Scientists advise caution in immunotherapy research

In a new study, Yale Cancer Center (YCC) scientists suggest that as the number of clinical trials in cancer immunotherapy grows exponentially, some caution should be exercised as we continue to better understand the biology of these new therapeutic targets. The findings are published today in the journal Cell. Researchers around the world have been racing to create therapies that unleash the power of our immune systems against cancer. The most successful of these immunotherapies, which target a molecular pathway known as PD-1/PD-L1, have brightened the landscape for many people suffering from lung cancer and other types of tumors.
Lieping Chen, M.D., who pioneered work on the PD-1/PD-L1 pathway, cautions that some immunotherapy research is going off track by moving into drug development without a firm foundation of basic biological understanding. Chen is the United Technologies Corporation Professor in Cancer Research and co-director of the Cancer Immunology Program at YCC. A case in point is the LAG-3 molecule, notes Chen. Like PD-1, the LAG-3 protein is found on the surface of the immune system's T cells, and tumors can use it to shield themselves from the T cell attack. Most scientists have believed that a surface protein called MHC class II (MHC-II) is the major "ligand" molecule that cancer cells can use to connect with the LAG-3 molecule in order to dial down T cell activity, and that targeting MHC-II will help to unblock the T cells.