Pfizer’s ritlecitinib, a first-in-class, selective, oral covalent inhibitor of JAK3 and the TEC family of kinases, was FDA-approved in June 2023 for the treatment of severe alopecia areata. Ritlecitinib derives its JAK-family kinase selectivity from the covalent modification of a unique cysteine on JAK3. This annotation reviews the discovery of ritlecitinib, highlighting the interpretation of selectivity assays, the PK optimization, the evolution of the JAK3 therapeutic hypothesis, and how this 2023 Molecule of the Year nominee has become a classic case study for covalent drug discovery.

Pfizer disclosed the structure and discovery of their oral small molecule BDK inhibitor/degrader, PF-07328948, during the ACS Fall 2024 First-Time Disclosures session in Denver. The team identified a thiophene carboxylic acid-based hit targeting an allosteric pocket on BDK. Through optimization, they overcame challenges such as potential IADRs and BDK-E2 complex stabilization. By manipulating the dihedral angle of the methoxy group, they enhanced binding interactions, verifying PF-07328948's unexpected mechanism of action in vivo. PF-07328948 is currently Ph. I trials.

VVD-214/RO7589831 is an oral covalent, reversible, and allosteric inhibitor of WRN helicase discovered by the San Diego-based biotech Vividion Therapeutics and being developed by Roche for tumors marked by microsatellite instability and/or mismatch repair deficiency. Vividion has utilized its chemoproteomics platform to discover and develop novel treatment options for oncology targets. The structure and initial preclinical pharmacology data for VVD-214 were recently disclosed at the AACR Annual Meeting 2024 in San Diego. VVD-214 is currently being evaluated in a Ph. I trial.

Novartis' NLRP3 inhibitor, NVP-DFV890, features a unique sulfonimidamide motif designed to reduce hydrolysis relative to traditional sulfonylureas. This potent compound, with promising PK in humans, is advancing through multiple clinical studies, including Ph. II trials for coronary heart disease and knee osteoarthritis. Presented by Angela Mackay at the EFMC-ISMC 2024 joint conference in Rome, this overview covers NVP-DFV890's discovery, as well as its preclinical PK and PD data.

Compound 20 is a galactose-based monosaccharide Gal-3 inhibitor from Bristol Myers Squibb that shows potential in targeting fibrotic diseases.