Comparison of Outcomes After Second Allogeneic Hematopoietic Cell Transplantation Versus Donor Lymphocyte Infusion in Allogeneic Hematopoietic Cell Transplant Patients.

BACKGROUND

Allogeneic hematopoietic cell transplantation (HCT) is potentially curative for hematological disease however can be complicated by relapse or graft failure (GF), for which second-HCT and donor lymphocyte infusions (DLI) are performed. This study aimed to compare outcomes following the two interventions.

METHODS

We retrospectively investigated 89 patients with relapse or GF after first-HCT, 50 (56%) underwent second HCT and 39 (44%) received (DLI), from June 2011 to September 2020.

RESULTS

Median age at intervention was 55 years (19-72). Second-HCT was performed for relapse in 19 patients and for GF in 31 patients (primary GF in 11 and secondary in 20 patients), same donor was used in 25 (50%) patients. DLI was performed for relapse in 20 and for secondary GF in 19 patients. Median number of DLI administered was 2 (range 1-11). Univariate analysis demonstrated 2 year overall survival (OS) for second-HCT was superior when performed for relapse (65%) compared to GF (44%) (P = .03). For DLI patients, 2 year OS was 49% for GF and 45% for relapse patients (P = .49). For relapse as an indication, second-HCT demonstrated borderline superiority compared to DLI (P = .07). Multivariable analysis demonstrated for OS for the entire cohort demonstrated donor mismatch (HR 0.50, 95% CI 0.26%-0.94%, P = .03), KPS at time of intervention (HR 2.10, 95% CI 1.14%-3.85%, P = .02) and time from first-HCT to intervention (HR 0.51, 95% CI 0.28%-0.93%, P = .03) as significant variables.

CONCLUSION

Second-HCT may improve outcomes when performed for relapse post-transplant if patients achieve remission again, while DLI may be reserved for patients with active disease.