In vitro and in vivo performance of SOLX® RBCs produced with the modified SOLX® System will be used to demonstrate the acceptability of both the proposed product modification and expanded indications. To accomplish this, the study will require a total of 120 evaluable donors completing the study. Enrolled donors will be assigned to either of two study arms. Each study arm will entail a randomized, paired, 2-x-2 crossover design where every study donor (n = 60 evaluable study donors who complete the study per arm) will donate a total of two whole blood units with individual units being donated at least 56 days (8 weeks) apart. One unit will be collected with the investigational product (IP) and the other unit will be collected with the control product (CP). The order in which the IP and the CP will be used to collect, filter and store the whole blood and appropriate blood products (within the context of the crossover design) will be randomized.
Each of the two study arms will evaluate outcomes resulting from different storage, filtration and processing conditions:
* Arm 1 will entail holding whole blood units at 20-24°C after collection for ≥ 20 hours (IP) or ≥ 6 hours (CP) prior to initiating room temperature filtration. Following room temperature centrifugation and subsequent separation, SOLX® PRBC will be placed at 1-6°C and plasma placed at ≤ -18°C within 24 hours (IP) or within 8 hour (CP) of collection. The first donation will occur with product indicated per randomization and the second donation will occur with product alternate to the randomization. Arm 1 will further entail an in vivo double-radiolabelled autologous RBC recovery substudy (n = 20-24, paired IP and CP data will be collected) and an evaluation of pre- and post-rejuvenation PRBC 2,3-DPG levels (all IP and CP units). The in vivo substudy and rejuvenation evaluation is limited to only Arm 1 and is not included in Arm 2.
* Arm 2 will entail holding whole blood units at 1-6°C after collection for ≥ 66 hours (both IP and CP) prior to initiating cold filtration. Following refrigerated centrifugation and subsequent separation, SOLX® PRBCs will be placed at 1-6°C within 72 hours of collection (both IP and CP). Plasma will not be evaluated for this arm and will be discarded. The first donation will occur with product indicated per randomization and the second donation will occur with product alternate to the randomization.
For each study arm that does not meet the protocol-defined in vitro acceptance criteria for exactly 1 unit, an additional 71 evaluable donors will be enrolled, thus increasing the number of evaluable enrolled donors completing the respective study arm to 131 donors. Only those acceptance criteria endpoints that were not met within their respective study arm will be evaluated and neither matched/paired crossover controls nor in vivo RBC recovery (Arm 1 In vivo substudy) will be evaluated. If all protocol defined in vitro acceptance criteria are met or \> 1 subject does not meet the protocol defined in vitro acceptance criteria relative to a specific study arm, then no enrollment will occur relative to the same study arm.
