Daraxonrasib and the RASolute 302 Trial: A Paradigm Shift in the RAS Targeting Era and Management of Pancreatic Cancer

Daraxonrasib and the RASolute 302 Trial: A Paradigm Shift in the RAS Targeting Era and Management of Pancreatic Cancer

Meghana Singh, MD,¹ Ibrahim Halil Sahin, MD²

¹ Department of Medical Oncology, West Virginia University
² Division of Hematology and Oncology, University of Michigan

Approximately 90% of PDAC tumors harbor oncogenic RAS mutations, with over 80% involving KRAS codon 12 substitutions (G12D, G12V, G12R). For decades, RAS was considered “undruggable.” KRAS G12C inhibitors (sotorasib, adagrasib) while provided proof of concept but were limited to the rare 1–2% of PDAC tumors harboring G12C mutations, with modest efficacy.

Daraxonrasib (RMC-6236) represents a fundamentally different approach. It is an oral, potent, RAS(ON) multiselective inhibitor targeting the active GTP-bound state of mutant and wild-type RAS across all three canonical isoforms (KRAS, NRAS, HRAS), including G12, G13, and Q61 variants. This multiselective mechanism offers comprehensive RAS on inhibition compared to G12C inhibitors, which target only the inactive GDP-bound state of a single mutation variant.

The RASolute 302 trial included patients with metastatic PDAC who had progressed on one prior line of therapy, either a fluoropyrimidine or gemcitabine-based regimen. Participants were randomized to receive investigator-choice SOC chemotherapy or single-agent Daraxonrasib at 300 mg daily dosing. The dual primary endpoints are mOS and PFS in the RAS G12-mutant population. Key secondary endpoints are median OS and pFS in the overall population. Darasonrasib resulted in significant improvement in overall survival with median OS of 13.2 months compared to 6.6 months with chemotherapy (HR 0.40, p<0.001).

Median PFS also improved to 7.3 months in the Daraxonrasib arm compared to 3.5 months in the chemotherapy arm (HR 0.45, p<0.001). Similar outcomes were noted in the overall population as well, meeting the key secondary endpoints. As for patient-reported outcomes, daraxonrasib was associated with a significant delay in time to deterioration in pain and global health/quality of life compared to chemotherapy.

This trial demonstrated robust hazard ratios indicating superiority over SOC, with benefits noted in the RAS G12-mutated and overall populations. Daraxonrasib will become the new standard of care for second-line metastatic PDAC, pending the regulatory review process for approval. The greatest benefit was observed in patients with RAS G12 mutations (91.8% of the trial population). Among the small subgroup of 41 patients with non-codon 12 RAS mutations, the OS HR still favored daraxonrasib (0.37), whereas the PFS favored chemotherapy (HR 1.38). Although this is scientifically to be further investigated particularly impact on non-codon 12 RAS mutations on disease biology, this should also be cautiously interpreted due to small cohort size for this population. Overall, the magnitude of OS and PFS benefit was highly impactful for a disease, where there was a major unmet need for drug development. It is important to note that the open-label design may have influenced AE reporting and treatment decisions. Notably, 15.1% of patients randomized to chemotherapy never received treatment, most by patient choice, potentially biasing OS against the chemotherapy arm. Subgroup analyses for uncommon RAS subtypes were exploratory and limited by small sample sizes

Daraxonrasib (RASolute 303) is currently being investigated as a frontline therapy with and without chemotherapy, and this is particularly important due to the fact that only about half of patients with metastatic PDAC receive second-line therapy. The tumor regression and duration of response noted in RASolute 302 also supports investigation in earlier-stage disease, including perioperative settings, to enhance resectability and cure rates in this aggressive biology.

Treatment-related adverse events of any grade were observed in all patients. The most common adverse events leading to dose reductions in the daraxonrasib group were dermatologic toxicities, including rash, as well as stomatitis. Notably, 43.6% of patients experienced grade 3 or higher adverse events, and treatment discontinuation due to adverse events occurred in two patients. As daraxonrasib moves toward broader clinical use, optimization of supportive care strategies will be essential. Recommended prophylactic measures include oral tetracycline antibiotics (doxycycline or minocycline), topical corticosteroids for rash prevention and management, sun protection, chlorhexidine mouth rinses.

It is important to note that, although the clinical activity of daraxonrasib is highly promising, its significant dermatologic toxicity may limit its utility in other malignancies, such as colorectal cancer, where anti-EGFR therapy has historically been required when targeting the RAS–MAPK pathway. This concern may be less pronounced with pan-RAS inhibitors, which also suppress wild-type RAS signaling. However, it remains unclear whether allele-specific KRAS or NRAS inhibitors, either alone or in combination with anti-EGFR therapy, may ultimately provide more durable responses than pan-RAS inhibition alone.

In addition, baseline EGFR activity may contribute to resistance through activation of the PI3K–AKT–mTOR pathway, which is not directly targeted by pan-RAS inhibitors. While the broad inhibitory profile of pan-RAS agents is clearly advantageous in mitigating certain resistance mechanisms, comparative data evaluating the durability of response achieved with pan-RAS versus allele-specific RAS inhibitors—with or without concomitant anti-EGFR therapy—will be critical in defining the optimal therapeutic strategy for colorectal cancer, as well as pancreatic cancer and other RAS-mutant malignancies. This question is particularly relevant in light of the marked heterogeneity in clinical outcomes observed across specific RAS alleles in the RASolute 302 study.

Conclusion

The RASolute 302 trial marks a transformative moment in pancreatic cancer therapeutics. For the first time, a targeted therapy has doubled overall survival compared to standard chemotherapy in second-line metastatic PDAC. Daraxonrasib validates the RAS(ON) inhibitor approach and establishes a new standard of care, pending regulatory approval. The next steps include first-line combinations, perioperative strategies, resistance-overcoming combinations, and expansion to other RAS-driven cancers. As RAS targeting changes the paradigm for several cancers and brings hope for our patients, several questions about the right strategy remain to be investigated further.