Cell-targeted PD-1 agonists that mimic PD-L1 are potent T cell inhibitors.

The PD-1/PD-L1 pathway is a key immune checkpoint that regulates T cell activation. There is strong rationale to develop PD-1 agonists as therapeutics against autoimmunity, but progress in this area has been limited. Here, we generated T cell receptor (TCR) targeting, PD-1 agonist bispecifics called ImmTAAI molecules that mimic the ability of PD-L1 to facilitate the colocalization of PD-1 with the TCR complex at the target cell-T cell interface.

A phase I first-in-human study with tefinostat - a monocyte/macrophage targeted histone deacetylase inhibitor - in patients with advanced haematological malignancies.

Tefinostat (CHR-2845) is a monocyte/macrophage targeted histone deacetylase inhibitor (HDACi). This first-in-human, standard 3 + 3 dose escalating trial of oral, once daily tefinostat was conducted to determine the safety, tolerability, pharmacokinetic and pharmacodynamic profile of tefinostat in relapsed/refractory haematological diseases. Eighteen patients were enrolled at doses of 20-640 mg.

Drug targeting to monocytes and macrophages using esterase-sensitive chemical motifs.

The therapeutic and toxic effects of drugs are often generated through effects on distinct cell types in the body. Selective delivery of drugs to specific cells or cell lineages would, therefore, have major advantages, in particular, the potential to significantly improve the therapeutic window of an agent. Cells of the monocyte-macrophage lineage represent an important target for many therapeutic agents because of their central involvement in a wide range of diseases including inflammation, cancer, atherosclerosis, and diabetes.

Discovery of 2-(6-{[(6-fluoroquinolin-2-yl)methyl]amino}bicyclo[3.1.0]hex-3-yl)-N-hydroxypyrimidine-5-carboxamide (CHR-3996), a class I selective orally active histone deacetylase inhibitor.

A novel series of HDAC inhibitors demonstrating class I subtype selectivity and good oral bioavailability is described. The compounds are potent enzyme inhibitors (IC₅₀ values less than 100 nM), and improved activity in cell proliferation assays was achieved by modulation of polar surface area (PSA) through the introduction of novel linking groups. Employing oral pharmacokinetic studies in mice, comparing drug levels in spleen to plasma, we selected compounds that were tested for efficacy in human tumor xenograft studies based on their potential to distribute into tumor.

CHR-2797: an antiproliferative aminopeptidase inhibitor that leads to amino acid deprivation in human leukemic cells.

CHR-2797 is a novel metalloenzyme inhibitor that is converted into a pharmacologically active acid product (CHR-79888) inside cells. CHR-79888 is a potent inhibitor of a number of intracellular aminopeptidases, including leucine aminopeptidase. CHR-2797 exerts antiproliferative effects against a range of tumor cell lines in vitro and in vivo and shows selectivity for transformed over nontransformed cells.