A second allogeneic hematopoietic stem cell transplantation (HSCT) is a reasonable treatment option for patients with relapsed acute myeloid leukemia (AML), according to a meta-analysis published in Transplantation and Cellular Therapy.
Furthermore, a second allogeneic transplant was more effective when it was performed in complete remission (CR) and in patients who had a later relapse from the first allogeneic HSCT, according to the investigators, led by Mohamed A. Kharfan-Dabaja, MD, MBA, FACP, of the Mayo Clinic in Jacksonville, Florida.
Investigators conducted the literature search in PubMed/MEDLINE and EMBASE on August 25, 2021, extracting data on both beneficial and harmful clinical outcomes, including the following:
- overall survival (OS)
- progression-free/disease-free survival (PFS/DFS)
- acute and chronic graft-versus-host disease
- non-relapse mortality (NRM)
The meta-analysis included 20 studies (n=2,772); the investigators found that a second allogeneic HSCT resulted in pooled CR, OS, PFS/DFS, NRM, and relapse rates of 67%, 34%, 30%, 27%, and 51%, respectively.
The investigators called the high pooled relapse rates “worrisome” and emphasized “the need to incorporate new therapies whether as post-transplant maintenance or consolidation, to mitigate relapse risk.”
The OS was two times higher when the second allogeneic HSCT was performed in CR (38% vs 17%) and three times higher in patients who had a later relapse from the first allogeneic transplant (34% vs 10%). There was no difference in pooled OS when comparing the same original donor or different donor (hazard ratio=1.01; 95% CI, 0.78-1.31; P=.94).
Dr. Kharfan-Dabaja and colleagues cautioned that the analysis was limited to patients receiving a second transplant for treating AML relapse. As such, they cautioned against “extrapolating these findings to other indications such as treatment of graft failure, poor graft function, or mixed donor chimerism.”
Kharfan-Dabaja M, Reljic T, Yassine F. Efficacy of a second allogeneic hematopoietic cell transplant in relapsed acute myeloid leukemia: results of a systematic review and meta-analysis. Cell Ther Transplant. 2022. doi:10.1016/j.jtct.2022.08.008