Response to Immunosuppressive Therapy in Aplastic Anemia—A Single Centre, Prospective Study of 158 Patients from a Tertiary Care Centre in India

Immunosuppressive therapy (IST) with Antithymocyte globulin (ATG) and cyclosporine is the therapy of choice in aplastic anemia (AA) patients who are more than 40 years of age and younger patients who do not have matched sibling donor for stem cell transplant (SCT). The overall response rate to IST is approximately 65%. The two preparations of ATG that are available in India are Atgam (Pfizer) and Thymogam (Bharat serum, India). Most of the published studies, from India, have used ATGAM. We present the largest study on IST (with Thymogam) from India. This is a single centre prospective study conducted in a tertiary care institute in southern India, from July 2016 to June 2022. All patients of age more than 13 years with diagnosis of aplastic anemia were included. Those with inherited bone marrow failure syndromes were excluded. Severity of AA and response rate was classified based on standard criteria. Patients were followed up till discharge and then monthly for at least 6 months. A total of 158 patients ( males-85, females- 73) received IST (Thymogam plus cyclosporine).Most of the patients had non severe AA(58%) followed by severe (28%) and very severe AA(14%). At 6 months post IST, the overall response rate (ORR) was 66% (complete response- 2% and partial response -64%) while the mortality rate was 13%.The ORR was 64% at 12 months and 61% at 24 months after IST. Age, Gender and severity at presentation did not influence response rates.