Atgam Efficacy and Safety in Moderate-to-Very Severe Acquired Aplastic Anemia: Outcome of a Large Multicenter Cohort of 634 Children and Adults from the French Authorization for Temporary Use Surveillance Program

• Published in: Blood 2023-11, Vol.142 (Supplement 1), p.1347-1347
• Main Authors: Sicre De Fontbrune, Flore, Fahd, Mony, Forcade, Édouard, Tavitian, Suzanne, Moluçon Chabrot, Cécile, Barraco, Fiorenza, Hicheri, Yosr, Lebon, Delphine, Maury, Sébastien, Menard, Anne-Lise, Możejko-Pastewka, Barbara, Wolter, Kevin D, Valtier, Bruno, Leblanc, Thierry, Peffault De Latour, Regis
• Format: Article
• Language: English
• Subjects: Human health and pathology; Life Sciences
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2023-186493

Introduction Acquired aplastic anemia (AA) is a rare immunological disease leading to bone marrow failure. First-line treatment in patients aged >40 years or without a matched related donor is immunosuppressive therapy (IST) based on anti-human T lymphocyte immunoglobulin (ATG) plus cyclosporine. This ATGAM Temporary Use Authorization program was a retrospective, multicenter study to report safety and efficacy surveillance data on ATGAM use in patients with AA. Methods This study collected surveillance data from the ATGAM Named Patients Program for French authorities ahead of ATGAM registration. Patients were treated with ATGAM 40 mg/kg for 4 days in addition to cyclosporine. Safety and efficacy data were collected from patients treated from September 2011 to August 2022 and reported to the French authority every 6 months. Patients were classified as severe AA if they had 2 of the following criteria: neutrophil count 2.0x10 9/L and platelet count >100x10 9/L; partial response: neutrophil count >1.0x10 9/L and platelet count >30x10 9/L; no response: transfusion dependent. Patients were classified as receiving first-line treatment (never received ATG), refractory (failed to respond to previous IST with ATG within 12 months before initial ATGAM), or relapse (recurrence of AA after a positive response to IST with ATG), regardless of AA severity. Results In total, 634 patients with moderate-to-very severe AA were treated with ATGAM (n=537 first-line; n=68 refractory/relapse; n=29 not classified) in addition to cyclosporine (40 first-line patients also received eltrombopag) from January 2012 to August 2022. By severity, n=124 were moderate, n=317 severe, n=133 very severe, and n=60 severity unknown. Patient demographics are shown in Table 1. Overall response (partial+complete) in patients on first-line th