Interstitial pneumonitis related to sacituzumab govitecan in a patient with metastatic triple-negative breast cancer: a case report

BACKGROUND: Sacituzumab-govitecan-related pulmonary toxicity is rare. Herein, we describe a case of sacituzumab-govitecan-induced interstitial pneumonitis that was successfully rechallenged with a reduced drug dose. CASE PRESENTATION: A 62-year-old Taiwanese female patient with metastatic triple-negative breast cancer was refractory to the previous four lines of chemotherapy. She was subsequently given therapy with sacituzumab govitecan (10 mg/kg). After the second cycle, she developed progressive dyspnea, dry cough, and diarrhea. Chest computed tomography revealed diffuse ground grass opacity of the bilateral lungs with multiple foci of black area (reverse hall sign) and thickening of the interlobular septa. In the absence of other potential causes, sacituzumab-govitecan-induced grade 3 interstitial pneumonitis was strongly suspected, with a Naranjo score of 7. Sacituzumab govitecan discontinuation and corticosteroid therapy (prednisolone 2 mg/kg/day) were initiated. Her clinical symptoms and radiographic pulmonary infiltrations were significant improvement within 1 week. Sacituzumab govitecan was rechallenged in half dose due to lack of alternative treatment for the metastatic triple-negative breast cancer. She completed four additional cycles without recurrent pneumonitis before disease progression. The progression-free survival was 5.37 months. CONCLUSION: Sacituzumab govitecan is a new generation of antibody-drug conjugates. Early detection of drug-induced interstitial lung disease, drug discontinuation ,and immediate steroid therapy are important. Permanent antibody-drug conjugates discontinuation is advised for patients with grade ≥ 2 drug-induced interstitial lung disease. In this case, due to the limited treatment for metastatic triple-negative breast cancer, the patient was rechallenged with half dose of sacituzumab govitecan without recurrent pneumonitis.