Bilateral Hemorrhagic Occlusive Retinal Vasculitis Induced by Osimertinib in a Patient with Non-Small Cell Lung Cancer.

PURPOSE: To report a case of bilateral retinal vasculitis in a patient with non-small cell lung cancer undergoing treatment with osimertinib. CASE REPORT: A 58-year-old woman with lung adenocarcinoma (T4N3M1a stage IV) presented with blurry vision in both eyes (OU). Eighteen months before symptom onset, the treatment was changed from afatinib (20 mg/day) to osimertinib (80 mg/day) because of tumor progression. The visual acuity was 20/30 and 20/25 in the right and left eyes, respectively. Clinical examination revealed few anterior chamber cells, 2+ vitreous cells, haze, and multiple retinal hemorrhages in the peripheral retinas (OU). Fluorescein angiography revealed retinal vasculitis with a severely non-perfused area in the periphery. These findings indicated hemorrhagic occlusive retinal vasculitis (HORV). Osimertinib was reduced to 40 mg/day, and oral prednisolone was started at 30 mg/day. This improved retinal vasculitis; however, the ischemic area did not improve. Pan-retinal photocoagulation was performed while tapering the oral prednisolone to 10 mg/day. Although macular edema (ME) occasionally occurred (OU), systemic and local treatment with steroid-stabilized HORV and ME helped increase the dose of osimertinib to 80 mg/day without cancer progression for 18 months. Her visual acuity remained 10/20 (OU). CONCLUSION: Osimertinib, a third-generation tyrosine kinase inhibitor, can be used to treat advanced non-small cell lung cancer with epidermal growth factor receptor mutation-induced bilateral HORV. This adverse effect can be managed with systemic and local steroid treatment and continued osimertinib administration.

Lipid-associated macrophages for osimertinib resistance and leptomeningeal metastases in NSCLC.

Leptomeningeal metastases (LMs) remain a devastating complication of non-small cell lung cancer (NSCLC), particularly following osimertinib resistance. We conducted single-cell RNA sequencing on cerebrospinal fluid (CSF) from EGFR-mutant NSCLC with central nervous system metastases. We found that macrophages of LMs displayed functional and phenotypic heterogeneity and enhanced immunosuppressive properties. A population of lipid-associated macrophages, namely RNASE1_M, were linked to osimertinib resistance and LM development, which was regulated by Midkine (MDK) from malignant epithelial cells. MDK exhibited significant elevation in both CSF and plasma among patients with LMs, with higher MDK levels correlating to poorer outcomes in an independent cohort. Moreover, MDK could promote macrophage M2 polarization with lipid metabolism and phagocytic function. Furthermore, malignant epithelial cells in CSF, particularly after resistance to osimertinib, potentially achieved immune evasion through CD47-SIRPA interactions with RNASE1_M. In conclusion, we revealed a specific subtype of macrophages linked to osimertinib resistance and LM development, providing a potential target to overcome LMs.

Mechanisms of resistance and correlation between pre-treatment co-alterations and p-prognosis to osimertinib in chemo-naïve advanced non-small cell lung cancer.

BACKGROUND: Several patients treated with osimertinib experience progressive disease. The aim was to clarify the mechanisms underlying resistance to osimertinib. METHODS: ELUCIDATOR: A multi-centre, prospective, observational study involved chemotherapy-naive patients with advanced non-small cell lung cancer receiving osimertinib. Mutations in cancer-associated genes, detected via ultrasensitive next-generation sequencing of circulating tumour deoxyribonucleic acid samples, were collected at baseline and after progressive disease detection. These paired plasma samples were compared. RESULTS: Of 188 patients enrolled (May 2019-January 2021), 178 (119 females [67 %]) median age 74 years, were included. Patients, n = 95 (53 %) had epidermal growth factor receptor exon 19 deletion mutations. Among 115 patients with progressive disease, circulating tumour deoxyribonucleic acid levels of 85 patients were analysed. MET amplification (n = 4), TP53 mutations (n = 4), PIK3CA mutations (n = 3), BRINP3 mutation (n = 2), BRAF mutation (n = 2), APC mutation (n = 1), RET mutation (n = 1) and epidermal growth factor receptor (EGFR) resistance mutation, and C797S (n = 1) were detected. Patients with baseline TP53 mutations, with MET or EGFR amplification had shorter progression-free (PFS) and overall survival. Patients with PIK3CA mutations tended to shorter PFS. CONCLUSION: MET amplification and PIK3CA mutation mechanisms underly resistance to osimertinib in patients. Patients with coexisting mutations or amplifications at baseline had shorter PFS and overall survival.

