Effectiveness of afatinib in an NSCLC patient with EGFR mutation and early progression to osimertinib: a case report.

Osimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), shows great clinical activity in non-small cell lung cancer (NSCLC) patients with EGFR mutations regardless of T790M mutation at first-line chemotherapy. Previous studies demonstrated that there are few patients with initial resistance to osimertinib. Here, we describe a case to report the efficacy of afatinib in an EGFR-mutated NSCLC patient with early progression to first-line osimertinib treatment. A 68-year-old Japanese male was diagnosed with stage IVB lung adenocarcinoma with the EGFR L858R mutation in exon 21. Two months after the start of osimertinib, his tumor progressed at the initial response evaluation. Because he refused to receive cytotoxic chemotherapy, afatinib treatment was initiated. He was administered afatinib, and the tumor shrank. After five months of afatinib treatment, nevertheless the primary tumor was not enlarged, he experienced disease progression with leptomeningeal metastasis and passed away. To elucidate the resistance mechanisms of osimertinib in this patient, we performed next-generation sequencing (NGS) on tumor samples from pleural effusions after osimertinib failure. NGS revealed no specific gene mutations causing resistance to osimertinib except for the EGFR L858R mutation; however, his tumor had a relatively high tumor mutational burden. Afatinib is considered an option for EGFR-mutated patients with early progression to osimertinib.

Nozaki K ，Watanabe S ，Nishio K ，Sakai K ，Kikuchi T ... -  《-》

Afatinib overcoming resistance to icotinib and osimertinib in NSCLC with leptomeningeal metastasis in patients with acquired EGFR L858R/T790M or L858R/S768I mutations: Two case reports.

Li G ，Fang M ，Zhou Y ，Liu X ，Tian P ，Mei F ... -  《Heliyon》

Rechallenge of afatinib for EGFR-mutated non-small cell lung cancer previously treated with osimertinib: a multicenter phase II trial protocol (REAL study).

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of advanced non-small cell lung cancer (NSCLC) and contributed to the development of precision medicine. Osimertinib is a standard first-line (1L) treatment for EGFR-mutated NSCLC and has demonstrated superior survival benefits over previous-generation TKIs. However, resistance to osimertinib is nearly inevitable, and subsequent treatment strategies remain unmet medical needs in this setting. Afatinib, a second-generation EGFR-TKI, exhibits activity against certain uncommon EGFR mutation types in the 1L setting. There are a few case reports on the efficacy of afatinib against EGFR-dependent resistance after osimertinib treatment, although these have not been prospectively investigated. The present phase II, single-arm multicenter trial aims to verify the efficacy and safety of afatinib rechallenge after 1L osimertinib resistance. Patients (aged ≥20 years) with advanced or recurrent non-squamous NSCLC harboring drug-sensitive EGFR mutations (deletion of exon 19 or L858R) who were previously treated with 1L osimertinib and second-line chemotherapy other than TKIs are considered eligible. Undergoing next-generation sequence-based comprehensive genomic profiling is one of the key inclusion criteria. The primary endpoint is the objective response rate; the secondary endpoints are progression-free survival, overall survival, and tolerability. Thirty patients will be recruited in December 2023. The results of this study may promote incorporating afatinib rechallenge into the treatment sequence after 1L osimertinib resistance, a setting in which concrete evidence has not been yet established. UMIN Clinical Trial Registry: UMIN000049225.

Araki T ，Kanda S ，Komatsu M ，Sonehara K ，Tateishi K ，Takada M ，Kato A ，Yamamoto M ，Nishie K ，Hama M ，Agatsuma T ，Kakizaki Y ，Yoshiike F ，Matsuo A ，Chiaki T ，Samizo K ，Takagi Y ，Yamaura M ，Hanaoka M ，Koizumi T ... -  《-》

Successful treatment of EGFR T790M-mutant non-small cell lung cancer with almonertinib after osimertinib-induced interstitial lung disease: a case report and literature review.

Third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) have revolutionized the standard treatment for EGFR T790M-positive non-small cell lung cancer (NSCLC). Osimertinib is one of the third-generation EGFR-TKIs and is currently the most advanced in clinical development. Interstitial lung disease (ILD) is a potentially fatal side effect of osimertinib use. Successful rechallenge with the second-generation TKI afatinib following osimertinib-induced ILD has been reported. However, few reports have discussed the safety and efficacy of third-generation TKI rechallenge in this patient population. In this paper, a case of lung adenocarcinoma is retrospectively analyzed, and the relevant literature is reviewed. The patient was initially diagnosed with early lung cancer, for which surgical treatment was performed. The postoperative diagnosis indicated stage IB (pT2N0M0) right lung adenocarcinoma. Genetic testing (amplification-refractory mutation system) revealed EGFR exon 19 deletion. More than 2 years after surgery, multiple metastases occurred in both lungs, so gefitinib (250 mg per day) was administered. However, 6 months after the start of gefitinib treatment, the tumor progressed. Lung tumor biopsy was performed for genetic testing (NGS) and an EGFR T790M mutation was observed. Subsequently, second-line treatment with osimertinib (80 mg per day) was given for 3 months. The evaluated response suggested a partial response (PR) with the occurrence of grade 3 ILD. Pemetrexed plus bevacizumab chemotherapy was subsequently administered, resulting in stable disease. However, following a severe drug reaction after six courses, the patient's chemotherapy was discontinued. Another third-generation TKI, almonertinib (110 mg per day), was rechallenged based on no ILD having been reported in a phase I/II study of this drug. After 4 months of almonertinib administration and 6 months without ILD recurrence, partial remission was attained. This is the first report of successful treatment with almonertinib after osimertinib-induced ILD. The results suggested that almonertinib had a significant effect in patients with EGFR T790M mutation, with fewer side effects and better survival benefits for patients with advanced lung cancer.

Wu L ，Zhong W ，Li A ，Qiu Z ，Xie R ，Shi H ，Lu S ... -  《-》

Osimertinib vs. afatinib as first-line treatment for patients with metastatic non-small cell lung cancer with an EGFR exon 19 deletion or exon 21 L858R mutation.

Gilardone S ，Thapa R ，Laborde J ，Shafique M ，Saltos A ，Creelan B ，Tanvetyanon T ，Chiappori A ，Simon G ，Haura EB ，Gray JE ，Chen DT ，Melzer D ，Pellini B ... -  《-》