Lung cancer response to pembrolizumab complicated by severe kidney injury

What happened, in summary

A 70-year-old man had been diagnosed with stage IV lung adenocarcinoma 6 months before referral. He also had venous thrombosis and was taking apixaban. Pembrolizumab was started 5 months before referral at 200 mg intravenously every 3 weeks. After 5 courses, CT showed that the tumor had decreased in size.

After the 6th course, he developed a peeling red rash on his lower leg. Pembrolizumab was postponed, and the rash resolved within 1 week. Treatment was then restarted. Seventeen days after the 7th course, he suddenly developed widespread swelling and gained 3.5 kg. His serum albumin had fallen from 3.8 g/dL to 1.3 g/dL, and his creatinine rose from 0.70 to 1.63 mg/dL, consistent with acute nephrotic syndrome and kidney injury.

Steroid treatment began on hospital day 2. By day 3, low urine output and fluid in the lungs caused shortness of breath, so hemodialysis was started. Oral prednisolone 40 mg replaced intravenous treatment on day 21. His urine output improved markedly on day 34, allowing dialysis to stop, and he was discharged on day 60.

Protein loss in the urine continued to improve and reached complete remission 50 days after discharge. At 8-month follow-up, creatinine was 0.91 mg/dL and serum albumin was 4.0 g/dL. The lung cancer had shown a response to pembrolizumab before the kidney complication.