P3.01-036 A Phase IIIb Open-Label, Single-Arm Study of Afatinib in EGFR TKI-Naïve Patients with EGFRm+ NSCLC: An Interim Analysis

Two Unusual Mutations in the Epidermal Growth Factor Receptor Gene in a Patient With Lung Adenocarcinoma

Adenocarcinoma (ADC) of the lung is the most frequent pathology corresponding to non-small cell lung cancer (NSCLC). The advent of target therapy and the discovery of drugs that block signaling pathways related to cellular events involved in the progression of the disease have led to a better prognosis in cases of ADC. Some of the targeted therapy focuses on the blockade of epidermal growth factor receptor (EGFR), targeting mutations in exon 19 and 21, with favorable clinical outcomes. However, there is limited evidence with respect to unusual mutations as in exon 18 (g719x) and 20 (s768). In this report, we present a case of a 65-year-old female with two unusual mutations in the EGFR gene, in exon 18 (g719x) and 20 (s768i), without central nervous system (CNS) involvement; these mutations are typically resistant to standard therapy. We decided to administer osimertinib because of its favorable toxicity profile and with a view to preventing future CNS relapse.

Biomarker subset analysis of a phase IIIb, open-label study of afatinib in EGFR tyrosine kinase inhibitor-naive patients with EGFRm+ non-small-cell lung cancer

Aim: To explore the relationship between mutations in cfDNA and response to afatinib. Patients & methods: In total, 64 patients from one Chinese site with locally advanced/metastatic EGFRm+ non-small-cell lung cancer, who received afatinib 40 mg once daily, were included. Results: Overall, 33 (82.5%) patients became EGFRm- by visit 3; median progression-free survival was longer in these patients vs those who did not (11.0 vs 5.5 months). Progression-free survival was shorter in 42 (45.2%) patients with non-EGFR co-mutations at baseline vs those without (8.1 vs 12.5 months). Neither difference was significant. Conclusion: Afatinib provided clinical benefit for patients with EGFRm+ non-small-cell lung cancer across all subgroups. EGFRm status assessment in plasma cfDNA is a useful method of monitoring treatment.

A Phase IIIb Open-Label, Single-Arm Study of Afatinib in EGFR TKI-Naïve Patients with EGFRm+ NSCLC: Final Analysis, with a Focus on Patients Enrolled at Sites in China

Background

Afatinib has been shown as a suitable option for the treatment of epidermal growth factor receptor mutation-positive (EGFRm+) non-small-cell lung cancer (NSCLC) in randomized controlled trials. However, patients treated in real-world clinical practice, including elderly patients, and those with brain metastases or poor Eastern Cooperative Oncology Group (ECOG) performance statuses, are often excluded from these studies.

Objective

To report the final results, with a particular focus on patients enrolled in China, from a prospective phase IIIb, “near real-world” study of afatinib in tyrosine kinase inhibitor (TKI)-naïve Asian patients with EGFRm+ NSCLC.

Patients and Methods

NCT01953913 was conducted at 34 centers across Asia. Entry criteria were broad to reflect real-world settings. Patients received afatinib 40 mg/day until tumor progression, lack of clinical benefit, or poor tolerability. Assessments included safety, time to symptomatic progression (TTSP), and progression-free survival (PFS).

Results

541 patients were treated, of whom 412 were enrolled in China. Dose reductions were implemented in 28.7% of patients overall, and 17.7% of patients from China. Safety findings were consistent with phase III studies of afatinib. Median TTSP in all patients was 14.0 months (95% CI 12.9–15.9), and median PFS was 12.1 months (95% CI 11.0–13.6). Median TTSP (13.8 months, 95% CI 12.7–16.1) and PFS (11.4 months, 95% CI 10.9–13.7) were similar in patients from China to the overall population. Among patients from China who had dose reductions, TTSP was numerically longer than in those who did not (16.4 vs. 13.8 months; P = 0.0703), while PFS was significantly longer (13.9 vs. 11.1 months; P = 0.0275). Among patients from China with brain metastases, TTSP was numerically shorter than in those without (11.0 vs. 14.4 months; P = 0.0869), whereas PFS was significantly shorter (9.2 vs. 12.9 months; P = 0.0075).

