By Julie Steenhuissen

CHICAGO, May 31 (Reuters) - An experimental drug made by Revolution Medicine to treat pancreatic cancer more than doubled survival rates compared to chemotherapy and relieved symptoms enough that some patients were able to resume activities they had stopped, researchers said on Sunday, setting a new standard for this deadly form of cancer.

The trial tested the effect of taking one pill of the experimental drug daily compared to conventional chemotherapy on patients who had not received positive results from a single round of chemotherapy.

The full results of the trial, which involved 500 patients, showed that the drug daraxonrazeb reduced the overall risk of death from this tumor by 60 percent compared to patients with advanced pancreatic cancer who received chemotherapy.

According to the results of the study presented Sunday to the American Society of Clinical Oncology, the treatment halted or reduced tumor progression by nearly a third overall, compared to only 10 percent among those who received chemotherapy.

Dr. Rachna Shroff, a pancreatic cancer expert at the University of Arizona Cancer Center and the American Society of Clinical Oncology, described the new experimental drug as "meeting all the criteria," noting that improvements such as doubling the survival rate and reducing the risk of death in patients whose cancers had worsened after chemotherapy constitute an unprecedented development.

Preliminary results released on April 13 showed that the drug increased the time between diagnosis and patient death to 13.2 months compared to 6.7 months for those receiving standard chemotherapy, leading to a 40 percent rise in the company's shares.

"These results will change the way scientists, doctors, and patients think about treating pancreatic cancer," said Dr. Brian Wolpin of Harvard University's Dana-Farber Cancer Institute, the lead researcher on the trial.

Skin rash was one of the main concerns regarding the drug's side effects, with 86.3 percent of patients experiencing it, but Wolpin said it could be largely controlled with antibiotics and topical steroids.

* Expanding the scope of interest

Pancreatic cancer is one of the deadliest forms of cancer. The American Cancer Society estimates that approximately 68,000 Americans will be diagnosed with pancreatic cancer this year, and expects about 53,000 of them to die from it.

Typically, no more than three percent of patients who survive five years after their pancreatic cancer has spread to other organs in the body are diagnosed at an advanced stage, or a stage at which the disease begins to spread.

Revolution Medicine CEO Mark Goldsmith said the company is already testing daraxonraceb in earlier stages of the disease with other treatments in the hope of increasing its effectiveness in achieving a "significant rise" in survival rates.

Dr. Shubham Pant, the lead researcher involved in the trial at MD Anderson Cancer Center, said one of his patients, an avid golfer, had to give up the sport, but was able to reduce his reliance on painkillers to cope with the symptoms of the disease and resume playing golf a month after receiving the new treatment. "I have many patients in the same situation," he said.