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.

Atrasentan, an ETA receptor antagonist discovered by Abbott (AbbVie) in the 1990s, was initially developed for prostate cancer. Due to insufficient clinical data for approval, AbbVie shifted its focus to chronic kidney diseases, conducting a large trial (SONAR) with over 5,000 patients. AbbVie later exited kidney disease drug development and out-licensed atrasentan to Chinook. Novartis then surprised everyone with a $3.2B buyout of Chinook. This case exemplifies the complexities of drug discovery for kidney diseases and the long journey from initial research to clinical success.

Vorasidenib (AG-881) is a brain-penetrant allosteric inhibitor of mutant isocitrate dehydrogenases 1 and 2 (mIDH1/2) from Agios and Celgene that made headlines summer 2023 due to its stunning efficacy for treatment of glioma in patients with mIDH1/2. This Featured Case Study reviews how it was discovered, how it works, and why it matters.

Nurix Therapeutics’ NX-1607 is the first oral small molecule inhibitor of CBL-B to enter clinical trials. CBL-B negatively regulates immune activation in T, B, and NK cells; while immune checkpoint inhibitors are often effective, they have limitations, including lack of efficacy in certain cancers, patient variability, and resistance. NX-1607 enhances T cell activation by gluing CBL-B in an inactive conformation and, driven by preclincial data, NX-1607 is currently in a Ph. I trial. This article details its discovery story and initial clincial results, presented at the ACS Spring 2024 meeting.

Kymera’s KT-413 is a CRBN-based dual-mechanism degrader that degrades both IRAK4 and the transcription factors IKZF1/3, acting as an IMiD, with promising clinical activity for the treatment of ABC-like subtype of DLBCL. This fascinating case study demonstrates how a dual-mechanism degrader of IKZF1/3 and IRAK4 can be designed to maximize NF-κB inhibition while simultaneously upregulating the Type I interferon response. This approach restores the apoptotic response and enables oncogene-mediated cell death, resulting in a robust antiproliferative and pro-apoptotic effect in MYD88 mutants.