A Retrospective Post-Marketing Surveillance Study on TGlobulin25®, the First Rabbit Anti-Thymocyte Globulin (r-ATG) Biosimilar Worldwide, as Induction Therapy in Adult Kidney Transplant Recipients

Abstract

Background Post-marketing surveillance studies are essential to establish a realistic assessment of TGlobulin25®, the first rabbit anti-thymocyte globulin (rATG) biosimilar approved in Iran, for the prevention of acute kidney transplant rejection. This study aimed to conduct a post-marketing surveillance investigation comparing TGlobulin25® with the originator product regarding efficacy and safety in adult kidney transplant recipients. Methods A comparative study of recipients who received either TGlobulin25® or Thymoglobulin® was conducted at the Abu-Ali Sina Transplant Center, Shiraz, Iran, from 21/03/2022 to 21/11/2022. Key outcomes, such as delayed graft function (DGF), biopsy-proven acute rejections, deaths, and adverse events, were assessed over a 1-year follow-up period. A multiple regression model was adjusted for confounding risk factors, and the normal distribution of continuous variables was evaluated using the Kolmogorov-Smirnov test. Results A total of 247 patients were enrolled (118 received TGlobulin25® and 129 received Thymoglobulin®). Except for the number of kidney transplantations, no statistically significant demographic differences were observed between the two groups. By the end of the study, DGF occurred in 19 patients (16.10%) in the TGlobulin25® group and 19 (14.72%) in the Thymoglobulin® group (P=0.76). Severe thrombocytopenia was reported in 3 (2.54%) patients in the TGlobulin25® group and 5 (3.88%) in the Thymoglobulin® group (P=0.55), while severe leukopenia was reported in 15 (12.71%) and 7 (5.43%) patients, respectively (P=0.07). No significant difference was observed in biopsy-proven acute rejections (P=0.39), and no statistically significant risk factor for rejection was identified. Four patients in each group died (3.38% and 3.12%, respectively), and three cases of allograft nephrectomy were reported in the Thymoglobulin® group. No significant difference was found in serum creatinine and calculated eGFR, except for eGFR at the end of the 12th month (P=0.013). The risk of viral infections was also non-significant. Conclusion Overall, no statistically significant differences were observed in major efficacy and safety outcomes. However, eGFR at 12 months was higher in the TGlobulin25® group. The incidence of Leukopenia was non-significantly higher in the TGlobulin25® group.