Stem Cell Transplantation and AML: WT1 Expression and Outcomes
Posted: Wednesday, September 9, 2020
Allogeneic hematopoietic stem cell transplantation (SCT) may be the best chance for a cure for acute myeloid leukemia (AML), yet there is an ongoing debate as to the optimal conditioning regimen, as well as the concern of relapse. A recent study conducted by Hee-Je Kim, MD, PhD, of The Catholic University of Korea, Seoul, and colleagues found that pretransplant Wilms tumor gene 1 (WT1) expression levels were predictive of a higher risk of relapse. The results of their study were published in Biology of Blood and Marrow Transplantation.
Researchers identified 257 eligible patients with AML for this study. Patients received either myeloablative or reduced-intensity conditioning, and bone marrow WT1 expression results were assessed before transplantation. Transcript levels of WT1 were normalized to copies per 104 ABL. Patients with ³ 250 copies/104 ABL were defined as having a high expression of WT1 (WT1high) and those with < 250 copies/104 ABL were considered to have a low expression of WT1 (WT1low). When WT1 250 copies/104 ABL were used as a cutoff value, 201 of 257 patients (78.2%) achieved either a WT1low complete response or a complete response with incomplete hematologic recovery.
Of the total, 74.3% of the patients (n = 191) received myeloablative conditioning, and 25.7% (n = 66) received reduced-intensity conditioning. There appeared to be no difference in overall survival, disease-free survival, and higher cumulative incidence of relapse between patients with WT1low who received either regimen. The median follow-up duration was 64.1 months. The incidence of relapse during this period was 14.0% and 38.1% in patients with pre-SCT WT1low and WT1high, respectively.
“This study showed that the pretransplant molecular response assessed by WT1 level was predictive for post-transplant survival, disease-free survival, and incidence of relapse,” explained the researchers. “These results may serve as a baseline for future studies toward optimized transplants through individualized conditioning strategies.”
Disclosure: The study authors reported no conflicts of interest.