Targeting RAS in Pancreatic Cancer: Emerging Clinical Evidence and the Promise of Next-Generation Inhibitors
Expert Perspectives · Lyn Brook · 2026-06-01
Pancreatic cancer remains one of the most challenging malignancies in oncology, with limited therapeutic options and historically poor outcomes. However, recent advances in targeting rat sarcoma (RAS)—long considered an “undruggable” oncogenic driver—are beginning to shift the treatment landscape. In this discussion, Waqas Haque, MD, MPH, sat down with Christos Fountzilas, MD, FACP, a Gastrointestinal (GI) Medical Oncologist and early-phase clinical trial investigator at Roswell Park Comprehensive Cancer Center, to highlight emerging data on pan-RAS inhibition, biomarker-driven strategies, and the evolving role of targeted therapies in pancreatic cancer.
From “Undruggable” Target to Therapeutic Opportunity
For decades, RAS mutations have been recognized as central drivers of multiple solid tumors, particularly pancreatic ductal adenocarcinoma. Yet efforts to directly inhibit RAS were historically unsuccessful due to structural challenges. As Dr. Fountzilas explained, RAS “was considered to be an undruggable protein” with few accessible binding sites.
This paradigm began to shift with the development of KRAS G12C inhibitors, which exploit a transient binding pocket in the inactive state of the protein. While these agents have demonstrated clinical activity, particularly in non–small cell lung cancer, their applicability in pancreatic cancer is limited due to the low prevalence of KRAS G12C mutations in this disease.
The development of broader strategies, including pan-RAS inhibitors and agents targeting multiple RAS isoforms, represents a critical next step. These newer therapies aim to overcome the limitations of mutation-specific inhibitors and expand treatment options for a wider population of patients.
Clinical Trial Spotlight: Pan-RAS Inhibition in Metastatic Disease
Dr. Fountzilas served as an investigator in the phase 3 RASOLUTE trial, which evaluated the investigational pan-RAS inhibitor daraxonrasib compared with standard chemotherapy in patients with metastatic pancreatic cancer who had received one prior line of therapy. The study was designed to assess improvements in progression-free survival and overall survival.
Although full peer-reviewed results are pending, early signals are encouraging. “We know a high-level outcome—it is a positive study with a very impressive signal,” Dr. Fountzilas noted. Supporting evidence from phase 1/2 data further underscores the drug’s activity, with an overall response rate of approximately 30% and median progression-free survival in the range of seven to eight months. These outcomes are comparable to, and in some cases may exceed, those seen with first-line chemotherapy regimens.
Importantly, these findings suggest that pan-RAS inhibition may represent a meaningful therapeutic advance in a disease setting where options remain limited.
Biomarker Testing and Patient Selection
A key component of advancing targeted therapies in pancreatic cancer is comprehensive biomarker testing. Dr. Fountzilas emphasized the importance of early and thorough molecular profiling at the time of diagnosis of advanced disease.
“We do test for both the tumor and the blood for somatic mutations from the very beginning,” he said. This includes evaluation of tumor mutation burden, microsatellite instability, and MTAP loss, along with both tissue-based and liquid biopsy approaches. Utilizing both modalities helps mitigate challenges such as insufficient tissue samples or low tumor DNA shedding.
In addition to somatic profiling, germline testing remains essential. Patients with BRCA1 or BRCA2 mutations may benefit from platinum-based chemotherapy and maintenance PARP inhibition. “We keep our reviews to all potentially targetable biomarkers,” Dr. Fountzilas explained, highlighting the importance of a comprehensive and proactive approach to molecular testing.
Interpreting Early Data and Managing Toxicities
While enthusiasm around daraxonrasib is growing, Dr. Fountzilas cautioned that clinicians should interpret preliminary results carefully until full phase 3 data and peer-reviewed analyses are available. Key considerations will include patient disposition, censoring patterns, and long-term outcomes.
The safety profile observed in early-phase studies appears manageable, with most adverse events reported as grade 1 or 2. The most common toxicities include gastrointestinal effects such as nausea, vomiting, and diarrhea, as well as mucositis and dermatologic reactions. While GI toxicities are generally familiar to oncology clinicians, skin-related adverse events may present additional management challenges.
“There has to be very clear instructions on how to better prevent and address the skin toxicity,” Dr. Fountzilas noted, emphasizing the need for proactive toxicity management strategies as these agents move closer to clinical practice.
Clinical Trial Implementation and Real-World Considerations
From an operational standpoint, the RASOLUTE trial reflects the importance of multidisciplinary collaboration and careful patient selection. Conducted across international sites, the study required coordinated efforts to identify eligible patients, conduct screening, and manage treatment protocols.
Dr. Fountzilas noted that the trial design was well-aligned with real-world clinical practice, particularly in the second-line metastatic setting. “It was a very well-designed study,” he said, with eligibility criteria that balanced patient safety and feasibility.
He also highlighted the importance of regional access to clinical trials, noting the ability to offer participation to patients in Western New York, an area with a relatively high incidence of pancreatic cancer.
The Future of RAS-Targeted Therapy
Looking ahead, the development of pan-RAS inhibitors may signal a broader turning point in oncology. However, Dr. Fountzilas emphasized that treatment strategies must remain grounded in tumor biology. The role of RAS varies across malignancies, and therapeutic responses may differ accordingly.
For example, while RAS is a central driver in pancreatic cancer, its role in colorectal cancer is more complex, often requiring combination strategies such as EGFR inhibition to achieve meaningful responses. “We always need to take into consideration the disease biology and build rational combinations,” he said.
Despite remaining challenges, Dr. Fountzilas views current progress as a significant milestone. Reflecting on the trajectory of RAS-targeted therapy, he remarked, “It’s not the beginning of the end, but it’s the end of the beginning,” signaling a transition into a new era of therapeutic possibility.
Key Takeaways
RAS, once considered “undruggable,” is now a viable therapeutic target with emerging pan-RAS inhibitors.
Early data for daraxonrasib show promising efficacy in metastatic pancreatic cancer.
Comprehensive biomarker testing (tumor, liquid, and germline) is essential at diagnosis.
Toxicities are manageable but require attention, particularly dermatologic effects.
Future progress will depend on biology-driven strategies and rational combination therapies.
About the Speakers
Christos Fountzilas, MD, FACP, is a Gastrointestinal Medical Oncologist and early-phase clinical trial investigator at Roswell Park Comprehensive Cancer Center. His work focuses on advancing targeted therapies and biomarker-driven treatment strategies in pancreatic and other gastrointestinal malignancies.
Waqas Haque, MD, MPH, is a second-year Hematology/Oncology Fellow at the University of Chicago. He recently completed his Internal Medicine Residency at New York University (NYU) in a Clinical Investigator Track. Dr. Haque has balanced his patient care work with a variety of research projects. During his fellowship training at the University of Chicago, he plans to further his work in innovative clinical trial design, value-based care delivery to cancer patients, and clinical investigation.