Conclusions

Safety data for afatinib when used in a “near real-world” setting in patients with EGFRm+ NSCLC was consistent with the known safety profile of afatinib. Supporting efficacy data of afatinib were provided in all patients, and in those enrolled in China. Tolerability-guided afatinib dose reduction allowed patients to remain on treatment and continue to experience clinical benefit.

Trial Registration Number and Date of Registration

NCT01953913 (1 October 2013).

Supplementary Information

The online version contains supplementary material available at 10.1007/s11523-021-00859-6.

Afatinib as First-Line Treatment in Asian Patients with EGFR Mutation-Positive NSCLC: A Narrative Review of Real-World Evidence

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are a standard of care in the first-line treatment of patients with EGFR mutation-positive metastatic non-small-cell lung cancer (NSCLC). EGFR mutations are relatively common in Asian patients with NSCLC, and there is an increasing number of studies supporting the effectiveness of the second-generation TKI afatinib in routine clinical practice in Asia. This article reviews these real-world studies investigating afatinib as first-line treatment for EGFR mutation-positive NSCLC in Asian patients. Evidence from real-world studies with afatinib in this patient population supports findings from randomized controlled trials (RCTs) showing that afatinib is associated with more favorable outcomes compared with the first-generation EGFR TKIs. The effectiveness of afatinib has also been shown in real-world studies in Asian patients with poor prognostic factors, who are often under-represented or excluded from RCTs, such as those with uncommon EGFR mutations, brain metastases, or poor performance status, and elderly patients. The tolerability profile of afatinib in the real-world setting reflects that seen in RCTs, with no new safety signals reported in real-world studies in Asian patients with EGFR mutation-positive NSCLC. Dose-modification strategies also seem to be effective in the real world, with results of the RealGido study, which included 44% Asian patients, confirming findings from prospective clinical trials showing that tolerability-guided afatinib dose modifications can reduce the incidence of adverse events without adversely affecting clinical outcomes. While further research, including clinical trial data, is needed, real-world data have also demonstrated the feasibility of sequential afatinib followed by the third-generation TKI osimertinib in T790M-positive EGFR mutation-positive patients, which showed longer overall survival. Together, these real-world results demonstrate the real-world clinical effectiveness of afatinib as first-line treatment for patients with EGFR mutation-positive NSCLC.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in non-small cell lung cancer harboring uncommon EGFR mutations: Focus on afatinib

The development of first-, second-, and third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has revolutionized the treatment of patients with non-small cell lung cancer (NSCLC) harboring mutations in the EGFR. However, limited data are available regarding the activity of available EGFR TKIs against uncommon EGFR mutations. This is an important question because improvements in screening techniques are facilitating the identification of patients with uncommon mutations for whom optimal treatment has not yet been clarified. This uncertainty reflects the fact that most prospective clinical trials of EGFR TKIs have been restricted to patients with tumor harboring common (Del19 or L858R) mutations. In this article, we discuss the nature of EGFR mutation heterogeneity in NSCLC and review recent preclinical and clinical data that have assessed the sensitivity of different mutations to different EGFR TKIs. Recent preclinical data indicate that second-generation ErbB family blockers, such as afatinib, have a broad activity profile across uncommon EGFR mutations. Emerging evidence indicates that the preclinical data for afatinib are reflected in the clinic. Subanalysis of clinical trials, and real-world data, demonstrate that EGFRs with defined, but uncommon mutations such as G719X, S768I, and L861Q are sensitive to afatinib, which is now approved for tumors harboring these mutations. A recent clinical trial has demonstrated that EGFRs harboring some of these less common mutations also appear to be sensitive to the third-generation EGFR TKI, osimertinib. Treatment options for tumors with other uncommon mutations, notably exon 20 insertion, remain an area of unmet need, although osimertinib has shown preclinical activity in this setting, and early clinical activity has been seen with the dual EGFR/HER2 TKIs, poziotinib and TAK-788. Further data are required to help drive appropriate treatment decisions in patients whose tumors harbor these uncommon EGFR mutations. To see an abstract video summarising the content of the paper, please visit http://usscicomms.com/oncology/masood/seminars-in-oncology/.

