Extensive chronic graft-versus-host disease (GVHD) occurred in 15% of patients with acute lymphoblastic leukemia (ALL) within 2 years of undergoing allogeneic hematopoietic stem cell transplantation (HSCT) in their first complete remission.
Martina Calabrò, MD, of Federico II University of Naples, and colleagues conducted the study to identify risk factors influencing allogeneic HSCT outcomes in patients with ALL who received a transplant between 2015 and 2021. Dr. Calabrò and colleagues presented the results at the 64th American Society of Hematology Annual Meeting and Exposition.
The researchers identified 2349 patients with ALL who received a transplant, including 870 who received a transplant from a human leukocyte antigen (HLA)-matched sibling donor. However, 1150 of the patients received a transplant from an unrelated donor, with 79% being a 10/10 match and 21% being a 9/10 match. They also identified 329 patients who received a transplant from a haploidentical donor. Peripheral blood was the stem cell source in 85.3% patients. Most patients (79%) received myeloablative conditioning, and the remaining patients received reduced intensity conditioning.
Most patients (56.4%) had Philadelphia chromosome positive B-cell ALL, 28.4% had Philadelphia chromosome negative B-cell ALL, and 15.2% had T-cell ALL. The median time from diagnosis to transplant was 5.8 months.
The cumulative incidence of grade II-IV acute GVHD at 180 days was 29.2%. The cumulative incidence of grade III-IV acute GVHD was 10.1% at that time point.
The 2-year overall rate of chronic GVHD was 34%, and the 2-year overall rate of extensive chronic GVHD was 15%. The 2-year GVHD-free/relapse-free survival rate was 48%.
The 2-year leukemia-free survival rate was 62.3%, and the 2-year overall survival rate was 73.9%. The 2-year relapse incidence was 22.2%, and the 2-year nonrelapse mortality rate was 15.4%.
Having a matched sibling donor was significantly associated with a lower risk of grade II-IV acute GVHD compared with having a 9/10 (hazard ratio [HR], 0.58; 95% CI, 0.44-0.78; P<.01) or 10/10 matched unrelated donor (HR, 0.70; 95% CI, 0.56-0.87; P<.01).
Total body irradiation was significantly associated with a higher risk of grade II-IV acute GVHD (HR, 1.54; 95% CI, 1.23-1.92; P<.01) and chronic GVHD (HR, 1.47; 95% CI, 1.16-1.87; P<.01) compared with chemotherapy. However, total body irradiation was also significantly associated with lower relapse incidence (HR, 0.78; 95% CI, 0.61-0.99; P=.04) and higher rates of leukemia-free survival (HR, 0.80; 95% CI, 0.67-0.96; P<.02).
Use of peripheral blood stem cells was independently associated with a higher risk of chronic GVHD, as was the use of a female donor to male recipient.
“Use of [total body irradiation] and HLA mismatches are both associated with lower [relapse incidence] despite a higher risk of GVHD, highlighting the importance of tailoring GVHD prophylaxis in these settings,” Dr. Calabrò and colleagues concluded.
Calabrò M, Labopin M, Battipaglia G, et al. Risk factors influencing transplant outcomes of adults with acute lymphoblastic leukemia in first complete remission: a retrospective analysis from the ALWP of the EBMT. Abstract #2124. Presented at the 64th ASH Annual Meeting and Exposition; December 10-13, 2022; New Orleans, Louisiana.