Promising results from a clinical trial show more patients with advanced non-small-cell lung cancer could benefit from the immunotherapy drug pembrolizumab. In the trial, compared with chemotherapy, the immunotherapy drug improved survival in all patients whose tumors express a protein called PD-L1.

Results from the phase 2/3 trial – published in The Lancet – were presented at the first European Society for Medical Oncology (ESMO) Asia Congress in Singapore earlier this week.

An immunotherapy cancer drug works by getting the immune system to fight the cancer. Pembrolizumab (brand name Keytruda), is already approved by the Food and Drug Administration (FDA) for the treatment of certain categories of advanced non-small-cell lung cancer (NSCLC) and advanced melanoma.

 

Pembrolizumab is an antibody drug that targets a cellular pathway called PD-1/PD-L1. PD-1 is a receptor, and PD-L1 is one of the molecules that binds to it. The pathway is an example of what is called an immune checkpoint.

Many cancers are able to avoid attack from a patient’s immune system by overriding their “immune checkpoints” – molecules on immune cells that need to be activated or silenced to start an immune response.

By blocking the PD-1/PD-L1 pathway, pembrolizumab may boost the immune system’s ability to fight the cancer cells.

Pembrolizumab is shown to be effective against various types of cancer, including melanoma and lung cancer, where it has shown durable anti-tumor activity and acceptable toxicity in previously treated and untreated patients with advanced NSCLC.

The new trial is the first to assess the effectiveness of the immunotherapy drug as a second or later line treatment in advanced NSCLC patients positive for PD-L1.

The trial – called KEYNOTE-010 – tested two doses of pembrolizumab against the commonly used chemotherapy drug docetaxel in patients with tumors expressing PD-L1.