Despite the remarkable emergence of HAART in the 1990s, the fight against HIV infection is by no means finished. At the ACS Fall 2024 meeting in Denver, CO, Gilead Sciences presented the structure and discovery story of elunonavir (GS-1156), a novel HIV protease inhibitor with remarkable metabolic stability and a human half-life exceeding two weeks. Based on BMS’ atazanavir, the compound incorporates structural elements inspired by Gilead’s HCV NS5A inhibitor program which led to ledipasvir, as “stabilizer” motifs to avoid the extensive CYP metabolism seen in current inhibitors.

Recently, a surge of (pre)clinical compounds inhibiting the NLRP3 inflammasome, often featuring a hexahydroindacene ring system, has emerged, including Nodthera’s ND-0796. In a push for new chemotypes, AZ and Mitsubishi Tanabe have disclosed their clinical compound, AZD4144, which is currently in Ph. I trials in healthy volunteers. The discovery story detailed their efforts to overcome PLD (phospholipidosis), genotoxicity, and hERG inhibition in a non-classical pharmacophore series. The discovery was presented by Anders Johansson at the EFMC-ISMC 2024 Meeting in Rome.

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.

BMS-986408 is an oral, dual DGK ⍺ and ζ inhibitor currently in a Ph. I/II trial in patients with solid tumors. The compound was identified stemming from a phenotypic screening approach, and subsequent target deconvolution revealed DGK to be the target. If approved, it would be a first-in-class intracellular checkpoint inhibitor of DGK. This is an excellent case study on how to overcome a DILI risk associated with BSEP inhibition, as well as how to improve solubility and PK properties of your compounds through the introduction of polarity, reduction of aromatic rings, and increase in f(sp3).

Infection with the malaria parasite, Plasmodium falciparum, is a leading cause of fatality in the tropical regions of the world, with >240M infections and >600K deaths each year, the majority of which are in sub-Saharan Africa. The need for new antimalarials is clear, given that over half of the world's population is at risk of infection, combined with the rise of resistance against current treatments. Novartis has played a key role in this fight and at the ACS Fall 2024 meeting in Denver, CO, they disclosed NVP-FVP954: a novel, fast-acting IV antimalarial for severe malaria.