Viability of red cells prepared with S‐303 pathogen inactivation treatment

BACKGROUND: A nucleic acid-targeted pathogen inactivation process with S-303 was developed to treat red blood cells (RBCs). STUDY DESIGN AND METHODS: Three studies in healthy subjects investigated posttransfusion recovery, life span, and immunogenic potential of autologous RBCs treated with S-303 and stored for 35 days. A two-arm trial in 42 subjects (1A) examined recovery of 35-day-old S-303 RBCs after a single transfusion. A one-arm study (1B) measured recovery and immune response in 28 subjects after multiple transfusions of S-303 RBCs. A randomized, crossover study (1C) in 29 subjects compared recovery and life span of 35-day-old S-303 RBCs and conventional RBCs. RESULTS: In Studies 1A and 1B, mean recovery of S-303 RBCs ranged from 78.7 to 84.4 percent. In Phase 1C, the mean 24-hour posttransfusion recoveries of S-303 and untreated RBCs were 81.7 +/- 6.3 and 84.5 +/- 6.2 percent (p = 0.05). The median life spans (t(1/2)) of S-303 and control RBCs were identical (37.4 days, p = 0.98). No antibodies to S-303 RBCs were detected. CONCLUSION: The mean 24-hour recovery of 35-day-old S-303 RBCs was less than untreated RBCs, but greater than 75 percent. RBCs treated with S-303 and stored for 35 days exhibited median life span not different from that of conventional RBCs.