A 52-year-old male with longstanding type 1 diabetes (T1D), long-term stable kidney transplant, and hypothyroidism received two separate anti-PD-1 monoclonal antibodies for metastatic melanoma.
All grades colitis (OR 8.7, 95% CI 5.8-12.9), hypophysitis (OR 6.5, 95% CI 3.0-14.3) and rash (OR 2.0, 95% CI 1.8-2.3) were more frequent with CTLA-4 mAbs; whereas pneumonitis (OR 6.4, 95% CI 3.2-12.7), hypothyroidism (OR 4.3, 95% CI 2.9-6.3), arthralgia (OR 3.5, 95% CI 2.6-4.8) and vitiligo (OR 3.5, 95% CI 2.3-5.3) were more common with PD-1 mAbs.
<b>Methods:</b> We report a case series of 10 patients who developed hypothyroidism after initiation of immune therapy (either anti-PD-1 alone or in combination with anti-CTLA-4).