Prospective Study of Gefitinib Readministration After Chemotherapy in Patients With Advanced Non–Small-Cell Lung Cancer Who Previously Responded to Gefitinib

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.

Response to the Combination of Osimertinib, Dabrafenib, and Trametinib in Leptomeningitis From EGFR-Mutant NSCLC With Acquired BRAF V600E Mutation: A Case Report

Molecular sequencing after highly potent targeted gene inhibitors have suggested resistant tumors can display substantial heterogeneity. Among these various mechanisms of resistance, secondary mutations on targetable oncogenes have been identified. BRAF V600E, as a bypass mechanism on disease progression while receiving osimertinib therapy, has been reported in 3% of EGFR-mutated patients. Few case reports described the efficacy of the association of osimertinib and dabrafenib plus trametinib. Here, we report, for the first time, a case of a patient treated with this association, with a prolonged response on leptomeningeal metastasis. We also provide a comprehensive overview of the available literature on the efficacy and tolerance of this association.

Rechallenge with previously administered epidermal growth factor receptor-tyrosine kinase inhibitors in EGFR-mutated non-small cell lung cancer with leptomeningeal metastasis

Objectives In EGFR-mutated non-small cell lung cancer (NSCLC) patients, approximately 80-90% of leptomeningeal metastasis (LM) develops after failed initial treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (EGFR-TKI). However, the efficacy of rechallenging with previously administered EGFR-TKIs in patients with EGFR-mutated NSCLC and the LM that develops following EGFR-TKI treatment failure remains unknown. Materials and methods We retrospectively reviewed medical records of patients with EGFR-mutated NSCLC and LM, from November 2011 to August 2019. The patients were classified according to the LM treatment type: switched to previously unadministered EGFR-TKIs (Switch-TKI) or rechallenge with previously administered EGFR-TKIs (Rechallenge-TKI). Results In total, 50 patients treated with EGFR-TKI after LM diagnosis were included; 35 were treated with Switch-TKI and 15 with Rechallenge-TKI. The median overall survival (OS) from the time of LM diagnosis was 6.2 months in all study patients. According to the treatment type, the median OS from the time of LM diagnosis was 6.9 months in Switch-TKI patients and 4.9 months in Rechallenge-TKI patients. There was no significant difference in the OS between the Switch-TKI and Rechallenge-TKI groups (P = 0.864). Thirty-five patients were treated with erlotinib and 15 with osimertinib; Regardless of the type for EGFR-TKI, there was no significant difference in OS between patients treated with Switch-TKI and those treated with Rechallenge-TKI. Conclusion Rechallenge of previously administered EGFR-TKIs may be a therapeutic option for LM development after EGFR-TKI treatment failure in patients with EGFR-mutated NSCLC, not only switching to previously unadministered EGFR-TKIs.

Efficacy and Safety of Gefitinib as Third-line Treatment in NSCLC Patients With Activating EGFR Mutations Treated With First-line Gefitinib Followed by Second-line Chemotherapy: A Single-Arm, Prospective, Multicenter Phase II Study (RE-CHALLENGE, CTONG1304)

Objective:

There is no standard care for advanced non–small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation in the third line. Our study aimed to assess the efficacy and safety of gefitinib as a third-line re-challenge treatment for advanced NSCLC patients with EGFR mutation.

Materials and Methods:

It was a multicenter, open-label, single-arm, phase II study. Stage IIIB/IV NSCLC patients with EGFR exon 19del/L858R mutation, who had benefited from first-line gefitinib treatment followed by second-line chemotherapy, received gefitinib 250 mg/d. The primary objective was disease control rate (DCR) at week 8.

Results:

Predefined DCR was achieved in 69.8% (95% confidence interval, 49.87-74.91) patients and objective response rate was reported in 4.7% (95% confidence interval, 0.78-13.06) patients. Median progression-free survival (PFS) was 4.4 months and overall survival (OS) was 10.3 months. Baseline T790M-negative patients achieved favorable DCR compared with T790M-positive patients (78.1% vs. 45.5%, P=0.0418), significantly longer median PFS (4.7 vs. 2.0 mo, P=0.0009) and median OS (15.2 vs. 7.7 mo, P=0.0132). We observed a negative correlation of PFS (r=−0.4396, P=0.0032), and OS (r=−0.3630, P=0.0167) with mutation abundance of exon 19del/L858R at baseline.

