The inter-vial homogeneity of the three lots of RM 8671 was assessed from the CZE data. The CV for main peak purity is less than 0.2% in each of the lots as calculated from the results listed in ESM Table S6. Standard deviation calculated for intra-vial variation compared to inter-vial variation on the raw data for main peak purity was also nearly identical (e.g. intra-vial SD = 0.109 vs. inter-vial SD = 0.131 for lot 14HB-D-001 main peak purity). Collectively this indicates inter-vial homogeneity with respect to charge purity was achieved.