Safety and Efficacy of Indigenous Equine Antithymocyte Globulin Along with Cyclosporine in Subjects with Acquired Aplastic Anemia

Abstract

To confirm the safety and efficacy of an indigenous equine antithymocyte globulin (eATG) along with cyclosporine in Indian subjects with acquired aplastic anaemia. Subjects >2 years old with acquired aplastic anaemia were enrolled at six hospitals between April 2011 and February 2013, after approval from respective Ethics Committees. Equine ATG at a dose of 40 mg/kg/day was infused for 4 days. Efficacy analysis defined a priori, was in subjects, who had completed eATG treatment and followed-up on day 90 and/or 180. Complete response (CR) was defined as—transfusion independent, haemoglobin ≥11 g/dL, absolute neutrophil count (ANC) >1.5 10 9 /L and platelet ≥150 10 9 /L; partial response (PR) was transfusion independent, haemoglobin ≥8 g/dL, ANC >0.5 10 9 /L and platelet ≥20 10 9 /L; non responders were transfusion dependent. Lymphocyte subsets (CD 2, 3, 4 and 8) in the blood were tested on days 0 (pre eATG infusion), 3, 5, 7, 14 and 21 after eATG. Of the 30 subjects (two children <12 years old) enrolled, 19 completed day 90 and 18 completed day 180 visit. Of the remaining 11 subjects, two died on days 12 and 45 due to septicaemia and pneumonia, one was withdrawn after the first dose of eATG due to jaundice and eight were lost to follow-up. The median age was 30 (9–58) years and weight was 57 (26–84) kg. On day 90, 12 of 30 subjects responded (CR 1, PR 11) and 15 of 30 (CR 2, PR 13) on day 180. The most common adverse event was fever related to eATG infusion. There were two serious adverse events (acute renal failure, febrile neutropenia) and both recovered with treatment. There were no unusual adverse events noted during the study period. Blood T lymphocytes showed a mean decrease of 91 % from baseline that recovered by day 21. We conclude that eATG is safe and in combination with cyclosporine showed overall response in 50 % of enrolled subjects. The trial was registered with the clinical trial registry-india (Registration no. CTRI/2012/03/002498).