mk-2866 and Prostatic-Neoplasms

In our effort to find small-molecule treatments of advanced prostate cancers (PCs), a novel series of indolyl and indolinyl propanamides (series II and III) were discovered as selective androgen receptor degraders (SARDs). Initial studies of androgen receptor (AR) antagonist (1) and agonist (2) propanamides yielded a tertiary aniline (3) with novel SARD activity but poor metabolic stability. Cyclization to II and III produced submicromolar AR antagonism and protein degradation selective to AR and AR splice variant (AR SV). II and III maintained potency against enzalutamide-resistant (Enz-R) mutant ARs and PC cells and were efficacious in Enz-R xenografts, suggesting their potential to treat advanced PCs. Design, synthesis, and biological activity of novel SARDs that could potentially be used for the treatment of a wide spectrum of PCs including castration-resistant, Enz-R, and/or AR SV-dependent advanced PCs that are often untreatable with known hormone therapies are discussed.

Topics: Amides; Androgen Receptor Antagonists; Androgens; Animals; Benzamides; Cell Line, Tumor; Cell Proliferation; Drug Design; Drug Resistance, Neoplasm; Humans; Indoles; Male; Mice; Nitriles; Phenylthiohydantoin; Prostatic Neoplasms; Proteolysis; Rats; Receptors, Androgen; Structure-Activity Relationship; Xenograft Model Antitumor Assays

Prostate cancer (PC) is one of the major causes of male death worldwide and the development of new and more potent anti-PC compounds is a constant requirement. Among the current treatments, (R)-bicalutamide and enzalutamide are non-steroidal androgen receptor antagonist drugs approved also in the case of castration-resistant forms. Both these drugs present a moderate antiproliferative activity and their use is limited due to the development of resistant mutants of their biological target. Insertion of fluorinated and perfluorinated groups in biologically active compounds is a current trend in medicinal chemistry, applied to improve their efficacy and stability profiles. As a means to obtain such effects, different modifications with perfluoro groups were rationally designed on the bicalutamide and enzalutamide structures, leading to the synthesis of a series of new antiproliferative compounds. Several new analogues displayed improved in vitro activity towards four different prostate cancer cell lines, while maintaining full AR antagonism and therefore representing promising leads for further development. Furthermore, a series of molecular modelling studies were performed on the AR antagonist conformation, providing useful insights on potential protein-ligand interactions.

Topics: Anilides; Antineoplastic Agents; Benzamides; Caco-2 Cells; Cell Line, Tumor; Cell Proliferation; Chemistry Techniques, Synthetic; Drug Design; Drug Resistance, Neoplasm; Humans; Male; Microsomes, Liver; Molecular Docking Simulation; Molecular Dynamics Simulation; Nitriles; Permeability; Phenylthiohydantoin; Prostatic Neoplasms; Protein Conformation; Receptors, Androgen; Tosyl Compounds

Several new androgen receptor antagonists were synthesized and found to have varying activities across typically anti-androgen resistant mutants (Thr877 → Ala and Trp741 → Leu) and markedly improved potency over previously reported pan-antagonists. X-ray crystallography of a new anti-androgen in an androgen receptor mutant (Thr877 → Ala) shows that the receptor can accommodate the added bulk presented by phenyl to naphthyl substitution, casting doubt on previous reports of predicted binding orientation and the causes of antagonism in bulky-B-ring antagonists.

Topics: Androgen Antagonists; Androgen Receptor Antagonists; Androgens; Crystallography, X-Ray; Drug Design; Drug Resistance, Neoplasm; Humans; Male; Molecular Structure; Molecular Targeted Therapy; Prostatic Neoplasms; Protein Binding; Receptors, Androgen; Structure-Activity Relationship