Merck antiviral cuts post-transplant infections
- Prophylaxis with Merck & Co.'s antiviral letermovir met its primary endpoint in a Phase 3 trial, preventing clinically-significant cytomegalovirus (CMV) infection to 24 weeks in people who were having a bone marrow transplant (allogeneic hematopoietic stem cell transplant) and who were CMV-positive but had undetectable levels of CMV DNA at the start of treatment.
- The results were positive in people at higher or lower risk of infection; treatment also cut deaths from all causes over 24 weeks. The most common serious adverse effects were infection, graft-versus-host disease (GVHD) and kidney injury.
- Letermovir has fast track designation from the Food and Drug Administration, and Merck plans to submit the drug for approval in both the U.S. and EU this year.
Anything up to 80% of people are infected with cytomegalovirus (CMV), often from childhood. In healthy people, it may pass unnoticed, or feel like a cold or a bout of flu, and the virus will remain dormant. But in people taking immunosuppressants post-transplant, the infection can kick off again, or be caught from an infected organ. This can lead to long-term damage to the transplanted organ, and may even be life-threatening.
"There is an unmet need for therapeutic options in the prevention of CMV infection in hematopoietic stem cell transplant recipients," said Nicholas Kartsonis, VP of infectious disease clinical research at Merck Research Laboratories.
According to Francisco Marty, associate professor of medicine at Harvard Medical School and attending physician in transplant and oncology infectious diseases at Dana-Farber Cancer Institute and Brigham and Women’s Hospital, letermovir as primary prophylaxis of CMV infection could be a new strategy for the prevention of CMV in this high-risk patient population.
There is currently no marketed CMV vaccine. Vical and its partner Astellas have been developing a therapeutic DNA vaccine, ASP0113, designed to prevent reactivation of CMV infection. The vaccine didn't meet its primary endpoints in a Phase 2 study of kidney transplant patients. Phase 3 results are expected in the fourth quarter 2017 in bone marrow transplant patients. Vical is also developing a prophylactic CMV vaccine, CyMVectin, with an aim to reduce the risk of mothers transmitting the infection to their babies during pregnancy, which is not yet in Phase 1.
- Merck & Co. Statement
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