Table 5.

Management of hypothyroidism induced by immune checkpoint inhibitors.

CTCAE Grade	Management	Treatment of Adverse Event
Grade 1	Continue ICI treatment	Continue to monitor TSH, FT3, and FT4 levels every 2–3 weeks
Grade 2	Stop ICI treatment until the symptoms ameliorate or test values become normal After amelioration of symptoms, resume administration of ICI	Consult an endocrinologist Start thyroid hormone replacement therapy if symptoms are present or the TSH level is high If thyroid function is stable, perform a thyroid function test every 6 weeks
Grade 3 or 4	Same as above	Consult an endocrinologist Start administration of β-blocker In case of myxedema coma, treat the patient in the intensive care unit Following stabilization of symptoms, treat as per the protocol for Grade 2 events

CTCAE, Common Terminology Criteria for Adverse Events; ICI, immune checkpoint inhibitor; TSH, thyroid-stimulating hormone; FT4, free T4; FT3, free T3.