Epidemiology and Treatment of Chronic Graft-versus-Host Disease Post-Allogeneic Hematopoietic Cell Transplantation: A US Claims Analysis.

Chronic graft-versus-host disease (cGVHD) is a complication of hematopoietic cell transplantation (HCT). Although the clinical outcomes of cGVHD are well documented, few studies have assessed treatment practices outside of clinical trials. The present study aimed to quantify the prevalence of cGVHD, examine provider prescribing patterns, and evaluate the healthcare cost and resource utilization (HCRU) in a US cGVHD population. We analyzed anonymized claims from the Medicare Fee-for-Service (FFS) 5% sample for beneficiaries enrolled between 2013 and 2016 and PharMetrics commercial 2013 to 2018 databases to identify cGVHD in allogeneic HCT recipients. cGVHD was identified based on International Classification of Diseases Ninth/Tenth Revision diagnosis codes for cGVHD or unspecified GVHD with a first diagnosis >180 days post-HCT or a maintained unspecified GVHD diagnosis for >12 months postindex of unspecified GVHD diagnosis. Longitudinal and line of therapy (LOT) analyses were based on the PharMetrics dataset for 2013 to 2018. Healthcare costs were calculated by adding the inpatient, outpatient, and pharmacy insurer and beneficiary paid amounts for the commercially insured population. Total HCRU was assessed using the number of inpatient and outpatient visits following the initial cGVHD diagnosis. In 2016, the projected prevalence of cGVHD in the United States based on the Medicare FFS and PharMetrics commercial databases was 14,017 individual patients. Within 3 years after undergoing allogeneic HCT, 42% of patients developed cGVHD; 66% of the cGVHD patients had a prior diagnosis of acute GVHD. The majority of cGVHD patients received at least one systemic therapy; 71% and 47% of cGVHD patients progressed to a second and third LOT, respectively. A total of 24 unique therapeutic agents and more than 150 combinations were used in the second and third LOTs. Corticosteroids and corticosteroid combination therapy were the most common forms of treatment across all examined LOTs. Furthermore, the most commonly used agents in the first LOT, second LOT, and third LOT were corticosteroids only, calcineurin inhibitors only, and corticosteroids only, respectively. In the 12 months postdiagnosis, cGVHD patients had an average of 21.0 cGVHD-related inpatient and outpatient visits (2.8 inpatient and 18.2 outpatient visits). A significant proportion of allogeneic HCT recipients continue to develop cGVHD, and despite advances in the understanding of cGVHD, corticosteroids remain the mainstay of therapy. Patients often progress beyond the first LOT, at which time the utilization of systemic therapies is highly variable, demonstrating the need for evidence-based treatment approaches.