Immune checkpoint inhibitors (ICIs) therapy has revolutionized cancer treatment. However, it is important to acknowledge that ICI therapy can lead to immune-related adverse events (irAEs), including myocarditis. While early-onset myocarditis is well-documented, late-onset cases are increasingly recognized. This case series presents four cases of late-onset ICI-associated myocarditis, emphasizing the need for long-term surveillance of this potentially fatal complication. Patients exhibited a range of cardiac symptoms, including chest pain, shortness of breath, and arrhythmias. The diagnosis was confirmed through cardiac magnetic resonance imaging (MRI) and elevated cardiac biomarkers. Treatment involved the immediate discontinuation of ICI therapy and the initiation of high-dose corticosteroids. In cases with an inadequate response, additional immunosuppressive agents were considered. This case series underscores the importance of prolonged monitoring for late-onset ICI-associated myocarditis. Further research is needed to establish optimal treatment strategies and long-term management approaches for this complex condition.

It would be fair to say that immune checkpoint inhibitor (ICI) therapy brought about a revolution in cancer treatment. However, it is important to note that ICI therapy can potentially lead to immune-related adverse events (irAEs), including myocarditis. While early-onset myocarditis is well-known, it is becoming increasingly recognized that late-onset cases may also occur. This case series presents four cases of late-onset ICI-associated myocarditis, which serve to underscore the importance of long-term surveillance for this potentially fatal complication. All patients presented with a variety of cardiac symptoms, including chest pain, shortness of breath, and arrhythmia. The diagnosis was confirmed through cardiac MRI and elevated cardiac biomarkers. Treatment involved immediate cessation of ICI therapy and initiation of high-dose corticosteroids. For patients with inadequate response, additional immunosuppressive agents were considered. This case series presents four cases of late-onset ICI-associated myocarditis, which highlights the importance of long-term surveillance for this potentially fatal complication. Further research is needed to establish optimal treatment strategies and long-term management for this complex condition.

Background/Objectives: We aimed to evaluate the real-world outcomes of first-line osimertinib in patients with advanced EGFR-mutant non-small cell lung cancer, together with the progression patterns, including the management and outcomes of oligoprogressive disease in the real-world setting. Methods: Patients who received first-line osimertinib at 33 oncology centers across Türkiye were retrospectively analyzed. Results: The median (IQR) age of 143 patients was 59.4 (50.9–68.9), 62.9% were female, and 68.5% were non-smokers. The most frequently identified EGFR mutations were exon 19 deletion (64.3%) and exon 21 L858R (28.7%). The median progression-free survival (PFS) was 17.6 months (95% CI 14.6–20.6). Exon 19 deletion subgroup had significantly longer median PFS than exon 21 L858R subgroup (22.0 vs. 11.7 months; HR = 0.40 [95% CI 0.25–0.64]; p < 0.001). Of the patients who experienced disease progression, 51.2% had oligoprogression. Among these, 81.8% received local ablative treatments (LATs) while continuing osimertinib. The median time to osimertinib discontinuation was significantly longer in patients treated with LATs than in those who continued osimertinib without LATs (8.5 vs. 3.0 months; p = 0.001). In the overall cohort, 12- and 24-month overall survival (OS) rates were 93.0% and 82.5%, respectively. The median OS was significantly longer in patients with oligoprogression compared to those with systemic progressive disease (57.7 vs. 36.5 months; p = 0.007). Any-grade and grade ≥ 3 osimertinib-related adverse events occurred in 55.2% and 6.3% of patients, respectively. Conclusions: This study supports the real-world effectiveness and tolerability of first-line osimertinib. Oligoprogression was associated with longer OS compared with systemic progression, and the integration of LATs in carefully selected patients with oligoprogression may be associated with prolonged osimertinib treatment duration and favorable post-progression outcomes.