Conclusions:

Re-challenge with gefitinib is effective and could be a choice for third-line patients after the first-line EGFR-TKI treatment and second-line chemotherapy, especially for the T790M-negative patients.

Liquid Biopsy Testing Can Improve Selection of Advanced Non-Small-Cell Lung Cancer Patients to Rechallenge with Gefitinib

The ICARUS trial is a phase II, open label, multicenter, single arm study conducted to investigate the efficacy, safety, and tolerability of a rechallenge treatment with the first-generation tyrosine kinase inhibitor (TKI) gefitinib in advanced non-small-cell lung cancer (NSCLC) patients carrying activating mutations of the epidermal growth factor receptor (EGFR). The ICARUS trial enrolled 61 patients who were rechallenged with gefitinib at progression after second-line chemotherapy. Serum-derived circulating cell-free DNA (cfDNA) collected before the rechallenge from a cohort of 29 patients, was retrospectively analyzed for the EGFR exon 19 deletions and for the p.L858R and p.T790M single nucleotide variants (SNV). The analysis of cfDNA detected the same EGFR activating mutation reported in the tumor tissue in 20/29 patients, with a sensitivity of 69%. Moreover, a p.T790M variant was found in 14/29 patients (48.3%). The median progression-free survival (PFS) was 2.7 months for p.T790M positive patients (CI 95% 1.4–3.1 months) versus 3.5 months for the p.T790M negative patients (CI 95% 1.6–5.3 months), resulting in a statistically significant difference (Long rank test p = 0.0180). These findings confirmed the role of the p.T790M mutation in the resistance to first-generation TKIs. More importantly, our data suggest that TKI rechallenge should be guided by biomarker testing.

Re-administration of osimertinib in osimertinib-acquired resistant non-small-cell lung cancer

BACKGROUND

Osimertinib is a tyrosine kinase inhibitor (TKI) that is an essential agent for the treatment of epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC). However, there is no established strategy for treatment following acquired resistance to this agent. One potential strategy for treating acquired resistance to EGFR TKIs is re-administration, which has been evaluated mainly using first- or second-generation EGFR TKIs. However, no clinical data are available with which to determine the significance of re-administration of osimertinib, a third-generation EGFR TKI. The aim of this study was to evaluate the efficacy of re-administering osimertinib to patients who had acquired resistance to this agent.

PATIENTS AND METHODS

We reviewed the medical records of consecutive patients with advanced NSCLC harboring EGFR-activating mutations and secondary T790M, who had undergone osimertinib re-administration to treat acquired resistance.

RESULTS

Seventeen patients were re-administered osimertinib after acquiring resistance to osimertinib. Of these, two received osimertinib to treat carcinomatous meningitis without any measurable lesion. Responses were evaluated in the remaining 15 patients. The objective response and disease control rates were 33% and 73%, respectively. Tumor shrinkage by osimertinib re-administration was associated with that due to initial osimertinib treatment (r = 0.585, 95% confidence interval [CI]: 0.104-0.844). In the remaining two patients without measurable lesions, one exhibited improved clinical symptoms following osimertinib re-administration. The median progression-free survival (PFS) time of all 17 patients was 4.1 months (95% CI: 1.9-6.7). The toxicity of re-administration was low, without interruption of the treatment due to adverse events (AEs). Most patients had grade 2 AEs or lower.

CONCLUSIONS

Re-administration of osimertinib for EGFR-mutant NSCLC yielded modest activity with tolerable toxicity.

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

BACKGROUND

Re-challenge of erlotinib after gefitinib failure is reported to yield some benefit in patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation. However, little is known about the re-challenge of afatinib after 1st generate on EGFR tyrosine kinase inhibitor (TKI) failure.

METHODS

From May 2015 to August 2018, 62 patients with advanced NSCLC harboring sensitive EGFR mutation received afatinib after gefitinib and/or erlotinib failure at our institution was included in our retrospective study.

RESULTS

The overall response rate (ORR) and disease control rate (DCR) of afatinib as re-challenge were 17.0% and 79.2%, respectively. The median time on treatment of 1st generation EGFR-TKI (1st TKI) was 14 months. By multivariate analysis, smoking, performance status (PS), and time on treatment of 1st TKI with more than 10 months were confirmed to be independent prognostic factors predicting a worse progression-free survival (PFS), and significant prognostic markers for overall survival (OS) were PS and time on treatment of 1st TKI with more than 10 months, especially in patients with exon 19 deletion.

