# Pembrolizumab-Induced Aplastic Anemia Successfully Treated With Thrombopoietin Receptor Agonist in a Patient With Lung Adenocarcinoma: A Case Report and Literature Review

## TL;DR

A lung cancer patient developed a rare immune-related blood disorder after immunotherapy, which was successfully treated with a drug that stimulates blood cell production.

## Contribution

This case report introduces thrombopoietin receptor agonists as a potential treatment for immune-related aplastic anemia resistant to standard therapies.

## Key findings

- A patient with lung adenocarcinoma developed aplastic anemia following pembrolizumab treatment.
- Eltrombopag led to gradual hematologic recovery in a patient unresponsive to standard immune-related adverse event treatments.
- This case suggests thrombopoietin receptor agonists may be effective in treating GC-resistant irAE-induced aplastic anemia.

## Abstract

A 71-year-old female with postoperative recurrence of lung adenocarcinoma was treated with chemotherapy plus immunotherapy (carboplatin, pemetrexed, and pembrolizumab). On day eight after the first cycle, she presented with fever and loss of appetite. Laboratory tests showed severe pancytopenia. Bone marrow biopsy revealed hypocellular marrow consistent with aplastic anemia (AA), which is considered an immune-related adverse event (irAE). Treatment with pulse glucocorticoid (GC) therapy, granulocyte colony-stimulating factor, and cyclosporine had a limited effect. On day 24, eltrombopag, a thrombopoietin receptor agonist, was started, subsequently leading to gradual hematologic recovery and discharge on day 34. IrAE-induced AA has a poor prognosis, with no established standard treatment. This case demonstrates the potential of thrombopoietin receptor agonists as a therapeutic option in GC-resistant irAE-induced AA.