👤 Axel Haupt

Tirzepatide, a single-molecule dual glucose-dependent insulinotropic polypeptide (GIP)/glucagon-like peptide-1 (GLP-1) receptor (R) agonist, has shown superiority in the reduction of blood glucose and body weight, above selective GLP-1R agonists, but the contribution of GIP to these effects remains incompletely understood. To characterize the preclinical and in-human effects of a long-acting GIPR agonist monotherapy in healthy participants and patients with type 2 diabetes (T2D). A long-acting GIPR agonist (LY3537021) was characterized in vitro and in Long-Evans diet-induced obese rats and Wistar rats. Next, a phase 1, randomized, placebo-controlled, single ascending dose (SAD)/multiple ascending dose (MAD) study explored the safety, tolerability, pharmacokinetics, and pharmacodynamics of LY3537021 in healthy participants and participants with T2D in Singapore. In vitro, LY3537021 demonstrated potency greater than native GIP and selectivity for the GIPR. In vivo in rats, chronic treatment with LY3537021 resulted in weight loss and improved glycemic control during a glucose tolerance test. The phase 1 clinical study enrolled 85 healthy participants and patients with T2D (SAD, n = 47 [aged 25-64 years]; MAD, n = 38 [aged 25-69 years]; average baseline BMI was 25.9-27.0 kg/m In vivo studies demonstrated that LY3537021 reduced body weight and improved glycemia during a glucose challenge in rats. The phase 1 study demonstrated that the long-acting GIPR agonist LY3537021 was well tolerated, induced weight loss, and improved glucose control in humans. These observations better define the therapeutic benefit of long-acting GIPR agonists and support a distinct contribution of GIP agonism to the benefits observed with multi-agonist peptides that act via the GIPR. Future studies are needed in more diverse populations and in cohorts with overweight/obesity to confirm these findings. GOV: NCT04586907. Show less

The aim of this study was to determine if retatrutide, a triple agonist of glucose-dependent insulinotropic polypeptide (GIP) receptor, glucagon-like peptide 1 (GLP-1) receptor and glucagon (GCG) receptor, may lower serum triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) levels in part by decreasing circulating concentrations of the angiopoietin-like protein 3/8 complex (ANGPTL3/8). In post-hoc analyses of two phase 2 retatrutide trials, concentrations of ANGPTL3/8, ANGPTL4/8 complex (ANGPTL4/8), ANGPTL3 and ANGPTL4 were measured using dedicated immunoassays to determine percent changes from baseline. Correlations of ANGPTL protein and complex levels with lipid and metabolic parameters at baseline were analysed. Correlations of the changes in ANGPTL protein and complex levels versus the changes in lipid and metabolic parameters at study endpoints were also analysed. Direct effects of retatrutide itself, GIP, GLP-1, GCG and a GCG receptor (GCGR) antagonist antibody on ANGPTL3/8 secretion were studied in vitro using primary human hepatocytes. ANGPTL3/8 reductions were observed with 8 and 12 mg retatrutide doses in participants with type 2 diabetes, and with 1, 4, 8 and 12 mg retatrutide doses in participants with obesity or overweight but without diabetes. In both cases, ANGPTL3/8 decreases paralleled retatrutide-induced reductions in TG and LDL-C. In primary human hepatocytes, both glucagon and retatrutide decreased ANGPTL3/8 secretion, and these reductions were blocked with the GCGR antagonist antibody. Together, these results suggest that the GCGR agonism of retatrutide could lead to reduced circulating ANGPTL3/8 concentrations, which may then contribute to decreases in TG and LDL-C levels. Show less