Identification of potential inhibitors for drug-resistant EGFR mutations in non-small cell lung cancer using whole exome sequencing data.

Epidermal growth factor receptor (EGFR) gene mutations are prevalent in about 50% of lung adenocarcinoma patients. Highly effective tyrosine kinase inhibitors (TKIs) targeting the EGFR protein have revolutionized treatment for the prevalent and aggressive lung malignancy. However, the emergence of new EGFR mutations and the rapid development of additional drug resistance mechanisms pose substantial challenge to the effective treatment of NSCLC. To investigate the underlying causes of drug resistance, we utilized next-generation sequencing data to analyse the genetic alterations in different tumor genomic states under the pressure of drug selection. This study involved a comprehensive analysis of whole exome sequencing data (WES) from NSCLC patients before and after treatment with afatinib and osimertinib with a goal to identify drug resistance mutations from the post-treatment WES data. We identified five EGFR single-point mutations (L718A, G724E, G724K, K745L, V851D) and one double mutation (T790M/L858R) associated with drug resistance. Through molecular docking, we observed that mutations, G724E, K745L, V851D, and T790M/L858R, have negatively affected the binding affinity with the FDA-approved drugs. Further, molecular dynamic simulations revealed the detrimental impact of these mutations on the binding efficacy. Finally, we conducted virtual screening against structurally similar compounds to afatinib and osimertinib and identified three compounds (CID 71496460, 73292362, and 73292545) that showed the potential to selectively inhibit EGFR despite the drug-resistance mutations. The WES-based study provides additional insight to understand the drug resistance mechanisms driven by tumor mutations and helps develop potential lead compounds to inhibit EGFR in the presence of drug resistance mutations.

Treatment of cavitated non-small cell lung cancer presenting as "Halloween pumpkin" following the consecutive NEOADAURA and ADAURA2 strategy: A case report.

Osimertinib is a third-generation tyrosine kinase inhibitor that targets mutant epidermal growth factor receptor (EGFR). The success of FLAURA and ADAURA trials prompted the license of Osimertinib for the treatment of EGFR mutant non-small cell lung cancer (NSCLC) at advanced stage and for patients with stages IB to IIIA disease in post-operative setting. In the present study, we described neoadjuvant use of Osimertinib in an EGFR mutant NSCLC patient with locally metastatic disease (T2aN2M0). Intriguingly, the cavitated NSCLC resembled an impressive"Halloween pumpkin" appearance that dramatically responded to Osimertinib treatment. Downstaging of N2 metastatic disease was reached and surgical resection was scheduled. The post-operative clinical stage was IA3. The patient was recommended to continue Osimertinib adjuvant treatment and our follow-ups showed no signs of disease recurrence. Our case study underscored the feasibility of Osimertinib as a neoadjuvant and adjuvant therapy for patients with locally advanced EGFR mutant NSCLC.

Case report: Durable response of ensartinib targeting EML4-ALK fusion in osimertinib-resistant non-small cell lung cancer.

Background: Despite significant benefits from targeted therapy in patients with driver mutations, inevitable drug resistance usually occurred in non-small cell lung cancer, highlighting the necessity for sequential treatments to prolong overall survival. Unfortunately, durable drug response has not been reported in posterior-line therapy of cases with acquired EML4-ALK fusion after resistance to osimertinib, urging the need of referable decision-making in clinical management. Case presentation: We present a case of a 71-year-old Chinese female, never smoker, diagnosed with invasive adenocarcinoma in the left inferior lobe of her lung, with metastases in regional lymph nodes. She received erlotinib treatment after the detection of coexistent EGFR L858R/G719S and BRAF V600E via next-generation sequencing of resected tumor tissue. Routine imaging revealed disease progression approximately 14 months after starting erlotinib treatment, followed by the detection of EGFR L858R through non-invasive liquid biopsy. Subsequently, osimertinib was administered, showing clinical activities for nearly 19 months until the emergence of an EML4-ALK fusion. Given the EML4-ALK fusion, a relatively rare resistance mechanism to osimertinib, she received third-line ensartinib treatment. One month later, alleviated tumor lesions plus normal serum marker levels demonstrated the effectiveness of ensartinib in overcoming resistance to osimertinib. Of note, the clinical response to ensartinib persisted for more than 14 months, superior to the previously reported efficacy of aletinib and crizotinib in osimertinib-failure cases. As of the last follow-up in July 2022, the patient showed no signs of recurrence and maintained a good life quality. Conclusion: We reported a third-line ensartinib therapy in a patient with lung adenocarcinoma who developed an acquired EML4-ALK fusion after sequential treatment with erlotinib and osimertinib. Given the rarity of the EML4-ALK fusion as a resistance mechanism to osimertinib, ensartinib emerges as a promising treatment option for this specific clinical challenge, offering superior efficacy and good safety.

