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

R. Mrsny1, B. Kanwar2, T. Mahmood3

1Applied Molecular Transport, Platform and Biology, South San Francisco, USA, 2Applied Molecular Transport, Clinical Development, South San Francisco, USA, 3Applied Molecular Transport, CEO, South San Francisco, USA

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.