In second-line metastatic PDAC, daraxonrasib monotherapy at 300 mg QD delivered a confirmed ORR of 35% in KRAS G12X tumors (n=26) and 29% across any RAS mutation (n=38), with DCR of 92% and 95%, median PFS of 8.5 and 8.1 months, and median OS of 13.1 and 15.6 months, respectively, after 16.7 months median follow-up. In first-line metastatic PDAC, initial monotherapy data showed a 47% ORR and 89% DCR at 9.3 months median follow-up (n=38 evaluable), while the combination of daraxonrasib 200 mg QD plus gemcitabine/nab-paclitaxel on Days 1 and 15 achieved a 55% ORR and 90% DCR at 6.9 months median follow-up (n=31 evaluable). Safety was consistent with prior experience, with no new signals; mean dose intensity was 85% for first-line monotherapy and 81% for the combination.
The core development moves are twofold. First, the company’s second line registrational study (RASolute 302) of daraxonrasib monotherapy is on track to complete global enrollment this year, setting up a 2026 readout. Second, based on the early first-line signals, a three-arm global Phase 3 (RASolute 303) is slated to start in Q4 2025, testing daraxonrasib monotherapy and daraxonrasib plus chemotherapy against a gemcitabine/nab-paclitaxel control. The chemotherapy schedule in combination is every two weeks rather than the conventional weekly regimen, intended to preserve daraxonrasib dose intensity while keeping toxicity competitive with standard chemotherapy.
Strategically, this is a bid to anchor a RAS-targeted franchise across both first- and second-line PDAC by leveraging a multi-selective RAS(ON) inhibitor that captures the breadth of RAS mutations prevalent in this disease. The three-arm first-line design hinges on the central question sponsors face in PDAC: can a targeted oral agent substitute for chemotherapy in the frontline, or is combination therapy the pragmatic route to durable benefit and regulatory acceptance? By running monotherapy and combination arms in parallel, the program preserves optionality for labeling while generating a clean, contemporary comparison to gemcitabine/nab-paclitaxel. The nonstandard Day 1/15 chemotherapy cadence is a calculated operational choice to enable continuous RAS suppression rather than dose-dense cytotoxic exposure.
For sites and CROs, two concurrent registrational programs in PDAC will intensify competition for the same patient pool but may ease screening friction. With >90% of PDAC harboring RAS alterations, broad mutation eligibility reduces the biomarker bottleneck seen with allele-specific inhibitors. The oral daily regimen simplifies logistics for monotherapy cohorts. At the same time, the biweekly chemotherapy combination may reduce infusion chair time compared to weekly GnP, although it introduces protocol-specific scheduling and safety monitoring nuances. Central lab strategies, acceptance of local RAS testing, and turnaround expectations will significantly impact first-line accrual when treatment initiation windows are tight. For regulators, the key methodological question will be whether OS or PFS drives the first-line primary endpoint and how a modified GnP schedule will be weighed against standard-of-care comparators.
What to watch next: durability and survival. The first-line datasets remain immature; the true differentiation will come from depth and duration of response, time on treatment, and ultimately OS. The combination uses a lower daraxonrasib dose than monotherapy, raising the typical exposure-versus-tolerability trade-off. Trial design details for RASolute 303—primary endpoint selection, stratification by ECOG and disease burden, allowance of local versus central RAS testing, and geographic site mix—will signal regulatory posture and operational risk. With multiple KRAS-directed agents advancing in PDAC, site congestion and crossover could complicate the interpretation of results. If the second line Phase 3 confirms the long-term signal in 2026, the first line program will need to show that monotherapy can hold its own against chemotherapy—or that the combination delivers enough incremental benefit to justify added complexity.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