Strategies for enhancing non-small cell lung cancer treatment: Integrating Chinese herbal medicines with epidermal growth factor receptor-tyrosine kinase inhibitors therapy.

Non-small cell lung cancer (NSCLC) poses a global health threat, and epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) such as gefitinib, afatinib, and osimertinib have achieved significant success in clinical treatment. However, the emergence of resistance limits the long-term efficacy of these treatments, necessitating urgent exploration of novel EGFR-TKIs. This review provides an in-depth summary and exploration of the resistance mechanisms associated with EGFR-TKIs, with a specific focus on representative drugs like gefitinib, afatinib, and osimertinib. Additionally, the review introduces a therapeutic strategy involving the combination of Chinese herbal medicines (CHMs) and chemotherapy drugs, highlighting the potential role of CHMs in overcoming NSCLC resistance. Through systematic analysis, we elucidate the primary resistance mechanisms of EGFR-TKIs in NSCLC treatment, emphasizing CHMs as potential treatment medicines and providing a fresh perspective for the development of next-generation EGFR-TKIs. This comprehensive review aims to guide the application of CHMs in combination therapy for NSCLC management, fostering the development of more effective and comprehensive treatment modalities to ultimately enhance patient outcomes.

Complete response in a lung adenocarcinoma with pleural metastases initially treated with gefitinib and switched to osimertinib after cerebral oligo-progression with unknown T790M mutation: a case report and review of literature.

BACKGROUND: First- and second-generation anti-epithelial growth factor receptor tyrosine kinase inhibitors have shown great efficacy in the treatment of advanced adenocarcinoma with epithelial growth factor receptor mutations, but this efficacy is limited by certain resistance mechanisms, in particular the T790M mutation, which must be screened before second-line treatment with osimertinib is indicated. The search for this mutation is sometimes difficult, especially in cases of intracranial relapse, through this case report we attempt to discuss the possibility of initiating treatment with osimertinib despite an unknown T790M mutation in such situation. CASE REPORT: We present the case of a 70-year-old Moroccan male patient diagnosed with non-small cell lung carcinoma initially metastatic to the pleura with an epithelial growth factor receptor mutation who received gefitinib in first line with a complete response, he subsequently presented with cerebral oligo-progression with extra cranial stability. The patient was started on osimertinib with unknown T790M status, as it was impossible to perform a cerebral biopsy, the evolution was characterized by a partial response followed by stereotactic radiotherapy then a complete response for 2 years. CONCLUSION: We can discuss osimertinib as an option for patients with stage IV non-small cell lung cancer with brain oligo-progression on prior tyrosine kinase inhibitors and unknown T790M status, further studies are needed in this area.

Osimertinib-induced DNA resistance mutations in cerebrospinal fluid of EGFR mutated NSCLC patients developing leptomeningeal metastases: ORA-LM study.

BACKGROUND: Diagnosis and treatment of leptomeningeal metastases (LM) in epidermal growth factor receptor mutation positive (EGFRm+) NSCLC is challenging. We aimed to identify resistance mechanisms (RM) to osimertinib in cerebrospinal fluid (CSF) and plasma. METHODS: EGFRm+ patients with new or progressive LM during osimertinib were enrolled. NGS Ampliseq was performed on DNA isolated from CSF. Patients were prescribed osimertinib dose escalation (DE, 160mg QD) following lumbar puncture. Clinical and radiological response was evaluated four weeks after osimertinib DE. RESULTS: Twenty-eight patients were included. The driver mutation was identified in 93% of CSF samples (n=26). Seven (27%) harbored ≥1 RM. Twenty-five patients (89%) were prescribed osimertinib DE. Four weeks afterwards, symptoms improved in five patients, stabilized in nine and worsened in eleven patients. Twenty-one (84%) patients underwent MR imaging. Four showed radiological improvement, fourteen stabilization, and three worsening. CONCLUSIONS: In 27% of patients an RM was found in CSF ctDNA, none of which are targetable at time of writing, and clinical efficacy of osimertinib DE seems limited. There is much to gain in diagnostic as well as therapeutic strategies in EGFRm+ NSCLC LM.

