Technically, stage 4 lung cancer doesn’t have a cure. But with the advent of immunotherapy, some patients with stage 4 non-small cell lung cancer are living for years with their disease in check.
After a decade or so of not much progress for lung cancer, doctors and researchers are using words like “game changer,” “a new era,” and even, with cautious optimism, “cure” to describe the recent advances in immunotherapy.
“I think that we’re just seeing the tip of the iceberg for how these types of treatments can improve these patients’ lives—from those with metastatic cancer to an earlier stage disease—in the hopes that we can increase the chance of cure,” says Dr. Julie Brahmer, Co-Director of the Upper Aerodigestive Department at the Bloomberg~Kimmel Institute for Cancer Immunotherapy at the Johns Hopkins Kimmel Cancer Center, who spoke with HealthCentral in a phone interview.
Dr. Thomas Marron, Assistant Director of Early Phase and Immunotherapy Trials at the Tisch Cancer Institute and an Assistant Professor of Medicine at the Icahn School of Medicine at Mount Sinai, says some of his patients have even completed two years of immunotherapy, been taken off, and have been living off therapy for two years.
“The majority of people on the current regimens are still going to die of lung cancer, but they’re living longer—and it appears that about 10 to 20 percent are being cured,” says Dr. Marron, who also spoke to HealthCentral in a phone interview.
When Dr. Marron was in med school and grad school in the 2000s, immunotherapy seemed so far-fetched that people joked about it being a cure. Then in 2014 came the first FDA approval of an immunotherapy drug targeting a protein found on certain immune cells called PD-1, for use after chemotherapy. Now, every few weeks seems to bring about a new development in how the drugs can be used. There have been 35 approvals so far, Dr. Marron notes.
The promise of immunotherapy doesn’t necessarily mean the end of chemo for all lung cancer patients. “In many cases, it’s the synergy between the chemo and the immunotherapy that produces results,” Dr. Marron says. “The chemo is sometimes needed to activate the immune system. And in some cases, single-drug immunotherapy directed at PD-1 or PD-L1 proteins doesn’t seem to help.”
But in other cases, immunotherapy works so well that patients can skip chemotherapy altogether. One of the recent studies showed that if at least 50 percent of tumor cells are positive for PD-L1, it’s better to use the immunotherapy drug pembrolizumab, alone than standard chemotherapy as a first-line treatment. That’s because PD-L1 is a marker of how well a patient is likely to respond to immune therapy. Think of PD-L1 as a stop sign, Marron explains, that prevents your immune system from attacking the tumor. Pembrolizumab is able to tear down those stop signs, so that your own immune system can get through and kill the cancer cells creating the tumor.
“It’s the immune system’s way of spreading the word to party in the tumor,” Dr. Marron says.
Other studies have shown that for tumors with lower levels of PD-L1, a combination of chemo and immunotherapy works best.
There’s still much research to be done on other protein markers besides PD-L1. When immunotherapy isn’t balanced just right, the immune system can get overactivated, resulting in toxicity.
“The holy grail is to find the combination of the most efficient and least toxic, and we’re not quite there yet,” Dr. Marron says.
While some of the new treatment options are life-changing, the excitement needs to be tempered with a dose of reality, Dr. Brahmer says.
“While this gives great hope, not everyone is suited to receiving these drugs,” she says. “So talking with your primary physician and working with an experienced team is very important.”