The investigation of extracorporeal photopheresis (ECP) plus standard of care (SoC) (SoC+ECP) in chronic graft-versus-host disease (cGVHD) within prospective, randomized clinical studies is limited, despite its frequent clinical use. This phase 1/pilot study was the first randomized, prospective study to investigate ECP use as first-line therapy in cGVHD, based on the 2015 National Institutes of Health (NIH) consensus criteria for diagnosis and response assessment. Adult patients with new-onset (≤3 years of hematopoietic stem cell transplantation) moderate or severe cGVHD were randomized 1:1 to 26 weeks of SoC+ECP vs SoC (corticosteroids and cyclosporine A/tacrolimus) between 2011 and 2015. The primary endpoint was overall response rate (ORR), defined as complete or partial response, at week 28 in the intention-to-treat population (ITT). Other outcomes included quality of life (QoL) measures and safety. Sixty patients were randomized; ITT included 53 patients (SoC+ECP: 29; SoC: 24). Week 28 ORR was 74.1% (SoC+ECP) and 60.9% (SoC). Investigator-assessed ORR was 56.0% (SoC+ECP) and 66.7% (SoC). Patients treated with SoC experienced a decline in QoL over the 28-week study period; QoL remained unchanged in SoC+ECP patients. Most frequent treatment-emergent adverse events (TEAEs) in SoC+ECP patients were hypertension (31.0%), cough (20.7%), dyspnea (17.2%), and fatigue (17.2%). Seventeen patients (SoC+ECP: 8; SoC: 9) experienced 35 serious adverse events (SAEs). No TEAEs or SAEs were considered related to the ECP instrument or methoxsalen. The encouraging short-term results of this study could inform the design of subsequent studies. This trial was registered at www.clinicaltrials.gov as #NCT01380535.
