Claudins are a type of protein that form a “fence” between cells, called a tight junction.
These fences create a seal and prevent unwanted substances from passing between the cells. Claudin 18.2 (CLDN18.2) is a specific type of protein found mostly in the stomach.
In a healthy situation, CLDN18.2 is only in the lining of the stomach. But in GI cancers, there are high levels of it expressed on tumor cells. This has made it a novel biomarker for treating gastric and GEJ cancers because drugs can target CLDN18.2 on tumor cells and spare the healthy cells.
Biomarker testing can be run on tumor samples to determine if a patient is CLDN18.2-positive or negative. Drugs called "monoclonal antibodies" target the cancer cells expressing CLDN18.2.
Gastric and GEJ cancers that is HER2-negative (in advanced, specific situations)
There are several promising clinical trials happening for other GI cancer types expressing CLDN18.2.
Your treatment plan will be unique and dependent on several factors. Ask your doctor how your biomarker test results are informing your treatment plan and if you qualify for any clinical trials.
