Equivalent CD34+ selection outcomes with CliniMACS Prodigy and CliniMACS Plus, enabling cryopreserved product processing

• Prodigy® enables clinical-grade automated CD34+ selection comparable to CliniMACS Plus® • Thawed apheresis products can be successfully processed for CD34+ selection • Whether performed on fresh or thawed products , all isolated CD34+ fractions met release criteria • Use of cryopreserved cells expand flexibility for graft or ATMP manufacturing The discontinuation of the CS2 version of the semi-automated CliniMACS Plus® device in 2024 prompted validation of a CD34+ immunoselection process using the fully automated CliniMACS Prodigy® (Miltenyi Biotec). This transition was leveraged to evaluate Prodigy®’s performance on thawed apheresis products. Results were compared with fresh donor apheresis previously processed on the CliniMACS Plus® and, within this validation, with fresh products processed on Prodigy®. Fresh apheresis products from rhG-CSF–mobilized related donors were processed using either device. Cryopreserved apheresis products intended for destruction were thawed (Viathaw®, Cytiva), washed on Sepax-II® and resuspended in MACS GMP® PBS/MgCl₂ with HSA and rh-DNase prior to CD34+ selection on Prodigy®. Flow cytometry (Stem Kit® – Beckman Coulter) was used for CD34+ and CD45+ cell quantification. From fresh products, immunoselections yielded similar CD34+ purities (95% vs. 97%) and viabilities (95% vs. 99%) for CliniMACS Plus® (n=10) and Prodigy® (n=10), respectively. T-cell depletion was slightly better with the CliniMACS Plus® (0.1 × 10⁴ vs. 0.4 × 10⁴ CD3⁺/kg), while CD34+ recovery was more efficient with Prodigy® (66% vs. 53%). Processing thawed apheresis with the Prodigy® archieved 98% CD34+ purity, 51% recovery, and 0.3 × 10⁴ CD3⁺/kg, all within our center’s acceptance criteria. The fully automated workflow significantly reduced hands-on time (2h vs. 5h) and operator intervention. Prodigy® platform enables reproducible CD34+ immunoselection from both fresh and thawed products, improving standardization, efficiency, and flexibility in graft engineering and ATMP manufacturing. The ability to process thawed products also broadens clinical options whenever cryopreserved products are available.