Re-challenge of afatinib after 1st generation EGFR-TKI failure in patients with previously treated non-small cell lung cancer harboring EGFR mutation

EGFR-TKI rechallenge in patients with EGFR-mutated non-small-cell lung cancer who progressed after first-line osimertinib treatment: A multicenter retrospective observational study

BACKGROUND

Rechallenge therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) is known to confer some clinical benefit for patients with metastatic EGFR-mutated non-small cell lung cancer (NSCLC). However, little is known about the efficacy of EGFR-TKI rechallenge after resistance to first-line (1L) osimertinib. This study aimed to assess the efficacy and safety of EGFR-TKI rechallenge therapy after resistance to 1L osimertinib in a Japanese clinical setting.

METHODS

Between April 2018 and August 2022, 26 patients who progressed after treatment with 1L osimertinib and received EGFR-TKI rechallenge were included in this multicenter retrospective analysis. Patients in whom 1L osimertinib was discontinued owing to toxicity and had subsequent disease progression were also included in the analysis.

RESULTS

Overall, the objective response rate for rechallenge therapy was 23.1%. The disease control rate was 53.9%, and the median progression-free survival (PFS) was 3.4 months. Patients who discontinued 1L osimertinib for toxicity had a higher response rate (42.9% vs. 15.8%) and longer PFS than those who discontinued it due to disease progression (median: 11.4 vs. 2.7 months, P = 0.001). Three patients (11.5%) developed rechallenge therapy-associated pneumonitis, two of which were grade ≥3.

CONCLUSIONS

Rechallenge with EGFR-TKI after 1L osimertinib resistance showed limited clinical efficacy. However, it could be considered as a subsequent salvage therapeutic option for patients in whom 1L osimertinib was discontinued owing to toxicity.

Clinical Efficacy and Safety of First- or Second-Generation EGFR-TKIs after Osimertinib Resistance for EGFR Mutated Lung Cancer: A Prospective Exploratory Study

BACKGROUND

Osimertinib monotherapy is a common treatment for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC); however, standard treatment strategies for acquired resistance to this drug have not been established. In addition, the clinical significance of first-generation (1G) or second-generation (2G) EGFR-tyrosine kinase inhibitors (TKI) in patients with EGFR-mutant NSCLC and osimertinib resistance has not yet been fully evaluated.

OBJECTIVE

We aimed to conduct a prospective multicenter observational study to evaluate the efficacy and safety of 1G and 2G EGFR-TKIs after the development of osimertinib resistance.

METHODS

Patients with EGFR-mutant NSCLC who received 1G or 2G EGFR-TKIs after developing resistance to osimertinib monotherapy were prospectively assessed at eight institutions in Japan. The primary endpoint was progression-free survival (PFS).

RESULTS

A total of 29 patients with advanced or recurrent EGFR-mutant NSCLC were analyzed. The objective response and disease control rates were 6.9% (2/29) and 58.6% (17/29), respectively. The median PFS was 1.9 months [95% confidence interval (CI): 1.3-5.3]. There was no significant difference in PFS between the 1G and 2G EGFR-TKI groups (3.7 versus 1.5 months, log-rank test p = 0.20). However, patients with normal cytokeratin 19 fragment (CYFRA 21-1) and pro-gastrin-releasing peptide (ProGRP) levels experienced longer PFS than those with elevated CYFRA 21-1 and/or ProGRP (5.5 versus 1.3 months, log-rank test p < 0.001).

CONCLUSION

Administration of 1G or 2G EGFR-TKIs after the development of osimertinib resistance has limited efficacy in patients with EGFR-mutant NSCLC. Moreover, normal CYFRA 21-1 and ProGRP levels could be promising indicators for 1G and 2G EGFR-TKI administration after osimertinib resistance development.

TRIAL REGISTRATION NUMBER

UMIN000044049.