Mixed dyslipidaemia, characterised by elevated concentrations of circulating triglycerides and LDL cholesterol (LDL-C), is associated with an increased risk of atherosclerotic cardiovascular disease. Solbinsiran, a GalNAc-conjugated small interfering RNA targeting hepatic angiopoietin-like protein 3 (ANGPTL3), reduced triglycerides and LDL-C concentrations in a phase 1 study. This study aimed to assess the durability and efficacy of solbinsiran in reducing concentrations of atherogenic lipoproteins in adults with mixed dyslipidaemia. This double-blind, parallel-arm, randomised, placebo-controlled, phase 2 trial enrolled adults (aged ≥18 years) with mixed dyslipidaemia at 41 clinical research units across seven countries. Patients receiving moderate-intensity or high-intensity statins, and with concentrations of fasting triglycerides between 1·69 mmol/L and 5·64 mmol/L, LDL-C of at least 1·81 mmol/L, and non-HDL cholesterol of at least 3·36 mmol/L were included. Using an interactive web-response system, patients were randomly assigned (1:2:2:2) to receive either solbinsiran 100 mg, solbinsiran 400 mg, solbinsiran 800 mg, or placebo, by subcutaneous injection on days 0 and 90. Patients were followed up for at least 270 days. The primary outcome was percent change in apolipoprotein B (apoB) concentration from baseline to day 180 with solbinsiran compared with placebo, analysed under an efficacy estimand (in patients who received at least one dose of the study drug). This trial is completed and registered with ClinicalTrials.gov, NCT05256654. Of 585 patients screened, 205 patients were enrolled in the study between July 20, 2022, and March 4, 2024. Patients (111 [54%] female and 94 [46%] male; median age 57 years [IQR 49-65]) were randomly assigned to receive solbinsiran 100 mg (n=30), solbinsiran 400 mg (n=58), solbinsiran 800 mg (n=59), or placebo (n=58). At baseline, median concentrations were 111 mg/dL (IQR 96-130) for apoB, 2·64 mmol/L (2·06-3·29) for triglycerides, and 3·16 mmol/L (2·57-3·82) for LDL-C. The placebo-adjusted percent change in apoB concentration from baseline at day 180 was -2·8% (95% CI -15·5 to 11·9; p=0·69) for solbinsiran 100 mg; -14·3% (-23·6 to -3·9; p=0·0085) for solbinsiran 400 mg; and -8·3% (-18·3 to 2·9; p=0·14) for solbinsiran 800 mg. Solbinsiran administration was well tolerated, with a low incidence of adverse events. The number of patients with treatment-emergent adverse events was 18 [60%] of 30 patients in the solbinsiran 100 mg group, 30 [52%] of 58 patients in the solbinsiran 400 mg group, 26 [44%] of 59 patients in the solbinsiran 800 mg group, and 37 [65%] of 57 patients in the placebo group. Solbinsiran 400 mg reduced apoB in patients with mixed dyslipidaemia and was generally well tolerated. The impact of solbinsiran on cardiovascular outcomes remains to be investigated. Eli Lilly and Company. Show less

Muvalaplin inhibits lipoprotein(a) formation. A 14-day phase 1 study demonstrated that muvalaplin was well tolerated and reduced lipoprotein(a) levels up to 65%. The effect of longer administration of muvalaplin on lipoprotein(a) levels in individuals at high cardiovascular risk remains uncertain. To determine the effect of muvalaplin on lipoprotein(a) levels and to assess safety and tolerability. Phase 2, placebo-controlled, randomized, double-blind trial enrolling 233 participants with lipoprotein(a) concentrations of 175 nmol/L or greater with atherosclerotic cardiovascular disease, diabetes, or familial hypercholesterolemia at 43 sites in Asia, Europe, Australia, Brazil, and the United States between December 10, 2022, and November 22, 2023. Participants were randomized to receive orally administered muvalaplin at dosages of 10 mg/d (n = 34), 60 mg/d (n = 64), or 240 mg/d (n = 68) or placebo (n = 67) for 12 weeks. The primary end point was the placebo-adjusted percentage change from baseline in lipoprotein(a) molar concentration at week 12, using an assay to measure intact lipoprotein(a) and a traditional apolipoprotein(a)-based assay. Secondary end points included the percentage change in apolipoprotein B and high-sensitivity C-reactive protein. The median age of study participants was 66 years; 33% were female; and 27% identified as Asian, 4% as Black, and 66% as White. Muvalaplin resulted in placebo-adjusted reductions in lipoprotein(a) of 47.6% (95% CI, 35.1%-57.7%), 81.7% (95% CI, 78.1%-84.6%), and 85.8% (95% CI, 83.1%-88.0%) for the 10-mg/d, 60-mg/d, and 240-mg/d dosages, respectively, using an intact lipoprotein(a) assay and 40.4% (95% CI, 28.3%-50.5%), 70.0% (95% CI, 65.0%-74.2%), and 68.9% (95% CI, 63.8%-73.3%) using an apolipoprotein(a)-based assay. Dose-dependent reductions in apolipoprotein B were observed at 8.9% (95% CI, -2.2% to 18.8%), 13.1% (95% CI, 4.4%-20.9%), and 16.1% (95% CI, 7.8%-23.7%) at 10 mg/d, 60 mg/d, and 240 mg/d, respectively. No change in high-sensitivity C-reactive protein was observed. No safety or tolerability concerns were observed at any dosage. Muvalaplin reduced lipoprotein(a) measured using intact lipoprotein(a) and apolipoprotein(a)-based assays and was well tolerated. The effect of muvalaplin on cardiovascular events requires further investigation. ClinicalTrials.gov Identifier: NCT05563246. Show less

