Fig. 4

REGN1908–1909 blocks Fel d 1 binding to polyclonal Fel d 1-specific IgE more efficiently than natural IgGs from specific immunotherapy (SIT) patients. a In a blocking ELISA, the ability of REGN1908, REGN1909, REGN1908–1909, or Cat-SIT-IgG to block 0.7 nM rFel d 1.mmh from binding to plate-captured Fel d 1-specific IgE from one donor was assessed. A representative experiment using IgE from 1 donor of 3 donors tested is shown. The mean and SD from duplicate wells are plotted. b Balb/c mice were administered subcutaneous (SC) injections of a combination of REGN1908–1909 (1:1 ratio, n = 10), an IgG4^P control antibody (n = 10), or concentrated Cat-SIT-IgG from donor 5 (n = 9), donor 7 (n = 10), donor 10 (n = 10) or Non-SIT-IgG from donor 3 (n = 10) or donor 4 (n = 10) prior to the passive cutaneous anaphylaxis model using nFel d 1. Donors 5, 7, and 10 correspond to Donors 2-03(5), 2-05(7), and 2-07(10), respectively in Fig. 1 and Supplementary Table 1. The number per group represents pooled data from two independent experiments. Data are presented as mean ± SE ng of Evans blue extracted per mg of ear tissue is based on the value obtained from each control peanut ear subtracted from the corresponding value from the challenge ear. The total IgG concentration injected (mg), and Fel d 1-specific concentration injected (mg) is represented by the numbers on the bar graphs, with the latter in parentheses. Statistical significance was determined using the Kruskal–Wallis test followed by Dunn’s post hoc test. **p < 0.01 or *p < 0.05