Individuals diagnosed with advanced lung cancer rarely survive more than a few years after their diagnosis, but all that may soon change. Two new studies unveiled over the weekend at a conference in Paris, France showed advanced lung cancer patients have a better chance of survival when their chemotherapy is paired with a drug that is designed to turn the body’s immune system against cancer.
According to both trials, 20% of participants who received chemotherapy and the drug Keytruda, which is manufactured by Merck, survived at least five years after their initial diagnosis. That is twice as long as the typical advanced cancer patient. Around 70% of patients who completed two years of treatment were still alive after five years.
The drug Keytruda, or pembrolizumab, was approved to treat lung cancer in 2015, but this is the first time researchers have studied the cumulative effects of the treatment when paired with chemo.
However, the team was quick to point out the limitations of the drug. For every patient that survived beyond the typical timeframe, there were four more who died within a year of their diagnosis.
But the researchers say the results are still remarkable for such a deadly disease.
“It’s wonderful to see,” said Dr. Pasi Jänne, a lung cancer specialist at the Dana-Farber Cancer Institute in Boston, who was not involved in the new research. In lung cancer, “we didn’t have the long-term survivors like you see in breast cancer and other cancers. Now we do.”
Lung cancer is the leading cause of cancer death in the U.S. Around 230,000 Americans were diagnosed with the disease in 2020 alone and 130,000 people died from it. About 80% of patients aren’t diagnosed until after their cancer has spread beyond the lung.
The five-year survival rate for metastatic lung cancer is around 7%.
Dr. Jacob Sands, a volunteer medical spokesperson for the American Lung Association, used a baseball analogy to explain the potential benefits of the drug. He compared it to hitting a single or double. It moves the patient in the right direction and has the potential to score a home run.
“The fact that there’s even a question as to whether or not there are individuals who will never need another treatment again, that’s incredible. That had been a dream 10 years, 5 years ago,” he said. “The fact that we’re seeing that is really extraordinary. Very exciting.”
The news is being celebrated by cancer patients and providers across the country.
Dr. Marina Garassino, who led one of the clinical trials, says there wasn’t a lot she could do for advanced cancer patients when she started her career 25 years ago. Their only option was to undergo harsh chemotherapy, and many of her patients chose to die instead of undergoing treatment.
But cancer treatments have come a long way since then.
Now, lung cancer patients don’t even lose their hair during chemotherapy. “It’s quite well tolerated,” she said.
But combining it with Keytruda can make all the difference. The drug doesn’t compound the side-effects of chemotherapy, Garassino said. However, some patients experienced autoimmune reactions that can easily be treated.
The patients involved in the studies received infusions every three weeks during the two-year treatment period. Most patients were still able to work during this time.
“The quality of life of these patients is quite high,” Garassino said. A shrinking tumor often corresponds with a better quality of life, she said, as breathing eases and weight loss stops.
But it’s still not clear who will benefit from the drug the most, considering the mixed results of the study.
Jänne, who directs Dana-Farber’s Lowe Center for Thoracic Oncology, said he wants to be able to identify who will benefit from the drug and who will not. “We have some ideas, but they’re imperfect,” he said. Jänne added that some patients don’t look like they’re responding to immunotherapy on their first scans, but they turn out to have a great response later. “It’s hard to predict,” Jänne said.
Smokers with advanced lung cancer seemed to fare better on the immunotherapy drug than non-smokers, he added. That’s likely due to the fact that tobacco causes lots of mutations in the cancer, making it easier for the immune system to recognize.
Initially, doctors worried that combining the two approaches “would somehow poison the immune system. That’s been proven wrong,” said Dr. Eric Rubin, senior vice president of clinical oncology for Merck, but that has turned out to be false.
It’s not clear how long the benefits of the new treatment will last or whether these patients will ever be cured of their cancer. But “If the disease hasn’t come back in 5 years that’s a pretty good sign that it may not,” Rubin said.