Impact of posttransplant cyclophosphamide-based GVHD prophylaxis in patients 70 years and older: an update from BMT...

Area of Science:

• Hematology
• Transplantation Immunology
• Geriatric Oncology

Background:

• Allogeneic hematopoietic cell transplant (allo-HCT) is underutilized in older adults (≥ 70 years) due to concerns about morbidity, particularly graft-vs-host disease (GVHD).
• Reduced intensity conditioning (RIC) regimens have been developed to mitigate transplant-related toxicity in this population.
• Optimizing GVHD prophylaxis is crucial for improving allo-HCT outcomes in elderly patients.

Purpose of the Study:

• To evaluate the efficacy of post-transplant cyclophosphamide (PTCy)-based GVHD prophylaxis compared to tacrolimus and methotrexate (Tac/MTX) in patients aged ≥ 70 years undergoing allo-HCT.
• To assess the impact of PTCy on GVHD-free, relapse-free survival (GRFS), non-relapse mortality (NRM), relapse rates, and overall survival in this specific age group.

Main Methods:

• Analysis of a subset of patients aged ≥ 70 years from the BMT CTN 1703 trial.
• Patients received allo-HCT after RIC and were randomized to either PTCy or Tac/MTX for GVHD prophylaxis.
• Outcomes including GRFS, NRM, relapse/progression, and survival were compared between the two prophylaxis arms.

Main Results:

• PTCy demonstrated superior GRFS rates (67.1% vs. 29.5%, p=0.001) in patients ≥ 70 years.
• PTCy was associated with lower 1-year NRM and reduced rates of relapse/progression.
• Significantly improved 1-year adjusted survival was observed with PTCy (94.3% vs. 60.2%, p=0.001).

Conclusions:

• PTCy-based GVHD prophylaxis is highly effective and should be considered standard care for older adults undergoing allo-HCT.
• The favorable outcomes, including low NRM and excellent survival, support increased consideration of allo-HCT for patients aged ≥ 70 years.
• PTCy offers a promising strategy to overcome barriers to allo-HCT utilization in the elderly population.