Afatinib versus cisplatin plus gemcitabine for first-line treatment of Asian patients with advanced non-small-cell lung cancer harbouring EGFR mutations (LUX-Lung 6): an open-label, randomised phase 3 trial

Trials to Overcome Drug Resistance to EGFR and ALK Targeted Therapies - Past, Present, and Future

Molecularly targeted agents are changing the therapeutic landscape in advanced non-small cell lung cancer. Since the discovery of sensitizing mutations in the epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) domain, clinical investigations have focused on optimizing the efficacy of EGFR and ALK tyrosine kinase inhibitors by addressing therapeutic resistance that commonly develops within a year of treatment initiation. Here, we review the clinical trials of novel therapies and combination regimens that have been undertaken in response to our evolving understanding of the mechanisms of resistance to targeted therapy. The aim of these trials was to enhance the therapeutic efficacy of targeted therapies by improving blockade and/or inhibiting parallel or compensatory signaling pathways. We have documented the sequential conduct of EGFR and ALK biomarker-driven trials in order to highlight particular pitfalls and successes, which should be considered in the design of future trials. Although there remain significant challenges, substantial gains have been made in our understanding of cellular resistance. This knowledge will drive the design of future trials to the benefit of lung cancer patients.

[A new perspective in the treatment of non-small-cell lung cancer (NSCLC). Role of afatinib: An oral and irreversible ErbB family blocker]

Tyrosine kinase inhibitors (TKI) that block epidermal growth factor receptor (EGFR) pathway have demonstrated a clinical benefit for patients with non-small-cell lung cancer (NSCLC) harboring EGFR mutations. The currently available TKI (gefitinib and erlotinib) are EGFR reversible inhibitors. Afatinib is an oral, irreversible ErbB family blocker that covalently binds and blocks signaling from EGFR (ErbB1), HER2 (ErbB2) and ErbB4. The compound inhibits also the transphosphorylation of ErbB3. With this mode of action, afatinib is thought to have a mechanistic advantage over EGFR blockade alone, in that it provides a sustained, covalent inhibition of ErbB homo- and hetero-dimers. In the pivotal LUX-Lung 3 study, afatinib demonstrated a prolonged progression free survival over standard pemetrexed plus cisplatin chemotherapy (11.1 versus 6.9 months; HR = 0.58, 95% CI: 0.43-0.78; P = 0.001) in EGFR mutation positive NSCLC patients. The compound has recently been granted a marketing authorization (MA) for the treatment of patients with locally advanced or metastatic NSCLC with activating EGFR mutation(s) and EGFR TKI-naive. In this paper are summarized the efficacy and safety data in this indication.

Phase I/randomized phase II study of afatinib, an irreversible ErbB family blocker, with or without protracted temozolomide in adults with recurrent glioblastoma

BACKGROUND

This phase I/II trial evaluated the maximum tolerated dose (MTD) and pharmacokinetics of afatinib plus temozolomide as well as the efficacy and safety of afatinib as monotherapy (A) or with temozolomide (AT) vs temozolomide monotherapy (T) in patients with recurrent glioblastoma (GBM).

METHODS

Phase I followed a traditional 3 + 3 dose-escalation design to determine MTD. Treatment cohorts were: afatinib 20, 40, and 50 mg/day (plus temozolomide 75 mg/m(2)/day for 21 days per 28-day cycle). In phase II, participants were randomized (stratified by age and KPS) to receive A, T or AT; A was dosed at 40 mg/day and T at 75 mg/m(2) for 21 of 28 days. Primary endpoint was progression-free survival rate at 6 months (PFS-6). Participants were treated until intolerable adverse events (AEs) or disease progression.

RESULTS

Recommended phase II dose was 40 mg/day (A) + T based on safety data from phase I (n = 32). Most frequent AEs in phase II (n = 119) were diarrhea (71% [A], 82% [AT]) and rash (71% [A] and 69% [AT]). Afatinib and temozolomide pharmacokinetics were unaffected by coadministration. Independently assessed PFS-6 rate was 3% (A), 10% (AT), and 23% (T). Median PFS was longer in afatinib-treated participants with epidermal growth factor receptor (EFGR) vIII-positive tumors versus EGFRvIII-negative tumors. Best overall response included partial response in 1 (A), 2 (AT), and 4 (T) participants and stable disease in 14 (A), 14 (AT), and 21 (T) participants.

