# Anti-thymocyte globulin-based treatment frequently leads to enduring treatment success in both old and young adult patients with aplastic anaemia: a real-world analysis from the Dutch aplastic anaemia registry

## TL;DR

Anti-thymocyte globulin treatment is effective and safe for both young and older patients with aplastic anemia, according to a real-world study.

## Contribution

The study provides real-world evidence that ATG-based therapy is effective and safe in older patients with aplastic anemia.

## Key findings

- ATG-based immunosuppressive therapy had a 79% overall survival rate at 5 years.
- Transplantation-, Treatment-, and Disease-Free Survival was 42% at 5 years after treatment initiation.
- Older age and absence of a PNH-clone reduced the likelihood of successful treatment outcomes.

## Abstract

Discussion remains concerning the safety and tolerability of anti-thymocyte globulin (ATG)-based immunosuppressive therapy (IST) in older patients with aplastic anaemia (AA). Using data of 127 consecutive patients from the Dutch adult AA registry, we evaluated long-term treatment success of standard ATG-based IST as first-line treatment with a multi-state model. Only one death was potentially associated with ATG. Overall survival at 5 years was 79%. We defined Transplantation-, Treatment- and Disease-Free Survival (TT-DFS) as the ultimate success of this treatment. This means that a patient is alive, is currently transfusion-independent without having received an allogeneic stem cell transplantation, has not developed AML or MDS, and has stopped all medication for AA. The probability of TT-DFS was 42% at 5 years after start of IST. In patients younger than 40 years (n = 36) and in patients aged 60 or above (n = 53), this was 58% and 34%, respectively. Older age, more severe AA and absence of a PNH-clone of ≥ 1% all reduced the likelihood of reaching TT-DFS. These analyses on unselected nationwide data indicate that ATG-based IST is effective and safe also in older patients. They suggest that age, AA severity and presence of a PNH-clone should be taken into account when considering this treatment in older patients.

The online version contains supplementary material available at 10.1007/s00277-026-06743-5.