Abstract Background Integrin α4β7 regulates the recruitment of T cells to intestinal mucosa through its interaction with mucosal addressin cell adhesion molecule (MAdCAM)-1. Disruption of this interaction has been clinically validated for the treatment of inflammatory bowel diseases (IBD) by the anti-α4β7 antibody vedolizumab. The current study was aimed at elucidating the preclinical efficacy of MT-103, a potent and selective small molecule α4β7 inhibitor in the clinically relevant CD4+CD45RBhi T cell transfer (TCT) colitis mouse model. Methods Mice were administered either MT-103 via subcutaneously implanted minipumps across 3 dose cohorts (3, 10, or 30 mg/ml), or an antibody specific for IL12p40 (25 mg/kg) or α4β7 (30 mg/kg), through intraperitoneal injections for 7 weeks. Colitis development was evaluated via readouts including body weights, gross colon weight by length ratios, colonic tissue gene expression, and histopathological scores. Results MT-103 significantly inhibited the development of colitis in mice at all 3 doses equivalently, as evident from significantly improved gross colon weight/length ratios in comparison to vehicle controls which presented with moderate-severe colitis (Figure 1A). MT-103 treatment also led to a significant protection from weight loss that occurred in vehicle-treated mice. Importantly, mice treated with MT-103 exhibited remarkably improved histopathology scores, including inflammation, hyperplasia, and gland loss compared to vehicle controls (Figure 1B). Furthermore, broad gene transcriptional analysis showed that MT-103 broadly suppressed pro-inflammatory pathways and processes within colonic tissues. Specifically, MT-103-induced downregulation of Ifng, Il17a, and Il1b, besides reduced Cd3 as a surrogate metric of T cell trafficking inhibition to the colon, and conversely enabled upregulation of anti-inflammatory cytokine Il10. The colitis-protective effects of MT-103 were equivalent, if not superior, to the saturating doses of α4β7 mAb or anti-IL12p40 mAb when compared to their respective vehicle controls. Conclusion Treatment with MT-103 protects from colitis by restoring colonic tissue homeostasis as measured by body fitness and an array of immunological and histopathological assessments. These proof-of-concept data demonstrate an α4β7-specific small molecule, MT-103, can occlude pathogenic T cells from initiating disease in a chronic IBD model, equivalent to an α4β7 blocking antibody.

Abstract Background Disruption of immune cell trafficking via integrins is a proven and effective mechanism for treating inflammatory bowel disease. When α4β7 integrin is inhibited through pharmacological intervention, immune cells destined for the gut tissue become sequestered in blood circulation and these alterations can be detected through several methods. MORF-057 is a novel, oral, selective, small molecule inhibitor of α4β7 integrin developed for treating IBD. MORF-057 demonstrated favorable tolerability, pharmacokinetic and pharmacodynamic profiles including saturating receptor occupancy and corresponding evidence for proof of biology based on effects on circulating cells during a Phase 1 clinical trial in healthy volunteers (Ray, ECCO 2021). Here we demonstrate an exposure:response relationship of α4β7 related biomarkers examined among MORF-057 treated non-human primates (NHPs) as a means for pre-clinical testing of inhibitors of this pathway. Methods Single-cell RNA sequencing (scRNAseq) was performed on NHP CD45+ blood cells to determine baseline populations potentially impacted through exposure to MORF-057. 40 Naïve cynomolgus monkeys were enrolled over 5 separate studies and dosed orally BID with MORF-057 over 2–7 days using several dose levels to examine biomarker dynamics over a wide range of exposures. Peripheral blood was sampled at various timepoints (n= 125) and assayed using: mass spectroscopy, flow cytometry (FACS), and mRNA quantification to determine MORF-057 exposure levels, on-target receptor occupancy (RO), immune cell subset changes, and CCR9 mRNA levels. Results MORF-057 Ctrough ranged from 3.3–429 ng/ml. In samples tested for RO, MORF-057 achieved >95% saturation of α4β7 even with the lowest Ctrough of 4.5 ng/ml. MORF-057 treatment led to significantly sustained increases in circulating β7high CD4+ T memory cells detectable as early as 24h post-exposure. A maximal effect where β7high cells accounted for approximately 60% of the T memory population was achieved at saturating receptor occupancy (Fig., left). CCR9 mRNA values demonstrated increases upon drug exposure (Fig., right). Conclusion In NHP, acute changes in circulating β7high T memory cells was a sensitive biomarker demonstrating a dose-dependent response to MORF-057 exposure. CCR9 mRNA levels also showed similar exposure related changes reflecting its expression on a subset of β7high cell types. Analysis of scRNAseq shows expression of α4β7 on other cell types beyond T memory cells including: NK, NKT, B cells, plasmablasts, monocytes, and eosinophils. Pharmacodynamic changes in NHP are consistent with human Phase 1 data in healthy volunteers.