Rechallenge with EGFR-TKI after failure of immunotherapy is considered an effective treatment for advanced lung adenocarcinoma patients with EGFR exon 19 deletion: a case report

In advanced lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutation, epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have an excellent and long-lasting therapeutic response; however, virtually all patients eventually develop drug resistance and experience disease progression. The use of immunotherapy after EGFR-TKIs may be a successful therapeutic option for individuals who are resistant to them. It is still unclear if EGFR-TKIs can be administered again after immunotherapy has failed. We describe a case of a 37-year-old woman who was found to have T4N3M1a stage IVa lung adenocarcinoma. Amplification refractory mutation system PCR (ARMS-PCR) genetic testing suggested EGFR exon 19 deletion. The patient was initially treated with a regimen of icotinib (125  mg tid) combined with anlotinib (8  mg qd d1-d14) with an optimal efficacy rating of partial response (PR) and was granted a PFS of 7  months. In second-line treatment, the patient received three cycles of a KN046 (KN046 is a bispecific antibody inhibitor of PD-L1 and CTLA-4) 295  mg d1, pemetrexed 800 mg d1, plus carboplatin 750  mg d1 regimen, with an optimal efficacy rating of stable disease (SD) on CT. The third-line therapy was chosen to be afatinib with docetaxel, and the patient was evaluated for PR on CT. Up to 15 August 2022, the patient had a progression free survival (PFS) of 14 months. The successful treatment of this patient is a reminder that EGFR-TKI rechallenge in EGFR exon 19 deletion patients with EGFR-TKI resistance, in which immunotherapy has failed, may be effective.

Stratification of non-small cell lung adenocarcinoma patients with EGFR actionable mutations based on drug-resistant stem cell genes

EGFR-TKIs were used in NSCLC patients with actionable EGFR mutations and prolong prognosis. However, most patients treated with EGFR-TKIs developed resistance within around one year. This suggests that residual EGFR-TKIs resistant cells may eventually lead to relapse. Predicting resistance risk in patients will facilitate individualized management. Herein, we built an EGFR-TKIs resistance prediction (R-index) model and validate in cell line, mice, and cohort. We found significantly higher R-index value in resistant cell lines, mice models and relapsed patients. Patients with an elevated R-index had significantly shorter relapse time. We also found that the glycolysis pathway and the KRAS upregulation pathway were related to EGFR-TKIs resistance. MDSC is a significant immunosuppression factor in the resistant microenvironment. Our model provides an executable method for assessing patient resistance status based on transcriptional reprogramming and may contribute to the clinical translation of patient individual management and the study of unclear resistance mechanisms.

Incidence of serious adverse events caused by tyrosine kinase inhibitor treatment following immune checkpoint inhibitor therapy in advanced NSCLC patients with oncogenic driver alterations

BACKGROUND

Sequential tyrosine kinase inhibitors (TKIs) following immune checkpoint inhibitors (ICIs) increases the incidence of serious adverse events (SAEs). However, the factors and the types of TKIs that affect the incidence of SAEs remain unknown.

METHODS

We retrospectively reviewed advanced non-small cell lung cancer (NSCLC) patients who received sequential TKIs following ICIs between November 2015 and April 2021. All AEs were evaluated using Common Terminology Criteria for Adverse Events (CTCAE) ver 5.0.

RESULTS

Among 1,638 NSCLC patients who received ICIs, 63 patients received sequential TKIs following ICIs. The types of TKIs included EGFR-TKIs in 48 patients, ALK-TKIs in 10 patients, and others in 5 patients. The median dosing interval was 57 days (range: 7-698). Eighteen (28.6%) patients developed SAEs (Grade 3/4 or hospitalized). The incidence of SAEs and withdrawal of TKIs due to AEs were significantly higher in patients (n = 40) who initiated TKI treatment within 3 months after ICIs than in patients (n = 23) who initiated TKI treatment 3 months after ICIs (SAEs, 40.0% vs. 4.3%, p < 0.01; withdrawal rate: 57.5% vs. 21.7%, p < 0.01). There was no significant difference in the incidence of SAEs and withdrawal rate due to AEs between EGFR-TKIs and other TKIs (SAE, 22.9% vs. 40.0%, p = 0.20; withdrawal rate: 41.7% vs. 53.3%, p = 0.55).

