Novartis’ HRO761 is an oral allosteric WRN helicase inhibitor, aimed at treating MSI-high and dMMR tumors. This article details the discovery of HRO761 and highlights the importance of selecting appropriate assays during early HTS as well as transferable medicinal chemistry strategies to optimize permeability and solubility through the modulation of LipE, neutral TPSA, chameleonicity, and non-classical zwitterions. It also explores the X-ray structure of HRO761 bound to WRN, how it differentiates from Vividion's VVD-214, its preclinical activity, clinical status, chemical synthesis, and more!

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.

AbbVie’s ABBV-467 is a highly potent, selective MCL-1 (myeloid cell leukemia-1) inhibitor which entered the clinic in 2022 in a Ph. I trial in patients with advanced hematologic cancers. MCL-1 has had a rough time in the clinic with multiple trials being halted or terminated due to cardiac toxicity, which is suspected to be an on-target effect. AbbVie’s approach with ABBV-467 was to target a highly potent/short half-life compound which could induce rapid apoptosis and tumor regressions in a short exposure period before the onset of any adverse events. Is this the end for MCL-1?

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.

BMS-986365 is a potential best-in-class heterobifunctional ligand-directed degrader of WT AR. This full case study details how this heterobifunctional degrader was engineered to have low intrinsic agonism and exert direct antagonism of WT AR through occupancy of its ligand-binding domain, how the dual modality of BMS-986365 results in deep AR pathway inhibition and allows antagonism to reinforce degradation to combat compensatory resistance mechanisms, its attractive preclinical profile, interim clinical data, how it differentiates from Arvinas’ first-to-clinic AR degraders, and more!