CONCLUSIONS

Afatinib has a manageable safety profile but limited single-agent activity in unselected recurrent GBM patients.

Activity of the EGFR-HER2 dual inhibitor afatinib in EGFR-mutant lung cancer patients with acquired resistance to reversible EGFR tyrosine kinase inhibitors

BACKGROUND

The purpose of this study was to evaluate the efficacy of afatinib in EGFR-mutant metastatic NSCLC patients with acquired resistance to erlotinib or gefitinib.

MATERIALS AND METHODS

We retrospectively analyzed the outcome of patients with EGFR-mutant advanced NSCLC treated with afatinib after failure of chemotherapy and EGFR TKIs.

RESULTS

A total of 96 individuals were included in the study. According to EGFR status, most patients (n = 63; 65.6%) harbored a deletion in exon 19, and de novo T790M mutation was detected in 2 cases (T790M and exon 19). Twenty-four (25%) patients underwent repeated biopsy immediately before starting afatinib and secondary T790M was detected in 8 (33%) samples. Among the 86 patients evaluable for efficacy, response rate was 11.6%, with a median progression free-survival (PFS) and overall survival (OS) of 3.9 and 7.3 months, respectively. No significant difference in PFS and OS was observed according to type of last therapy received before afatinib, type of EGFR mutation or adherence to Jackman criteria, and patients benefiting from afatinib therapy had longer PFS and OS (P < .001). Outcome results for repeated biopsy patients were similar to the whole population, with no evidence of response in T790M-positive patients. All patients were evaluable for toxicity, and 81% experienced an AE of any grade, with grade 3 to 4 AEs, mainly diarrhea and skin toxicity, occurring in 19 (20%) patients.

CONCLUSION

Our results showed that afatinib has only modest efficacy in a real life population of EGFR mutant NSCLC patients with acquired resistance to erlotinib or gefitinib.

Anaplastic lymphoma kinase rearrangement in lung cancer: its biological and clinical significance

Anaplastic lymphoma kinase (ALK) has been found to fuse with other partners, such as echinoderm microtubule-associated protein-like 4 (EML4), leading to potent malignant transformation in lung cancer, specifically non-small-cell lung cancer (NSCLC). The frequency of the ALK rearrangement in patients with NSCLC is reported to be 4-7%, and the rearrangement is frequently observed in relatively younger patients, non- or light smokers and those with adenocarcinoma histology without other genetic disorders, such as mutations of the epidermal growth factor receptor gene. Crizotinib, which is a first-in-class ALK tyrosine kinase inhibitor (TKI), was shown to be effective and well tolerated in ALK-positive NSCLC patients by a single-arm phase I study. Furthermore, a phase III randomized study demonstrated the superiority of crizotinib to standard chemotherapy (pemetrexed or docetaxel) in the treatment of NSCLC patients harboring the ALK rearrangement who had received one prior platinum-based chemotherapy. However, the mechanisms of resistance to crizotinib are major concerns when administering crizotinib to ALK-positive NSCLC patients, and they include second mutations and a gain in the copy number of the ALK gene, activation of other oncogenes, etc. Treatment strategies to overcome these mechanisms of resistance have been developed, including the use of second-generation ALK inhibitors, such as alectinib and ceritinib, heat shock protein 90 inhibitors and so on. In this article, we review the pre-clinical and clinical data regarding the biologal and clinical significance of the ALK rearrangement in lung cancer.

Drug resistance to molecular targeted therapy and its consequences for treatment decisions in non-small-cell lung cancer

Our ability to detect and directly target the oncogenic alterations responsible for tumor proliferation has contributed significantly to the management of lung cancer in the last decade. The therapeutic efficacy of molecularly targeted therapy is, however, mainly limited to patients harboring certain genetic mutations and is generally short-lived. Herein, we review primary and secondary drug resistance using the most well-studied of the molecularly targeted agents, the tyrosine kinase inhibitors targeting the epidermal growth factor (EGF) receptor, and the anaplastic lymphoma kinase (ALK) rearrangement, the current limitations of targeted therapies and their consequences on the management of patients with lung cancer.

