Survival appeared comparable among patients with lymphoma whether they underwent hematopoietic stem cell transplantation with a haploidentical related donor or matched sibling donor, according to the results of a retrospective study.
However, patients with haploidentical matched donors had a significantly lower risk for chronic graft-versus-host disease, results showed.
“For patients who need allogeneic transplants, HLA–matched sibling donors are considered the gold standard,” Nilanjan Ghosh, MD, PhD, director of the lymphoma program at Carolinas HealthCare System’s Levine Cancer Institute, told HemOnc Today. “If a matched sibling donor is not possible, then a matched unrelated donor search is initiated. Haploidentical donors are readily available, but in the past, these donors have not been regularly used due to the risk for excessive GVHD.”
Patients lacking an HLA–matched sibling donor have increasingly undergone haploidentical HSCT from related donors, followed by post-transplantation cyclophosphamide.
Ghosh and colleagues used the Center for International Blood and Marrow Transplant Research database to compare outcomes of 987 patients undergoing haploidentical (n = 180) or HLA–matched (n = 807) allogeneic HSCT after reduced-intensity conditioning regimens.
Patients undergoing haploidentical HSCT received post-transplantation cyclophosphamide as GVHD prophylaxis, with or without a calcineurin inhibitor and mycophenolate.
Patients who underwent HLA–matched HSCT received calcineurin inhibitor–based GVHD prophylaxis.
OS served as the primary endpoint.
A greater proportion of patients undergoing haploidentical HSCT were aged 60 years or older (35% vs. 24%; P < .001) and were of African American ethnicity (15% vs. 4%; P < .001).
The median follow-up for surviving patients was 3 years.
A similar proportion of both groups achieved 28-day neutrophil recovery (haploidentical vs. HLA–matched, 95% vs. 97%); however, a significantly greater proportion of patients undergoing HLA–matched HSCT achieved 28-day platelet recovery (91% vs. 63%; P = .001).
Although both groups had a similar 100-day cumulative incidence of acute GVHD (27% vs. 25%), the 1-year rates of chronic GVHD significantly favored haploidentical HSCT (12% vs. 45%; P < .001).
A multivariate analysis confirmed the long-term benefit of haploidentical HSCT for chronic GVHD (RR = 0.21; 95% CI, 0.14-0.31).
The haploidentical and HLA–matched cohorts had similar rates of 3-year nonrelapse mortality (15% vs. 13%), relapse or progression (37% vs. 40%), PFS (48% for both) and OS (61% vs. 62%). Multivariate analyses showed no significant differences in any of these areas.
“It was reassuring to see that the low incidence of chronic GVHD was not associated with an increased risk for relapse,” Ghosh said. “The OS and PFS outcomes were nearly identical between the two groups.”
Recurrent or progressive disease served as the most common cause of death for patients undergoing haploidentical or HLA–matched transplant (47% vs. 52%). Thirteen patients who underwent HLA–matched HSCT died of GVHD, compared with one patient who underwent haploidentical HSCT.
The researchers acknowledged limitations of their study, including the inclusion of patients with differing histologies and their inability to determine the extent to which physician and hospital preferences influenced treatment choice.
“This study demonstrated that haploidentical HSCT has equal efficacy and lower toxicity — especially with regard to chronic GVHD — compared with the ‘gold standard’ donor choice,” Ghosh said. “This information — coupled with the widespread availability of haploidentical donors, the shorter time-to-transplant and lower costs compared with the other alternative donor choices — should make allogeneic transplantation widely available for patients with lymphoma.” – by Cameron Kelsall
For more information:
Nilanjan Ghosh, MD, PhD, can be reached at email@example.com.
Ghosh reports consultant roles with AbbVie, Celgene and Janssen. Please see the full study for a list of all other researchers’ relevant financial disclosures.