Continuation of Secondary Systemic Treatment Among Patients with Chronic Graft Versus Host Disease in the United States Is Associated with Reduced Hospital Cost (2009-2016)

Introduction Chronic graft-versus-host disease (cGvHD) is a complication following allogeneic hematopoietic stem-cell transplants (HSCT) occurring when immune cells transplanted from a non-identical donor (i.e., the graft) recognize the transplant recipient (i.e., the host) as foreign. Systemic therapy for ≥1 year is required for patients who meet criteria for moderate-to-severe cGvHD using NIH consensus criteria. This study assessed continuation of secondary systemic treatments (SSTs) in cGvHD patients in the United States (US). Methods A retrospective analysis was conducted using the Truven Health MarketScan ® claims databases (2009–2016). Adult cGvHD patients receiving SST with continuous enrollment (3 months before first cGvHD diagnosis [baseline] and 6 months after SST initiation) were eligible. SST was defined by Flowers et al (2015) 1 and included extracorporeal photopheresis (ECP), rituximab, imatinib, pentostatin, or mTOR inhibitors, continuous SST use was defined as ≥180 days of therapy (yes vs. no) and treatment persistence was evaluated using a 45-day gap. Patient demographics, clinical characteristics, health care resource use, and costs were summarized by SST continuation status. A multivariate regression model assessed factors associated with SST continuation. Results The study included 464 patients with ≥2 SST claims (mean age 49.7 years; 61.0% male). The most frequently used SSTs (not mutually exclusive) were mTOR inhibitors 293 (63.1%), ECP 210 (45.3%) and imatinib 51 (11.0%). The mean (median) treatment duration was 12.9 (8.3), 11.1 (8.0), and 12.5 (7.5) months for mTOR inhibitors, ECP and imatinib, respectively. A total of 172 (37.1%) patients were SST continuers and 292 (62.9%) were discontinuers. Baseline demographic and clinical characteristics were similar between SST continuers and discontinuers. The mean time from cGvHD diagnosis to initiation of SST was shorter for discontinuers vs. continuers (5.0 vs 6.2 months, ( P =.118). Compared with SST continuers, SST discontinuers had higher average monthly hospital costs post-SST initiation ($15,848 vs. $6,286, P =0.047). The proportion of SST continuers was the highest (52.9%) among ECP patients, followed by patients receiving imatinib (33.3%) and mTOR inhibitors (21.5%). Regression results revealed that ECP patients were >3 times more likely to be SST continuers (adjusted OR: 3.18, P Conclusions Approximately 2 in 5 cGvHD patients were SST continuers with median treatment duration of 15 months. SST continuers had lower monthly hospitalization costs than discontinuers during the follow-up period, indicating a potential cost benefit for treatment continuity. Multivariate regression analysis indicated that ECP treatment is significantly associated with SST continuation. These findings should be interpreted with caution as the reasons for discontinuation are unknown.