Myeloablative conditioning before HSCT confers survival benefit in AML, myelodysplastic syndrome
ORLANDO — Myeloablative conditioning before hematopoietic stem cell transplantation conferred a long-term survival advantage compared with reduced-intensity conditioning among patients with acute myeloid leukemia or myelodysplastic syndrome, according to extended follow-up of the randomized phase 3 MAvRIC trial presented at TCT | Transplantation & Cellular Therapy Meetings.
“If there is a choice and a patient is an eligible candidate for it, myeloablative chemotherapy should be preferred,” Bart Scott, MD, associate member of the transplantation program in the clinical research division at Fred Hutchinson Cancer Research Center, told Healio. “We have seen that now after a long-term follow-up, which was important to establish.”
Scott and colleagues randomly assigned 272 patients (median age, 55 years) with myelodysplastic syndrome (n = 54) or AML (n = 218) and less than 5% marrow blasts by morphology to either myeloablative or reduced-intensity conditioning before HSCT.
The most common myeloablative regimen was fludarabine/busulfan (FluBu)4 (64%). The most common reduced-intensity regimen was FluBu2 (81%).
Previous results showed longer RFS at 18 months among patients in the myeloablative conditioning group.
At median follow-up of 50 months, results showed 4-year OS rates of 65% for the myeloablative conditioning group and 49% for the reduced-intensity group (P = .02).
Multivariate analysis showed an HR for death with reduced-intensity vs. myeloablative conditioning of 1.54 (95% CI, 1.07-2.2). Other mortality risk factors included protocol-defined high-risk disease (HR = 1.77) and age 50 years or older (HR = 2.2).
Researchers also reported 4-year RFS rates of 34% with reduced-intensity conditioning and 58% with myeloablative conditioning (HR = 2.06; 95% CI, 1.48-2.85).
A subset analysis of patients with myelodysplastic syndrome appeared directionally similar to the analysis of the overall cohort; however, this was not statistically significant, probably due to limited power, according to the researchers.
Among patients with AML, post-HSCT results showed relapse survival rates of 24% in the myeloablative conditioning group and 26% in the reduced-intensity group 3 years after leukemia relapse.
“The bottom line is that myeloablative chemotherapy is superior to reduced-intensity chemotherapy,” Scott said. “It should be used if the patients are eligible.” – by John DeRosier
Scott BL, et al. Abstract 11. Presented at: TCT | Transplantation & Cellular Therapy Meetings; Feb. 19-23, 2020; Orlando.
Scott reports consultant/advisory roles with Agios, Celgene, Jazz Pharmaceuticals and Novartis, as well as research funding from Novartis. Please see the abstract for all other authors’ relative financial disclosures.