CONCLUSIONS

Re-challenge of afatinib was identified as one of the therapeutic options after 1st TKI failure in the patients with advanced NSCLC harboring EGFR mutation when the time of treatment by prior 1st TKI is more than 10 months.

A phase II trial of EGFR-TKI readministration with afatinib in advanced non-small-cell lung cancer harboring a sensitive non-T790M EGFR mutation: Okayama Lung Cancer Study Group trial 1403

PURPOSE

The aim of this study was to evaluate the efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) readministration using afatinib in patients with non-small-cell lung cancer (NSCLC) with a sensitive non-T790M EGFR mutation who had received cytotoxic chemotherapy after acquiring resistance to EGFR-TKIs.

METHODS

Eligible patients had EGFR-mutant tumors resistant to first- or second-generation EGFR-TKIs and an EGFR-TKI-free period with cytotoxic agents. Confirmation of absence of the T790M mutation was required before registration. Afatinib (40 mg/body) was administered daily. The primary endpoint was progression-free survival (PFS). We assumed estimated and threshold PFS times of 3.3 and 1 months, with an α of 0.05 and β of 0.1, respectively.

RESULTS

Twelve patients were enrolled from December 2014 to May 2017. The objective response rate and disease control rate were 17% and 84%, respectively. The median PFS time was 4.2 months (95% confidence interval [CI] 2.0-5.8), which met the pre-defined primary endpoint. The median overall survival was 11.6 months (95% CI 9.2-not reached). Grade 3 or worse adverse events included diarrhea (25%), elevated creatinine levels (8%), and hypokalemia (8%), without any treatment-related deaths.

CONCLUSION

EGFR-TKI readministration with afatinib for sensitive EGFR-mutant NSCLC without T790M after resistance to a first- or second-generation EGFR-TKI yielded modest activity with tolerable toxicity. It might be one of the treatment options in patients who do not possess T790M tumors, although further studies in this patient setting are warranted.

Apatinib plus icotinib in treating advanced non-small cell lung cancer after icotinib treatment failure: a retrospective study

Background

Treatment failure frequently occurs in patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) who respond to EGFR tyrosine kinase inhibitors initially. This retrospective study tried to investigate the efficacy and safety of apatinib plus icotinib in patients with advanced NSCLC after icotinib treatment failure.

Patients and methods

This study comprised 27 patients with advanced NSCLC who had progressed after icotinib monotherapy. Initially, patients received oral icotinib (125 mg, tid) alone. When the disease progressed, they received icotinib plus apatinib (500 mg, qd, orally). Treatment was continued until disease progression, unacceptable toxicity or consent withdrawal.

Results

Followed up to December 2016, the median time of combined therapy was 7.47 months, and eight of 27 patients were dead. The median overall survival was not reached, and median progression-free survival (PFS) was 5.33 months (95% CI, 3.63–7.03 months). Moreover, the objective response rate (ORR) was 11.1%, and the disease control rate (DCR) was 81.5%. A total of 14 patients received combined therapy as the second-line treatment, and the ORR and DCR were 7.1% and 78.6%, respectively; 13 patients received drugs as the third- or later-line treatment, with an ORR and a DCR of 15.4% and 84.6%, respectively. In addition, 11 patients experienced icotinib monotherapy failure within 6 months with median PFS of 7.37 months, and 16 patients had progression after 6 months with median PFS of 2.60 months. The common drug-related toxic effects were hypertension (44.4%) and fatigue (37.0%).

Conclusion

Apatinib plus icotinib is efficacious in treating patients with advanced NSCLC after icotinib treatment failure, with acceptable toxic effects.

Predictive factors for EGFR-tyrosine kinase inhibitor retreatment in patients with EGFR-mutated non-small-cell lung cancer - A multicenter retrospective SEQUENCE study

BACKGROUND

Acquired resistance occurs in most non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations experiencing a response to EGFR-tyrosine kinase inhibitor (TKI) initially. We investigated EGFR-TKI retreatment in patients who had previously received EGFR-TKI followed by chemotherapy.

MATERIALS AND METHODS

This was a retrospective multicenter study. Patients with locally advanced or metastatic adenocarcinoma or TTF-1 (+) NSCLC, positive EGFR sensitive mutation, and EGFR-TKI reuse after initial EGFR-TKI followed by chemotherapy were enrolled. The objectives were to assess the objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) of EGFR TKI switched retreatment.

