--- title: "RASolute 302 Trial: A New Era for RAS-Targeted Drug Discovery" description: The RASolute 302 trial marks a breakthrough in RAS-targeted therapy, revealing new design philosophies that prioritise allele breadth and state-dependence. image: https://blog.huborganoids.nl/hubfs/assets2026/pdo-screen.jpg --- [![HUB Organoids](https://blog.huborganoids.nl/hubfs/raw_assets/public/HUBOrganoids_May2021/images/logo-huborganoids-white.svg "HUB Organoids")](https://huborganoids.nl/) ![merk-m-logo-blue](https://blog.huborganoids.nl/hs-fs/hubfs/merk-m-logo-blue.png?width=728&height=225&name=merk-m-logo-blue.png) - [services](https://huborganoids.nl/services) - [services overview](https://www.huborganoids.nl/services-overview/) - [drug screening](https://www.huborganoids.nl/services/hub-drug-screening/) - [model and assay development](https://www.huborganoids.nl/services/) - [clinical trials in a dish](https://www.huborganoids.nl/hub-organoid-clinical-trial-in-a-dish/) - [Technology](https://huborganoids.nl/hub-technology) - [Company](https://huborganoids.nl/about) - [about us](https://huborganoids.nl/about) - [Careers](https://huborganoids.nl/careers) - [events](https://www.huborganoids.nl/meet-us/) - [latest news](https://www.huborganoids.nl/news-insights-2/) - [Resources](https://huborganoids.nl/resources/) - [Blog](https://blog.huborganoids.nl) - [license program](https://www.huborganoids.nl/licenses/) - [Contact](https://resources.huborganoids.nl/contact-hub) [discover organoid services](https://www.huborganoids.nl/services-overview/) - [services](https://huborganoids.nl/services) - [services overview](https://www.huborganoids.nl/services-overview/) - [drug screening](https://www.huborganoids.nl/services/hub-drug-screening/) - [model and assay development](https://www.huborganoids.nl/services/) - [clinical trials in a dish](https://www.huborganoids.nl/hub-organoid-clinical-trial-in-a-dish/) - [Technology](https://huborganoids.nl/hub-technology) - [Company](https://huborganoids.nl/about) - [about us](https://huborganoids.nl/about) - [Careers](https://huborganoids.nl/careers) - [events](https://www.huborganoids.nl/meet-us/) - [latest news](https://www.huborganoids.nl/news-insights-2/) - [Resources](https://huborganoids.nl/resources/) - [Blog](https://blog.huborganoids.nl) - [license program](https://www.huborganoids.nl/licenses/) - [Contact](https://resources.huborganoids.nl/contact-hub) ## HUB's blog # RASolute 302 Trial: A New Era for RAS-Targeted Drug Discovery Published by HUB Organoids on Sept 25, 2026 RASolute 302 Trial: A New Era for RAS-Targeted Drug Discovery 1:23 ![RASolute 302 Trial: A New Era for RAS-Targeted Drug Discovery](https://blog.huborganoids.nl/hubfs/assets2026/pdo-screen.jpg) When the first Kaplan-Meier curve from the Phase 3 RASolute 302 trial appeared on the screens at the 2026 ASCO Plenary Session, the room didn't just applaud — it stood, and some attendees were reportedly in tears. Daraxonrasib, Revolution Medicines' oral RAS(ON) multi-selective inhibitor, had nearly doubled median overall survival against chemotherapy in previously treated metastatic pancreatic ductal adenocarcinoma — 13.2 months versus 6.7 — in a 500-patient trial across 59 sites. Discussant Elizabeth Knox summarized the shift bluntly: "we have a new standard of care in the second-line setting," adding that RAS-targeted therapy "should dominate trials across the full spectrum of pancreatic cancer clinical presentations". The emotional reaction is understandable and well covered elsewhere. What deserves more scrutiny from a drug discovery audience is *why this particular molecule got there* — and what that mechanism implies for the pipeline of programs now positioning themselves as the next wave of RAS therapeutics. ### Two design choices that separate daraxonrasib from the first generation Daraxonrasib (RMC-6236) is a noncovalent tri-complex inhibitor (TCI). Rather than occupying a mutation-specific pocket on RAS itself, it binds the ubiquitously expressed chaperone cyclophilin A and, together with CypA, forms a composite interface with the switch regions of the active, GTP-bound state of RAS — mutant and wild-type alike. This is mechanistically distinct from every approved KRAS inhibitor to date. Sotorasib and adagrasib are covalent, mutation-specific binders of the inactive, GDP-bound state, engaging the switch-II pocket that is only accessible in the G12C allele. That specificity is precisely what limits them: efficacy is confined to a single mutation, and clinical benefit in colorectal cancer — where G12C accounts for only 3-4% of cases — has been modest and short-lived. Two structural consequences follow directly from the tri-complex, state-dependent design, and both carry direct translational weight. ![tile-image](https://blog.huborganoids.nl/hs-fs/hubfs/assets2026/poster-kras-resistance.png?width=250&name=poster-kras-resistance.png) #### POSTER ### Modeling KRAS inhibitor drug tolerance and resistance with patient-derived organoids Discover how our advanced drug exposure protocol enables the development of KRAS inhibitor-tolerant and resistant organoid clones. [download poster](https://resources.huborganoids.nl/modeling-kras-inhibitor-drug-tolerance-and-resistance-with-patient-derived-organoids) ### First, allele breadth is a property of the mechanism, not a bonus feature. Because the CypA-RAS interface targeted by daraxonrasib is largely conserved across G12, G13, and Q61 mutants, the compound doesn't need a separate binding solution per mutation. In the Phase 1/2 dataset that supported RASolute 302, outcomes were similar among patients with RAS G12, G13, or Q61 mutations, and RASolute 302 itself enrolled tumors with a broad range of RAS variants as well as tumors without an identified RAS mutation, with survival benefit observed largely irrespective of RAS mutation status. That is not incremental optimization of the G12C playbook; it is a categorically different approach to what "selectivity" even means for a RAS inhibitor. ### Second, targeting the active (ON) state changes the resistance calculus. Covalent OFF-state inhibitors depend on the