KEYTRUDA® (pembrolizumab) is a medicine that may treat certain cancers by working with your immune system. KEYTRUDA can cause your immune system to attack normal organs and tissues in any area of your body and can affect the way they work. These problems can sometimes become serious or life-threatening and can lead to death.
Call or see your doctor right away if you develop any symptoms of the following problems or these symptoms get worse:
Lung problems (pneumonitis). Symptoms of pneumonitis may include shortness of breath, chest pain, or new or worse cough.