Re-Treatment with EGFR-TKIs in NSCLC Patients Who Developed Acquired Resistance

In the era of personalized medicine, epidermal growth factor receptor (EGFR) inhibition with tyrosine kinase inhibitor (TKI) has been a mainstay of treatment for non-small cell lung cancer (NSCLC) patients with an EGFR mutation. Acquired resistance, especially substitution of methionine for threonine at position 790 (T790M), which has accounted for more than half of the cases, developed inevitably in patients who were previously treated with EGFR-TKI. At present, there is no standard treatment for patients who have developed a resistance to EGFR-TKI. Several strategies have been developed or suggested to treat such patients. This article aimsto review the EGFR-TKI re-treatment strategy and the efficacy of different generations of EGFR-TKIs in patients with acquired resistance to prior EGFR-TKI.

Prognostic significance of genotype and number of metastatic sites in advanced non-small-cell lung cancer

BACKGROUND

TNM stage remains the most important prognostic factor in clinical practice. The 7th edition lung cancer staging system has not considered some important prognostic factors, such as the number of metastatic organ sites and the molecular biologic characterization.

PATIENTS AND METHODS

Using driver gene alternation and tumor burden, advanced NSCLC cases were divided into 3 groups: M1-I group, epidermal growth factor (EGFR)-positive and/or anaplastic lymphoma kinase (ALK)-positive; MI-II, wild-type EGFR and ALK with intrathoracic metastasis or 1 distant metastatic organ with ≤ 3 metastasis lesions; and MI-III, wild-type EGFR and ALK with 1 distant metastatic organ with > 3 metastasis lesions or multiple metastatic organs. Overall survival was comparable between the 7th edition staging system and our category of M descriptors.

RESULTS

A total of 627 patients with stage IV NSCLC newly diagnosed at Guangdong Lung Cancer Institute between January 2009 and July 2012 were enrolled in the present study. The median overall survival (OS) was 22.2 (95% CI, 19.590-24.810), 15.5 (95% CI, 13.176-17.824), and 10.0 (95% CI, 8.033-11.967) months for M1-I, M1-II, and M1-III, respectively (P < .001). According to the 7th edition of the TNM staging system, the median OS of the M1a and M1b groups was 22.8 (95% CI, 19.484-26.116) and 13.7 (95% CI, 11.793-15.607) months, respectively (P < .001). The maximum of the absolute values of the M1 category for our study and the 7th TNM staging system was 5.881 and 5.089, respectively.

CONCLUSION

Advanced NSCLC could potentially be further divided into 3 subgroups according to the genotype and number of metastatic organ sites and metastasis lesions.

Pharmacokinetics of afatinib in subjects with mild or moderate hepatic impairment

Purpose

Afatinib, an oral irreversible ErbB family blocker, undergoes minimal metabolism by non-enzyme-catalysed adduct formation with proteins or nucleophilic small molecules and is predominantly non-renally excreted via the entero-hepatic system. This trial assessed whether mild or moderate hepatic impairment influences the pharmacokinetics of afatinib.

Methods

This was an open-label single-dose study. Pharmacokinetic parameters after afatinib 50 mg were investigated in subjects with mild (n = 8) or moderate (n = 8) hepatic impairment (Child-Pugh A and B) and healthy controls (n = 16) matched for age, weight and gender. Plasma and urine samples for pharmacokinetic assessment were collected before and up to 10 days after dosing. Additional blood samples were drawn to determine ex vivo plasma protein binding of afatinib. Primary endpoints were comparisons of afatinib C_max and AUC_0–∞ between subjects with hepatic impairment and healthy matched controls. Study progression was based on drug-related toxicity (CTCAE v. 3.0) and C_max of afatinib.

Results

Afatinib pharmacokinetic profiles and plasma protein binding were similar in subjects with impaired liver function and healthy controls. Compared with matched controls, the afatinib-adjusted geometric mean ratio for AUC_0–∞ was 92.6 % (90 % CI 68.0–126.3 %) and C_max was 109.5 % (90 % CI 82.7–144.9 %) for subjects with mild hepatic impairment, and 94.9 % (90 % CI 72.3–124.5 %) and 126.9 % (90 % CI 86.0–187.2 %), respectively, for subjects with moderate hepatic impairment. For all parameters, the 90 % CI included 100 %. Afatinib was generally well tolerated with no serious adverse events reported.

Conclusion

Mild to moderate hepatic impairment had no clinically relevant effect on the pharmacokinetics of a single 50 mg dose of afatinib, implying that adjustments to the starting dose of afatinib are not considered necessary in this patient population.

Protein kinase inhibitors to treat non-small-cell lung cancer

INTRODUCTION

Activating mutations of the EGFR and rearrangement of anaplastic lymphoma kinase (ALK) best illustrate the therapeutic relevance of molecular characterization in NSCLC patients.

