Rasonque \(Daraxonrasib\): A First-in-Class RAS\(ON\) Inhibitor Reaches Patients with Pancreatic Cancer
On 26 August 2026, the FDA approved Rasonque \(daraxonrasib\), developed by Revolution Medicines, as the first-in-class targeted therapy for metastatic pancreatic adenocarcinoma, the most common form of pancreatic cancer and one of the hardest to treat. For a disease that has seen few genuine advances in systemic therapy, this approval marks a notable shift. Oncogenic RAS mutations are present in more than 90% of pancreatic ductal adenocarcinoma cases, yet the active, GTP-bound conformation of RAS has long been considered one of the more challenging targets in oncology, lacking an obvious deep pocket for a small molecule to engage. Daraxonrasib approaches the problem differently. Rather than relying on a conventional binding pocket on RAS alone, it forms a noncovalent tri-complex with the intracellular chaperone cyclophilin A \(CypA\) and active RAS, creating a composite binding pocket at the CypA–RAS interface. This interaction blocks RAS from engaging downstream effectors such as RAF and disrupts MAPK pathway signalling. This multi-selective mode of action, spanning multiple mutant and wild-type RAS isoforms across KRAS, NRAS and HRAS rather than a single mutation, sets it apart from earlier mutation-specific RAS inhibitors such as those targeting KRAS G12C. The approval was supported by the Phase III RASolute 302 trial, a randomised, open-label, multicentre study of 500 adults with previously treated metastatic pancreatic adenocarcinoma. Median overall survival reached 13.2 months with daraxonrasib compared with 6.7 months for standard chemotherapy. Median progression-free survival was also improved, at 7.2 versus 3.6 months, while objective response rates were 30% versus 11%. The FDA described the results as unprecedented in an area of high unmet need. For medicinal chemists, daraxonrasib is also a useful case study in how far RAS drug discovery has travelled. Its macrocyclic, beyond-rule-of-five architecture and noncovalent tri-complex mechanism demonstrate how creating a new composite binding interface can make previously challenging protein surfaces accessible to small molecules. The approach may help inform the next generation of RAS-directed therapies and other protein–protein interaction inhibitors. How do you think this approval will shape future RAS inhibitors? Could our building blocks help you overcome the challenges of your project. Explore our range of building blocks at https://lnkd.in/eVbfw6Ua Further reading: Discovery of Daraxonrasib \(RMC-6236\), a Potent and Orally Bioavailable RAS\(ON\) Multi-selective, Noncovalent Tri-complex Inhibitor for the Treatment of Patients with Multiple RAS-Addicted Cancers https://lnkd.in/eppADx8k
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