Hypophysitis: A rare but noteworthy immune-related adverse event secondary to camrelizumab therapy

The programmed cell death 1 (PD-1) inhibitor - camrelizumab - is a promising agent for the treatment of several malignancies. Secondary hypophysitis has been reported in patients treated with the other PD-1 inhibitors such as nivolumab and pembrolizumab. However, camrelizumab-related hypophysitis has not yet been described. Herein, we report three cases of hypophysitis secondary to camrelizumab therapy. Case 1 was a 60-year-old male patient with non-small-cell lung carcinoma, who was diagnosed with central adrenal insufficiency associated with hypophysitis after 11 cycles of camrelizumab treatment (200 mg every 2 weeks). Glucocorticoid therapy rapidly improved his symptoms. Case 2 was a 68-year-old male patient with hepatocellular carcinoma who received ten cycles of camrelizumab (200 mg every 2 weeks) plus apatinib (250 mg daily), before the diagnosis of hypophysitis. Steroid therapy was also efficacious. Case 3 was a 69-year-old male patient diagnosed with renal carcinoma. After eight cycles of camrelizumab therapy (200 mg every 2 weeks) combined with oral apatinib (250 mg daily), the patient presented with hypophysitis, which responded well to glucocorticoid therapy. These results suggest a caution for hypophysitis in patients treated with camrelizumab.