Induction EGFR tyrosine kinase inhibitors prior to definitive chemoradiotherapy in unresectable stage III EGFR-mutated non-small cell lung cancer

INTRODUCTION

Increasing evidence suggests that consolidation durvalumab confers limited benefits for patients with stage III EGFR-mutated NSCLC. Induction or maintenance EGFR tyrosine kinase inhibitors (TKIs) added to concurrent chemoradiotherapy (CRT) may optimize definitive treatment, but there are limited data supporting an induction TKI strategy.

METHODS

We evaluated the efficacy and safety of induction EGFR TKIs administered before concurrent CRT in a retrospective series of patients with unresectable locally advanced EGFR-mutated NSCLC. Circulating tumor DNA (ctDNA) analysis was performed on a patient subset using CAPP-seq and correlated with outcomes.

RESULTS

Of six patients, three received erlotinib and three osimertinib as induction therapy before CRT. Induction TKIs were administered for a median of 2.5 months. The objective response rate after induction TKI was 83%. One patient had a complete response to induction erlotinib and continued erlotinib for 4 years until local progression, which was treated with CRT. Two patients completed maintenance erlotinib after CRT, and another received consolidation durvalumab. After a median follow-up of 20.5 months, only one patient developed disease recurrence, with rising ctDNA coinciding with recurrence. ctDNA remained undetectable in patients without recurrence, or low-level in a patient receiving maintenance erlotinib. Adverse events were mild and expected, and none developed pneumonitis.

CONCLUSION

Induction EGFR TKI before CRT may achieve high disease control rates with promising signs of durability in patients with locally advanced EGFR-mutated NSCLC. ctDNA analysis after CRT can correlate well with clinical outcomes. Prospective studies are needed to define the role of induction EGFR TKIs in this setting.

Recent advances and new insights in the management of early-stage epidermal growth factor receptor-mutated non-small-cell lung cancer

Patients with early-stage non-small-cell lung cancer (NSCLC) are candidates for curative surgery; however, despite multiple advances in lung cancer management, recurrence rates remain high. Adjuvant chemotherapy has been demonstrated to significantly prolong overall survival (OS), but this benefit is modest and there is an urgent need for effective new therapies to provide a cure for more patients. The high efficacy of tyrosine kinase inhibitors (TKIs) against epidermal growth factor receptor-mutated (EGFR) in patients with advanced EGFR-mutated NSCLC has led to the evaluation of these agents in early stages of the disease. Multiple clinical trials have evaluated the safety and efficacy of EGFR TKIs as an adjuvant treatment, in patients with resected EGFR-mutated NSCLC, and shown that they significantly prolong disease-free survival (DFS), but this benefit does not translate to OS. Recently, an interim analysis of the ADAURA trial demonstrated that, surprisingly, osimertinib improved DFS. This led to the study being stopped early, leaving many unanswered questions about its potential effect on OS and its incorporation as a standard adjuvant treatment in this patient subgroup. These targeted agents are also being evaluated in locally-advanced disease, with promising results, although prospective studies with larger sample sizes are needed to confirm these results. In this article, we review the most relevant studies on the role of EGFR TKIs in the management of early-stage EGFR-mutated NSCLC.

Osimertinib Maintenance After Definitive Chemoradiation in Patients With Unresectable EGFR Mutation Positive Stage III Non-small-cell Lung Cancer: LAURA Trial in Progress

The LAURA trial (NCT03521154) will evaluate the efficacy and safety of osimertinib as maintenance therapy in patients with locally advanced, unresectable, epidermal growth factor receptor mutation-positive (EGFRm), stage III non-small-cell lung cancer (NSCLC) without disease progression during/following definitive platinum-based chemoradiation therapy (CRT). Eligible patients include adults aged ≥ 18 years (≥ 20 years in Japan) with locally advanced, unresectable, stage III NSCLC with local/central confirmation of an EGFR exon 19 deletion/L858R mutation. Patients must have received ≥ 2 cycles of concurrent/sequential platinum-based CRT, have no investigator-assessed progression, and have creatinine < 1.5 × upper limit of normal and creatinine clearance ≥ 30 mL/min. In this phase III trial, patients will be randomized 2:1 to once-daily osimertinib 80 mg or placebo, until objective radiological disease progression per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, confirmed by blinded independent central review (BICR). The primary objective is to assess the efficacy of osimertinib per BICR-confirmed progression-free survival (PFS). Secondary objectives include central nervous system PFS, overall survival, PFS by mutation status and safety. Patients with BICR-confirmed disease progression (or investigator-confirmed progression if after primary PFS analysis) may be unblinded and receive open-label osimertinib; all will have post-progression follow-up. Serious adverse events and adverse events of special interest will be collected throughout the trial and survival follow-up. The first patient was enrolled in July 2018, with results expected in late 2022.

Gefitinib With Concurrent Thoracic Radiotherapy in Unresectable Locally Advanced NSCLC With EGFR Mutation; West Japan Oncology Group 6911L

INTRODUCTION

About 10% of patients with locally advanced NSCLC (LA-NSCLC) harbor EGFR mutation and recent reports suggested the declined benefit with an immune checkpoint inhibitor in this population. The attempt that introduces EGFR tyrosine kinase inhibitor into the treatment of LA-NSCLC with EGFR mutation has been warranted.

METHODS

Chemotherapy-naive patients with unresectable LA-NSCLC with sensitive EGFR mutation (exon 19 deletion or exon 21 L858R point mutation) were enrolled. Patients were treated with gefitinib (250 mg/d for 2 y) plus concurrent thoracic radiotherapy (64 Gy/32 fractions). The primary end point was progression-free survival (PFS) at 2 years (trial identifier, UMIN000008366).

RESULTS

Between August 2012 and November 2017, a total of 28 patients were enrolled and 27 were eligible. The median age was 67 years (range: 45-74); never/current or former smoker in 15/12 patients, respectively; Eastern Cooperative Oncology Group performance status of 0/1 in 19/8; EGFR exon 19 deletion/exon 21 L858R in 13/14; and c-stage IIIA/IIIB in 14/13. The PFS rate at 2 years by independent review was 29.6% (one-sided 95% confidence interval [CI]: 17.6%-). The overall response rate was 81.5% (95% CI: 63.3%-91.3%), median PFS was 18.6 months (95% CI: 12.0-24.5 mo), and median overall survival was 61.1 months (95% CI: 38.1 mo-not reached). Approximately half of the patients exhibited solitary brain metastasis as their first site of relapse. Adverse events greater than or equal to grade 3 were fatigue, skin reaction, and appetite loss (3.7% each).

CONCLUSIONS

This prospective study revealed the tolerability and the possible efficacy of gefitinib plus concurrent thoracic radiotherapy in patients with LA-NSCLC having EGFR mutation.