Pediatric Transplant and Cellular Therapy Consortium RESILIENT Conference on Pediatric Chronic Graft-Versus-Host Disease Survivorship After Hematopoietic Cell Transplantation: Part I. Phases of Chronic GVHD, Supportive Care, and Systemic Therapy Discontinuation.

Current literature lacks details on the impact of pediatric chronic graft-versus-host disease (cGVHD) on long-term survivorship after allogeneic hematopoietic cell transplantation (HCT). Nonetheless, cGVHD remains a leading cause of post-transplant morbidity and mortality in children and adolescents, which is particularly relevant given the longer life-expectancy after HCT (measured in decades) compared to older adults. To address this knowledge gap, leaders of the Pediatric Transplant and Cellular Therapy Consortium convened a multidisciplinary taskforce of experts in pediatric cGVHD and HCT late effects known as RESILIENT after Chronic GVHD (Research and Education towards Solutions for Late effects to Innovate, Excel, and Nurture after cGVHD). Our goals were to define: (1) the current state of understanding about how cGVHD impacts long-term survivorship in children transplanted <18 yr of age; (2) practical aspects of care to help clinicians managing long-term pediatric cGVHD survivors; and (3) develop a research framework for the next decade to further our knowledge. Four working groups were formed, each tasked with addressing a unique theme: (1) cGVHD natural history (phases of cGVHD) and its impact on clinicians' ability to taper and durably discontinue systemic therapy; (2) organ dysfunction and immune reconstitution in relation to survivorship; (3) how cGVHD and its treatment impact growth, metabolism, and development in children; and (4) psychosocial health and patient reported outcomes. The 4 groups met before the 2024 BMT Tandem Meeting in San Antonio, Texas, and then convened a larger in-person RESILIENT conference held on February 20, 2024, at the Tandem meeting to put forth recommendations from their respective working groups and garner feedback. These recommendations are now presented in a series of 4 manuscripts. This current manuscript focuses on the first theme and discusses the phases of cGVHD, challenges in differentiating clinically active from quiescent cGVHD in clinical practice, and the resultant difficulties in determining when and if to taper systemic therapy. To overcome these challenges, we propose revised categorization of long-term cGVHD outcomes and practical recommendations for clinicians and researchers around the long-term follow-up for these patients, including determining when and if to taper systemic therapy, along with the integration of non-immunosuppressive supportive care interventions.