Optimization of TEAD P-Site Binding Fragment Hit into In Vivo Active Lead

The dysregulated Hippo pathway and, consequently, hyperactivity of the transcriptional YAP/TAZ-TEAD complexes is associated with diseases such as cancer. Prevention of YAP/TAZ-TEAD triggered gene transcription is an attractive strategy for therapeutic intervention. The deeply buried and conserved lipidation pocket (P-site) of the TEAD transcription factors is druggable. The discovery and optimization of a P-site binding fragment (1) are described. Utilizing structure-based design, enhancement in target potency was engineered into the hit, capitalizing on the established X-ray structure of TEAD1. The efforts culminated in the optimized in vivo tool MSC-4106, which exhibited desirable potency, mouse pharmacokinetic properties, and in vivo efficacy. In close correlation to compound exposure, the time- and dose-dependent downregulation of a proximal biomarker could be shown.

Discovery of Benzimidazole CYP11B2 Inhibitors with in Vivo Activity in Rhesus Monkeys

We report the discovery of a benzimidazole series of CYP11B2 inhibitors. Hit-to-lead and lead optimization studies identified compounds such as 32, which displays potent CYP11B2 inhibition, high selectivity versus related CYP targets, and good pharmacokinetic properties in rat and rhesus. In a rhesus pharmacodynamic model, 32 produces dose-dependent aldosterone lowering efficacy, with no apparent effect on cortisol levels.

High-resolution crystal structures of factor XIa coagulation factor in complex with nonbasic high-affinity synthetic inhibitors

Factor XI (FXI) is a key enzyme in the coagulation pathway and an attractive target for the development of anticoagulant drugs. A small number of high-resolution crystal structures of FXIa in complex with small synthetic inhibitors have been published to date. All of these ligands have a basic P1 group and bind exclusively in the nonprime side of the active site of FXIa. Here, two structures of FXIa in complex with nonbasic inhibitors that occupy both the prime and nonprime sides of the active site are presented. These new structures could be valuable in the design and optimization of new FXIa synthethic inhibitors.

Phase I trial of a mouse monoclonal antibody against GD3 ganglioside in patients with melanoma: induction of inflammatory responses at tumor sites

Twenty-one patients were entered into a phase I trial to evaluate toxicity, antitumor effects, and biological responses at tumor sites during treatment of R24, an immunoglobulin G3 (IgG3) mouse monoclonal antibody (mAb) against GD3 ganglioside. Toxicity was related to dose of R24. Urticaria and pruritus were the most prominent side effects, with nausea, vomiting, and diarrhea occurring at the highest dose levels. Partial responses were observed in four patients lasting from 6 to 46 weeks, and mixed responses were seen in two patients. Responses occurred as early as 4 weeks and as late as 10 weeks after beginning treatment. Twenty of the 21 patients developed human IgG antibodies against R24. Antimouse Ig antibodies were first detected at a median of 14 days after starting treatment, but three of the four patients who had a partial response developed the antimouse Ig responses later than 20 days. Peak serum levels of R24 were related to dose and ranged from a mean of 0.9 micrograms/mL at the lowest dose level (1 mg/m2/d) to 44 micrograms/mL at the highest dose (50 mg/m2/d). The amount of R24 reaching tumor sites corresponded to the dose administered, and R24 could be detected in tumors as late as 30 days after finishing treatment. Inflammation at tumor sites was observed during treatment. Biopsies of tumors taken before, during, and after treatment revealed that R24 induced deposition of complement components, increased numbers of mast cells with mast cell degranulation, and infiltration of T lymphocytes. These results suggest that treatment with R24 can produce a localized inflammatory response at tumor sites that is capable of producing tumor regression.

Mouse monoclonal IgG3 antibody detecting GD3 ganglioside: a phase I trial in patients with malignant melanoma

R24 is an IgG3 mouse monoclonal antibody that identifies GD3, a prominent ganglioside on the surface of melanoma cells and other cells of neuroectodermal origin. Twelve patients with metastatic melanoma were treated with R24 at three dose levels, 8, 80, or 240 mg/m2, over a period of 2 weeks. Peak antibody levels in the serum were dose related and ranged from less than 0.1 to 62 micrograms/ml. Inflammatory reactions (urticaria, pruritus, erythema, subcutaneous ecchymoses) were observed around tumor sites in patients treated at doses greater than or equal to 80 mg/m2. Tumor biopsies during and after treatment showed lymphocyte and mast cell infiltration, mast cell degranulation, and complement deposition. Side effects were mild and were readily controlled by antihistamines. Major tumor regression has been observed in three patients.