CONCLUSION

The dosing interval from last ICI to the initiation of TKI treatment can affects the incidence of SAEs and the withdrawal rate due to AEs regardless of the types of TKIs.

Clinical efficacy of dacomitinib in rechallenge setting for patients with epidermal growth factor receptor mutant non-small cell lung cancer: A multicenter retrospective analysis (TOPGAN2020-02)

Background

Dacomitinib is the second‐generation epidermal growth factor receptor (EGFR)‐tyrosine kinase inhibitor (TKI) for mutant non–small cell lung cancer (NSCLC). EGFR‐TKIs are often re‐administered in Japan after the disease progression prior EGFR‐TKI. There is little evidence of dacomitinib in rechallenge setting. This study evaluated clinical outcomes of dacomitinib in rechallenge setting.

Methods

Patients who received dacomitinib for advanced EGFR‐mutant NSCLC who had progressed after EGFR‐TKI in nine institutions in Japan were included in the analyses.

Results

In total, 43 patients were analyzed. The median progression‐free survival (PFS) was 4.3 months (95% confidence interval [CI], 2.5–5.6). The overall survival (OS) was 10.5 months (95% CI, 7.4–not reached). The overall response rate was 25.5% (95% CI, 13.1–33.7). Subset analysis indicated that patients with EGFR exon 21 L858R showed longer PFS than those with EGFR exon 19 deletion (5.8 vs. 4.1 months) (p = 0.018). The most common adverse events leading to dose modification were diarrhea, paronychia, rash, and oral mucositis.

Conclusion

In the real practice in Japan, dacomitinib showed a worthwhile treatment option for NSCLC patients with EGFR mutation after failure of previous EGFR‐TKI. The benefit was especially pronounced in patients with the exon 21 mutation.

Personalized drug testing in a patient with non-small-cell lung cancer using cultured cancer cells from pleural effusion

Objective

Patients with non-small-cell lung cancer (NSCLC) and primary or acquired resistance do not respond to targeted drugs. We explored whether cancer cells can be cultured from liquid biopsies from patients with primary resistance to tyrosine kinase inhibitors (TKIs). We aimed to predict patients’ responses to drugs according to in vitro drug testing results.

Methods

Cancer cell cultures were established from the pleural effusion of a patient with TKI-resistant NSCLC using a conditional reprogramming technique. Phenotypic drug sensitivity tests were performed using the Cell Counting Kit-8 assay. We tested individual drugs and compared the synergistic and inhibitory effects of drug combinations.

Results

The results of our in vitro sensitivity test using the combination of cisplatin and pemetrexed were correlated with the patient’s response.

Conclusion

This represents the first successful report of predictive testing for combination therapy in patients with epidermal growth factor receptor-mutant NSCLC and primary TKI resistance. This strategy should be applicable to both chemotherapies and targeted therapies, and it will significantly improve the clinical treatment and management of patients with NSCLC and primary or acquired resistance to targeted therapies, as well as patients lacking targetable mutations.

Effectiveness of EGFR-TKI rechallenge immediately after PD-1 blockade failure

Background

There is currently insufficient information available on effective therapies that can be administered to patients with non‐small cell cancer (NSCLC) who develop resistance to epidermal growth factor receptor‐tyrosine kinase inhibitors (EGFR‐TKIs). However, sequential treatment via programmed death‐1 (PD‐1) blockade followed by EGFR‐TKI rechallenge is suggested to improve the therapeutic efficacy in such patients.

