Shawnta Anakwah, MD: This is a 48-year-old man who presented with a right renal mass. He went for a right radical nephrectomy and a renal vein thrombectomy. His pathology at the time of resection showed a T3 lesion, 10 cm in diameter. The tumor was grade 4, with both rectal and sarcomatoid features with extensive necrosis. However, he did have high PD-L1 expression at 90%. He was followed with CT scans by his urology provider. At his 3-month CT scan he had a new, tiny pulmonary nodule that was less than 1 cm. At 6 months, he had an additional nodule with a slight increase in the previous nodule. At his 9-month scan, he had increase in both nodules with a third new lesion. One lesion was biopsied and confirmed as metastatic RCC [renal cell carcinoma].

His labs on presentation were pretty unremarkable, with normal white blood cell, hemoglobin, and platelet counts; calcium was normal. He was deemed to be intermediate risk based on the fact that he had metastatic disease within 1 year of his nephrectomy. The decision was made to proceed with ipilimumab and nivolumab. After cycle 2 on day 9 of dual immunotherapy, the patient developed severe headache with fever, which was 10 of 10. He also had photophobia with severe nausea and vomiting, so he was sent to the emergency department. He was found to have a fever of 101.6. He had tachycardia. His blood pressure was 101/67, with an oxygen saturation of 95%.

His labs showed that new transaminitis. His cortisol level was elevated at 25.8 µg/dL. His TSH [thyroid stimulating hormone] was suppressed at 0.05 U/mL, and his fT4 was elevated at 4.5 ng/dL. An MRI of the brain, with or without contrast, showed an enhancing, enlarged pituitary gland with thickening of the pituitary stalk. Those findings that are seen in the setting of immune checkpoint inhibitor–associated hypophysitis.

He was started empirically on 1.5 mg/kg of prednisone and had immediate improvement in all his symptoms. After the steroids and liver test normalized, his TSH increased, his fT4 dropped, and he was continued on steroid taper over about 6 weeks. He was managed in combination with endocrinology and was placed on testosterone, hydrocortisone, and levothyroxine supplementation. The patient consented to rechallenge with the single-agent PD-L1 inhibitor. On his scans at the initiation of nivolumab, he was confirmed to have had a partial remission [PR]. The patient is now about 10 months out from treatment and still maintaining his PR with no evidence of disease progression.

Transcript edited for clarity.