In a recent multicenter, retrospective study of pediatric patients with severe aplastic anemia, researchers reported that responses to immunosuppressive therapy (IST) were higher than those that have been seen with adult patients in previous studies. The study results were published in Haematologica.
The researchers conducted a chart review from 25 institutions within the North American Pediatric Aplastic Anemia Consortium and included 314 patients with pediatric severe aplastic anemia who were evaluated for outcomes with IST as their initial treatment.
Horse antithymocyte globulin (hATG) with cyclosporine (CyA) was the most common IST among patients in this study, used with 84.1% of patients. Median follow-up was 61 months for those receiving hATG/CyA and 62 months for the overall study population.
The estimated 5-year overall survival rate was 93% for patients treated with hATG/CyA and 92% for the overall study population. The objective response rate was 71.2% for patients given hATG/CyA and 70.7% for the overall study. Complete response was achieved by 59.8% of patients treated with hATG/CyA and in 60.2% of the overall study population. Deep response (complete response plus very good partial response) was seen in 68.2% of patients who received hATG/CyA and in 67.5% of the overall study population.
The estimated event-free survival (EFS) rate at 5 years was 64% for patients receiving hATG/CyA, compared with 62% for the overall study population. For patients with relapsed or refractory disease, the EFS rate was better for further treatment using hematopoietic stem cell transplantation (HSCT) compared with undergoing a second round of IST (hazard ratio, 0.19; P =.0003).
The researchers indicated that responses were higher for this pediatric population, and the clonal progression rate was potentially lower, compared with the response rates that are often seen with adult patients. However, they noted that the low EFS seen with IST in this study is a concern for this young population, and that ongoing studies may be demonstrating a role for HSCT from matched unrelated donors in the treatment of pediatric severe aplastic anemia.
- Rogers ZR, Nakano TA, Olson TS, et al. Immunosuppressive therapy for pediatric aplastic anemia: a North American Pediatric Aplastic Anemia Consortium study. Haematologica. 2019;104:1974-1983.