BAY 2413555 is a M2R PAM that has the potential to counter parasympathetic withdrawal and restore autonomic balance in heart failure patients. The preclinical and clinical data of BAY 2413555 showed it has positive effects on heart rate and heart rate variability and a relatively long human t1/2 of 37 h. The Ph. I trial, however, was terminated in March 2024 due to findings from a chronic toxicology study. This article covers the discovery of BAY 2413555, presented by Alexandros Vakalopoulos of Bayer at the EFMC-ISMC 2024 conference in Rome and published in the Journal of Medicinal Chemistry.

CDI (Clostridioides difficile) infection is a leading cause of healthcare-associated diarrhea with significant morbidity and mortality, and with the rise of hypervirulent and resistant strains, novel and selective antibiotics to treat these infections are needed. Cadazolid, a hybrid antibiotic that combines pharmacophores of two classes of antibacterials, demonstrated potent activity in vitro against relevant C. difficile strains, while avoiding native gut flora. Additionally, the compound was designed to be gut-restricted, with minimal systemic circulation following PO dosing.

AZ-PRMT5i-1 is an orally bioavailable MTA-cooperative PRMT5 inhibitor that specifically targets MTAP-deleted cancers and is structurally related to AZ’s clinical candidate, AZ3470. This case study is an excellent example of utilizing bioisosteric replacements for polar guanidine headgroups, rigidifying scaffolds through spirocyclization to reduce rotatable bonds, and leveraging fluorine atoms beyond simply blocking metabolic soft spots.

Chiesi Farmaceutici’s CHF-6523 is an inhaled, lung-restricted, selective PI3Kδ inhibitor designed to provide relief to patients with COPD. Its development involved optimization of permeability and solubility as well as identification of a solid form amenable for dry powder inhalation. Disclosed at the EFMC-ISMC 2024 joint conference in Rome, Italy, this article covers the structure, development, and early clinical data of CHF-6523, which ultimately indicates that PI3Kδ inhibition may not provide clinical effect in reduction of lung inflammation.

HiberCell recently disclosed the discovery of HC-7366, a potential first-in-class, intentionally discovered, orally bioavailable, potent, selective, small-molecule kinase activator of GCN2. HC-7366 has now progressed to Ph. I trials to treat ccRCC and AML. This case study is a fantastic example of how to mitigate CYP3A4 inhibition and improve oral bioavailability via judicious choice of salt formulation.