Immunotherapy Shows Promise, Destroys Metastatic Brain Tumors

Lung cancer is the leading cause of death in both men and women in the U.S., with smokers bearing an elevated risk of the disease. This form of cancer can be asymptomatic in the early stages, escaping detection until it has progressed to an advanced stage, where it can spread, or metastasize, to other regions in the body.

A team of cancer researchers at Yale have published their findings on a promising therapeutic strategy targeting a subset of lung cancer patients with brain metastases. For these patients, which account for about a quarter of all those diagnosed with lung cancer, radiation is often prescribed — a treatment that has significant side effects. The study was published in The Lancet Oncology.

Corresponding author, Sarah Goldberg, Assistant Professor of Medical Oncology at the Yale School of Medicine works as a clinician in the Thoracic Oncology group at the Yale Cancer Center and conducts research on new therapeutic strategies against lung cancer. 

Here, a cohort of 42 patients were selected for the trial, all of which had brain metastases that had not responded to radiology or had not received treatment. The immunotherapy tested was pembrolizumab (sold under the trade name Keytruda®), a monoclonal antibody administered to patients whose cancers expressed the biomarker PD-L1. Significantly, this checkpoint inhibitor therapy extended patient survival and had drastically fewer side effects than radiation.

Speaking on the significance of the study, Goldberg said, “We have clearly shown, for the first time, that brain metastasis responds to a targeted immunotherapy treatment for lung cancer.” 

“In general, we found that the benefit offered by pembrolizumab to the lungs in patients with advanced lung cancer was mirrored in control of their brain tumors. The brain and body response were the same.”

Interestingly, patients whose brain tumors expressed high levels of PD-L1 experienced longer lasting positive effects from the pembrolizumab therapy, a finding that warrants further investigation.

These results point to a need to reassess the gold standard therapeutic strategies for lung cancer patients with brain metastases. “It might make sense for some patients to try a checkpoint inhibitor first to treat both their lung cancer and brain metastasis. Radiation could follow, if necessary,” said Goldberg.

Sources: Yale News, The Lancet Oncology.