Low response rate to ATG-based immunosuppressive therapy in very severe aplastic anaemia - A Swedish nationwide cohort study

Eur J Haematol. 2018 Jun;100(6):613-620. doi: 10.1111/ejh.13057. Epub 2018 Apr 10.

Abstract

Objectives: Antithymocyte globulin (ATG)-based immunosuppression remains a cornerstone in aplastic anaemia (AA) treatment. However, most ATG studies are not population-based and knowledge about real-world results concerning response and outcome could offer important information for treating physicians.

Methods: We have recently performed a nationwide retrospective cohort study on all AA patients diagnosed in Sweden in 2000-2011 and now present treatment and outcome data on patients receiving first-line ATG. In total, 158 patients showed a 47.0% response rate which was similar in all age groups (range 41.5%-51.7%) with no difference regarding ATG formulation. The response was significantly associated with severity grade-especially at time of treatment initiation: very severe (VSAA) 22.7%; severe (SAA) 54.5% (P < .001); and non-severe 88.5% (P < .001). A logistic regression-based predictive model indicated that VSAA patients with an absolute reticulocyte count <25 × 109 /L had only a 19% probability of response. In a multivariable analysis, age and VSAA at the time of treatment were the independent factors for inferior survival.

Conclusions: Real-world VSAA patients respond poorly to ATG which indicates the need for a different treatment approach. Our findings suggest that age alone should not be a discriminating factor for administering ATG treatment.

Keywords: age; antithymocyte globulin; aplastic anaemia; real-world data; response rate.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anemia, Aplastic / diagnosis
  • Anemia, Aplastic / drug therapy*
  • Anemia, Aplastic / epidemiology
  • Anemia, Aplastic / immunology
  • Antilymphocyte Serum / therapeutic use*
  • Biomarkers
  • Child
  • Child, Preschool
  • Cohort Studies
  • Combined Modality Therapy
  • Female
  • Hematopoietic Stem Cell Transplantation
  • Humans
  • Immunosuppressive Agents / therapeutic use*
  • Incidence
  • Male
  • Middle Aged
  • Odds Ratio
  • Severity of Illness Index
  • Survival Analysis
  • Sweden / epidemiology
  • Young Adult

Substances

  • Antilymphocyte Serum
  • Biomarkers
  • Immunosuppressive Agents