Paradigm Shift in Mesothelioma Treatment: Targeting PD-1 Biomarker for Improved Outcomes

A recent study in mesothelioma patients opens a new chapter in the fight against this challenging disease. It enhances our understanding of how the immune system battles cancer. And it also introduces a novel approach to selecting the right treatment for mesothelioma patients.

Instead of relying only on one biomarker, doctors can now focus on many markers to make better decisions about the most effective treatment. This marks a paradigm shift in mesothelioma care, offering hope and improved outcomes for patients.

The Missing Puzzle Piece in Mesothelioma Treatment

Mesothelioma is a complex disease and finding the right treatments can be hard. It is caused by exposure to a toxic mineral called asbestos and can take decades to be diagnosed.

One emerging type of treatment for mesothelioma is called immune checkpoint blockade, but it’s not always easy to know which patients will benefit from it.

An international team of scientists decided to look for any markers that could tell doctors if a mesothelioma patient would respond well to immune checkpoint blockade. They published the results of their research in the Journal for Immunotherapy of Cancer.

The scientists studied samples from a big study called PROMISE-meso. It included 144 patients with mesothelioma. Some of the patients received a medicine called pembrolizumab. Others were treated with standard chemotherapy. They used a special technique to look at different cells in the tumors. This included CD8+T cells and CD68+macrophages. They also checked for proteins called PD-1 and PD-L1 on these cells and on the cancer cells themselves. This helped them understand which cells were involved in the immune response.

The study showed that just looking at PD-L1 alone was not enough to predict which patients would benefit from immune checkpoint blockade. They also found that counting the number of CD8 T cells or CD68+macrophages did not give a clear answer, either.

However, the scientists discovered something really interesting. They saw that when CD8+T cells and CD68+macrophages both had PD-1 on them, it was a good sign that the treatment would work well for that patient.

This study helps doctors understand more about how the immune system fights cancer. It also gives them a new way to choose the right treatment for patients with mesothelioma. Instead of just looking at one marker, like PD-L1, they can now pay attention to PD-1 on both CD8+T cells and CD68+macrophages. This can help them make better decisions about which treatment will be most effective.

Source

Homicsko K, Zygoura P, Norkin M, et al. PD-1-expressing macrophages and CD8 T cells are independent predictors of clinical benefit from PD-1 inhibition in advanced mesothelioma. J Immunother Cancer. 2023;11(10):e007585. doi:10.1136/jitc-2023-007585. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10603330/