Figure 5.

Complement activation by Doxil does not correlate with the titer of antibodies reactive to PEG in individual human donors. (A) The complement activation and antibody titer data are presented in a heat map format. The complement stimulation index by Doxil (C-SI) is aligned with the antibody titer (Ab-titer). Darker red and blue show higher levels of the complement activation and antibody titer, respectively. The antibody titer is plotted for IgM and IgG and indicates the antigen used to capture the reactive antibodies (Doxebo, PEG, or mPEG). The molecular weight of PEG is 2000 and is equal in all samples. mPEG contains a methoxy terminal group that is also present in the PEG2000 used to produce Doxil and Doxebo. D—donor; (B–G) Regression analysis was performed to understand the correlation between the antibody titer and the complement activation by Doxil. Doxil stimulation index (SI) was compared with the titer of IgG reactive to Doxebo (B), PEG2000 (C), or mPEG2000 (D), as well as the titer of IgM reactive to Doxebo (E), PEG2000 (F), or mPEG2000 (G). p-value was used to assess the significance of the confidence interval of 95%. No analyses revealed a significant correlation. The residual analysis conducted in parallel with this test did not change the conclusions of the analysis (data not shown).