Graft vs host disease (GvHD) can lead to serious, even deadly complications following bone marrow transplant. According to the results of a new study, a monoclonal antibody-based treatment, called PRO 140, under development for GvHD was able to stop the disease in a mouse model. CytoDyn, the company behind the trial is currently enrolling patients for follow up Phase II clinical trials for prevention of the disease in leukemia patients.
PRO 140 is a humanized anti-CCR5 antibody. CCR5 acts as a receptor for chemokines and is crucial for development of acute GvHD and other inflammatory conditions. Previous clinical studies have shown that blocking CCR5 can reduce impact of acute GvHD without significantly affecting the transplant of bone marrow stem cells (BMSCs).
For the current study, immunocompromised mice were transplanted with human BMSCs. The mice were given PRO 140 at a dosing schedule that approximates the dose being used in a current clinical trial. The mice that received the antibody treatment showed successful engraftment of human hematopoietic cells with no signs of GvHD up to 70 days after treatment at which point they were sacrificed for flow cytometric analysis. Control mice showed signs of the disease after 25 days and all had to be sacrificed after 54 days. A 10-fold reduction in the dose of the drug also showed protective effects, but more moderately than the full dose.
The study was published last week in the journal Biology of Blood and Marrow Transplantation.