For more than four decades, oncologists have known that a single protein drives nearly all pancreatic cancers, and for just as long, they have had no way to shut it off. The protein, KRAS, mutates in roughly 90% of pancreatic adenocarcinomas, fueling tumor growth through a signaling cascade that resists conventional chemotherapy. Every attempt to drug KRAS directly failed so thoroughly that researchers gave the target a grim nickname: undruggable.
That label is now being tested. The FDA has authorized an Expanded Access treatment protocol for daraxonrasib (RMC-6236), a multi-RAS inhibitor developed by Revolution Medicines (NASDAQ: RVMD). The authorization allows patients with advanced pancreatic cancer who have exhausted standard treatments and cannot enroll in a clinical trial to receive the investigational drug under physician supervision. Full Phase 1/2 results from the compound’s ongoing trial are scheduled for presentation at the American Society of Clinical Oncology (ASCO) annual meeting on Sunday, June 1, 2026, a disclosure that could reshape the treatment landscape for one of the deadliest cancers in medicine.
Why KRAS has been so hard to target
KRAS belongs to the RAS family of proteins, molecular switches that toggle between “on” and “off” states to regulate cell growth. When KRAS mutates, it gets stuck in the “on” position, sending constant growth signals that drive tumor formation. The protein’s smooth, pocket-free surface gave drug designers almost nothing to grab onto, and decades of screening campaigns came up empty.
A breakthrough arrived in 2021 when the FDA approved sotorasib (Lumakras) for non-small cell lung cancer harboring a specific KRAS G12C mutation. Adagrasib (Krazati) followed in 2022 for the same target. But those drugs were engineered for a mutation found in about 13% of lung cancers and only 1% to 2% of pancreatic tumors. The KRAS variants that dominate pancreatic cancer, primarily G12D and G12V, remained untouched.
Daraxonrasib takes a fundamentally different approach. Rather than locking onto a single mutant form, the compound inhibits multiple active-state RAS proteins, covering the G12D and G12V variants that together account for the majority of KRAS-mutant pancreatic adenocarcinomas. That broader mechanism is what makes the drug the first investigational therapy to directly target the dominant KRAS mutations in pancreatic cancer.
What the FDA’s authorization actually means
Expanded Access, sometimes called compassionate use, is not approval. It sits well below that threshold on the regulatory ladder. The FDA permits it when three conditions are met: the patient has a serious or life-threatening condition, no comparable alternative therapy exists, and the potential benefit justifies the potential risks based on available evidence.
In practical terms, the agency reviewed safety and early efficacy data from daraxonrasib’s Phase 1/2 trial and determined that the drug could be administered outside the controlled trial setting without unacceptable risk. The authorization establishes a structured protocol with investigator oversight and mandatory safety tracking, but it does not specify how many patients will be treated, how many clinical sites will participate, or what outcomes have been observed so far under expanded access.
For context, advanced pancreatic cancer carries a five-year survival rate below 5% when diagnosed at a distant stage, according to the National Cancer Institute’s SEER database. Standard treatment typically involves combination chemotherapy regimens such as FOLFIRINOX (fluorouracil, leucovorin, irinotecan, and oxaliplatin) or gemcitabine with nab-paclitaxel. Both regimens extend survival modestly but rarely produce durable responses. The unmet need is enormous, and it explains why regulators moved to open an expanded access pathway before Phase 1/2 data have even been fully presented.
The clinical evidence behind the decision
The primary clinical data come from a Phase 1/2 study registered on ClinicalTrials.gov as NCT05379985 (study designation RMC-6236-001). The trial uses a dose-escalation and dose-expansion design: the first phase identifies the safest effective dose range across patients with various RAS-mutant solid tumors, and the second phase tests that dose in specific tumor types, including a dedicated pancreatic cancer cohort.
Peer-reviewed results published in the New England Journal of Medicine describe the drug’s antitumor activity in previously treated patients, documenting tumor responses in heavily pretreated individuals whose cancers had progressed on standard chemotherapy. That publication provided the scientific foundation for the FDA’s expanded access decision.
However, the NEJM paper and the ClinicalTrials.gov record leave several critical questions open. Long-term survival data for the pancreatic cancer cohort have not been publicly reported. Durability of response, meaning how long tumors stay shrunk after initial response, has not been broken out for pancreatic patients specifically. And detailed adverse-event profiles at the recommended Phase 2 dose remain under wraps ahead of the ASCO presentation.
Those gaps matter. Oncologists weighing whether to pursue expanded access for a given patient need granular safety data to compare daraxonrasib’s risk-benefit profile against existing chemotherapy regimens. A drug that shrinks tumors but causes severe toxicity in a frail, heavily pretreated population may not represent a meaningful advance. Sunday’s ASCO presentation is expected to fill in many of these blanks.
The competitive landscape around KRAS
Daraxonrasib is not the only program chasing KRAS mutations beyond G12C. Eli Lilly is developing a KRAS G12D-specific inhibitor, and several biotech companies have disclosed preclinical or early-stage clinical programs targeting other RAS-family variants. But daraxonrasib’s multi-RAS mechanism and its advanced clinical stage in pancreatic cancer give it a lead that competitors have not yet matched in published data.
Revolution Medicines has positioned the drug as a potential backbone therapy, one that could eventually be combined with other agents such as immunotherapies or targeted drugs to deepen responses. Whether that vision holds will depend heavily on the data presented at ASCO and on subsequent randomized trials comparing daraxonrasib-based regimens to current standards of care.
What Sunday’s ASCO presentation needs to show
The ASCO disclosure will be the most comprehensive public look at daraxonrasib’s performance in pancreatic cancer to date. Oncologists and analysts will be watching several specific metrics:
- Objective response rate (ORR) in the pancreatic cancer cohort at the recommended Phase 2 dose. A response rate meaningfully above what second-line chemotherapy delivers (typically in the single digits) would be a strong signal.
- Duration of response (DoR), which will indicate whether tumor shrinkage is transient or sustained long enough to translate into a survival benefit.
- Progression-free survival (PFS) data, even if immature, to give a sense of how long patients stay on therapy before their disease advances.
- Safety and tolerability at the Phase 2 dose, including rates of dose reductions, treatment discontinuations, and any serious adverse events that could limit the drug’s use in a fragile patient population.
If the data are strong, Revolution Medicines could pursue accelerated approval from the FDA, a pathway that allows drugs to reach the market based on surrogate endpoints like tumor response rate before long-term survival data are available. If the data are mixed, the company may need to run a larger, randomized Phase 3 trial before seeking approval, adding years to the timeline.
What this means for patients right now
For people living with advanced pancreatic cancer driven by KRAS mutations, the expanded access authorization opens a door, but a narrow one. Eligibility is limited to patients who have run out of standard options and cannot participate in the ongoing clinical trial. Treatment must occur under the supervision of a qualified investigator at a participating site, and patients will be monitored under a structured safety protocol.
Expanded access does not create a commercial supply chain or guarantee long-term availability. If the ASCO data disappoint or if unexpected safety signals emerge, the program could be modified or withdrawn. Conversely, strong results could accelerate the path to formal approval and broader access.
The practical step for patients and their oncologists is to contact Revolution Medicines or check ClinicalTrials.gov for information on expanded access eligibility and participating sites. The company’s medical information line and the trial’s principal investigators can provide guidance on whether a specific patient’s clinical situation fits the protocol’s criteria.
After 40 years of calling KRAS undruggable, the field is finally running a real-world test of whether that label was permanent or just premature. Sunday’s data will go a long way toward answering that question.
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*This article was researched with the help of AI, with human editors creating the final content.
