👤 David R Patton

Biased agonism of the glucagon-like peptide-1/glucose-dependent insulinotropic polypeptide receptors (GLP-1R/GIPR) yields greater weight loss and better glycemic control than unbiased agonism in preclinical models. To evaluate whether biased agonism translates into improved efficacy for weight loss and glycemic control in clinical settings, we developed and characterized CT-388, a unimolecular peptide-based dual GLP-1R/GIPR agonist that is cAMP signal-biased at both receptors. In cell-based assays, CT-388 activated GLP-1R and GIPR with both having minimal receptor internalization vs their native ligands. CT-388 improved glycemic control in mice and monkeys, and reduced bodyweight, suppressed appetite, and improved metabolic dysfunction-associated steatohepatitis pathology in mice. In a phase 1, double-blind, randomized, placebo-controlled clinical study (NCT04838405) of CT-388 (subcutaneously administered single doses [0.5-7.5 mg] or 4 once-weekly doses [5-12 mg]) in otherwise healthy participants with overweight or obesity, CT-388 was generally well tolerated with a safety profile consistent with other incretin-based therapies; most treatment-emergent adverse events were mild or moderate. Glycemic parameters were improved during fasting conditions and an oral glucose tolerance test. The mean percent change in bodyweight from baseline to day 29 was -4.7% to -8.0% across CT-388 doses vs -0.5% with placebo. CT-388 pharmacokinetics supported once-weekly dosing. In conclusion, CT-388 demonstrated strong translatability from preclinical to clinical studies with consistent pharmacokinetics and pharmacodynamics across multiple species. In clinical settings, 4 weeks of CT-388 treatment produced clinically meaningful weight loss and improved glycemic control with favorable tolerability. These findings warrant further clinical evaluation of CT-388 for treating obesity and type 2 diabetes. Show less

Glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) agonists have recently been shown to play a significant role in the treatment of diabetes and obesity. Better understanding of their signaling and mechanism of action could further improve their therapeutic effects. In the current study, we investigate the impact of biased cyclic AMP (cAMP) signaling of GLP-1R and GIPR, individually, as well as the combined effects of a unimolecular dually biased GLP-1R/GIPR agonist, CT-859, on glucose, food consumption, and body weight regulation. Our data demonstrate that biased agonism of either GLP-1R or GIPR leads to better glycemic regulation, greater food intake suppression, and weight loss. In addition, concerted biased activation of both GLP-1R and GIPR results in substantially higher efficacy. Activation of GLP-1R and GIPR with a combination of individually biased agonists or via a dually biased unimolecular approach with CT-859 may provide significant therapeutic advantages for the treatment of diabetes and obesity. Show less

Despite fibroblast growth factor receptor ( EAY131-K1 was an open-label, single-arm, phase II study with central confirmation of presence of Thirty-five patients were enrolled into this study with 18 included in the prespecified primary efficacy analysis. The median age of the 18 patients was 60 years, and 78% had received ≥3 previous lines of therapy. There were no confirmed responses to erdafitinib; however, five patients experienced stable disease (SD) as best response. One patient with an Erdafitinib did not meet its primary end point of efficacy as determined by ORR in treatment-refractory solid tumors harboring Show less

Subprotocol K2 (EAY131-K2) of the NCI-MATCH platform trial was an open-label, single-arm, phase II study designed to evaluate the antitumor efficacy of the oral FGFR1-4 inhibitor, erdafitinib, in patients with tumors harboring FGFR1-4 mutations or fusions. Central confirmation of tumor FGFR1-4 mutations or fusions was required for outcome analysis. Patients with urothelial carcinoma were excluded. Enrolled subjects received oral erdafitinib at a starting dose of 8 mg daily continuously until intolerable toxicity or disease progression. The primary end point was objective response rate (ORR) with key secondary end points of safety, progression-free survival (PFS), and overall survival (OS). Thirty-five patients were enrolled, and 25 patients were included in the primary efficacy analysis as prespecified in the protocol. The median age was 61 years, and 52% of subjects had received ≥3 previous lines of therapy. The confirmed ORR was 16% (4 of 25 [90% CI, 5.7 to 33.0], This study met its primary end point in patients with several pretreated solid tumor types harboring FGFR1-3 mutations or fusions. These findings support advancement of erdafitinib for patients with fibroblast growth factor receptor-altered tumors outside of currently approved indications in a potentially tumor-agnostic manner. Show less

