Effectiveness of high-dose third-generation EGFR-tyrosine kinase inhibitors in treating EGFR-mutated non-small cell lung cancer patients with leptomeningeal metastasis.

BACKGROUND: Leptomeningeal metastasis (LM) is associated with an extremely poor prognosis in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). The third-generation EGFR-tyrosine kinase inhibitors (TKIs), currently the preferred drug of choice, have significantly improved treatment outcomes in these patients. However, the optimal dose of third-generation EGFR-TKIs for clinical use remains undetermined in NSCLC patients with LM. METHODS: We retrospectively analyzed the clinical characteristics and treatment outcomes of 105 patients with EGFR-mutated NSCLC and cytologically confirmed LM who had received third-generation EGFR-TKI treatment after LM diagnosis. Patients were stratified into high- and standard-dose groups based on the treatment dose of third-generation EGFR-TKI. Subsequent treatments for LM were collected, particularly the efficacy of different doses of third-generation EGFR-targeted drugs. RESULTS: The median follow-up period was 28.7 months (range 0.6-40.2) at the cut-off date of August 27, 2023. The 105 included patients who received third-generation EGFR-TKI treatment had a clinical response rate (CRR) of 54.3 % (57/105), and the median overall survival (OS) from LM diagnosis was 12.3 months (95 % confidence interval [CI] = 10.0-15.0). Among them, 46 (43.8 %) patients received a high-dose regimen, and the remaining 59 (56.2 %) patients were treated with standard-dose drugs. Patients treated with high-dose third-generation EGFR-TKIs showed a higher CRR and longer OS than those treated with standard-dose therapy (65.2 % vs. 45.8 %, p = 0.047; 15.0 vs. 10.2 months, p = 0.014). Importantly, high-dose third-generation EGFR-TKI showed superior OS than standard-dose treatment in all subgroups (prior first-/second-generation EGFR-TKI resistance group, 19.5 vs. 9.8 months, p = 0.047; third-generation EGFR-TKI resistance group, 10.0 vs. 4.3 months, p = 0.045; EGFR-TKI naive group, not reach vs. 15.6 months, p = 0.031). Multivariate analysis revealed that high-dose third-generation EGFR-TKIs, intrathecal chemotherapy, previous TKI treatment history, and Karnofsky Performance Status score were independent predictors of OS (all p < 0.05). CONCLUSIONS: High-dose third-generation EGFR-TKIs are effective treatments for NSCLC patients with EGFR mutations and LM, regardless of previous EGFR-TKI exposure.

Targeting HER2 alterations in non-small cell lung cancer: Therapeutic breakthrough and challenges.

In non-small cell lung cancer (NSCLC) with human epidermal growth factor receptor 2 (HER2) alterations, chemotherapy remains the standard treatment over a decade, due to the minor efficacy of traditional pan-HER tyrosine kinase inhibitors (TKIs) and HER2-targeted monoclonal antibodies. In recent years, novel selective HER2 TKIs have been developed for pretreated HER2-mutant patients. In particular, pyrotinib has shown moderate efficacy as well as a manageable safety profile, and it is now being further evaluated as monotherapy or combined with other existing therapies; by contrast, while poziotinib has demonstrated promising preliminary results, the high rates of toxicity has hampered subsequent studies. Most notably, trastuzumab deruxtecan (T-DXd, DS-8201) has led to a significant breakthrough, with the most encouraging efficacy data (response rate of 55 %, median progression-free survival of 8.2 months and median overall survival of 17.8 months) among all the anti-HER2 agents. This is certainly remarkable progress, and T-DXd is undoubtedly the key drug for the treatment of this disease. Future developments regarding T-DXd are favourable, including shifting from monotherapy to combination strategies, improving structural design to optimise antitumour activity and minimise toxicity, identifying the potential resistance mechanisms and developing therapeutic strategies to overcome them. Several other challenges need to be addressed, such as the intracranial activity of anti-HER2 agents and the optimal sequencing of therapies. Here, we summarise recent therapeutic advances in targeting HER2 alterations in NSCLC and highlight the future perspectives of these patient populations.