Long‑term survival with tocilizumab treatment for tislelizumab‑related pneumonitis in a patient with non‑small cell lung cancer: A case report

Tislelizumab, an immune checkpoint inhibitor (ICI) that is approved for the treatment of non-small cell lung cancer (NSCLC), has shown superior overall and progression-free survival benefits compared with chemotherapy in clinical trials. However, like other ICIs, tislelizumab administration may lead to a series of immune-related adverse events (irAEs), including checkpoint inhibitor pneumonitis. Corticosteroids are recommended as the first-line treatment for the management of irAEs. However, biological immunomodulatory agents, such as infliximab and tocilizumab, are often needed in patients with steroid-refractory or steroid-resistant irAEs. The present study reports the case of a patient with NSCLC and tislelizumab-related pneumonitis, who showed complete resolution of symptoms and clear computed tomography imaging after tocilizumab treatment, and achieved a long-term survival period of >5 years. In the current patient, the involvement of interleukin-6 (IL-6) in corticosteroid-refractory pneumonitis was demonstrated by elevated serum IL-6 levels, and subsequent treatment with the IL-6 receptor inhibitor tocilizumab achieved complete resolution and long-term survival. The present case suggests that IL-6 may be involved in the pathogenesis of irAEs and that tocilizumab may be an effective option for treating steroid-refractory or steroid-resistant irAEs.