Primary open angle glaucoma (POAG) is the most prevalent form of glaucoma, accounting for approximately 90% of all cases. The aqueous humor (AH), a biological fluid in the anterior and posterior chambers of the eye, is involved in a multitude of functions including the maintenance of IOP and ocular homeostasis. This fluid is very close to the pathologic site and is also known to have a significant role in glaucoma pathogenesis. The purpose of this study was to identify proteomic alterations in AH from patients with POAG. AH samples were extracted from 47 patients undergoing cataract surgery (controls: n = 32; POAG: n = 15). Proteomic analysis of the digested samples was accomplished by liquid-chromatography-mass spectrometry. The identified proteins were evaluated using a variety of statistical and bioinformatics methods. A total of 33 proteins were significantly altered in POAG subjects compared with the controls. The most abundant proteins in POAG subjects are IGKC (13.56-fold), ITIH4 (4.1-fold), APOC3 (3.36-fold), IDH3A (3.11-fold), LOC105369216 (2.98-fold). SERPINF2 (2.94-fold), NPC2 (2.88-fold), SUCLG2 (2.70-fold), KIAA0100 (2.29-fold), CNOT4 (2.23-fold), AQP4 (2.11-fold), COL18A1 (2.08-fold), NWD1 (2.07-fold), and TMEM120B (2.06-fold). A significant increasing trend in the odds ratios of having POAG was observed with increased levels of these proteins. Proteins identified in this study are implicated in signaling, glycosylation, immune response, molecular transport, and lipid metabolism. The identified candidate proteins may be potential biomarkers associated with POAG development and may lead to more insight in understanding the mechanisms underlying the pathogenesis of this disease. Show less

Familial hypertrophic cardiomyopathy (HCM) is a leading cause of sudden cardiac death among young and apparently healthy people. Autosomal dominant mutations within genes encoding sarcomeric proteins have been identified. An autosomal recessive form of HCM has been discovered in a group of Amish children that is associated with poor prognosis and death within the first year of life. Affected patients experienced progressive cardiac failure despite maximal medical treatment. Postmortem histology showed myofibre disarray and myocyte loss consistent with refractory clinical deterioration in affected infants. To conduct a genome-wide screen for linkage and try to identify an autozygous region which cosegregates with the infant cardiac phenotype An autozygous region of chromosome 11 which cosegregates with the infant cardiac phenotype was identified. This region contained the MYBPC3 gene, which has previously been associated with autosomal dominant adult-onset HCM. Sequence analysis of the MYBPC3 gene identified a splice site mutation in intron 30 which was homozygous in all affected infants. All surviving patients with the homozygous MYBPC3 gene mutations (3330+2T>G) underwent an orthotopic heart transplantation. Homozygous mutations in the MYBPC3 gene have been identified as the cause of severe infantile HCM among the Amish population. Show less

Progression through the cell cycle requires the coordination of basal metabolism with the cell cycle and growth machinery. Repression of the sulfur gene network is mediated by the ubiquitin ligase SCF(Met30), which targets the transcription factor Met4p for degradation. Met30p is an essential protein in yeast. We have found that a met4Deltamet30Delta double mutant is viable, suggesting that the essential function of Met30p is to control Met4p. In support of this hypothesis, a Met4p mutant unable to activate transcription does not cause inviability in a met30Delta strain. Also, overexpression of an unregulated Met4p mutant is lethal in wild-type cells. Under non-permissive conditions, conditional met30Delta strains arrest as large, unbudded cells with 1N DNA content, at or shortly after the pheromone arrest point. met30Delta conditional mutants fail to accumulate CLN1 and CLN2, but not CLN3 mRNAs, even when CLN1 and CLN2 are expressed from strong heterologous promoters. One or more genes under the regulation of Met4p may delay the progression from G(1) into S phase through specific regulation of critical G(1) phase mRNAs. Show less