With an increasing prevalence of obesity, there is a need for new therapies to improve body weight management and metabolic health. Multireceptor agonists in development may provide approaches to fulfill this unmet medical need. LY3437943 is a novel triple agonist peptide at the glucagon receptor (GCGR), glucose-dependent insulinotropic polypeptide receptor (GIPR), and glucagon-like peptide-1 receptor (GLP-1R). In vitro, LY3437943 shows balanced GCGR and GLP-1R activity but more GIPR activity. In obese mice, administration of LY3437943 decreased body weight and improved glycemic control. Body weight loss was augmented by the addition of GCGR-mediated increases in energy expenditure to GIPR- and GLP-1R-driven calorie intake reduction. In a phase 1 single ascending dose study, LY3437943 showed a safety and tolerability profile similar to other incretins. Its pharmacokinetic profile supported once-weekly dosing, and a reduction in body weight persisted up to day 43 after a single dose. These findings warrant further clinical assessment of LY3437943. Show less

An early symptom of Alzheimer's disease (AD) is an impaired sense of smell, for which the molecular basis remains elusive. Here, we generated human olfactory neurosphere-derived (ONS) cells from people with AD and mild cognitive impairment (MCI), and performed global RNA sequencing to determine gene expression changes. ONS cells expressed markers of neuroglial differentiation, providing a unique cellular model to explore changes of early AD-associated pathways. Our transcriptomics data from ONS cells revealed differentially expressed genes (DEGs) associated with cognitive processes in AD cells compared to MCI, or matched healthy controls (HC). A-Kinase Anchoring Protein 6 ( Show less

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease affecting the central nervous system in young adults. Heparan sulfate proteoglycans (HSPGs) are ubiquitous to the cell surface and the extracellular matrix. HSPG biosynthesis is a complex process involving enzymatic attachment of heparan sulfate (HS) chains to a core protein. HS side chains mediate specific ligand and growth factor interactions directing cellular processes including cell adhesion, migration and differentiation. Two main families of HSPGs exist, the syndecans (SDC1-4) and glypicans (GPC1-6). The SDCs are transmembrane proteins, while the GPC family are GPI linked to the cell surface. SDC1 has well-documented interactions with numerous signalling pathways. Genome-wide association studies (GWAS) have identified regions of the genome associated with MS including a region on chromosome 13 containing GPC5 and GPC6. International studies have revealed significant associations between this region and disease development. The exostosin-1 (EXT1) and sulfatase-1 (SULF1) are key enzymes contributing to the generation of HS chains. EXT1, with documented tumour suppressor properties, is involved in the initiation and polymerisation of the growing HS chain. SULF1 removes 6-O-sulfate groups from HS chains, affecting protein-ligand interactions and subsequent downstream signalling with HS modification potentially having significant effects on MS progression. In this study, we identified significant associations between single nucleotide polymorphisms in SDC1, GPC5 and GPC6 and MS in an Australian Caucasian case-control population. Further significant associations in these genes were identified when the population was stratified by sex and disease subtype. No association was found for EXT1 or SULF1. Show less