RESULTS

In total, 205 patients were enrolled, with a median age of 61.8 years (range 31.4-92.9). There was a larger proportion of females (62.9%) than males, and more never-smokers (73.2%) than ever-smokers. In the initial EGFR-TKI administration, 57.6% of patients showed a complete response (CR) or partial response (PR), and 34.6% had stable disease (SD); in the second-line chemotherapy, 13.7% had PR, and 58.0% had SD; in the EGFR-TKI retreatment, 7.3% had PR, and 37.1% had SD. The median PFS of first-line EGFR-TKI was 8.0 months (95% CI 7.3-8.2), and retreatment EGFR-TKI was 4.1 months (95% CI 2.7-4.6). The median OS since the start of the first-line EGFR-TKI therapy was 35.9 months (95% CI 28.8-50.9), and since the start of EGFR-TKI retreatment was 12.6 months (95% CI 10.4-20.9). In the univariable and multivariable regression analysis of factors associated with PFS of EGFR-TKI retreatment, time interval between the two EGFR TKIs equal to or more than 7 months was statistically significant (HR=0.62, 95% CI 0.44-0.86; HR=0.6, 95% CI 0.43-0.86), both p<0.01. Females with exon 21 mutation also showed a significant difference between the two groups (HR=0.51, 95% CI 0.30-0.86; HR=0.52 (0.31-0.88), both p<0.05).

CONCLUSIONS

EGFR-TKI retreatment was effective in prolonging survival, and was shown to be a worthwhile option for EGFR-mutated NSCLC patients after failure of first-line EGFR-TKI and chemotherapy. The survival benefit was especially pronounced in patients with longer drug holidays from the initial EGFR-TKI and in females with the exon 21 mutation.

Detection of microRNA-200b may predict the inhibitory effect of gefitinib on non-small cell lung cancer and its potential mechanism

The present study aimed to investigate the association and underlying mechanisms between microRNA-200b level and the inhibitory effect of gefitinib on non-small cell lung cancer. In total, 100 patients (43 males and 57 females; median age, 63 years) with advanced non-small cell lung cancer (NSCLC) were selected. All patients were administered with gefitinib orally (250 mg/day) and the effect of gefitinib was evaluated according to the Response Evaluation Criteria in Solid Tumors guidelines. Tumor tissue and plasma samples were collected prior to and subsequent to therapy. The microRNA-200b levels in tissues and plasma were determined by quantitative polymerase chain reaction (PCR). A549 cells were cultured in vitro and transfected with microRNA-200b mimic. Using Cell Counting Kit-8 assay, the proliferation inhibition detected was induced by 0.1 µM gefitinib in transfected or non-transfected A549 cells. Cell apoptosis and cell cycle progression were analyzed by flow cytometry and the migration of cells was observed by Transwell assay. In addition, mRNA and protein levels of insulin-like growth factor 1 receptor (IGF-1R), protein kinase B (AKT) and extracellular signal-related kinase (ERK), together with the phosphorylation of AKT and ERK in A549 cells, were determined by quantitative PCR and western blot analysis, respectively. The microRNA-200b levels in gefitinib-insensitive patients were decreased compared with gefitinib-sensitive patients. Transfection with microRNA-200b mimic increased the gefitinib induced proliferation inhibition, apoptosis and cell cycle arrest in A549 cells. Also, transfection with microRNA-200b mimic increased the migration inhibitory effect of gefitinib on A549 cells. Decreased IGF-1R expression together with reduced phosphorylation of AKT and ERK were observed following transfection of A549 cells with the microRNA 200b mimic. In conclusion, detection of microRNA-200b may predict the inhibitory effect of gefitinib on NSCLC. Upregulation of microRNA-200b led to the elevated sensitivity of glioma cells to gefitinib, and this effect may be explained as microRNA-200b being able to inhibit the expression of IGF-1R, thereby reducing the activation of downstream phosphoinositide 3-kinase/AKT and mitogen-activated protein kinase signaling pathways.

