Recent Developments in Drug Therapy for Aplastic Anemia

Objective: This article reviews recent developments in immunosuppressive therapy (IST) for aplastic anemia (AA) patients who are not candidates for stem cell transplant (SCT); including, front-line, salvage, and novel treatment options with a focus on response rates (RRs) and overall survival (OS). Data Sources: A PubMed literature search was performed from 1977 to June 2014 using the search terms aplastic anemia, horse antithymocyte globulin (hATG), rabbit ATG (rATG), thymoglobulin, and cyclosporine (CSA). Additional references were identified from a review of literature citations. Study Selection and Data Extraction: All English-language studies investigating IST for treatment of AA in non–SCT candidates were evaluated. Data Synthesis: Studies indicate addition of CSA and corticosteroids to hATG for treatment of AA improves RRs, decreases relapse rates, and improves 5-year OS. hATG improved RRs, relapse rates, and OS compared to rATG in the front-line setting. Studies support the use of rATG when front-line IST with hATG fails or when hATG is unavailable. Front-line daclizumab can be considered for nonsevere AA (NAA); however, data is limited. Alemtuzumab or eltrombopag are options for relapsed AA in select patients. Conclusions: hATG with methylprednisolone and CSA is recommended for front-line treatment of AA, whereas rATG is reserved for salvage therapy. Front-line use of daclizumab has been studied in NAA patients, but additional prospective trials are needed before this is adopted into clinical practice. Alemtuzumab and eltrombopag have been studied for treatment of AA; recruiting is ongoing in clinical trials to assess the appropriate dosing strategy and place in therapy.