Sequential treatment of afatinib and osimertinib or other regimens in patients with advanced non-small-cell lung cancer harboring EGFR mutations: Results from a real-world study in South Korea

Does dose reduction of afatinib affect treatment outcomes of patients with EGFR-mutant metastatic non-small cell lung cancer in real-world clinical practice?

Background

Afatinib can be started at a dose lower than the recommended starting dose of 40 mg/day for the treatment of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC), however treatment outcomes in real-world clinical practice remains unclear.

Methods

This retrospective study of patients with NSCLC from 18 major hospitals (public, private or university teaching hospitals) enrolled in Malaysia's National Cardiovascular and Thoracic Surgical Database (NCTSD) assessed the efficacy of lower doses of afatinib on treatment outcomes in a real-world clinical practice. Data on clinical characteristics, afatinib dosing, and treatment outcomes for patients included in NCTSD from 1st January 2015 to 31st December 2020 were analyzed.

Results

Of the 133 patients studied, 94.7% had adenocarcinoma. Majority of the patients (60.9%) had EGFR exon 19 deletion and 23.3% had EGFR exon 21 L858R point mutation. The mean age of patients was 64.1 years and majority (83.5%) had Eastern Cooperative Oncology Group performance status of 2-4 at diagnosis. The most common afatinib starting doses were 40 mg (37.6%), 30 mg (29.3%), and 20 mg (26.3%) once daily (OD), respectively. A quarter of patients had dose reduction (23.3%) due to side effects or cost constraints. Majority of the patients had partial response to afatinib (63.2%) whilst 2.3% had complete response. Interestingly, the objective response rate was significantly higher (72.3%) with afatinib OD doses of less than 40 mg compared to 40 mg (54.0%) (P=0.032). Patients on lower doses of afatinib were two times more likely to achieve an objective response [odds ratio =2.64; 95% confidence interval (CI): 1.20-5.83; P=0.016]. These patients had a numerically but not statistically longer median time to treatment failure (TTF). Median TTF (95% CI) for the overall cohort was 12.4 (10.02-14.78) months. Median overall survival (95% CI) was 21.30 (15.86-26.75) months.

Conclusions

Lower afatinib doses (<40 mg OD) could be equally effective as standard dose in patients with EGFR-mutant advanced NSCLC and may be more suited to Asian patients, minimizing side effects that may occur at higher dosages of afatinib leading to dose interruptions and affecting treatment outcomes.

Final Report on Real-World Effectiveness of Sequential Afatinib and Osimertinib in EGFR-Positive Advanced Non-Small Cell Lung Cancer: Updated Analysis of the RESET Study

PURPOSE

This study aimed to report the final analysis of time-on-treatment (TOT) and overall survival (OS) in patients with advanced-stage epidermal growth factor receptor (EGFR)+ non-small cell lung cancer (NSCLC) who received sequential afatinib and osimertinib and to compare the outcomes with other second-line regimens (comparator group).

MATERIALS AND METHODS

In this updated report, the existing medical records were reviewed and rechecked. TOT and OS were updated and analyzed according to clinical features using the Kaplan-Meier method and log-rank test. TOT and OS were compared with those of the comparator group, in which most patients received pemetrexed-based treatments. A multivariable Cox proportional hazard model was used to evaluate features that could affect survival outcomes.

RESULTS

The median observation time was 31.0 months. The follow-up period was extended to 20 months. A total of 401 patients who received first-line afatinib were analyzed (166 with T790M+ and second-line osimertinib, and 235 with unproven T790M and other second-line agents). Median TOTs on afatinib and osimertinib were 15.0 months (95% confidence interval [CI], 14.0 to 16.1) and 11.9 months (95% CI, 8.9 to 14.6), respectively. The median OS in the osimertinib group was 54.3 months (95% CI, 46.7 to 61.9), much longer than that in the comparator group. In patients who received osimertinib, the OS was longest with Del19+ (median, 59.1; 95% CI, 48.7 to 69.5).

CONCLUSION

This is one of the largest real-world studies reporting the encouraging activity of sequential afatinib and osimertinib in Asian patients with EGFR+ NSCLC who acquired the T790M mutation, particularly Del19+.