Phase II Study of the EGFR-TKI Rechallenge With Afatinib in Patients With Advanced NSCLC Harboring Sensitive EGFR Mutation Without T790M: Okayama Lung Cancer Study Group Trial OLCSG 1403

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) as first-line therapy for patients with EGFR-mutated non-small-cell lung cancer (NSCLC) have shown a significantly better objective response rate and progression-free survival than platinum doublet therapy. However, acquired resistance often occurs within 12 months. One of the potential strategies for treating acquired resistance in NSCLC is the readministration of EGFR-TKIs, a strategy that has mainly been evaluated using gefitinib or erlotinib. The aim of the present study is to investigate the efficacy and safety of EGFR-TKI readministration with afatinib in patients with advanced NSCLC harboring activating EGFR mutations without T790M. The primary endpoint is progression-free survival. The secondary endpoints include the objective response rate, disease control rate, overall survival, toxicity, and quality of life. A total of 12 patients will be enrolled in this trial.

Efficacy and safety of rechallenge treatment with gefitinib in patients with advanced non-small cell lung cancer

OBJECTIVES

Although patients with advanced non-small cell lung cancer (NSCLC) and an activating epidermal growth factor receptor (EGFR) mutation benefit from the use of EGFR-tyrosine kinase inhibitors (TKI), most of them progress within 12 months from treatment start due to acquired resistance. In clinical practice, many physicians frequently offer these patients retreatment with EGFR-TKIs after a chemotherapy break, based on small or retrospective studies.

MATERIALS AND METHODS

A phase II trial was conducted in patients with stage III/IV NSCLC, to assess the efficacy, safety and impact on quality of life (QoL) and disease-related symptoms of gefitinib rechallenge. Eligible patients had initially responded to first-line gefitinib and progressed after second-line chemotherapy.

RESULTS

Of 61 enrolled patients, 73.8% were female, 100% had EGFR-mutated adenocarcinoma and 67.2% were never-smokers. Thirty-two (52.5%) patients obtained a clinical benefit, with 3 (4.9%) achieving a partial response and 29 (47.5%) having stable disease. Median progression-free survival was 2.8 months, overall survival 10.2 months and duration of gefitinib treatment 3.6 months. The most common all grade-adverse events were diarrhea (27.6%), nausea and/or vomiting (20.3%), rash (14.7%) and dyspnea (10.3%); no new toxicities were apparent.

CONCLUSION

Findings from this study indicate that gefitinib rechallenge offers modest benefit and may be taken into consideration only for patients for whom no other treatment option exists.

EGFR-TKI rechallenge with bevacizumab in EGFR-mutant non-small cell lung cancer

BACKGROUND

Efficacies of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) rechallenge have been demonstrated in EGFR-mutant non-small cell lung cancer (NSCLC). However, their efficacies were only moderate. Some preclinical studies suggested synergistic effects of bevacizumab to EGFR-TKI in TKI-resistant models.

METHODS

We retrospectively evaluated clinical efficacy and safety of EGFR-TKI rechallenge with bevacizumab. Rebiopsy was performed on all studied cases to examine T790M-resistant mutation status.

RESULTS

Between January 2010 and June 2014, a total of 24 EGFR-mutant NSCLC patients who had been previously treated with EGFR-TKIs (gefitinib, erlotinib, and/or afatinib) received EGFR-TKI rechallenge with bevacizumab. Twenty-two (92 %) patients underwent erlotinib and two (8 %) gefitinib as rechallenge EGFR-TKIs in combination with bevacizumab. Three patients achieved partial response, and 18 had stable disease, resulting in the response rate (RR) of 13 % and disease control rate (DCR) of 88 %, respectively. The median progression-free survival (PFS) was 4.1 [95 % confidence interval (CI) 2.3-4.9] months, and the median overall survival (OS) was 13.5 (95 % CI 9.7-27.4) months. The RR, DCR, median PFS, and median OS for T790M-positive versus T790M-negative were 0 versus 18 % (p = 0.530), 86 versus 88 % (p = 1.00), 3.3 versus 4.1 months (p = 0.048), and 15.1 versus 13.5 months (p = 0.996), respectively. Severe adverse events (≥grade 3): grade 3 of 1 (4 %) rash; grade 3 of 1 (4 %) paronychia; grade 3 of 1 (4 %) hypertension; and grade 3 of 1 (4 %) anemia, were observed.

CONCLUSIONS

EGFR-TKI rechallenge with bevacizumab demonstrated higher DCR and modestly longer PFS than historical data on EGFR-TKI rechallenge alone. Its activity was notably higher in T790M-negative population.

