RA drug nearly eliminates Graft-Versus-Host disease.

Presented at the Seattle Children's Research Institute’s 59th American Society of Hematology (ASH) recent Annual Meeting, results from a Phase II clinical trial showed that Abatacept (Orencia) nearly eliminated life-threatening severe acute graft-versus-host disease (GvHD) in patients receiving hematopoietic stem cell transplants.

Acute GvHD, noted Seattle Children's Research Institute, is understood to be the most deadly complication that might arise from stem cell transplantation. The condition occurs, explained study authors, when donor T-Cells make a “vigorous” attack on a patient’s vital organs. For people receiving donor T cells, the rate of contracting acute GvHD is as high as 80% according to the institute.

When added to a standard drug regimen Abatacept reduced the occurrence of acute grade III-IV GvHD from 32% to 3% in adult and pediatric patients who experienced mismatched, unrelated stem cell transplants to treat blood disorders and cancer.

The trial's principal investigator, Associate Director Dr. Leslie Kean of the Ben Towne Center for Childhood Cancer Research at Seattle Children's noted: "Given the serious threat of graft-versus-host disease, new approaches to make stem cell transplants safer for patients remain a critical unmet need. To see such striking results in patients at extremely high risk for graft-versus-disease is incredibly encouraging."

Kean became interested in using abatacept to prevent GvHD after the drug proved its success successfully treating patients with rheumatoid arthritis. Abatacept, explained the institute, inhibits T-cell activation and helps halt the chain of events that lead to the more debilitating impact of RA on joint health.

"Preventing graft-versus-host disease and relapse after transplant requires a difficult balance of eliminating the bad, overactive effector T cells, without suppressing the good, regulatory T cells," said Kean, who is a member of the Fred Hutchinson Cancer Research Center. "As we make improvements to our toolbox of agents capable of achieving this Holy Grail of stem cell transplant, it's essential to include targeted approaches like abatacept."