Immuno-oncology is currently among the most discussed topics in cancer research, and anti-PD-L1/PD-1 antibodies are driving the conversation as some of the most unique anti-cancer therapeutic approaches. But many remain unaware of the science behind this class of treatments that could bring hope to patients facing deadly cancers.
PD-L1 (programmed cell death ligand-1) helps cancerous tumors evade detection by the immune system through binding to the PD-1 receptor on cytotoxic T lymphocytes, also known as T cells. When this happens, T cells are unable to identify and attack cancerous cells, giving the cancer an opportunity to spread. Researchers have identified the so-called pathway between PD-L1 and PD-1 as a target for a new generation of cancer therapies: by disabling interaction between PD-L1 and PD-1, the T cells retain their ability to identify and attack cancerous cells, contributing to the ability of the immune system to fight cancer.
With this evolving understanding of how cancer avoids detection, researchers have several types of approaches to re-enable the immune system, involving different pathways. Two of these pathways are anti-PD-1 antibodies, which interfere with the PD-1 receptor on the immune system’s T cells, and anti-PD-L1 antibodies, which interfere with the PD-L1 receptors. Antibodies inhibiting the PD-1/PD-L1 pathway have shown encouraging antitumor activity across multiple tumor types, such as specific types of bladder cancer, head and neck squamous cell carcinoma, non-small cell lung cancer, pancreatic cancer, liver cancer, renal cell carcinoma, and melanoma.
Clinical studies conducted and ongoing by multiple investigators also suggest the potential for improving treatment efficacy by using a variety of combination approaches, including immunotherapeutic agents that target different pathways, such as PD-L1 and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4). Since PD-L1 and CTLA-4 regulate immune responses by different mechanisms, investigations targeting both checkpoints provide the potential to enhance the effects.
“Each day, our scientists are gaining a more thorough understanding of what drives cancers: how they spread and avoid detection by the immune system,” said Andrew Coop, Vice President, Medical Affairs, Oncology at AstraZeneca US. “We are at the precipice of potential new treatment paradigms — with the potential to make a meaningful difference for patients who have limited options. At AstraZeneca, we are more driven than ever to bring new immuno-oncology options to patients facing devastating diagnoses.”
Research is underway to explore this important new class of therapies, and that research is rapidly evolving. For more information, click here.