Trochlear nerve schwannoma with concomitant osimertinib-responsive stage IV lung adenocarcinoma: illustrative case.

BACKGROUND: The prognosis for cancer patients has been improved because of the development of molecularly targeted drugs. Treatment of intracranial tumors must be personalized while prioritizing the treatment of comorbid cancers. OBSERVATIONS: A 38-year-old man presented with bloody sputum, bilateral multiple nodules, and a mass in the lower lobe of his right lung. Bronchoscopy revealed stage IV lung adenocarcinoma with an epidermal growth factor receptor (EGFR) mutation. Screening head magnetic resonance imaging revealed a 38-mm-diameter mass in the left petroclival area. Because the patient was neurologically intact, the treatment of lung adenocarcinoma was prioritized, and the third-generation EGFR-tyrosine kinase inhibitor osimertinib was used. Although nodules in the lung began to shrink, the intracranial lesion expanded and caused hydrocephalus, necessitating a ventriculoperitoneal shunt. The tumor also caused diplopia, dysarthria, and gait abnormalities. A left anterior transpetrosal approach was used to remove the tumor derived from the trochlear nerve. The pathological examination revealed schwannoma. Neurological symptoms improved following surgery. Osimertinib was continued during the perioperative period. LESSONS: Osimertinib was effective for lung adenocarcinoma but not for trochlear nerve schwannoma, which required surgical intervention. It is necessary to tailor the treatment of benign brain tumors in patients with concurrent malignant cancers. https://thejns.org/doi/10.3171/CASE24144.

Osimertinib-induced BRAF mutation in a single metastatic lesion among multiple pulmonary lesions in a case of lung cancer with EGFR exon 19 deletion.

One of the resistant mechanisms of EGFR-TKIs is BRAF V600E mutation. Herein, we present the case of a 54-year-old Japanese female who underwent a right middle lobectomy for pathological stage IIB lung adenocarcinoma. One year and nine months after the surgery, she developed multiple intrapulmonary metastases. Osimertinib was administered due to EGFR exon 19 deletion. Although all intrapulmonary metastases had shrunk, the nodule at the superior segment of left lung enlarged after postoperative 4 years. The tumour was resected and BRAF V600E mutation and exon 19 deletion were detected. Three months after treatment with dabrafenib and trametinib instead of osimertinib, the remaining intrapulmonary metastases increased again. The continued growth of the metastatic foci even after EGFR-TKI may indicate an acquired resistance. Thus, a repeat biopsy will aid in confirming the new gene expression. It should have been necessary to administer an additional dose of dabrafenib and trametinib without discontinuing osimertinib.

The Ineffectiveness of Osimertinib in Epidermal Growth Factor Receptor (EGFR)-Mutated Stage IV Lung Adenocarcinoma With Bone Metastasis: A Case Report.

This case report examines the effectiveness of osimertinib in a 64-year-old non-smoking female diagnosed with stage IV lung adenocarcinoma and an epidermal growth factor receptor (EGFR) exon 19 mutation, focusing on the treatment's impact on bone metastasis. Despite initial responsiveness to osimertinib, the patient's bone lesions remained largely unresponsive, prompting a comprehensive exploration of alternative treatments and clinical trials. This report highlights the patient's clinical journey, from diagnosis through various treatment phases, culminating in palliative care, and underscores the need for further research into targeted treatments for bone metastasis in lung cancer.

Synchronous Double Primary Lung Adenocarcinomas With EGFR L858R Point Mutation and MET Exon 14 Skipping Mutation.

