The Food and Drug Administration on Wednesday approved Rasonque, a once-daily pill developed by Revolution Medicines that blocks several forms of the RAS protein — the mutation that drives tumor growth in most pancreatic cancers and in roughly a quarter of all human cancers overall.

The approval covers adults with metastatic pancreatic adenocarcinoma who have already tried one round of treatment or cannot receive combination chemotherapy, and it does not require a test to identify a specific RAS mutation first. (Adenocarcinoma is cancer that begins in glandular cells — the cells that line organs and produce substances like mucus, digestive enzymes, or hormones. It is one of the most common cancer types overall, and in the pancreas specifically it accounts for 90% to 95% of all cases.)

For investors like Dr. Danish Nagda, an early shareholder in Revolution, the approval matters less for what it does in pancreatic cancer than for what it proves: that a mechanism long considered “undruggable” finally works — and works in one of oncology’s hardest cases. For physicians and patients, it also marks a rare expansion of treatment options in a disease where survival gains have lagged far behind other cancers and where many people are diagnosed only after the cancer has already spread.

Brian Wolpin, the trial’s principal investigator and director of the Hale Family Center for Pancreatic Cancer Research at Dana-Farber Cancer Institute, said the approval “gives physicians the confidence that directly inhibiting RAS can make a striking difference for patients.” Anna Berkenblit of the Pancreatic Cancer Action Network called it “the most significant advance we have seen in the fight against pancreatic cancer.”

Fast-tracked FDA review

The decision came 6.5 months before the FDA’s user-fee deadline, aided by new changes at the agency that let international regulators review oncology applications alongside the FDA. “This drug showed unprecedented results in an area of high unmet need,” said Angelo de Claro, director of the FDA’s Oncology Center of Excellence.

The application was reviewed under the FDA’s National Priority Voucher pilot program, and the drug also carries Breakthrough Therapy and Orphan Drug designations — statuses that help explain the compressed review timeline.

In the trial that led to approval, patients with previously treated metastatic pancreatic adenocarcinoma who took the drug lived a median of 13.2 months, compared with 6.7 months on standard chemotherapy, according to the company. Rasonque cut the risk of death by 60%, and patients went longer before their disease progressed and before pain and quality-of-life measures worsened.

The drug targets a mutation in the KRAS gene found in nearly all pancreatic cancers and in many cases of lung, colorectal, and ovarian cancer. Revolution Medicines is already advancing daraxonrasib through late-stage lung cancer trials, giving the approval relevance beyond one tumor type because the same pathway is implicated across multiple solid cancers.

Revolution Medicines set a list price of $39,800 for a 30-day supply, with eligible insured patients paying as little as $0 through a new support program. An expanded access program that opened in May has already reached more than 2,000 patients.

Why oncologists call it a breakthrough

The stakes explain why oncologists are calling this a breakthrough rather than an incremental gain. Pancreatic cancer kills a disproportionate share of the people who develop it: an estimated 67,530 Americans will be diagnosed in 2026, and about 52,740 will die from it, according to the American Cancer Society’s Cancer Statistics 2026 report. It is the third-leading cause of cancer death in the U.S. and the only major cancer with a five-year survival rate below 20% — a rate stuck at 13% for three years running even as survival across all cancers combined has reached 70%. About 80% of patients are not diagnosed until the cancer has spread, Revolution Medicines said, and for them, five-year survival runs around 3%.

“An entire platform to go after RAS”

“This to me is incredibly exciting,” Nagda told Fortune. “I’m obviously a shareholder of RVMD. I’ve been very, very bullish on RVMD.”

RAS mutations appear in roughly a quarter of all human cancers, Nagda said. “Think about how big of a platform this is,” he said. “Instead of developing one drug for just pancreatic cancer, they’ve actually built an entire platform to go after this core issue called RAS.”

RAS was long considered too difficult to target directly, Nagda said. “You didn’t know how to shut it off, and this was a big issue.” He described the mutation as a kind of switch: “There is a turn — the mutation that occurs is an on switch of RAS, which makes the cancer grow faster. So essentially what they do is they go after this RAS-on inhibitor. They’re literally turning the on switch off.”

Because pancreatic cancer is among the hardest cancers to treat, Nagda said, proving the drug works there is significant. “It works in the worst one, which is pancreatic cancer,” he said. “So now we know that this could really work for everyone.” He said the approval means the drug can now be prescribed off-label for other cancers, and he predicted heavy use beyond its approved indication. “I expect off-label utilization of this to go wild,” he said.

Nagda drew a contrast with the mRNA cancer vaccines he discussed with Fortune in coverage of Moderna and Merck’s melanoma trial results. Those vaccines work by finding antigens on the surface of a cancer cell, he said, comparing the approach to targeting the spike protein in COVID-19 vaccines. “This affects the inside. It affects the molecular aspect of the cell,” he said. “So now we can attack the cell on its surface, and now we can attack the cell on the inside.”

Nagda predicted the two approaches, paired together, could transform cancer treatment within the decade. “I think we are within five years of us having combination therapies that essentially get rid of the cancer,” he said. “We are maybe half a decade away from the post-cancer era.”

This story was originally featured on Fortune.com.