New Vaccine Reduces Complications of Chicken Pox and Mono-Related Virus in Transplant Multiple Myeloma Patients
Most folks over 40 walk around with Cytomegalovirus (CMV) and don't even know about it because it rarely causes problems in healthy people. CMV is related to the viruses that cause chickenpox, herpes simplex and mononucleosis. The virus is transmitted through bodily fluids (tears, saliva, etc.) but not by casual contact. Once infected, the virus stays in your body for life. CMV is a major cause for concern for those with a weakened immune system, as is the case with many multiple myeloma patients. The Mayo Clinic provides a nice summary of what CMV complications can occur in patients with a weakened immune system:
- 'Vision loss, due to inflammation of the light-sensing layer of the eye (retinitis);
- Digestive system problems, including inflammation of the colon (colitis), esophagus (esophagitis) and liver (hepatitis);
- Nervous system problems, including brain inflammation (encephalitis);
- Pneumonia.
CMV infections occur in about 20% of patients undergoing allo-stem cell transplants (SCT). A recent article in the journal Annals of Internal Medicine provides hope to help us with the incidence rate of CMV after SCT. The article reports on the outcomes of a Phase II clinical study where patients at risk for CMV infections were given a new vaccine after transplant (intramuscular injection on days 28 and 56). The official, scientific name of this vaccine is "modified vaccinia Ankara, engineered to induce a robust and durable virus-specific T cell response to three immuno-dominant proteins linked to CMV complications in stem cell transplant recipients." The vaccine is also called the Triplex vaccine. The study enrolled a total of 102 patients, half of whom were given the vaccine and half who were given a placebo injection. The results are impressive:
- Reactivation of CMV in those patients who received the Triplex vaccine (9.8 %) was 50 % lower than those patients who had received placebo injections.
- No serious (grade 3 or 4) adverse events were observed within two weeks of vaccination.
- The incidence rate of severe Graft-versus-Host Disease (GvHD) was similar between the two groups of patients, and the authors of the study make it a point to note that those patients who received high doses of steroids to prevent GvHD did not have as strong a response to the vaccine than those who had not been treated with steroids.
- The immunity against CMV infections lasted a year post transplant.
- 'Triplex is a best-in-class, universal recombinant viral vector vaccine that can be given without restrictions to all eligible transplant recipients and/or their donors.'
There is currently a supplemental trial underway at City of Hope in Los Angeles. The trial:
"vaccinates the patient's donor with Triplex. That could provide the patient with earlier and greater immunity against CMV, which is particularly important for patients undergoing high-risk transplants in which they have a haploidentical donor (a half-matched bone marrow donor.)"
The study in question is a relatively small study. Before we will see this vaccine in clinical practice it will still need to complete a larger Phase III study and then go through FDA/regulatory review. I am hopeful, however, that FDA will designate this vaccine as a 'breakthrough medicine', meaning that the Biologics License Application will be fast-tracked through the Agency and that we may see this vaccine in routine use in a relatively short period of time (hopefully, a few years).
