in patients with GvHD and, indeed, for the potential use of these cells to treat a wide range of other conditions.”

In an additional study (currently underway), GvHD was induced using a lower dose of human PBMCs so that the symptoms are less severe and progress less rapidly. This study is also investigating alternative CYP-001 dose levels and additional outcome measures. The majority of animals in this study have yet to reach the study endpoint, so the extent of the treatment effect in this model is not yet known. Results are expected soon.

Cynata Therapeutics (ASX:CYP) shares were trading 5.13% higher at $0.41 as of around 1 pm on Thursday.