Daraxonrasib and the heart: cardiovascular implications of the first clinically successful pan-RAS(ON) inhibitor

Daraxonrasib (RMC-6236), the first orally bioavailable pan-RAS(ON) inhibitor, produced a significant survival benefit in the Phase 3 RASolute 302 trial in previously treated metastatic pancreatic ductal adenocarcinoma (PDAC), reducing the risk of death by 60% versus chemotherapy (hazard ratio [HR] 0.40; p < 0.0001). Its mechanism, high-affinity engagement of GTP-loaded KRAS, NRAS and HRAS through a cyclophilin A (CypA)-mediated tri-complex, cannot distinguish oncogenic RAS(ON) from the wild-type RAS(ON) that is constitutively active in cardiomyocytes, endothelium and vascular smooth muscle. To establish what cardiovascular harm has actually been documented for this agent in trial and post-marketing data, to interpret those observations mechanistically, and to specify the amendments that established cardio-oncology surveillance guidance requires before pan-RAS(ON) inhibition enters routine use. PubMed, EMBASE, ClinicalTrials.gov, the Cochrane Library and major congress proceedings were searched through 31 May 2026, together with the FDA Adverse Event Reporting System (FAERS), EudraVigilance, WHO VigiBase and publicly available FDA and EMA regulatory documents. Each claim was assigned an evidence tier and a strength grade (Established, Probable, Possible or Speculative), applied consistently throughout. Three cardiovascular observations are reproducible in exposed patients: peripheral oedema in approximately 40%, treatment-emergent hypertension in a minority, and no published cardiac-specific endpoint at Phase 3 scale, meaning no left ventricular ejection fraction (LVEF), strain, troponin or electrocardiographic data. No disproportionality signal could be computed in FAERS, EudraVigilance or VigiBase, because marketing exposure is too recent to have generated an analysable case series. That says how immature the surveillance data are, and it should not be read as demonstrated safety. Wild-type RAS(ON) signalling sustains cardiomyocyte survival, endothelial function and vascular homeostasis through RAF–MEK–ERK, PI3K–AKT–mTOR and RALGDS–RAC1 effectors. Three liabilities follow: endothelial dysfunction through reduced eNOS activation (Probable), paradoxical ERK activation in wild-type-RAS vascular smooth muscle promoting hypertension (Probable), and impaired reperfusion injury salvage kinase (RISK) signalling at reperfusion (Possible, downgraded from Probable in this revision). Reduced oxidative stress through NOX2 suppression is a potential counterbalancing benefit (Possible). RASopathy genotype–phenotype associations provide the human genetic validation for RAS–cardiac coupling. Claims relating to ischaemic conditioning have been graded conservatively: randomised trials of ischaemic pre-, post- and remote conditioning have been largely neutral, and routine peri-infarct pharmacotherapy already recruits the same pro-survival kinases. The cardiovascular effects of daraxonrasib are biologically plausible and, in the vasculature, already partly visible; myocardial consequences remain inferential. Because the two reproducible clinical signals are vascular rather than myocardial, and because no cardiac endpoint has been collected, what is needed now is protocol-mandated cardiovascular measurement embedded in the trials that are already running, rather than further mechanistic argument.