First-line afatinib for the treatment of EGFR mutation-positive non-small-cell lung cancer in the 'real-world' clinical setting

Afatinib is an ErbB family blocker that is approved for the treatment of epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC). Pivotal randomized clinical studies demonstrated that afatinib significantly prolonged progression-free survival compared with platinum-based chemotherapy (LUX-Lung 3, LUX-Lung 6), and with gefitinib (LUX-Lung 7), with manageable side effects. However, these results were derived from controlled studies conducted in selected patients and are not necessarily representative of real-world use of afatinib. To gain a broader understanding of the effectiveness and safety of first-line afatinib, we have undertaken a literature review of real-world studies that have assessed its use in a variety of patient populations. We focused on patients with uncommon EGFR mutations, brain metastases, or those of advanced age, as these patients are often excluded from clinical studies but are regularly seen in routine clinical practice. The available real-world studies suggest that afatinib has clinical activity, and is tolerable, in diverse patient populations in an everyday clinical practice setting. Moreover, consistent with LUX-Lung 7, several real-world comparative studies indicate that afatinib might confer better efficacy than first-generation EGFR tyrosine kinase inhibitors. Tolerability-guided dose adjustment, undertaken in 21-68% of patients in clinical practice, did not appear to reduce the efficacy of afatinib. Taken together, these findings provide further support for the use of afatinib as a treatment option in patients with EGFR mutation-positive NSCLC.

Afatinib in the first-line treatment of patients with non-small cell lung cancer: clinical evidence and experience

Epidermal growth factor receptor ( EGFR) gene mutations identify a molecularly defined subset of non-small cell lung cancer (NSCLC) patients who display an excellent sensitivity to EGFR tyrosine kinase inhibitors (TKIs). First-generation reversible EGFR TKIs, gefitinib and erlotinib have been proven to improve the objective response rate and to prolong the progression-free survival compared with standard chemotherapy in large phase III trials. Unfortunately, virtually all patients develop resistance to treatment, usually within 9-12 months. Afatinib is an irreversible ErbB family inhibitor initially designed to overcome the development of resistance. Compared with gefitinib in a first-line setting, afatinib prolonged progression-free survival and time to treatment failure, without impacting on overall survival in the general population of EGFR-mutant patients. However, afatinib has been shown to prolong overall survival in the subset of patients with an EGFR exon 19 deletion compared with chemotherapy. The aim of this review is to summarize the clinical evidence available to date and to critically discuss the place in therapy of afatinib in the rapidly expanding landscape of EGFR-mutant NSCLC first-line therapy.

Tumor clonality and resistance mechanisms in EGFR mutation-positive non-small-cell lung cancer: implications for therapeutic sequencing

While the development of EGFR-targeted tyrosine kinase inhibitors (TKIs) has revolutionized treatment of EGFR mutation-positive non-small-cell lung cancer, acquired resistance to therapy is inevitable, reflecting tumor evolution. Recent studies show that EGFR mutation-positive non-small-cell lung cancer is highly heterogeneous at the cellular level, facilitating clonal expansion of resistant tumors via multiple molecular mechanisms. Here, we review the mechanistic differences between first-, second- and third-generation EGFR-targeted TKIs and speculate how these features could explain differences in clinical activity between these agents from a clonal evolution perspective. We hypothesize that the molecular dissection of tumor resistance mechanisms will facilitate optimal sequential use of EGFR TKIs in individual patients, thus maximizing the duration of chemotherapy-free treatment and survival benefit.

Afatinib in advanced NSCLC: a profile of its use

Afatinib [Giotrif^® (EU); Gilotrif^® (USA)] is an orally administered, irreversible inhibitor of the ErbB family of tyrosine kinases that provides an important first-line treatment option for advanced non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutations (i.e. EGFR^actMUT+), and an additional treatment option for squamous NSCLC that has progressed following first-line platinum-based chemotherapy. Relative to gefitinib in the first-line treatment of EGFR^actMUT+ advanced lung adenocarcinoma, afatinib prolonged progression-free survival (PFS) and time to treatment failure (TTF), but not overall survival (OS). Afatinib also prolonged PFS, but not OS, versus cisplatin-based chemotherapy in this setting; however, afatinib improved OS versus chemotherapy in the subgroup of patients with deletions in exon 19. As a second-line treatment for advanced squamous NSCLC, afatinib prolonged PFS and OS compared with erlotinib, regardless of EGFR mutation status. Afatinib had a predictable and manageable tolerability profile.