Nuvalent’s lead compound, NVL-520, is an oral, brain-penetrant, TRK-sparing, and potential best-in-class ROS1 kinase inhibitor that recently entered Ph. II of the ARROS-1 trial (NCT05118789) in patients with advanced ROS1-positive NSCLC. This article highlights what makes the Nuvalent’s NVL-520 program scientifically notable, including what gives it a potential best-in-class profile as a ROS1 inhibitor, the emerging toxicology of hard-to-avoid off-targets, an interesting synthetic route to the small macrocycle, and more.

MK-1084 is an oral covalent inhibitor of KRAS(G12C) being developed by Merck (as part of a collaboration with Taiho and Astex), which is currently in a Ph. I trial (NCT05067283) for the treatment of solid tumors either as a monotherapy or in combination with their checkpoint inhibitor immunotherapy pembrolizumab (Keytruda™). The medicinal chemistry story was recently presented at the ACS Spring 2024 meeting in New Orleans, following a presentation of the Ph. I interim results by Merck at ESMO in Oct. 2023.

Merck’s macrocyclic PCSK9 protein-protein interaction (PPI) inhibitor, MK-0616, is a once-daily PCSK9-lowering and LDL-cholesterol-lowering small molecule that has recently demonstrated antibody-like efficacy as an oral agent in the clinic. The program highlights numerous technical achievements at the forefront of modern drug discovery, and will set a standard for modern “classics in drug discovery” for some time.

LUNA18 is an orally bioavailable, cell-penetrant, macrocyclic peptide pan-RAS inhibitor (Chugai ’21Q3 earnings call) intended for the treatment of KRAS-mutant cancers. It disrupts the protein-protein interaction between KRAS and SOS, preventing RAS activation.

BI-0115 inhibits the C-type lectin family member lectin-like oxidized LDL-receptor-1 (LOX-1) by stabilizing an inactive tetrameric form of the protein. Interestingly, co-crystollography demonstrates that inter-ligand interactions between two BI-0115 molecules contribute to the dimerization of LOX-1 homodimers.