The Food and Drug Administration on Wednesday approved a groundbreaking new drug for the most common form of pancreatic cancer, offering U.S. patients a more effective treatment against one of the deadliest types of cancer.

FDA officials gave expedited approval to the first-of-a-kind pill, called daraxonrasib, that blocks a mutated protein that fuels tumoUr growth in more than 90% of pancreatic cancer cases. It’s an approach that previously eluded drugmakers for decades.

The daily pills will be sold by Revolution Medicines under the brand name Rasonque.

Patients taking the drug nearly doubled their survival time, with fewer severe side effects, in a study that randomly assigned them to receive the experimental treatment or more chemotherapy. The company-funded study enrolled 500 patients whose metastatic, or spreading, cancer had quit responding to prior treatment.

Patients getting the new treatment lived for a median of 13.2 months compared with 6.7 months for chemotherapy recipients.

“This is not a cure, it’s one more option for these patients,” said Dr Pashtoon Kasi of City Hope Orange County, a California-based cancer centre. “But it’s the best option we’ve ever had.”

Pancreatic cancer is among the most deadly forms in large part because it is hard to detect before it starts spreading to other organs. The American Cancer Society estimates about 67,000 new cases will be diagnosed in the United States this year and more than 52,000 people will die from the disease. The five-year overall survival rate is 13%.

The drug garnered public attention earlier this year when former Sen. Ben Sasse, R-Neb., described on CBS’ “60 Minutes” how he has had less pain while taking it. A surge in public interest led the FDA to allow “expanded access,” before the drug’s official approval, for patients who met certain criteria.

FDA regulators noted on Wednesday that they approved the drug more than six months ahead of their target date.

“It is our fundamental duty to deliver more cures and meaningful treatments to patients as quickly as possible,” the FDA’s acting commissioner, Kyle Diamantas, said in a statement.

Unlike with other cancers that have benefited from a variety of chemotherapy alternatives, pancreatic cancer has been harder to tackle.

The new drug targets mutations in the RAS gene family that normally regulates cell growth. What are known as KRAS mutations are especially critical in fueling pancreatic cancer. But a structure that made it hard for drugs to stick to the mutated proteins meant this cancer driver was long considered “undruggable.”

Doctors who treat pancreatic cancer hope the drug may usher in more new options for other forms of cancer, with scores of experimental drugs in development.

“I think this has opened doors for many other companies,” Kasi said. “Downstream I think there are going to be a lot more trials looking at this approach in other tumour types.”

Revolution Medicines’ drug uses what’s essentially a molecular glue to bind with multiple KRAS subtypes. The Redwood City, California-based drugmaker is studying its technology for several other forms of cancer, including lung cancer.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.