The utility of routine endocrinopathy testing in patients treated with ipilimumab for solid malignancies.

Abstract

e19250 Background: It is recommended to periodically screen for endocrine immune-related adverse events during the administration of ipilimumab(ipi) and nivolumab(nivo) immunotherapy. ACTH and TSH levels are used to screen for possible autoimmune dysfunction of the pituitary and thyroid glands. Patients treated with immunotherapy at our institution undergo pre-set laboratory testing of ACTH and TSH levels prior to initial administration, and then a minimum of every 6-8 weeks depending on the treatment interval and physician preference. We aimed to evaluate the impact of routine endocrinopathy testing on clinical management and the overall utility of this testing. Methods: This is a retrospective chart review of patients treated at the UF Health Cancer Center Orlando with ipilimumab and the combination of Ipi/Nivo immune checkpoint inhibitors for solid malignancies over a 28-month period. We collected ACTH, TSH, Cortisol, and T4 laboratory data during the first 100 days of treatment and analyzed the electronic medical record for endocrinopathy diagnoses, influencing factors for ACTH results, and changes in clinical management as a result of routine ACTH screening. Results: In total, 7 patients were treated with ipilumumab single agent, and 35 patients were treated with Ipi/Nivo combination. An Immune related endocrinopathy was diagnosed in 6(14%) patients. 20 (48%) patients had at least one abnormally low ACTH value during the first 100 days of treatment. 75% of patients with abnormally low values had an ACTH level checked while on steroids. 62% of abnormally low ACTH tests did not have an accompanying cortisol level ordered. 57% of patients had ACTH testing performed in both the morning and afternoon. None of the patients with abnormally low ACTH levels had documentation which supported that ACTH/TSH testing led to brain imaging or additional pituitary hormone testing. None of the patients had their immunotherapy medication delayed or stopped as a result of routine ACTH testing. Conclusions: ACTH testing in patients treated with immunotherapy is frequently abnormal and can be exceedingly difficult to interpret. ACTH testing at our institution was often performed in the setting of multiple changing variables and abnormal values were frequently not investigated further. Routine ACTH testing did not impact clinical management.