First-line therapeutic options for advanced non-small-cell lung cancer in the molecular medicine era

Lung cancer is the leading cause of cancer-related mortality worldwide in both sexes, expected to account, in the near future, for more than 30% of all cancer-related deaths. Recently, improvements in the systemic therapy of non-small-cell lung cancer according to histology and tumor molecular characteristics led to a progressive prolongation of survival, more clinically meaningful in selected groups of patients with tumors harboring specific genomic alterations. As the search for individualized therapeutic approaches could represent one of the potential ways to improve survival expectancy of non-small-cell lung cancer patients with advanced disease stage, the aim of this review is to discuss how currently to select the best front-line therapeutic strategy.

Subsequent treatment choices for patients with acquired resistance to EGFR-TKIs in non-small cell lung cancer: restore after a drug holiday or switch to another EGFR-TKI?

The outcomes of first-generation EGFR-TKIs (Gefitnib and Erlotinib) have shown great advantages over traditional treatment strategies in patients with non-small cell lung cancer (NSCLC), but unfortunately we have to face the situation that most patients still fail to respond in the long term despite initially good control. Up to now, the mechanism of acquired resistance to EGFR-TKIs has not been fully clarified. Herein, we sought to compile the available clinical reports in the hope to better understanding the subsequent treatment choices, particularly on whether restoring after a drug holiday or switching to another EGFR-TKI is the better option after failure of one kind of EGFR-TKI.

Rationale and study design of the IRENE-trial (NVALT-16): a phase II trial to evaluate iressa rechallenge in advanced NSCLC patients with an activating EGFR mutation who responded to an EGFR-TKI used as first-line or previous treatment

BACKGROUND

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have shown improved progression-free survival (PFS) and overall survival (OS) over chemotherapy in a molecularly defined subgroup of advanced non-small-cell lung cancer (NSCLC) patients (ie, patients with an activating mutation in the EGFR gene). Nevertheless, all EGFR-mutated NSCLC patients develop TKI resistance eventually and there is no registered treatment or therapeutic strategy available for these patients. Several retrospective or small cohort studies have described patients who re-responded to EGFR-TKI treatment after a TKI-free interval ('drug holiday'). To date, no large prospective evaluation of the clinical effects of EGFR-TKI rechallenge in EGFR-mutated NSCLC patients has been performed.

PATIENTS AND METHODS

The IRENE (Iressa RE-challenge in advanced, EGFR-mutated NSCLC patients who responded to an EGFR-TKI used as first-line or previous treatment) (Dutch association for pulmonologists [NVALT]-16) trial is a multicenter, open-label, single-arm, single-stage, phase II study to evaluate gefitinib rechallenge in EGFR-mutated NSCLC patients who were previously treated with a TKI followed by a subsequent line of treatment (excluding EGFR-TKIs). The primary objective is disease control rate according to Response Evaluation Criteria in Solid Tumors criteria. Secondary objectives are objective response rate, PFS, OS, mutation characterization of sequential biopsies, VeriStrat correlation to PFS and OS, analysis of tumor-derived RNA in blood platelets and analysis of cell-free DNA in blood plasma.

RESULTS

The IRENE (NVALT-16) trial will evaluate the safety, efficacy, and feasibility of readministration of gefitinib after an EGFR-TKI-free interval in EGFR-mutated NSCLC patients.

CONCLUSION

The study will evaluate gefitinib re-challenge in EGFR-mutated NSCLC patients. The study will also provide more insight into the dynamic development of molecular characteristics of EGFR-mutated NSCLC along the course of the disease.

Readministration of EGFR tyrosine kinase inhibitor in non-small cell lung cancer patients after initial failure, what affects its efficacy?

Few therapeutic options are available for non-small cell lung cancer (NSCLC) after failure to primary epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs). Since TKI rechallenge is one of the most common salvage approaches in clinical practice, we sought to identify the independent factors that associated with 2^nd progression progression-free survival (PFS) and overall survival (OS). Seventy-two consecutive EGFR-mutated NSCLC patients with TKI retreatment after initial failure were retrospectively analyzed in this study. Univariate survival analysis and Cox proportional hazards regression model was used to determine if EGFR-TKIs readministration is tolerable as well as efficacious for a certain group of patients.

