Aim: Alongside the proven efficacy, immunotherapy in treatment of malignant diseases can cause immune-related adverse events different from commonly known chemotherapy-related toxicities. Case presentation: During nivolumab treatment of metastatic squamous cell lung cancer, the patient developed a symptomatic inflammatory myositis confirmed with muscle biopsy and primary hypothyroidism. After initiation of corticosteroids and thyroid hormone replacement, the clinical and laboratory improvement occurred. To the best of our knowledge, this is the first description of a case of nivolumab-induced synchronous manifestation of immune-related myositis and hypothyroidism. Conclusion: Immunotherapy can trigger a wide spectrum of immune-related adverse events that could occur simultaneously. If not detected and treated, these events could become severe or even fatal and require clinicians' awareness and routine check-ups.

Background: The standard first-line systemic treatment for patients with non-oncogene addicted advanced nonsquamous non-small cell lung cancer (NSCLC) is immunotherapy with immune checkpoint inhibitors (ICI) and/or chemotherapy (ChT). Therapy after failing ICI +/− ChT remains an open question, and docetaxel plus nintedanib represent a valid second line option. Patients and methods: A multicenter retrospective trial of real-life treatment patterns and outcomes of patients with advanced lung adenocarcinoma treated with docetaxel plus nintedanib after the failure of ICI and/or ChT was performed. Patients from 2 Slovenian and 1 Croatian oncological center treated between June 2014 and August 2022 were enrolled. We assessed objective response (ORR), disease control rate (DCR), median progression free survival (PFS), median overall survival (OS), and safety profile of treatment. Results: There were 96 patients included in the analysis, with ORR of 18.8%, DCR of 57.3%, median PFS of 3.0 months (95% CI: 3.0–5.0 months), and a median OS of 8.0 months (95% CI: 7.0–10.0 months). The majority of patients (n = 47,49%) received docetaxel plus nintedanib as third-line therapy. The ORR for this subset of patients was 19.1%, with a DCR of 57.4%. The highest response rate was observed in patients who received second-line docetaxel plus nintedanib after first-line combination of ChT-ICI therapy (n = 24), with an ORR of 29.2% and DCR of 66.7% and median PFS of 4.0 months (95% CI: 3.0–8.0 months). Fifty-three patients (55.2%) experienced adverse events (AEs), most frequently gastrointestinal; diarrhea (n = 29, 30.2%), and increased liver enzyme levels (n = 17, 17.7%). Conclusions: The combination of docetaxel and nintedanib can be considered an effective therapy option with an acceptable toxicity profile for patients with advanced NSCLC after the failure of ICI +/− ChT.