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Enteric‐coated capsule intestinal delivery of human immunoglobulin G in cynomolgus macaques (LB603)
Author(s) -
Mabus John,
Muzammil Salman,
Cooper Philip,
Brezski Randall,
Kunta Jeevan,
Huebert Norman,
Kliwinski Connie,
Bradley Dino,
GilesKomar Jill,
Hornby Pamela
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.lb603
Subject(s) - ileum , isotype , chemistry , antibody , capsule , immunoglobulin g , monoclonal antibody , small intestine , microbiology and biotechnology , chromatography , biochemistry , immunology , biology , botany
In adult primates, immunoglobulin G (IgG) is not detectable in the serum when taken orally due to enzymatic degradation and low intestinal permeation. Direct IgG infusion (2 mg/kg) into the ileum/proximal colon of cynomolgus macaques (n=3), where FcRn is expressed in enterocytes, resulted in ~ 0.3% fractional uptake at 90 min (124±104 ng/mL; mean±SD; Hornby et al., 2013). Here we tested whether a protease‐resistant, high FcRn binding monoclonal antibody (mAb), loaded in enteric‐coated capsules for release in the ileum, would achieve higher circulating levels. An IgG2 isotype, or IgG1 with complete IgG2 hinge insertion, had increased survival over IgG1 in fluid extracted from cynomolgus ileum. Thus, an IgG2 isotype was formulated (10 mM histidine, pH 5.7, 8.5% sucrose, 0.04% PS80), lyophilized, and milled. This isotype (50 mg/mL) was stable in PBS at 40°C and retained molecular integrity in simulated fasted small intestinal fluid (37°C; 48 hr). The pH of cynomolgus ileum was determined by operator‐assisted IntelliCap® technology (Medimetrics) to be > 7.5 (n = 3); thus, size 3 hard gel capsules (0.3 mL) were loaded with either ~ 3 mg/kg mAb or titanium oxide, and coated with hydroxypropyl methylcellulose acetate succinate for dissolution at pH 7.5. Three hours after oral dosing, passage of intact titanium capsules through the pyloric sphincter and subsequent dissolution was confirmed by x‐ray (n = 6). Single capsule mAb dosing achieved serum levels of 0.2±0.1 ng/mL at 24 hours (n = 5). Once weekly dosing for 5 weeks achieved serum levels of 0.4±0.2 ng/mL. Increasing the dose to one capsule biweekly, or two capsules biweekly, did increase serum levels above 1 ng/mL. Intestinal delivery of mAb in cynomolgus macaques resulted in very low oral bioavailability, consistent with a minimal epithelial FcRn contribution in ileum/colon to IgG transcytosis in adults. Engineering protease resistant IgGs increases their survival in the intestinal lumen and may be useful in the oral treatment of intestinal diseases.