In most eukaryotes, commitment to cell division occurs in late G1 phase at an event called Start in the yeast Saccharomyces cerevisiae, and called the restriction point in mammalian cells. Start is triggered by the cyclin-dependent kinase Cdc28 and three rate-limiting activators, the G1 cyclins Cln1, Cln2 and Cln3. Cyclin accumulation in G1 is driven in part by the cell-cycle-regulated transcription of CLN1 and CLN2, which peaks at Start. CLN transcription is modulated by physiological signals that regulate G1 progression, but it is unclear whether Cln protein stability is cell-cycle-regulated. It has been suggested that once cells pass Start, Cln proteolysis is triggered by the mitotic cyclins Clb1, 2, 3 and 4. But here we show that G1 cyclins are unstable in G1 phase, and that Clb-Cdc28 activity is not needed fgr G1 cyclin turnover. Cln instability thus provides a means to couple Cln-Cdc28 activity to transcriptional regulation and protein synthetic rate in pre-Start G1 cells. Show less

Bardet-Biedl syndrome (BBS) is a clinically and genetically heterogeneous autosomal recessive disorder characterized by retinitis pigmentosa, polydactyly, obesity, hypogenitalism, mental retardation, and renal anomalies. To detect linkage to BBS loci, 29 BBS families, of mixed but predominantly European ethnic origin, were typed with 37 microsatellite markers on chromosomes 2, 3, 11, 15, 16, and 17. The results show that an estimated 36-56% of the families are linked to the 11q13 chromosomal site (BBS1) previously described by M. Leppert et al. (1994, Nature Genet. 7, 108-112), with the gene order cen-D11S480-5 cM-BBS1-3 cM-D11S913/D11S987-qter. A further 32-35% of the families are linked to the BBS4 locus, reported by R. Carmi et al. (1995, Hum. Mol. Genet. 4, 9-13) in chromosomal region 15q22.3-q23, with the gene order cen-D15S125-5 cM-BBS4-2 cM-D15S131/D15S204-qter. Three consanguineous BBS families are homozygous for three adjacent chromosome 15 markers, consistent with identity by descent for this region. In one of these families haplotype analysis supports a localization for BBS4 between D15S131 and D15S114, a distance of about 2 cM. Weak evidence of linkage to the 16q21 (BBS2) region reported by A. E. Kwitek-Black et al. (1993, Nature Genet. 5, 392-396) was observed in 24-27% of families with the gene order cen-D16S408-2 cM-BBS2-5 cM-D16S400. A fourth group of families, estimated at 8%, are unlinked to all three of the above loci, showing that at least one other BBS locus remains to be found. No evidence of linkage was found to markers on chromosome 3, corresponding to the BBS3 locus, reported by V. C. Sheffield et al. (1994, Hum. Mol. Genet. 3, 1331-1335), or on chromosome 2 or 17, arguing against the involvement of a BBS locus in a patient with a t(2;17) translocation. Show less

In budding yeast, cell division is initiated in late G1 phase once the Cdc28 cyclin-dependent kinase is activated by the G1 cyclins Cln1, Cln2, and Cln3. The extreme instability of the Cln proteins couples environmental signals, which regulate Cln synthesis, to cell division. We isolated Cdc53 as a Cln2-associated protein and show that Cdc53 is required for Cln2 instability and ubiquitination in vivo. The Cln2-Cdc53 interaction, Cln2 ubiquitination, and Cln2 instability all depend on phosphorylation of Cln2. Cdc53 also binds the E2 ubiquitin-conjugating enzyme, Cdc34. These findings suggest that Cdc53 is a component of a ubiquitin-protein ligase complex that targets phosphorylated G1 cyclins for degradation by the ubiquitin-proteasome pathway. Show less