Cancer drug tested at UC Davis offers new hope for patients

A groundbreaking drug that was tested on lung cancer patients at UC Davis Medical Center has been shown to greatly improve survival rates, so much so that the study has been cut short and the drug is being fast-tracked for Food and Drug Administration approval.

Keytruda is being looked at as a first line of treatment for patients with non-small-cell lung cancer. A Phase III clinical trial testing Keytruda was so successful that manufacturers called an end to the study and will now be administering the drug to everyone in the trial, according to a news release from manufacturer Merck & Co. on Thursday.

The trial began in August 2014 with 305 cancer patients from all over the world, including five from UC Davis, said Dr. David Gandara, director of the center’s thoracic oncology program. Patients in the control group, who were previously treated with chemotherapy, can now switch to Keytruda.

While specific trial results have not been released, the news release said patients on Keytruda showed longer progression-free periods and higher rates of overall survival than their counterparts in the control group. It’s only a matter of time until the drug receives FDA approval as a first line of treatment for certain patients, which would mean they could bypass chemotherapy entirely, Gandara said.

“They would not have done that if the results were not very impressive,” Gandara said of the trial closing. “We know that it’s positive, and it will undoubtedly now make immunotherapy the first line of treatment for patients with metastatic lung cancer.”

Oncologists worldwide have been awaiting the approval of an immunotherapy drug that can be administered instead of chemotherapy, Gandara said. Keytruda has been FDA-approved for lung cancer treatment since 2015, but only after chemotherapy fails.

Many physicians prefer immunotherapy because it is less toxic and better tolerated by patients. Compared with chemotherapy, which floods the body with anti-cancer drugs that also kill healthy cells, immunotherapy is much more targeted.

“Some patients don’t survive chemotherapy,” he said. “They die and don’t get to try immunotherapy. What this means is that the first line a doctor can offer will be immunotherapy. It’s a total game changer.”

Some lung cancer patients have a high concentration of PD-L1 proteins on their T cells, which inhibits those cells from recognizing and fighting cancer. When Keytruda disables the PD-L1 proteins, the T cells become free to attack the cancer cells growing in the lungs.

“These are drugs that work by a totally different mechanism from anything we’ve had in the past,” Gandara said. “This protein is the screen the stealth bomber uses to keep radar from detecting it. ... If you block the PD-L1, that allows the T cells to identify the cancer and go destroy it.”

This story was originally published June 19, 2016 at 2:30 PM with the headline "Cancer drug tested at UC Davis offers new hope for patients."