Mutation abundance affects the efficacy of EGFR tyrosine kinase inhibitor readministration in non-small-cell lung cancer with acquired resistance

There is no consensus in the salvage treatment for non-small-cell lung cancer (NSCLC) with acquired resistance to primary epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs). Fifty-one consecutive EGFR-mutated NSCLC patients with TKI retreatment after acquired resistance were enrolled in this study. The quantitation of mutation abundance was performed by real-time fluorescent quantitative PCR. The correlation between mutation abundance and outcomes of readministrated TKI was analyzed by survival analysis. Patients with high (H) mutation abundance (24/51) had a significantly (log-rank, P < 0.05) longer (5.27-2.53 months) median progression-free survival (PFS), compared with the low (L) abundance group (27/51), whereas the median overall survival showed no difference (21.00-18.20 months, log-rank P = .403) between the two groups. Objective response and disease control rates in group H and group L regarding the second round TKI treatment were 8.3, 70.8 and 0, 48.1 %, respectively. Groupings with different mutation abundances were significantly associated with PFS under multivariate Cox proportional hazards regression model [hazard ratio (HR) for group H vs. L, 0.527; P = .036]. Mutation abundance affects the efficacy of EGFR-TKIs readministration in NSCLC with acquired resistance. The quantitative mutation abundance of EGFR may be a potential predictor for selecting optimal patients to readministrate EGFR-TKIs after acquired resistance to primary TKI.

A retrospective analysis of 335 Japanese lung cancer patients who responded to initial gefitinib treatment

BACKGROUND

Gefitinib treatment results in considerably better progression-free survival compared with that of platinum doublets in the first line treatment of nonsmall-cell lung cancer (NSCLC) carrying an activating epidermal growth factor receptor (EGFR) mutation. Some patients who respond to gefitinib have an overall survival (OS) of more than 5 years, whereas other initial responders do less well. Although there has been considerable effort made to elucidate the mechanisms of acquired resistance, there have only been a few studies that addressed the effect of clinical backgrounds and treatment histories on the survival of the patients who had responded to an EGFR-tyrosine kinase inhibitor (TKI). In this study, we especially focused on the clinical benefit of EGFR-TKI administration after progression.

PATIENTS AND METHODS

We retrospectively analyzed consecutive patients with advanced NSCLC who were diagnosed before October 2010, treated with gefitinib after July 2002, and responded to it. The primary objective of this study was to evaluate how clinical backgrounds and treatment histories influence survival of the patients who respond to gefitinib. The secondary objectives were to evaluate the safety of long-term gefitinib use and to establish the optimal treatment sequence using a dynamic treatment regimen analysis (DTRA).

RESULTS

A total of 335 patients were recruited. Twenty-eight (8.4%) patients survived more than 5 years. Sixty-five and 93 patients received gefitinib as rechallenge and beyond progressive disease (BPD), respectively. A statistically significant difference in OS was observed between the patients who underwent gefitinib rechallenge and those who did not rechallenge (median: 1272 days vs. 774 days; p < 0.001), a result supported by a DTRA. Patients treated with gefitinib BPD also showed a tendency of longer survival.

CONCLUSIONS

Gefitinib rechallenge and BPD played a central role in long term survival of the patients who initially responded to gefitinib.

The relationship between tyrosine kinase inhibitor therapy and overall survival in patients with non-small cell lung cancer carrying EGFR mutations

For patients with epidermal growth factor receptor (EGFR) mutation-positive lung cancer, the relationship between the dose or duration of treatment with tyrosine kinase inhibitor (TKI) and overall survival remains unclear. Here, we analyzed clinical data of 39 patients who were diagnosed with EGFR mutation-positive non-small cell lung cancer and treated with TKI, but subsequently died. Several parameters were measured in this study: overall survival; first, second, and overall TKI therapy durations; first TKI intensity (actual dose/normal dose); and TKI rate (overall TKI therapy duration/overall survival). The response rate to TKI therapy was 50%, and the median survival was 553 days. After TKI therapy failed, 38.5% patients were re-challenged with TKI. We observed a moderate relationship [r = 0.534, 95% confidential interval (CI) = 0.263 to 0.727, P < 0.001] between overall TKI therapy duration and overall survival. However, we found no relationship between overall survival and first TKI intensity (r = 0.073, 95% CI = -0.380 to 0.247, P = 0.657) or TKI rate (r = 0.0345, 95% CI = -0.284 to 0.346, P = 0.835). Non-small cell lung cancer patients with mutation-positive tumors remained on TKI therapy for, on average, 33% of the overall survival time. These findings suggest that patients with EGFR mutation-positive tumors should not stick to using TKIs.