Drug Discovery
Ideas and explainers on the samples that help researchers ask better questions.
Keytruda (Pembrolizumab): The Immune Brake that Became a $26B Drug…and Just Got a New Partner
Keytruda works by releasing a brake, not by attacking cancer directly. Tumors often hijack a checkpoint pathway called PD-1/PD-L1 to hide from the immune system. Researchers studying tumor biopsies with immunohistochemistry (IHC) found that tumors expressing high PD-L1 were essentially waving a "don't attack me" flag at immune cells. With that realization, blocking that flag…