SAT-448 Surveillance for Endocrine Dysfunction in the Setting of Immunotherapy Use

Abstract Disclosure: S.N. Vodnala: None. E. Taha: None. C. Segura: None. R. Atodaria: None. A. Sanjel: None. R. Abdelmasih: None. Background: With the emergence of immune checkpoint inhibitors such as nivolumab and ipilimumab for the treatment of malignancy, there have been reported instances of associated endocrinopathy. Clinical Case: A 78-year-old man with bipolar disorder, atrial fibrillation, hypertension, hyperlipidemia, metastatic malignant melanoma, and tardive dyskinesia presented due to a fall. Associated concerns included vomiting, excessive daytime sleepiness, weight loss, frequent falls, and a functional decline over the past 2 weeks. Of note, he had received 12 cycles of nivolumab for metastatic melanoma initially with a good response. He had previously been on combination therapy with ipilimumab. However, he required two years of steroid therapy as he could not tolerate the immunotherapy. The steroids were tapered and eventually stopped one year prior to admission, after which his functional status was noted to decline. Upon presentation, his vitals were stable. Physical exam revealed dry mucous membranes, decreased skin turgor, an irregular heart rhythm, and epigastric tenderness. Labs were significant for AM cortisol of 1.0 mcg/dL (4.5 - 23.0 ug/dL), PM cortisol of 2.3 mcg/dL (1.7 - 14.0 ug/dL), and TSH of 3.71 mUI/mL (0.45 - 4.70 mIU/L). CT of the head and neck was normal. Endocrinology was consulted due to concern for adrenal insufficiency (AI), with the possibility of adrenalitis versus hypophysitis. He was treated with hydrocortisone therapy after which he demonstrated a return to his previous functional baseline. He remained stable and was discharged with planned outpatient workup with ACTH, DHEA-S and CT abdomen and pelvis for further evaluation of the etiology of AI. Conclusion: We present a case of adrenal insufficiency associated with nivolumab (anti-PD-1) and ipilimumab (anti-CTLA-4) combination therapy. As checkpoint inhibitors, these medications have a variety of uses in the treatment of malignancies, such as melanomas and renal cell carcinoma. However, this combination therapy has been identified as the cause of hypophysitis in 6.4% of patients. In another study, 29% of patients using this combination therapy developed secondary adrenal insufficiency within eight weeks of starting treatment. Given the risk of life-threatening complications from adrenal insufficiency, such as persistent hypotension, prompt recognition and diagnosis are imperative. Therefore, we propose that patients on immunotherapy have routine lab work to monitor for the potential development of endocrinopathies. Furthermore, physicians should educate patients on warning signs that could represent the onset of an endocrinopathy. Learning Objectives•Recognize the use of immunotherapy as a risk factor for adrenal insufficiency.•Evaluate patients on immunotherapy for endocrinopathy. Presentation: Saturday, July 12, 2025