Anti-Cancer Drug Effective Against Stem Cell Transplant Complications

Bortezomib found to effectively treat chronic graft-versus-host disease.

An anti-cancer drug may hold the answer to a problem that commonly impacts patients who receive stem cell transplants.

The drug bortezomib was found in a recent study to effectively treat chronic graft-versus-host disease (GVHD), which is a debilitating side effect from allogeneic hematopoietic stem cell transplants. In a clinical trial conducted by researchers at UC Davis and published in the October issue of the journal Blood, bortezomib was found to provide better outcomes than existing treatments without inhibiting the immune response against residual cancer cells or the graft-versus-tumor effect (GVT).

"Bortezomib helped a group of patients who desperately needed a treatment, having failed multiple different therapies," lead author Mehrdad Abedi said in a press release. "The drug fights chronic graft-versus host disease, and unlike other GVHD therapies such as steroid, cyclosporine, or mycophenolate, it treats chronic GVHD without dampening the graft-versus-tumor effect, which can be critically important to help patients avoid relapse. In fact, because bortezomib is an anti-cancer drug, it potentially attacks cancer cells in its own right."

Chronic GVHD afflicts patients receiving stem cell transplants that are commonly referred to as allogeneic transplants. Despite the fact that the transplants are close matches, they are not identical, which can cause the donor cells to attack the recipient. This attack can cause damage to the skin, lungs, kidneys, and other organs, and can cause potentially life threatening complications.

Treatment with bortezomib, which is used to treat multiple myeloma, leukemia, and lymphoma, was found to suppress the donor immune cells that cause GVHD.

"Almost all the patients who tolerated and remained on the treatment responded,” Abedi said. “In some cases, individual responses were quite dramatic. We were able to stop their other immunosuppressive medications and keep the patients under control with just weekly injections of bortezomib."

Researchers are currently evaluating an oral version of the drug combined with a similar treatment with the goal of alleviating the need for weekly injections, which could carry fewer side effects.