Peptide Binder to Glypican-3 as a Theranostic Agent for Hepatocellular Carcinoma.

Glypican-3 (GPC3) is a membrane-associated glycoprotein that is significantly upregulated in hepatocellular carcinomas (HCC) with minimal to no expression in normal tissues. The differential expression of GPC3 between tumor and normal tissues provides an opportunity for targeted radiopharmaceutical therapy to treat HCC, a leading cause of cancer-related deaths worldwide. Methods: DOTA-RYZ-GPC3 (RAYZ-8009) comprises a novel macrocyclic peptide binder to GPC3, a linker, and a chelator that can be complexed with different radioisotopes. The binding affinity was determined by surface plasma resonance and radioligand binding assays. Target-mediated cellular internalization was radiometrically measured at multiple time points. In vivo biodistribution, monotherapy, and combination treatments with 177Lu or 225Ac were performed on HCC xenografts. Results: RAYZ-8009 showed high binding affinity to GPC3 protein of human, mouse, canine, and cynomolgus monkey origins and no binding to other glypican family members. Potent cellular binding was confirmed in GPC3-positive HepG2 cells and was not affected by isotope switching. RAYZ-8009 achieved efficient internalization on binding to HepG2 cells. Biodistribution study of 177Lu-RAYZ-8009 showed sustained tumor uptake and fast renal clearance, with minimal or no uptake in other normal tissues. Tumor-specific uptake was also demonstrated in orthotopic HCC tumors, with no uptake in surrounding liver tissue. Therapeutically, significant and durable tumor regression and survival benefit were achieved with 177Lu- and 225Ac-labeled RAYZ-8009, as single agents and in combination with lenvatinib, in GPC3-positive HCC xenografts. Conclusion: Preclinical in vitro and in vivo data demonstrate the potential of RAYZ-8009 as a theranostic agent for the treatment of patients with GPC3-positive HCC.

Development of Novel Immunoprophylactic Agents against Multidrug-Resistant Gram-Negative Bacterial Infections.

The widespread emergence of antibiotic resistance, including multidrug resistance in Gram-negative (G-) bacterial pathogens, poses a critical challenge to the current antimicrobial armamentarium. Antibody-drug conjugates (ADCs), primarily used in anticancer therapy, offer a promising treatment alternative due to their ability to deliver a therapeutic molecule while simultaneously activating the host immune response. The Cloudbreak platform is being used to develop ADCs to treat infectious diseases, composed of a therapeutic targeting moiety (TM) attached via a noncleavable linker to an effector moiety (EM) to treat infectious diseases. In this proof-of-concept study, 21 novel dimeric peptidic molecules (TMs) were evaluated for activity against a screening panel of G- pathogens. The activities of the TMs were not impacted by existing drug resistance. Potent TMs were conjugated to the Fc fragment of human IgG1 (EM), resulting in 4 novel ADCs. These ADCs were evaluated for immunoprophylactic efficacy in a neutropenic mouse model of deep thigh infection. In colistin-sensitive infections, 3 of the 4 ADCs offered protection similar to that of therapeutically dosed colistin, while CTC-171 offered enhanced protection. The efficacy of these ADCs was unchanged in colistin-resistant infections. Together, these results indicate that the ADCs used here are capable of potent binding to G- pathogens regardless of lipopolysaccharide (LPS) modifications that otherwise lead to antibiotic resistance and support further exploration of ADCs in the treatment of infections caused by drug-resistant G- bacteria.

Discovery and development of a novel class of phenoxyacetyl amides as highly potent TRPM8 agonists for use as cooling agents.

The paper presents the activity trends for a novel series of phenoxyacetyl amides as human TRPM8 receptor agonists. This series encompasses in vitro activity values ranging from the micromolar to the picomolar levels. Sensory evaluation of these molecules highlights their relevance as cooling agents for oral applications. The positive outcome of the complete evaluation of N-(1H-pyrazol-3-yl)-N-(thiophen-2-ylmethyl)-2-(p-tolyloxy)acetamide resulted in its approval for Generally Recognized As Safe (GRAS) status by the Flavor & Extract Manufacturer Association (FEMA) as FEMA 4809.

Structure-activity relationships of ring C-secotaxoids. 1. Acylative modifications.

The acylative modification of IDN 5390 (3a), a 7,8-secotaxoid under preclinical development, was investigated. A modest decrease of potency was observed upon acylation of the primary and the enolic hydroxyls, suggesting that, just like in paclitaxel, the hydroxyl groups in the upper right-hand sector are not critical for cytotoxicity. The activity of these analogues, and especially of the chemically robust carbonates 3c and 3d, makes it unlikely that the activity of IDN 5390 is due to in vivo oxidation to a fledgling 7-aldehyde and re-aldolization to the corresponding taxane derivative.

Synthesis and biological evaluation of paclitaxel-thiocolchicine hybrids.

The bifunctional taxoid-colchicinoid hybrids 6-8 were synthesized and evaluated in assays of cytotoxicity and tubulin assembly/disassembly. All compounds showed a high degree of cytotoxicity, but, while 6 and 7 behaved as bifunctional tubulin binders not unlike an equimolecular mixture of taxol and thiocolchicine, 8 was surprisingly devoid of tubulin activity, acting on a distinct and yet to identify molecular target.