Drug effectively fights infection in stem cell patients

Receiving donor stem cells can be a life-saving treatment for patients with cancers of the blood or bone marrow such as leukemia, multiple myeloma and other types of lymphoma.

In these patients, the immune system sometimes is weakened or destroyed by radiation or chemotherapy before the transplant. Immature stem cells taken from a donor’s bloodstream and bone marrow, then transplanted into patients, can form new cells to help patients battle cancer.

Yet, many patients wind up getting ill or even dying when they acquire a cytomegalovirus (CMV) infection following transplantation.

An MD Anderson Cancer Center-led study has revealed that the drug letermovir shows promise in lessening the likelihood of CMV infection in patients who have received donor stem cells.

The study’s results, published in May's New England Journal of Medicine, are reported by Roy Chemaly, M.D., professor in Infectious Diseases, and Richard Champlin, M.D., chair of Stem Cell Transplantation and Cellular Therapy.

The phase 2, double-blind placebo study compared the effects of three oral dosages of letermovir, also known as AIC246, in 131 transplant recipients. Patients randomly received either 60, 120 or 240 mg per day or a placebo. The drug was provided for 12 weeks following transplantation.

The result? The drug showed evidence of preventing CMV infection, and the higher the dose, the more effective the drug. Side effects were minimal.

“This is especially good news given that the virus is reported in 50 to 60 percent of recipients who receive blood or bone marrow stem cells from a donor. Many of these patients may progress to CMV disease,” said Chemaly.

The multi-center study took place from March 2010 to October 2011 and demonstrated remarkable results. Of patients who received a placebo, 36% later had signs of CMV antigen or DNA in the blood and were removed from the study and treated. Patients were assessed weekly for CMV infection.

“Patients who received letermovir experienced the following levels of detectable CMV antigen: 21% at 60 mg, 9% at 120 mg and 6% at 240 mg,” said Chemaly.

Letermovir also produced few side effects and no blood or kidney toxicity. Some patients experienced adverse effects such as diarrhea, nausea and vomiting.

“This trial showed that preventive therapy with letermovir was as safe as placebo, with no apparent safety concerns,” said Chemaly.

Collaborators in the study included the University of Dresden, University of Wurzburg and the University of Munster in Germany; the University of Iowa in Iowa City; the University of Chicago Medical Center; and Stanford University Hospital in Stanford, Calif.

The study was funded by AiCuris, a German pharmaceutical company.