Targeting the eNAMPT/TLR4 pathway to reduce Inflammatory Bowel Disease severity

ABSTRACT Inflammatory bowel disease (IBD) is a debilitating disease (without curative therapies) that is critically influenced by dysregulated inflammatory pathways. This A0 R42 STTR application focuses on a highly novel humanized monoclonal antibody (mAb), ALT-100, to target and neutralize eNAMPT (extracellular nicotinamide phosphoribosyltransferase), a damage-associated molecular pattern protein (DAMP) that robustly activates innate immunity-driven inflammatory pathways via ligation of the Toll-like receptor 4 (TLR4). We speculate the eNAMPT-neutralizing ALT-100 mAb to be a strategy to address the unmet need for therapies that limit inflammatory bowel injury/fibrosis and reduce the severity of IBD. Published and unpublished data strongly support involvement of eNAMPT in human IBD pathobiology. First, NAMPT RNA and protein expression are significantly increased in intestinal tissues from IBD patients and are highly upregulated by IBD-relevant stimuli including growth factors and cytokines. Second, plasma/serum eNAMPT levels are elevated in IBD subjects and correlate with disease severity and responses to anti-TNFa therapies. Thirdly, NAMPT polymorphisms (SNPs), previously linked to inflammatory disease severity in ARDS and pulmonary hypertension (PH), associate with IBD severity in GWAS studies. Lastly, compellingly published data demonstrate eNAMPT is a highly druggable target, with ALT-100 mAb profoundly attenuating multiple preclinical systemic inflammation/organ injuries (ARDS, PH, radiation-induced fibrosis, cancer). Importantly, ALT-100 mAb reduces preclinical IBD severity, colon inflammation and fibrosis. The feasibility of ALT-100 mAb as an IBD therapy is supported by completed acute IND-enabling pharmacokinetic (PK) studies and 28-day toxicity studies showing the IV ALT-100 mAb formulation has a T1/2 half-life of 10 days and is without discernable toxicity (rats and pigs). In addition, we have completed CMC manufacturing development (stable cell line, Research/Master Cell Banks) and a 200L GMP Bioreactor run (expression 6 gms/L) of the IV ALT-1000 mAb formulation (10mg/mL). We anticipate FDA IND submission for ARDS in May 2022. In PHASE I of this R-42 STTR PHASE I/II Fast Track application, Specific Aims #1/2 will assess pharmacodynamic (PD) properties of ALT-100 mAb in well-established acute (7 days) and chronic (28 days) preclinical DSS-induced murine colitis models and optimize ALT-100 mAb dosing (0.4 mg/kg, 1mg/kg, 4 mg/kg) and route of delivery (IV vs subQ) using IV formulations (10 mg/mL) and subQ formulations (100 mg/mL). In PHASE II studies conducted in rats and minipigs, Specific Aim #3 will characterize the pharmacokinetic (PK) characteristics of the subQ and IV ALT-100 mAb formulations and Specific Aim #4 will evaluate chronic subQ ALT-100 mAb toxicokinetic properties. Successful completion of these PHASE I/ II STTR studies will establish ALT-100 mAb as a viable IBD therapeutic and enable the submission of an FDA IND application to allow Aqualung to conduct IBD clinical trials that address ALT-100 mAb as a novel therapeutic to address the unmet needs in subjects with severe IBD, especially in subjects who fail biologic therapies.NARRATIVE PUBLIC HEALTH RELEVANCE: Inflammatory Bowel Disease is a debilitating disease without a cure, a serious unmet need. The inflammatory protein, eNAMPT (extracellular nicotinamide phosphoribosyltransferase), is a key driver of unchecked inflammation and a highly novel therapeutic target and candidate gene in IBD. Our Phase I/II goals are to validate and optimize the eNAMPT- neutralizing humanized mAb, ALT-100, as a therapeutic strategy for IBD, and to complete IND-enabling studies that will facilitate ALT-100 development in human IBD trials.