Various driver mutations and the corresponding molecular-targeted drugs have been detected and developed in non-small cell lung cancer. There were many cases in which surgical specimens had happened to find double primary cancers. However, to our knowledge, our case was the first report of synchronous double primary lung adenocarcinomas harboring epidermal growth factor receptor (EGFR) L858R and mesenchymal-to-epithelial transition (MET) exon 14 skipping mutations. A 75-year-old Japanese woman with chronic heart and renal failures was referred to our department because of a growing nodule in the right upper lung field on chest X-ray films. Chest computed tomography (CT) detected a nodule in the right S1 and another nodule in the left S1+2. Bronchoscopic biopsy diagnosed the right S1 nodule as moderately differentiated adenocarcinoma. Oncomine Dx Target Test Multi-CDx system of the right S1 adenocarcinoma detected EGFR L858R mutation. The 18F-fluorodeoxyglucose positron emission tomography/CT showed abnormal uptakes both in the right S1 and the left S1+2 nodules, and in the bilateral inferior paratracheal lymph nodes. We made a diagnosis of c-stage IIIA (cT1bN2M0) of adenocarcinoma in the right S1 and suspected another primary lung cancer in the left S1+2. Considering her general conditions, comorbidities and wishes, we started osimertinib. The right S1 cancer achieved partial response (PR), while the left S1+2 nodule and lymph nodes enlarged. Aspiration cytology from the left supraclavicular lymph node showed adenocarcinoma. The FoundationOne® Liquid CDx tumor profiling test detected not only EGFR L858R, but also MET exon 14 skipping mutation. We made a diagnosis of another primary adenocarcinoma from the left S1+2 nodule (cT1bN3M0, c-stage IIIB) with MET mutation, and changed osimertinib to capmatinib. Although the left S1+2 cancer achieved and maintained PR by capmatinib, the right S1 cancer increased, and several new metastases appeared. The subsequent switch from capmatinib to osimertinib could not control cancers. In this case, we tried to switch monotherapies from osimertinib to capmatinib for double primary adenocarcinomas harboring different two driver mutations, according to each cancer progression. The temporal and spatial heterogeneity reinforces the need for primary tissue biopsy if dual primaries are suspected. Temporally distinct liquid biopsies, not standard at present, may be considered.

Oral lichenoid drug eruption due to osimertinib for lung cancer.

INTRODUCTION: Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR) are linked with side effects involving skin and mucosa. Herein, we present a unique case of oral lichenoid drug eruption (LDE) in a patient treated with osimertinib. CASE REPORT: A 75-year-old woman was diagnosed with metastatic EGFR-mutated lung adenocarcinoma, and started on osimertinib 80 mg PO daily. At 24 months of therapy, the patient developed a painful, red, and white striated oral lesion involving the left buccal mucosa and the adjacent buccal aspect of gingivae. Biopsy showed oral LDE. Causality assessment between osimertinib and the oral LDE via Naranjo Adverse Drug Reaction probability scale revealed a score of 5. MANAGEMENT AND OUTCOME: Osimetinib discontinuation was not felt to be in the best interest of the patient. Therefore, diphenhydramine HCL mouthwash every 6 h PRN (before meals) was started. Spicy and hot foods were discontinued. At a four-week follow-up visit, the patient reported moderate improvement in her symptoms. CONCLUSION: Oral LDEs are considered premalignant lesions as they can transform into squamous cell carcinoma; therefore, regular follow-up is needed. Awareness of this potential side effect of osimertinib would also prevent unnecessary (and potentially costly) work-up and lead to its prompt diagnosis and treatment.

Radical resection in a patient with stage IIIA non-small cell lung cancer with the EGFR exon 19 deletion mutation after neoadjuvant targeted therapy with osimertinib: a case report.

Background: With the advent of targeted therapies, the survival rates of patients with locally advanced lung cancer have significantly improved. However, there is limited research on the efficacy of neoadjuvant targeted therapy in resectable advanced non-small cell lung cancer (NSCLC) patients with positive driver genes. This article reports a case of stage IIIA NSCLC with an epidermal growth factor receptor (EGFR) 19del mutation that successfully underwent radical lung cancer surgery following neoadjuvant targeted therapy. By observing the perioperative treatment outcomes and side effects in this patient, we aimed to provide insights and summarize experiences for treating similar cases in the future. Case Description: We report a case of a 54-year-old female diagnosed preoperatively with stage IIIA adenocarcinoma of the left upper lung (cT1cN2M0). The patient's course was complicated by acute sick sinus syndrome and was cured by implanting a permanent pacemaker. After multidisciplinary discussion, it was decided to administer neoadjuvant targeted therapy with osimertinib. Following 6 weeks of treatment, the tumor assessment showed partial response (PR), making the patient eligible for surgery. The patient underwent single-port thoracoscopic left upper lobectomy + mediastinal lymphadenectomy. Intraoperatively, the left hilar lymph nodes were found to be tightly adherent to the apical-anterior branch of the left upper pulmonary artery. The main trunk of the left pulmonary artery was temporarily occluded with a vascular clamp to safely dissect the left upper pulmonary artery. The procedure was completed without conversion to open thoracotomy, achieving an R0 resection. Postoperative pathology confirmed stage IIIA (ypT1bN2M0), and the patient continued adjuvant therapy with osimertinib. Conclusions: Neoadjuvant targeted therapy with osimertinib is expected to become one of the options for neoadjuvant therapy in locally advanced NSCLC with sensitizing EGFR mutations. And for those with advanced lung cancer involving tumors close to the hilum or mediastinal lymph node metastasis, preblocking of the left upper pulmonary artery can help improve surgical safety and better ensure R0 resection.

