Liu, Hien

ABSTRACT Collection of hematopoietic progenitor cells and mononuclear cells by leukocytapheresis is a critical step of procuring cellular starting materials for future therapeutic use. Leukocytapheresis requires use of anticoagulant to prevent blood clotting in the extracorporeal circuit during collection. A commonly used anticoagulant is Acid Citrate Dextrose Solution A (ACD‐A). ACD‐A primarily prevents blood clotting by reversibly chelating free ionized calcium, which is essential for the clotting cascade. Electrolytes frequently affected by ACD‐A include calcium, magnesium, potassium, phosphate, and bicarbonate. Risks for development of electrolyte derangements include procedure‐related parameters as well as patient comorbidities. Symptoms range from mild paresthesias to life‐threatening cardiac arrhythmias. Recognition of related signs and symptoms is important for prompt intervention with procedure modification and electrolyte replacement to optimize patient safety. This paper will provide an enhanced understanding of the underlying pathophysiology and assist in timely identification and management of electrolyte abnormalities associated with cellular therapy collections.

Abstract Standard initial therapy of chronic graft vs. host disease (cGVHD) with glucocorticoids results in suboptimal response. Safety and feasibility of therapy with ofatumumab (1000 mg IV on days 0 and 14) and prednisone (1 mg/kg/day) was previously established in our phase I trial (n = 12). We now report the mature results of the phase II expansion of the trial (n = 38). The overall NIH severity of cGVHD was moderate (63%) or severe (37%) with 74% of all patients affected by the overlap subtype of cGVHD and 82% by prior acute cGVHD. The observed 6 month clinician-reported and 2014 NIH-defined overall response rates (ORR = complete + partial response [CR/PR]) of 62.5% (1-sided lower 90% confidence interval=51.5%) were not superior to pre-specified historic benchmark of 60%. Post-hoc comparison of 6 month NIH response suggested benefit compared to more contemporaneous NIH-based benchmark of 48.6% with frontline sirolimus/prednisone (CTN 0801 trial). Baseline cGVHD features (organ involvement, severity, initial immune suppression agents) were not significantly associated with 6-month ORR. The median time to initiation of second-line therapy was 5.4 months (range 0.9-15.1 months). Failure-free survival (FFS) was 64.2% (95% CI 46.5-77.4%) at 6 months and 53.1% (95% CI 35.8-67.7%) at 12 months, whereas FFS with CR/PR at 12 months of 33.5% exceeded a benchmark of 15% in post-hoc analysis, and was associated with greater success in steroid discontinuation by 24 months (odds ratio 8 (95% CI 1.21-52.7). This single-arm phase II trial demonstrated acceptable safety and potential efficacy of the upfront use of ofatumumab in combination with prednisone in cGVHD. This trial was registered at www.clinicaltrials.gov as #NCT01680965.