Molecular profile of liquid biopsies: next generation biomarkers to improve lung cancer treatment

Afatinib for the treatment of EGFR mutation-positive NSCLC: A review of clinical findings

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors represent the standard of care in patients with EGFR mutation-positive (EGFRm+) non-small cell lung cancer (NSCLC). The availability of several EGFR tyrosine kinase inhibitors approved for use in the first-line or later settings in NSCLC warrants an in-depth understanding of the pharmacological properties of, and clinical data supporting, these agents. The second-generation, irreversible ErbB-family blocker, afatinib, has been extensively studied in the context of EGFRm+ NSCLC. Results from the LUX-Lung 3 and 6 studies showed that afatinib was more active and better tolerated than chemotherapy in patients with tumors harboring EGFR mutations. Subanalysis of these trials, along with real-world data, indicates that afatinib is active in patients with certain uncommon EGFR mutations (S768I/G719X/L861Q) as well as common mutations (Del19/L858R), and in patients with active brain metastases. In LUX-Lung 7, a head-to-head phase IIb trial, afatinib improved progression-free survival and time-to-treatment failure versus the first-generation reversible EGFR tyrosine kinase inhibitor, gefitinib, albeit with a higher incidence of serious treatment-related adverse events. Nevertheless, afatinib is generally well tolerated, and adverse events are manageable through supportive care and a well-defined tolerability-guided dose adjustment scheme. In this review, we provide a detailed overview of the pharmacology, efficacy, and safety of afatinib, discuss treatment sequencing strategies following emergence of different resistance mechanisms, and shed light on the economic impact of afatinib. We also provide a comparison of afatinib with the available EGFR tyrosine kinase inhibitors and discuss its position within treatment strategies for patients with EGFRm+ NSCLC.

Epidermal growth factor receptor tyrosine kinase inhibitors for the treatment of non-small cell lung cancer

Introduction: Epidermal growth factor receptor (EGFR) mutations are well-described drivers of non-small cell lung cancer (NSCLC) and EGFR tyrosine kinase inhibitors (TKIs) have become key components of the NSCLC front-line treatment landscape. Tumors inevitably develop resistance to these agents, and development efforts continue to focus on identifying mechanisms of resistance and drugs to target these mechanisms. Areas covered: With several EGFR TKIs approved for use in the first-line or in later-line settings, an understanding of the efficacy and safety of these inhibitors in various populations is warranted. Furthermore, given the frequent emergence of drug resistance in NSCLC, examination of tumor tissue throughout the disease course provides the opportunity to select treatments based on the tumor's mutation profile. Here, we discuss: key efficacy and safety findings for approved and investigational EGFR TKIs; known mechanisms of resistance, particularly the T790M acquired EGFR mutation; and recent advances in EGFR mutational testing that may facilitate less invasive tissue testing and guide treatment selection. Expert commentary: The expanding armamentarium of EGFR TKIs, improvements in the understanding of resistance mechanisms and technological developments in the molecular analysis of tumors may help render EGFR mutation-positive NSCLC a chronic disease in many patients by facilitating optimal sequential therapy.

Circulating and tissue biomarkers in early-stage non-small cell lung cancer

OBJECTIVE

We sought to characterise circulating and tissue tumour biomarkers of patients who developed early-stage non-small cell lung cancer (NSCLC) during long-term follow-up of a chemoprevention trial (NCT00321893).

MATERIALS AND METHODS

Blood and sputum samples were collected from 202 high-risk asymptomatic individuals with CT-detected stable lung nodules. Real-time PCR was performed on plasma to quantify free circulating DNA. Baseline serum was investigated with a previously validated test based on 13 circulating miRNAs (miR-Test). Promoter methylation status of p16, RASSF1a and RARβ2 and telomerase activity were assessed in sputum samples. DNA was extracted from each tumour developed during follow-up and subjected to a mutation survey using the LungCarta panel on the Sequenom MassARRAY platform.

RESULTS

During follow-up (9 years) six individuals underwent surgery for stage I NSCLC with a median time of disease onset of 20.5 months. MiR-Test scores were positive (range: 0.14-7.24) in four out of six baseline pre-disease onset sera. No association was identified between free circulating DNA or sputum biomarkers and disease onset. All tumours harboured at least one somatic mutation in well-known cancer genes, including KRAS (n = 4), BRAF (n = 1), and TP53 (n = 3).

CONCLUSION

Circulating miRNA tests may represent valuable tools to detect clinically-silent tumours. Early-stage lung adenocarcinomas harbour recurrent genetic events similar to those described in advanced-stage NSCLCs.