Abstract Background MORF-057 is a potent and selective small molecule inhibitor of the α 4β 7 integrin. Using a receptor occupancy (RO) assay under physiologically relevant conditions, MORF-057 achieves 90% α 4β 7 RO at approximately 10 nM in human whole blood. The current studies evaluate nonclinical pharmacokinetics (PK) and properties of absorption, distribution, metabolism, and excretion (ADME) to enable dose/exposure projection to humans. Methods PK studies were conducted in mouse, rat, dog, and monkey following intravenous (IV) and oral administration. ADME studies were conducted in vitro and in rats using carbon-14 [14C] labeled MORF-057. MORF-057 levels were quantified using liquid chromatography coupled with tandem mass spectrometry. Human PK was predicted based on body weight allometry, well-stirred and semi-physiological models. Results MORF-057 exhibited low to moderate clearance (CL) in animals with species dependent volume of distribution (Vdss) resulting in half-lives of 1.1 to 2.7 hours (Table 1). Following an oral dose, absorption was high with bioavailability ranging from 15% to 49%. MORF-057 is highly protein bound and distribution of [14C]MORF-057 derived radioactivity in rat was predominantly in the small intestine wall, liver, and stomach wall. Rifampin, an inhibitor of organic anion transporting polypeptides, decreased MORF-057 clearance by 3-fold in monkeys suggesting MORF-057 elimination involves hepatic uptake transport. MORF-057 is further cleared via CYP3A metabolism followed by biliary/fecal elimination of metabolites. MORF-057 is predicted to have moderate bioavailability (40%) and CL (6.5 mL/min/kg) in humans. Wajima transformation shows good agreement of the normalized PK across animal species, with a predicted human concentration-time profile supporting >90% α 4β 7 RO at trough following 200 mg twice daily dose (Figure 1). Conclusion These data demonstrate that MORF-057 is well absorbed and PK properties in animals support the potential for achieving high α4β7 RO following oral administration in humans. These nonclinical results provided a basis for the progression of MORF-057 into a first-in-human Phase 1 clinical study assessing safety, pharmacokinetics, and receptor occupancy (results being reported separately).

