New research suggests that outcomes for patients who have undergone stem cell transplants from unrelated or mismatched donors could be improved with the use of a drug called bortezomib, also known as velcade. This is according to a study presented at the annual meeting of the American Society of Hematology.

Stem cell transplants are treatments carried out in an attempt to cure some cancers affecting the body’s bone marrow, such as leukemia, lymphoma and myeloma.

The treatment involves very high doses of chemotherapy (myeloablation) or whole body radiotherapy to clear a person’s bone marrow and immune system of cancerous cells.

After this process, the killed cells are replaced with healthy stem cells through a drip that flows into a vein. These stem cells can be from the patient’s own body or from a donor – preferably a sibling.

According to researchers from the Dana-Farber Cancer Institute who conducted the study, stem cells from unrelated or mismatched donors are likely to lead to worse patient outcomes following transplantation.

These patients tend to have a higher mortality rate as a result of the treatment and are more likely to experience graft-versus-host-disease (GVHD). This is a disease in which the transplanted cells attack the immune system of the recipient.

According to the researchers, recipients of mismatched donor transplants have a severe GVHD rate of 37%, a 1-year treatment-related mortality rate of 45%, and a 1-year overall survival rate of 43%.

Recipients of unrelated donor transplants have a severe GVHD rate of 28%, a 1-year treatment-related mortality rate of 36%, and a 1-year overall survival rate of 52%.

But in a new phase II trial, the investigators have looked to use of the drug bortezomib to potentially improve outcomes for patients who have undergone stem cell transplantations from donors who were unrelated or who were not a close match.

Bortezomib is a drug that is used as a treatment for multiple myeloma. As well as inducing cancer cell death, the drug is known to improve some immune responses. The researchers say that this suggests the drug may be useful in reducing severity of GVHD.

The investigators recruited 34 patients with bone marrow-related cancers who had undergone myeloablative stem cell transplantation.

The patients received three doses of bortezomib on the first, fourth and seventh day following transplantation, as well as the standard drugs for GVHD – tacrolimus and methotrexate.

Results of the study revealed that the rate of GVHD in patients treated with bortezomib was only 12% at 180 days after transplant.

At 2 years after transplant, 8.8% of patients had died from treatment-related mortality and 5.9% had died from relapse of the condition. Overall survival at 2 years after transplantation was at 84%.

Commenting on their findings, John Koreth, of the Dana-Farber Cancer Institute and lead author of the study, says:

This regimen appears to improve not just GVHD prevention but more importantly, overall and relapse-free survival for myeloablative transplant recipients lacking matched sibling donors.”

The investigators say they are continuing to investigate the use of bortezomib for the prevention of GVHD.

Medical News Today recently reported on a study suggesting that switching off a gene in cancer stem cells that trigger colon cancer could prevent the cells from being able to renew themselves, opening new treatments to combat the cancer.