Methods

A total of 75 patients with advanced NSCLC harboring sensitive EGFR mutations treated with afatinib, erlotinib, or gefitinib after EGFR‐TKI treatment failure were retrospectively analyzed. Among them, 13 patients were treated with EGFR‐TKI rechallenge immediately after the failure of PD‐1 blockade therapy (experimental group) and the remaining 62 patients did not receive PD‐1 inhibitor therapy before EGFR‐TKI rechallenge (control group). Blood samples were collected at two time points; before the initiation of anti‐PD‐1 therapy and at EGFR‐TKI rechallenge.

Results

The objective response rates of EGFR‐TKI rechallenge in the experimental and control groups were 46.1% and 16.1%, respectively, with a significant difference (p = 0.026). In the experimental group, the median progression‐free survival (PFS) and overall survival (OS) after EGFR‐TKI rechallenge were 5.0 and 25.0 months, respectively, and no statistically significant difference in the percentage of lymphocytes before immune checkpoint inhibitor (ICI) therapy and EGFR‐TKIs was observed in patients with partial response (PR) and without PR after EGFR‐TKI rechallenge. In particular, the sequential treatment of PD‐1 blockade therapy followed by EGFR‐TKI rechallenge was consecutively repeated three times in two out of 13 patients in the experimental group, and EGFR‐TKI rechallenge consecutively for the third time yielded a PR without increased toxicities.

Conclusions

EGFR‐TKI rechallenge immediately after PD‐1 blockade treatment was identified as an effective therapy for NSCLC patients with resistance to EGFR‐TKIs.

Potential of modern circulating cell-free DNA diagnostic tools for detection of specific tumour cells in clinical practice

Personalized medicine is a developing field of medicine that has gained in importance in recent decades. New diagnostic tests based on the analysis of circulating cell-free DNA (cfDNA) were developed as a tool of diagnosing different cancer types. By detecting the subpopulation of mutated DNA from cancer cells, it is possible to detect the presence of a specific tumour in early stages of the disease. Mutation analysis is performed by quantitative polymerase chain reaction (qPCR) or the next generation sequencing (NGS), however, cfDNA protocols need to be modified carefully in preanalytical, analytical, and postanalytical stages. To further improve treatment of cancer the Food and Drug Administration approved more than 20 companion diagnostic tests that combine cancer drugs with highly efficient genetic diagnostic tools. Tools detect mutations in the DNA originating from cancer cells directly through the subpopulation of cfDNA, the circular tumour DNA (ctDNA) analysis or with visualization of cells through intracellular DNA probes. A large number of ctDNA tests in clinical studies demonstrate the importance of new findings in the field of cancer diagnosis. We describe the innovations in personalized medicine: techniques for detecting ctDNA and genomic DNA (gDNA) mutations approved Food and Drug Administration companion genetic diagnostics, candidate genes for assembling the cancer NGS panels, and a brief mention of the multitude of cfDNA currently in clinical trials. Additionally, an overview of the development steps of the diagnostic tools will refresh and expand the knowledge of clinics and geneticists for research opportunities beyond the development phases.

Successful afatinib rechallenge in a patient with non-small cell lung cancer harboring EGFR G719C and S768I mutations

Recent studies have indicated that afatinib is beneficial for patients with non‐small cell lung cancer (NSCLC) harboring uncommon epidermal growth factor receptor (EGFR) mutations, while the effectiveness of afatinib rechallenge has not been fully defined. Here, we report a long‐term survival case of NSCLC harboring concomitant EGFR G719C and S768I mutations who received afatinib rechallenge followed by chemotherapy. The present case suggests that combined therapeutic strategies such as afatinib plus sequential chemotherapy would be beneficial based on appropriately timed rebiopsies from recurrent lesions.

Key points

Significant findings of the study and what this study adds

A NSCLC patient carrying EGFR G719X/S768I mutations survived for a long period of time with afatinib rechallenge followed by chemotherapy. Combined therapeutic strategies should be considered based on rebiopsies in appropriate timing in NSCLC with uncommon EGFR mutations.