Fig 2: Single-dose cynomolgus monkey study with reformatted MAB9231: Three cynomolgus monkeys were treated with the reformatted MAB9231 antibody at 1.5 mg/kg, and the circulating Ang1 level in each animal was measured over time. The circulating Ang1 level increased in all animals after treatment with the antibody.

Fig 3: Evaluation of Ang1 non-neutralizing antibodies: (A) Alexa 647-labeled Ang1 CC-FLD dimer was incubated with Tie2-expressing cells in the presence of antibodies: mouse IgG2B MAB9231, reformatted MAB9231 (MAB9231-RF) with human IgG1 Fc, mAB-NN human IgG1 wild type, mAB-NN human IgG1 with YTE mutations, an IgG isotype control, and an Ang1 blocker. MAB9231 and MAB9231-RF enhanced Ang1’s binding to the cells. Neither mAB-NN wild type (WT) nor mAB-NN YTE blocked Ang1’s binding to the Tie2-expressing cells at concentrations up to 100 nM. (B) AKT phosphorylation resulting from Ang1-mediated Tie2 activation. To mimic the native conditions, full-length human Ang2 was included in the assay at a fixed concentration of 2 µg/mL. Ang2’s inhibition of the Tie2 activation and AKT phosphorylation was reversed by increasing the amount of full-length human Ang1. The Ang1-mediated AKT phosphorylation was not affected by the mAB-NN antibody.

Fig 4: Heat-Maps for correlations between the expression of SST and angiogenesis systems (Spearman's Rho)Significant negative correlations are shown in red and significant positive correlations in green. Bottom left triangle shows correlations in tumor tissues and top-right hand triangle shows correlations in non-tumor adjacent tissues. In tumor samples, SST and CORT showed a significant positive correlation with sst1-5, and these subtypes were also positively correlated between themselves in a significant way. sst5TMD4 showed a positive correlation with SST and sst1, and sst5TMD5 with sst1. A positive correlation was found between the four angiogenic makers and a negative one between each one of them and sst3 and sst4. Ang-1, Ang-2, Tie-2 and VEGF were positively correlated with sst5MD4. Analyses of correlations in adjacent non-tumor tissues showed similar findings regarding CORT and sst1–5. However, SST was only correlated with sst5, and no correlation was observed between truncated receptors and the rest of subtypes. Asterisks mark significant p-values (*p < 0.05, **p < 0.01, two-sided).

Fig 5: Multiple-dose cynomolgus monkey study with mAB-NN wild type and mAB-NN YTE: Three cynomolgus monkeys were used for each testing group: vehicle, mAB-NN wild type, and mAB-NN YTE. The animals were treated with antibody at 1.5 mg/kg once a week for three weeks (indicated by arrows). The circulating Ang1 level (A) and total antibody level (B) were measured up to 71 days after the first dose. Compared with the Ang1 level, the circulating Ang2 level remained relatively unchanged (C).