AREAS COVERED

For this review article, all published data on the most relevant Phase III trials with tyrosine kinase inhibitors (TKIs) for the treatment of NSCLC were collected and analyzed.

EXPERT OPINION

Eight Phase III trials clearly established EGFR TKIs as the best therapeutic option for front-line therapy in EGFR-mutated patients. In pretreated NSCLC, EGFR TKIs are considered more effective than standard monotherapy with cytotoxics in presence of classical EGFR mutations, whereas in the EGFR wild-type population, a similar efficacy to docetaxel or pemetrexed in term of survival has been demonstrated. In ALK-translocated NSCLC, a Phase III trial demonstrated the superiority of a multi-target TKI, including ALK, in terms of progression-free survival, response rate and toxicity profile when compared to standard second-line chemotherapy. New agents targeting EGFR or ALK are under evaluation particularly in individuals with acquired resistance to EGFR TKIs or crizotinib.

Afatinib: first global approval

Afatinib, an irreversible inhibitor of the ErbB family of tyrosine kinases, is under development with Boehringer Ingelheim for the once-daily, oral treatment of cancer. Afatinib downregulates ErbB signalling by covalently binding to epidermal growth factor receptor (EGFR), human epidermal growth factor receptor (HER) 2 and HER4, irreversibly inhibiting tyrosine kinase autophosphorylation. It also inhibits transphosphorylation of HER3. Oral afatinib (Gilotrif™) has been approved in the US for the first-line treatment of patients with metastatic non-small-cell lung cancer (NSCLC) who have tumours with EGFR exon 19 deletions or exon 21 (L858R) substitution mutations as detected by a US FDA-approved test. Afatinib has also been approved in Taiwan for the first-line treatment of patients with EGFR mutation-positive NSCLC. In addition, the European Medicines Agency's Committee for Medicinal Products for Human Use has recommended the approval of afatinib (Giotrif®) for the treatment of patients with locally advanced or metastatic NSCLC with activating EGFR mutations who are EGFR tyrosine kinase inhibitor naïve. Afatinib is also under regulatory review in Canada, Japan and other Asian countries. This article summarizes the milestones in the development of afatinib, leading to this first approval in patients with metastatic NSCLC.

50 Years of progress in the systemic therapy of non-small cell lung cancer

Non-small cell lung cancer constitutes 85% to 90% of lung cancer and is the most common cause of cancer death. Over the past 50 years, substantial progress has been made in all aspects of lung cancer including screening, diagnostic evaluation, surgery, radiation therapy, and chemotherapy. This review focuses on the advances in systemic therapy during this half century.

Treatment of advanced non-small-cell lung cancer with epidermal growth factor receptor (EGFR) mutation or ALK gene rearrangement: results of an international expert panel meeting of the Italian Association of Thoracic Oncology

The availability of targeted drugs has made the assessment of the EGFR mutation and ALK rearrangement critical in choosing the optimal treatment for patients with advanced non-small-cell lung cancer (NSCLC). In May 2013, the Italian Association of Thoracic Oncology (AIOT) organized an International Experts Panel Meeting to review strengths and limitations of the available evidence for the diagnosis and treatment of advanced NSCLC with EGFR or anaplastic lymphoma kinase (ALK) alterations and to discuss implications for clinical practice and future clinical research. All patients with advanced NSCLC, with the exclusion of pure squamous cell carcinoma in former or current smokers, should be tested for EGFR mutations and ALK rearrangements before decisions are made on first-line treatment. First-line treatment of EGFR-mutated cases should be with an EGFR tyrosine kinase inhibitor (TKI). Any available agent (gefitinib, erlotinib, or afatinib) can be used, until further data from comparative studies may better guide TKI selection. As general rule, and when clinically feasible, results of EGFR mutational status should be awaited before starting first-line treatment. Panelists agreed that the use of crizotinib is justified in any line of treatment. Although solid evidence supporting the continuation of EGFR TKIs or crizotinib beyond progression is lacking, in some cases (minimal, asymptomatic progression, or oligoprogression manageable by local therapy), treatment continuation beyond progression could be justified. Experimental strategies to target tumor heterogeneity and to treat patients after failure of EGFR TKIs or crizotinib are considered high-priority areas of research. A number of relevant research priorities were identified to optimize available treatment options.