The majority of EGFR mutations (85–90%) are exon 19 deletions and L858R point mutation of exon 21, characterized by high sensitivity to EGFR-tyrosine kinase inhibitors (TKIs). Less is known about uncommon mutations (10-15% of EGFR mutations). Predominant mutation types in this category include exon 18 point mutations, exon 21 L861X, exon 20 insertions and exon 20 S768I. This group presents a heterogeneous prevalence, partly due to the different testing methods and to the presence of compound mutation, which in some cases leads to shorter overall survival and different sensitivity to different TKIs than simple mutations. EGFR-TKI sensitivity may also vary depending on the specific mutation and the tertiary structure of the protein. The best strategy remains uncertain and the data of TKIs efficacy are founded of few prospective and some retrospective series. Newer investigational agents are still under study and there are no other approved specific treatment targeting uncommon EGFR mutations. Defining the best treatment option for this patient population remain un unmet medical need. The objective of this review is to evaluate existing data on outcomes, epidemiology and clinical characteristics of lung cancer patients with rare EGFR mutations, with a focus on intracranial activity and response to immunotherapy.

Background: This study assessed the nephrotoxicity of oral BRAF inhibitors (BRAFi), regorafenib (REG) and encorafenib (ENC), in metastatic colorectal cancer (mCRC), through an analysis of re-ports from the US Food and Drug Administration's Adverse Event Reporting System (FAERS) da-tabase. Methods: A descriptive and disproportional analyses were performed for all reports with ENC and REG as the primary suspect. Results: A total of 379 reports had at least one renal ADR, mainly related to REG (93.1%). Potential safety signals for REG particularly included chromaturia (n = 44; ROR = 12.00, CI 95% = 8.92-16.16; IC = 2.36, IC025-IC075 = 2.06-2.66), hydronephrosis (10; 8.70, 4.67-16.19; 1.85, 1.23-2.47), nephrotic syn-drome (7; 5.73, 2.73-12.03; 1.47, 0.73-2.21), renal impairment (53; 4.16, 3.17-5.45; 1.39, 1.12-1.66), dys-uria (19; 3.06, 1.95-4.81; 1.06, 0.61-1.52), renal failure (38; 1.66, 1.20-2.28; 0.49, 0.17-0.81), and acute kidney injury (AKI) (43; 1.46, 1.08-1.97; 0.37, 0.07-0.67). For ENC, consistent disproportionalities were observed for AKI (n = 11; ROR = 3.79, CI 95% = 2.09-6.90; IC = 1.32, IC025-IC075 = 0.72-1.91) and dysuria (4; 6.50, 2.43-17.39; 1.86, 0.88-2.85). Conclusions: These findings highlighted some not extensively reported renal ADRs that required further investigations to better characterize the safety profile of BRAFi in patients with mCRC.