OP39 Treatment of ulcerative colitis With AMT-101, a novel oral interleukin-10 immunomodulatory fusion biologic that traffics across the intestinal epithelium

Background While different chronic inflammatory diseases can be correlated with distinct pro-inflammatory cytokines, interleukin-10 (IL-10) represents a central anti-inflammatory cytokine capable of modulating many pro-inflammatory signals. Previous clinical efforts to capture the benefit of IL-10 in suppressing the pro-inflammatory state in inflammatory bowel disease (IBD) patients have been limited by dose-limiting systemic side effects. Methods We have designed a chimaera of human IL-10 genetically fused to a non-toxic and poorly immunogenic fragment of the cholix exotoxin, termed AMT-101, that demonstrated rapid receptor-mediated transcytosis in vitro and in vivo and could activate phospho-STAT3 in cells within the lamina propria following luminal administration (data not shown). Mice with oxazolone-induced colitis were dosed by oral gavage with AMT-101 daily for 12 days, at which time colon tissue and serum were examined for hallmarks of inflammation. Enteric-coated capsules were used to deliver either 1 or 5 mg of AMT-101 to the distal ileum of cynomolgus monkeys; serum was collected to examine PK and PD outcomes in this non-inflamed model. Results Histological changes of colonic tissue associated with oxazolone-induced colitis was blocked by the oral gavage of AMT-101. Increases in serum levels of pro-inflammatory cytokines IL-1b, IL-6, and IL-17A were blunted by AMT-101 treatment. Remarkably, endogenous IL-10 increased in this model in an attempt to correct inflammation, but this was also decreased by the delivery of AMT-101. Cynomolgus monkeys dosed orally with AMT-101 capsules showed very low serum levels compared with those observed after IV injection of 0.5 mg/kg AMT-101. Strikingly, serum levels of IL-1 receptor antagonist (IL-1RA) as an anti-inflammatory PD marker were increased to a greater extent following oral capsule dosing compared with IV administration. Conclusion These studies provide strong pre-clinical evidence that AMT-101 can effectively reach the intestinal lamina propria to delivery biologically-active IL-10 following transcytosis across the intestinal epithelium. Importantly, the gut-selective nature of the responses observed suggests AMT-101 may alleviate the previous issues of dose-limiting side effects observed with systemic administration of IL-10 and point to the intestinal lamina propria as a critical site of IL-10’s immunomodulatory actions. AMT-101 has advanced to the clinic and is currently being evaluated in a Phase1b trial in patients with active ulcerative colitis.