Factors Associated With Successful Discontinuation of Immune Suppression After Allogeneic Hematopoietic Cell Transplantation.

Importance: Immune suppression discontinuation is routinely attempted after allogeneic hematopoietic cell transplantation (HCT) and under current practices may lead to graft-vs-host disease (GVHD)-associated morbidity and death. However, the likelihood and predictive factors associated with successful immune suppression discontinuation after HCT are poorly understood.

Objectives: To examine factors associated with successful immune suppression discontinuation and risk for immune suppression discontinuation failure under conventional HCT approaches and develop a practical tool to estimate successful immune suppression discontinuation likelihood at the clinical point of care.

Design, Setting, and Participants: Using long-term follow-up data from 2 national Blood and Marrow Transplant Clinical Trial Network studies (N = 827), a multistate model was developed to investigate the probability and variables associated with immune suppression discontinuation success. The study began in July 2015, and analyses were completed in August 2019.

Main Outcomes and Measures: Immune suppression discontinuation and immune suppression discontinuation failure.

Results: Of the 827 patients included in the analysis, 456 were men (55.1%). Median age at transplant was 44 (range, 50 vs

Conclusions and Relevance: Successful immune suppression discontinuation is uncommon in the setting of peripheral blood stem cell grafts. The data suggest earlier attempts at ISD conferred no long-term benefit, given frequent ISD failure, limited subsequent success after initial failed ISD attempt, and no evidence of relapse reduction. Using a risk model-based clinical application, physicians may be able to identify individual patients' probability of successful immune suppression discontinuation.