Abstract Background MORF-057 is an orally administered small molecule designed to inhibit the α 4β 7 receptor, addressing an unmet medical need in inflammatory bowel disease (IBD) patients, and avoiding the need for periodic therapeutic infusions and the risk for infusion-related reactions. This study evaluated single (SAD) and multiple ascending doses (MAD) of MORF-057 in healthy volunteers. Methods This was a randomized, double-blind, placebo-controlled, single and multiple doses, phase 1 study of the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of MORF-057 conducted in a Phase I Unit in the USA. Subjects were randomized 3:1 to MORF-057 or placebo capsules once daily in the SAD cohorts: 25, 50, 100, 150, and 400 mg; or twice daily (BID) in the MAD cohorts: 100 and 200 mg total daily doses (dosed as 50 and 100 mg BID, respectively). In the MAD cohorts, trough PK samples were obtained premorning or pre-evening dose following administration of 50 or 100 mg BID, respectively. Blood samples to assess receptor occupancy (RO) of α 4β 7 and α 4β 1 integrins were obtained prior to the first dose and 12 hours after treatment. Results To date, 51 healthy subjects were dosed; 1 subject withdrew consent on Day 2 for personal reasons. Eleven non-serious adverse events (AEs) were reported; AEs were mild and did not result in discontinuation. Two reversible mild AEs in the 200 mg MAD cohort were possibly related to MORF-057 (macular / maculopapular rash). No safety signals were identified to date. Following dosing, MORF-057 was rapidly absorbed and systemic exposure increased approximately dose-proportionally (Fig.1). Mean α 4β 7 RO was found to be greater than 95% after each of the three highest single doses (Fig.2). In multiple dosing, mean α 4β 7 RO was greater than 90% at the lower dose, while the highest dose tested resulted in α 4β 7 RO saturation at steady state. α 4β 1 RO was below the limit of quantitation with mean trough values estimated to be <10% at any of the dose levels. Conclusion Current results demonstrated that single and multiple ascending doses of MORF-057 were well tolerated, with only mild, non-serious AEs reported that did not result in study drug discontinuation. MORF-057 demonstrated a favorable PK profile where target engagement was confirmed and resulted in α4β7 receptor saturation in many subjects receiving higher doses. These results support further investigation of MORF-057 and provide a basis for dose selection phase 2 studies in patients with IBD. (NCT04580745)

Abstract Background Integrins play a key role in facilitating immune cell trafficking throughout the body and represent an important receptor family for therapeutic intervention. In particular, the α4β7 integrin is a clinically validated target for the treatment of inflammatory bowel diseases (IBD), as exemplified by the humanised monoclonal antibody vedolizumab, which blocks the interactions between α4β7-expressing lymphocytes and its ligand MAdCAM-1. This blockade leads to the inhibition of these circulating lymphocytes from exiting the bloodstream and entering intestinal mucosal tissues resulting in a decrease in mucosal inflammation in patients. While oral inhibitors of the α4β7 integrin are advantageous over biologics, the efforts have been impeded by challenges to achieve desired selectivity and optimal DMPK properties. The aim of this study was to develop and characterise orally bioavailable small-molecule inhibitors of the α4β7 integrin and to determine their therapeutic potential. Methods Oral small-molecule inhibitors targeting the α4β7 integrin were discovered using Morphic Integrin Technology (MInT) platform. These small-molecule inhibitors were tested for potency and selectivity against a broad panel of integrin family members in multiple biochemical and cell-based functional assays in a ligand-competitive fashion. An acute PD assay with CFSE-labelled lymphocytes was developed to evaluate the activity of the small-molecule compounds in blocking lymphocyte trafficking to gut-associated lymphoid tissues in mice. The in vivo activity was also examined through changes in circulating α4β7+ CD4+ T memory cells in a relevant non-human primate model. Results Key drug candidate small molecules demonstrated over 1000-fold selectivity in vitro against a broad panel of integrin family members, including the α4β1 integrin. These compounds effectively blocked lymphocyte trafficking to mesenteric lymph nodes and Peyer’s patches in the gut in a dose-dependent manner, similar to an α4β7-specific antibody, in an acute gut-homing assay in mice. Additionally, these inhibitors also demonstrated effective occlusion of immune trafficking in a relevant non-human primate model. The lead compound has favourable DMPK properties, good oral bioavailability and is projected to have sufficient exposure in humans to effectively block α4β7-expressing immune cells in circulation. Conclusion Potent, selective, oral small-molecule inhibitors of α4β7 integrin have been discovered that demonstrate on-target, mechanistic efficacy in two animal models relevant to human IBD. It has the potential to be an effective and safe therapeutic in monotherapy as well as serving as a backbone for combination with other IBD drugs.