Background: Lung cancer is the leading cause of cancer-related deaths globally, with epidermal growth factor receptor (EGFR) mutations present in approximately 17–39% of non-small cell lung cancer (NSCLC) cases. Osimertinib, a third-generation oral EGFR tyrosine kinase inhibitor (EGFR-TKI), has become a cornerstone in the treatment of EGFR-mutated NSCLC. However, the full scope of its potentially life-threatening adverse effects, particularly cardiomyopathy, remains underexplored. Methods: This retrospective study was conducted using data from a multi-center registry of NSCLC patients with EGFR mutations treated with first-line osimertinib therapy between December 2018 and April 2024. Osimertinib-related cardiotoxicity was defined as a composite of reduced ejection fraction (EF) and cardiac death. Results: The study cohort consisted of 17 patients, and most of the patients had a history of smoking. Cardiac toxicity onset varied from 1 to 28 months following osimertinib initiation, with 70.59% of the patients experiencing symptoms within the first 6 months of treatment. Fourteen patients showed some degree of symptom improvement and EF recovery, although most did not return to baseline EF levels. Comorbidities, including heart failure, hypertension, and dyslipidemia, were prevalent across the cohort. Conclusions: While osimertinib remains an effective treatment for EGFR-mutated NSCLC, its associated cardiac toxicity, particularly in patients with pre-existing conditions, presents a significant challenge. Close monitoring, early intervention, and individualized management strategies are critical in mitigating these risks. Patients with mild cardiac toxicity may be suitable for rechallenge, while those with more severe or persistent toxicity should generally be excluded from further osimertinib treatment.

Background/Objectives: The Lung Immune Prognostic Index (LIPI) has emerged as a promising biomarker for predicting outcomes in advanced non-small cell lung cancer (aNSCLC). We assessed whether LIPI, in combination with baseline clinical characteristics, can guide first-line treatment selection between pembrolizumab (P) and pembrolizumab plus platinum-based chemotherapy (PCT) in patients with PD-L1 tumor proportion score (TPS) ≥ 50% and EGFR/ALK/ROS1 wild-type. Methods: A predictive score was developed using baseline clinical variables, including age, sex, smoking status, and LIPI, in a proof-of-concept cohort (n = 241). This model was then validated in an independent cohort of 409 patients. OS was compared between patients treated with P versus PCT, stratified by predictive score. Results: In the proof-of-concept cohort, the median OS was 18.3 months for P and 26.6 months for PCT (p = 0.001). In the validation cohort, the median OS was 28.0 months for P and 22.2 months for PCT (p = 0.062). Stratification using the predictive score showed that patients with high scores (3–5) had improved OS with PCT compared to P (31.2 vs. 25.5 months, p = 0.001), while those with low scores (0–2) derived similar benefits from both treatments. Conclusions: This LIPI-based predictive score may assist in identifying aNSCLC patients who derive greater benefit from chemo-immunotherapy over immunotherapy. Its simplicity and clinical relevance support integration into treatment decision-making, pending prospective validation.