Background Although chronic graft-versus-host-disease (cGvHD) is an important long-term complication after allogenic hematopoietic cell transplantation (allo-HCT) and is associated with increased healthcare resource utilization, real-world evidence is scarce. Objectives The aim of the study was to evaluate survival of patients with cGvHD in Germany and to analyze hospitalization and treatment patterns. Patients and Methods Based on a German claims database with 4.9 million enrollees, a retrospective longitudinal analysis covering a 6-year period between 2013 and 2018 was conducted. Patients with allo-HCT in 2014 or 2015 (index date) and no record of transplantation or documentation of GvHD 365 days prior to index were included. Patients who subsequently developed a cGVHD were compared with those who did not develop a cGVHD within 3 years after index date. cGVHD cases were identified based on documented International Classification of Diseases, Tenth Revision (ICD-10) diagnosis and treatment algorithms. Since the onset of cGvHD is defined at 100 days after allo-HCT, only those alive beyond day 100 were considered in the survival analysis. Patients who did not survive the first 100 days after allo-HCT were censored to prevent a selection bias due to early mortality within patients without GvHD. Survival rates were plotted using the Kaplan-Meier estimator. The number of hospitalizations and average lengths of stay as well as treatment patterns were descriptively examined. Results Overall, 165 cGvHD patients were identified and compared with 43 patients without cGVHD. Short-term survival rates were better for patients with cGvHD; the 6-month survival probability was 95.8% for patients with cGVHD and 83.7% for patients without cGVHD. However, long-term survival was better in patients without GvHD; The 30-month survival probability was 65.5% for patients with cGVHD and 76.7% for patients without cGVHD. While overall 90% of cGvHD patients were hospitalized at least once, the share was only half for patients without GvHD (44%). 78.2% of patients with cGVHD received corticosteroids in combination with other predefined immunosuppressants. Conclusion Findings from this study reveal a high disease burden associated with cGvHD. This underlines the high medical need for new interventional strategies to improve survival and morbidity after allo-HCT.

Graft-versus-host disease (GvHD) can occur as an immunological response after an allogeneic hematopoietic cell transplantation (allo-HCT). Due to the rarity of the disease German epidemiological data are scarce. Moreover, not all cases of GvHD are properly documented in daily practice. Against this background, this study aims at providing new estimates on the incidence of GvHD in Germany. MethodsBased on a large German claims database, a retrospective longitudinal analysis was conducted over a six-year period. Patients were selected that received allo-HCT between 2014 and 2015. Follow up period was three years. To adjust the incidence for undocumented cases, steroid prescriptions after an allo-HCT was used as an approximation. Based on both documented and undocumented GvHD patients, incidence rates were calculated. ResultsAmong 3,737,317 eligible database enrollees, we identi ed 297 patients who received an allo-HCT between 2014 and 2015. Depending on the extrapolation method, this corresponds to a yearly incidence of 2,760-3,246 in Germany. 134 of the 297 patients (i.e. 45.1%) developed a documented GvHD within three years after the transplantation which translates into a yearly incidence of 1,278-1,419 GvHD patients. Based on the medication regimens, we identi ed 83 additional patients with an suspected GvHD without a documented diagnosis. Extrapolated to the German population, our estimates suggests that the annual incidence of GvHD including undocumented cases could be as high as 2,069 − 2,298 which is higher than previously reported. ConclusionMore patients may be affected by GvHD in Germany than reported. Appropriate adjustments need to be made when utilizing administrative data.

Introduction Graft-versus-host disease (GvHD) can occur as an immunological response after an allogeneic hematopoietic cell transplantation (allo-HCT). Due to the rarity of the disease German epidemiological data are scarce. Moreover, not all cases of GvHD are properly documented in daily practice. Against this background, this study aims at providing new estimates on the incidence of GvHD in Germany. Methods Based on a large German claims database, a retrospective longitudinal analysis was conducted over a six-year period. Patients were selected that received allo- HCT between 2014 and 2015. Follow up period was three years. To adjust the incidence for undocumented cases, steroid prescriptions after an allo-HCT was used as an approximation. Based on both documented and undocumented GvHD patients, incidence rates were calculated. Results Among 3,737,317 eligible database enrollees, we identified 297 patients who received an allo-HCT between 2014 and 2015. Depending on the extrapolation method, this corresponds to a yearly incidence of 2,760-3,246 in Germany. 134 of the 297 patients (i.e. 45.1%) developed a documented GvHD within three years after the transplantation which translates into a yearly incidence of 1,278–1,419 GvHD patients. Based on the medication regimens, we identified 83 additional patients with an suspected GvHD without a documented diagnosis. Extrapolated to the German population, our estimates suggests that the annual incidence of GvHD including undocumented cases could be as high as 2,069 − 2,298 which is higher than previously reported. Conclusion More patients may be affected by GvHD in Germany than reported. Appropriate adjustments need to be made when utilizing administrative data.