Treatment Strategies for Non-Small Cell Lung Cancer with Common EGFR Mutations: A Review of the History of EGFR TKIs Approval and Emerging Data

The development of targeted therapies over the past two decades has led to a dramatic change in the management of EGFR-mutant non-small cell lung cancer (NSCLC). While there are currently five approved EGFR tyrosine kinase inhibitors (TKIs) for treating EGFR-mutant NSCLC in the first-line setting, therapy selection after progression on EGFR TKIs remains complex. Multiple groups are investigating novel therapies and drug combinations to determine the optimal therapy and treatment sequence for these patients. In this review, we summarize the landmark trials and history of the approval of EGFR TKIs, their efficacy and tolerability, and the role of these therapies in patients with central nervous system metastasis. We also briefly discuss the mechanisms of resistance to EGFR TKIs, ongoing attempts to overcome resistance and improve outcomes, and finalize by offering treatment sequencing recommendations.

Application of several machine learning algorithms for the prediction of afatinib treatment outcome in advanced-stage EGFR-mutated non-small-cell lung cancer

BACKGROUND

The present study aimed to evaluate the performance of several machine learning (ML) algorithms in predicting 1-year afatinib continuation and 2-year survival after afatinib initiation and to identify the differences in survival outcomes between ML-classified strata.

METHODS

Data that were also used in the RESET study were retrospectively collected from 16 hospitals in South Korea. A stratified random sampling method was applied to split the data into training and test sets (70:30 split ratio). Clinical information, such as age, sex, tumor stage, smoking, performance status, metastasis, type of metastasis, dose adjustment, and pathologic information on EGFR mutations were inputted. Training was performed using eight ML algorithms: logistic regression, decision tree, deep neural network, random forest, support vector machine, boosting, bagging, and the naïve Bayes classifier. The model performance was assessed based on sensitivity, specificity, and accuracy. Area under the receiver operator characteristic curve (AUC) was calculated and compared between the ML models using DeLong's test. A Kaplan-Meier (KM) curve was used to visualize the identified strata obtained from the ML models.

RESULTS

No significant differences in the input variables were observed between the training and test datasets. The best-performing models were support vector machine in predicting 1-year afatinib continuation (AUC 0.626) and decision tree in 2-year survival after afatinib start (AUC 0.644), although the performances of the ML models were comparable and did not display any predictive roles. KM analysis and log-rank test revealed significant differences between the strata identified from the ML model (p < 0.001) in terms of both time-on-treatment (TOT) and overall survival (OS).

CONCLUSION

The performances of ML models in our study found no discernible roles in predicting afatinib-related outcomes, although the identified strata revealed different TOT and OS in the KM analysis. This implies the strength of ML in predicting the survival outcome, as well as the limitation of electronic medical record-based variables in ML algorithms. Careful consideration of variable inclusion is likely to improve the general model performance.

Sequential treatment in advanced non-small cell lung cancer harboring EGFR mutations

BACKGROUND

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are standard treatments for advanced EGFR-mutated non-small cell lung cancer (NSCLC) patients. Osimertinib is an effective therapy for NSCLC patients with acquired resistance due to T790M mutation after first- and second-generation EGFR-TKI treatment. This study aimed to analyze the clinical outcomes of sequential therapy following first-line EGFR-TKIs and the predictive factors of an acquired T790M mutation.

METHODS

Between January 2014 and December 2018, data from 2190 advanced NSCLC patients with common EGFR mutations (exon 19 deletion and L858R) receiving first- and second-generation EGFR-TKIs in Linkou, Kaohsiung, Chiayi and Keelung Chang Gung Memorial Hospitals were retrospectively retrieved and analyzed.

RESULTS

Until August 2021, among 1943 patients who experienced progressive disease, 526 underwent T790M mutation tests, and their T790M-positive rate was 53.6%. Exon 19 deletion mutation and progression-free survival (PFS) of >12 months were positively associated with secondary T790M mutation. Different first-line first- and second-generation EGFR-TKI therapies did not affect the appearance of acquired T790M mutations. The median overall survival (OS) was 58.3 [95% confidence interval (CI): 49.0-67.5] months among the patients with T790M mutation who received second-line osimertinib therapy compared with 31.0 (95% CI: 27.5-34.5) months among the patients without T790M mutation who received chemotherapy alone. The multivariate analysis showed that a poor performance status (score: >2), nonadenocarcinoma histology, stage IV cancer, liver metastasis, brain metastasis, PFS while on first-line EGFR-TKIs, and subsequent chemotherapy without third-generation EGFR-TKIs were significant independent unfavorable prognostic factors for OS.

CONCLUSION

This study demonstrated the efficacy of first-line EGFR-TKIs and sequential osimertinib therapy. The results of our study suggest that T790M mutation tests are important for the use of subsequent osimertinib, which yielded favorable survival outcomes.