target cycling through an inactive conformation they can trap — a vulnerability that adaptive tumors exploit through pathway reactivation and bypass signaling. A molecule that occludes effector binding directly on the active state removes that escape route, at least for the mechanisms tumors have used against first-generation inhibitors. That does not mean daraxonrasib is resistance-proof: [a companion analysis](https://www.nature.com/articles/s41591-026-04537-w) in *Nature Medicine* of circulating tumor DNA from 44 PDAC patients on daraxonrasib monotherapy has already begun cataloguing acquired resistance alterations, most clustering at the CypA-RAS inhibitor-binding interface itself, and using that map to propose rational combination strategies. The point is not that resistance disappears — it's that the resistance biology is now a different, and in some ways more tractable, problem than switch-II pocket evasion. ### Is this a platform moment, not a single-molecule moment? The tri-complex modality behind daraxonrasib is not a one-off. Revolution Medicines has already produced a family of related molecules built on the same CypA-glue chemistry — elironrasib (RMC-6291), a covalent G12C-selective tri-complex inhibitor, and RMC-9805, a covalent G12D-selective analogue — suggesting the company is systematically re-deriving the entire KRAS-allele landscape through one chemical platform rather than one molecule at a time. Independently, Boehringer Ingelheim's BI-2865/BI-2493 series and its clinical successor BI-3706674 pursue broad allele coverage through direct, noncovalent OFF-state RAS binding rather than a chaperone-mediated interface — a mechanistically distinct but philosophically parallel bet that breadth, not allele precision, is where durable clinical benefit lives. BridgeBio's BBO-11818 and Insilico Medicine's recently nominated ISM6166 preclinical candidate extend the same logic into ON/OFF dual-state and multi-allele coverage, respectively. Set against a pipeline landscape that recently tracked mora than 100 active KRAS-inhibitor trials across 61 sponsors, the RASolute 302 result functions less as validation of one asset than as validation of a design philosophy: state-dependence and allele breadth as primary optimization targets, rather than secondary considerations bolted onto a G12C-first program. It would be reasonable to expect licensing activity, next-generation TCI candidates, and repositioned "pan-RAS" programs from mid-size biopharma to accelerate materially over the next 18–24 months, particularly as tumor types beyond PDAC — NSCLC, colorectal, NRAS-mutant melanoma — are already listed among daraxonrasib's active development indications. ![tile-image](https://blog.huborganoids.nl/hs-fs/hubfs/cover-kras-research.png?width=250&name=cover-kras-research.png) #### FACTSHEET ### Patient-derived organoids as translational avatars for KRAS research Learn how PDOs support lead identification and modelling resistance mechanism. [download factsheet](https://resources.huborganoids.nl/modelling-kras-inhibitor-resistance-with-patient-derived-organoids-pdos) ### Why this changes what "preclinical" needs to mean Here is the operational problem RASolute 302 leaves for every discovery team now designing the next multi-selective candidate: the bar for preclinical evidence has quietly moved. A molecule engineered for allele- and state-independence cannot be adequately characterized against two or three cell lines representing the historically "easy" mutations. If the clinical hypothesis is that a compound works across G12, G13, and Q61 variants and irrespective of tissue of origin, the preclinical package has to demonstrate exactly that breadth, under conditions that permit real cross-model comparison — not sequential, incomparable experiments run months apart on whatever cell line happened to be in the freezer. Conventional 2D cancer cell lines are a poor instrument for this question. They drift genetically under passage, lose the co-mutation background that shapes real-world response heterogeneity, and cannot recapitulate the tissue-specific adaptive signaling that determines whether a state-dependent mechanism actually translates from target engagement to tumor regression. This is precisely the gap that patient-derived organoids (PDOs) are structurally suited to close. PDOs retain the genomic complexity, co-mutation context, and three-dimensional signaling architecture of the tumor of origin without the passaging artifacts of immortalized lines — allowing simultaneous evaluation of efficacy, off-tumor toxicity, and mode of action within the same biologically faithful system. For programs benchmarking against the daraxonrasib standard specifically, that means testing candidate multi-selective or RAS(ON) compounds across organoid panels spanning G12, G13, and Q61 alleles and multiple tumor indications under standardized, comparable assay conditions — the only way to generate the kind of allele-by-indication efficacy matrix that a state-dependent, broad-spectrum mechanism actually requires to be credible before it reaches a clinical protocol. It also means building resistance biology into the discovery timeline earlier rather than later: induced-resistance organoid models and single-cell transcriptomic profiling of persister and resistant clones can surface combination rationale — much as the ctDNA resistance mapping in the *Nature Medicine* daraxonrasib dataset already has — well before a Phase 1 dose-escalation cohort forces the question. RASolute 302 didn't just produce a standing ovation. It produced a template. The molecules that follow it into the clinic successfully will be the ones whose preclinical packages were built with the same breadth the mechanism demands — not retrofitted to it after the fact. ![tile-image](https://blog.huborganoids.nl/hs-fs/hubfs/assets2024/kras-pink-teal.png?width=250&name=kras-pink-teal.png) #### TARGET KRAS ### PAN-KRAS PDO Screen Test the efficacy of your compound(s) in a panel of 25 patient-derived organoids representing colorectal, lung, and pancreatic cancer. 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