Algorithm for initial management of SAA. In patients who are not candidates for a matched related HSCT, immunosuppression with horse ATG + CsA should be the initial therapy. We assess for response at 3 and 6 months, but usually wait 6 months before deciding on further interventions in nonresponders. In patients who are doing poorly clinically, with persistent neutrophil count < 200/μL, we proceed to salvage therapies earlier, between 3 and 6 months. Transplantation options are reassessed at 6 months and donor availability, age, comorbidities, and neutrophil count become important considerations. We favor a matched UD HSCT in younger patients with a histocompatible donor and repeat IST for all other patients. In patients with a persistently low neutrophil count in the very severe range, we may consider a matched UD HSCT in older patients. In patients who remain refractory after 2 cycles of IST, further management is then individualized by taking into consideration suitability for a higher-risk HSCT (ie, mismatched UD, haploidentical or UC donor), age, comorbidities, neutrophil count, and overall clinical status. Some authorities in SAA consider 50 years of age as the cutoff for sibling HSCT as frontline therapy. Adapted with permission from Scheinberg and Young.¹