Sequential Afatinib and Osimertinib in Asian Patients with EGFR Mutation-Positive Non-Small Cell Lung Cancer and Acquired T790M: Combined Analysis of Two Global Non-Interventional Studies

Objective

Two recent non-interventional trials, GioTag and UpSwinG, demonstrated encouraging time-to-treatment failure (TTF) and overall survival (OS) in patients with epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC) (Del19 or L858R) who received sequential afatinib/osimertinib, especially in Asians. Here, we have undertaken a combined analysis of Asian patients from both studies.

Materials and Methods

Existing medical/electronic records were identified for consecutive EGFR-tyrosine kinase inhibitor (TKI)-naïve patients who received first-line afatinib/second-line osimertinib in “real-world” practice (all T790M-positive). Patients with active brain metastases were excluded. The primary objective was TTF. OS was a key secondary objective.

Results

One hundred and sixty-eight patients were analyzed. Most patients were recruited from South Korea or Japan (52/21%). At the start of afatinib, median age (range) was 61.5 years (35–88), 58% were female, Eastern Cooperative Oncology Group Performance Status (ECOG PS) (0/1/≥2) was 29/62/9%, 17% had brain metastases, and EGFR mutation status (Del19/L858R) was 65/35%. At the start of osimertinib, ECOG PS (0/1/≥2) was 22/61/17% and 14% had brain metastases. Median TTF and OS were 30.0 months (95% CI: 24.5–32.5) and 45.2 months (95% CI: 41.7–71.1), respectively. Median OS was 63.5 months in patients with a Del19 mutation. Median OS in patients with brain metastases or ECOG PS ≥2 was 26.4 and 33.1 months, respectively.

Conclusion

Sequential afatinib/osimertinib showed encouraging activity in Asian patients with EGFR mutation-positive NSCLC and T790M-mediated acquired resistance, especially those with Del19-positive disease. Activity was observed across “real-world” patients including those with poor ECOG PS and/or brain metastases. ECOG PS and incidence of brain metastases remained stable prior to, and after, afatinib.

Optimizing Patient Outcomes Through Sequential EGFR TKI Treatment in Asian Patients With EGFR Mutation-Positive NSCLC

Patients from Asia with non-small-cell lung cancer (NSCLC) often have mutations in the epidermal growth factor receptor (EGFR) gene. While an increasing number of EGFR tyrosine kinase inhibitors (TKIs) are now available for patients with EGFR mutation-positive NSCLC, most patients inevitably develop resistance to the treatment. Evidence from clinical studies suggests that treatment outcomes and resistance mechanisms vary depending on the choice of TKI therapy in the first-line setting. Hence, it is important to develop optimal treatment sequencing strategies that can provide maximum survival benefit for the patient. In this review we present clinical evidence in Asian patients with NSCLC for various EGFR TKIs, with the goal of supporting the optimization of treatment sequencing.

Survival benefits from afatinib compared with gefitinib and erlotinib among patients with common EGFR mutation in first-line setting

Background

Epidermal growth factor receptor‐tyrosine kinase inhibitors (EGFR‐TKIs) are recommended as first‐line treatment in non‐small cell lung cancer (NSCLC) patients with sensitizing EGFR mutations. The sequential use of different EGFR‐TKIs has been reported to demonstrate improvement in overall survival of NSCLC patients with EGFR mutations. There are limited reports on comparisons between regimens with first‐line use of afatinib, gefitinib or erlotinib, followed by osimertinib upon disease progression with acquired T790M mutation.

Methods

A retrospective cohort study of Chinese patients with metastatic NSCLC harboring EGFR mutations who received first‐line gefitinib, erlotinib or afatinib treatment, followed by osimertinib upon disease progression with acquired T790M mutation, was conducted. The differences in overall survival (OS) and progression‐free survival (PFS) with first‐line EGFR‐TKI (PFS1) and time to second objective disease progression (PFS2) were compared among patients on different first‐line EGFR‐TKIs.

Results

Among 155 patients, 101 (65.2%), 38 (24.5%) and 16 (10.3%) patients were on first‐line gefitinib, erlotinib or afatinib, respectively. Patients treated with afatinib in the first‐line setting had significantly longer OS compared with those on gefitinib or erlotinib, while the PFS1 and PFS2 were longer for patients on afatinib but did not reach statistical significance.

Conclusions

First‐line afatinib, followed by osimertinib upon disease progression with T790M mutation, demonstrated significantly longer OS compared to that using other EGFR‐TKI in the first‐line setting.