Antibodies derived from rabbits called anti-thymocyte globulin (ATG) could reduce leukemia-associated risks and could boost the survival, found researchrs from Virginia Commonwealth University Massey Cancer Center. ATG antibodies can improve relapse outcomes of leukemia and myelodysplasia patients, who received a stem cell transplant from an unrelated donor.
Stem cell transplants from an unrelated donor are normally measured as high-risk treatment because of previously higher rates of disease relapse and GVHD (graft-versus-host disease) in comparison to stem cells transplants from donors related to the patients. This is the first study that used anti-thymocyte globulin (ATG) in stem cell transplantation.
ATG works by reducing the number of circulating T-lymphocytes, a key element of the immune system. It is primarily used in organ transplantation to prevent patients’ immune systems from rejecting transplanted tissue. It is also used to treat aplastic anemia, a condition where the bone marrow does not create enough new cells.
A team led by Dr Amir Toor from Virginia Commonwealth University Massey Cancer Center’s Bone Marrow Transplant Program, compared the outcomes of fifty patients who received rabbit anti-thymocyte globulin (ATG) prior to receiving a transplant of stem cells from an unrelated donor with the outcomes of forty-eight patients who received a transplant of stem cells from a related donor.
Although, unrelated stem cell transplants typically have inferior outcomes than related stem cell transplants, but study findings demonstrated analogous outcomes for each group in terms of mortality, relapse and the development of GVHD, a common complication that can occur after a stem cell or bone marrow transplant in which the newly transplanted material attacks the transplant recipient’s body.
Dr Toor stated unfortunately, they cannot always find a related or a genetically similar donor for patients in need of stem cell transplantation. Obtaining better outcomes with unrelated donor stem cell transplants could represent a significant advancement in extending the lives of more patients with blood cancers.
No survival differences between the two groups of patients despite of age or diagnosis were found. Besides relapse rates and incidence of GVHD were also similar. Chronic GVHD, alternatively, was diagnosed less frequently in patients in the ATG group. They also noticed a higher rate of infections in patients who received the highest dose of ATG.
In addition, the researchers noticed a higher rate of infections in patients receiving the highest dose of ATG, but this risk was diminished in patients who received slightly lower doses. The study was published in the journal Bone Marrow Transplantation.