Primary open-angle glaucoma (POAG) refers to a group of heterogeneous diseases involving optic nerve damage. Two well-established risk factors for POAG are elevated intraocular pressure (IOP) and a thinner central corneal thickness (CCT). These endophenotypes exhibit a high degree of heritability across populations. Large-scale genome-wide association studies (GWASs) of outbred populations have robustly implicated several susceptibility gene variants for both IOP and CCT. Despite this progress, a substantial amount of genetic variance remains unexplained. Population-specific variants that might be rare in outbred populations may also influence POAG endophenotypes. The Norfolk Island population is a founder-effect genetic isolate that has been well characterized for POAG endophenotypes. This population is therefore a suitable candidate for mapping new variants that influence these complex traits. Three hundred and thirty participants from the Norfolk Island Eye Study (NIES) core pedigree provided DNA. Ocular measurements of CCT and IOP were also taken for analysis. Heritability analyses and genome-wide linkage analyses of short tandem repeats (STRs) were conducted using SOLAR. Pedigree-based GWASs of single-nucleotide polymorphisms (SNPs) were performed using the GenABEL software. CCT was the most heritable endophenotype in this cohort (h These study results indicate that CCT and IOP exhibit a substantial degree of heritability in the NI pedigree, indicating a genetic component. A genome-wide linkage analysis of POAG endophenotypes did not reveal any major effect loci, but the GWASs did implicate several known loci, as well as a potential new locus in DLG2, suggesting a role for neuronal signaling in development in IOP and perhaps POAG. These results also highlight the need to target rarer variants via whole genome sequencing in this genetic isolate. Show less

Heparan sulfate proteoglycans (HSPGs) are key components of the extracellular matrix that mediate cell proliferation, invasion, and cellular signaling. The biological functions of HSPGs are linked to their co-stimulatory effects on extracellular ligands (e.g., WNTs) and the resulting activation of transcription factors that control mammalian development but also associated with tumorigenesis. We examined the expression profile of HSPG core protein syndecans (SDC1-4) and glypicans (GPC1-6) along with the enzymes that initiate or modify their glycosaminoglycan chains in human breast cancer (HBC) epithelial cells. Gene expression in relation to cell proliferation was examined in the HBC cell lines MCF-7 and MDA-MB-231 following treatment with the HS agonist heparin. Heparin increased gene expression of chain initiation and modification enzymes including EXT1 and NDST1, as well as core proteins SDC2 and GPC6. With HS/Wnt interactions established, we next investigated WNT pathway components and observed that increased proliferation of the more invasive MDA-MB-231 cells is associated with activation of the Wnt signaling pathway. Specifically, there was substantial upregulation (>5-fold) of AXIN1, WNT4A, and MYC in MDA-MB-231 but not in MCF-7 cells. The changes in gene expression observed for HSPG core proteins and related enzymes along with the associated Wnt signaling components suggest coordinated interactions. The influence of HSPGs on cellular proliferation and invasive potential of breast cancer epithelial cells are cell and niche specific. Further studies on the interactions between HSPGs and WNT ligands may yield clinically relevant molecular targets, as well as new biomarkers for characterization of breast cancer progression. Show less

Heparan sulfate proteoglycans cooperate with basic fibroblast growth factor (bFGF/FGF2) signaling to control osteoblast growth and differentiation, as well as metabolic functions of osteoblasts. FGF2 signaling modulates the expression and activity of Runt-related transcription factor 2 (Runx2/Cbfa1), a key regulator of osteoblast proliferation and maturation. Here, we have characterized novel Runx2 target genes in osteoprogenitors under conditions that promote growth arrest while not yet permitting sustained phenotypic maturation. Runx2 enhances expression of genes related to proteoglycan-mediated signaling, including FGF receptors (e.g., FGFR2 and FGFR3) and proteoglycans (e.g., syndecans [Sdc1, Sdc2, Sdc3], glypicans [Gpc1], versican [Vcan]). Runx2 increases expression of the glycosyltransferase Exostosin-1 (Ext1) and heparanase, as well as alters the relative expression of N-linked sulfotransferases (Ndst1 = Ndst2 > Ndst3) and enzymes mediating O-linked sulfation of heparan sulfate (Hs2st > Hs6st) or chondroitin sulfate (Cs4st > Cs6st). Runx2 cooperates with FGF2 to induce expression of Sdc4 and the sulfatase Galns, but Runx2 and FGF2 suppress Gpc6, thus suggesting intricate Runx2 and FGF2 dependent changes in proteoglycan utilization. One functional consequence of Runx2 mediated modulations in proteoglycan-related gene expression is a change in the responsiveness of bone markers to FGF2 stimulation. Runx2 and FGF2 synergistically enhance osteopontin expression (>100 fold), while FGF2 blocks Runx2 induction of alkaline phosphatase. Our data suggest that Runx2 and the FGF/proteoglycan axis may form an extracellular matrix (ECM)-related regulatory feed-back loop that controls osteoblast proliferation and execution of the osteogenic program. Show less