What are the side effects of Cemiplimab?

Cemiplimab (Cemiplimab) is associated with side effects related to immune system activity, which may be serious, although most side effects disappear with appropriate treatment or after stopping cemiplimab. The most common immune-related effects (which may affect up to 1 in 10 people) are hypothyroidism (an underactive thyroid gland, associated with fatigue, weight gain, and skin and hair changes), pneumonia (inflammation of the lungs, causing shortness of breath and coughing), skin reactions, hyperthyroidism (an overactive thyroid gland, which may lead to overactivity, sweating, weight loss, and thirst), and hepatitis (inflammation of the liver).