First-line Osimertinib for Lung Cancer With Uncommon EGFR Exon 19 Mutations and EGFR Compound Mutations.

Introduction: Up to 20% of EGFR-mutated NSCLC cases harbor uncommon EGFR mutations, including atypical exon 19 and compound mutations. Relatively little is known about the efficacy of osimertinib in these cases. Methods: Patients treated with first-line osimertinib for NSCLC with rare EGFR exon 19 (non E746_A750del) or compound mutations were included. Response assessment and time to progression were determined using Response Evaluation Criteria in Solid Tumors version 1.1 criteria. Kaplan-Meier analyses were used to estimate progression-free survival (PFS), time to treatment discontinuation (TTD), and overall survival (OS). Results: Thirty-seven patients with NSCLC harboring an atypical EGFR exon 19 mutation or compound mutation were treated with first-line osimertinib at Johns Hopkins from 2016 to 2021. Overall response rate (ORR) was 76% and median PFS, TTD, and OS were 13 months (95% confidence interval [CI]: 10-15), 22 months (95% CI: 17-32) and 36 months (95% CI, 29-48), respectively. Among atypical exon 19 mutations (n = 25), ORR was 80%, median PFS was 12 months (95% CI: 10-15), median TTD was 19 months (95% CI: 17-38), and median OS was 48 months (95% CI: 25-not reached). Compound mutations (n = 12) had an ORR of 67%, median PFS of 14 months (95% CI: 5-22), median TTD of 26 months (95% CI: 5-36), and median OS of 36 months (95% CI: 20-46). Twelve patients (32%) continued first-line osimertinib after local therapy for oligoprogression. Conclusions: Osimertinib exhibited favorable outcomes for rare EGFR exon 19 and compound mutations. The heterogeneity in outcomes among these groups of tumors with similar mutations underscores the need for continued reporting and further study of outcomes among rare variants to optimize management for each patient.

Comparing the Effectiveness of Afatinib and Osimertinib for Patients With PD-L1-positive EGFR-mutant Non-small Cell Carcinoma.

Background/Aim: Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are effective for treating non-small cell lung cancer (NSCLC) harboring EGFR mutations. However, higher tumor programmed death ligand-1 (PD-L1) expression is associated with a poor response to EGFR-TKIs, and information on the comparison between afatinib and osimertinib in PD-L1-positive EGFR-mutant NSCLC is scarce. Patients and Methods: We retrospectively analyzed data of patients with PD-L1-positive EGFR-mutant NSCLC to compare the effectiveness of afatinib and osimertinib. Results: A total of 177 patients were included in the study. The Cox proportion hazard model was adjusted for age, sex, performance status, EGFR mutation status, PD-L1 expression level, and brain metastasis, revealing that there was no significant difference in risk for progression [hazard ratio (HR)=0.99, 95% confidence interval (CI)=0.64-1.53] or death (HR=0.96, 95% CI=0.54-1.73) between afatinib and osimertinib. Conclusion: In conclusion, the EGFR-TKI treatment duration and overall survival after the treatment with afatinib or osimertinib were similar in patients with PD-L1-positive EGFR-mutant NSCLC in the present study.

Durable Response of Pembrolizmab for EGFR Mutation-positive Lung Adenocarcinoma with Early Progression to Osimertinib in First-line Treatment.

Osimertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), is the standard first-line treatment for EGFR mutation-positive non-small-cell lung cancer (NSCLC) and demonstrates favorable disease control. Conversely, immune checkpoint inhibitors (ICIs) that target programmed cell death-1/programmed cell death ligands demonstrate a restrictive tumor response. We herein report a patient who achieved a durable response to pembrolizumab following early progression within two months of osimertinib administration for EGFR mutation-positive lung adenocarcinoma. Our findings suggest that treatment with ICIs for patients with EGFR mutation-positive NSCLC experiencing early progression to osimertinib as first-line treatment might represent a viable approach.