Erlotinib at a dose of 25 mg daily for non-small cell lung cancers with EGFR mutations

Clinical implications of PNA‑sequencing as a complementary test for EGFR mutation analysis in human lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the first-line regimen for the treatment of non-small cell lung cancer (NSCLC) patients with EGFR mutations. However, false-negative results are occasionally observed, even with FDA-approved molecular tests. Such examples in have been reported in our pilot study showing a slightly upward-shifted amplification curve using commercial reverse transcription-quantitative (RT-q)PCR. Verification using peptide nucleic acid (PNA) clamping-sequencing, which has a sensitivity of ~0.1%, may allow better prediction of which patients will benefit from EGFR-TKI therapy. To confirm this hypothesis, samples were prospectively collected from 1,783 lung cancer cases diagnosed in National Cheng Kung University Hospital between 2012-2018. An independent lung cancer cohort of 1,944 cases was also recruited from other hospitals. The clinical significance of mutant-enriched PCR with PNA-sequencing was analyzed and patient outcomes were followed. A total of 17 of 34 cases (50%) were found to harbor EGFR mutations by PNA-sequencing. A total of 22 cases were discovered in the independent lung cancer cohort, and 14 of these (63.6%) cases had EGFR mutations. TKIs were administered to 14 of the 17 mutation-positive patients, and a partial response was observed in 4 cases and stable disease in 10 cases. Patients with EGFR mutations receiving a TKI regimen had a longer overall survival (OS) (median: 40.0 vs. 10.0 months) compared with those without treatment. The difference in OS was not significant. Based on the results of the present study, combining RT-qPCR with PNA-sequencing may be a practical supplementary technology in a clinical molecular laboratory for a subset of lung cancer patients in selection of EGFR TKI therapy.

Targeting Cell Signaling Pathways in Lung Cancer by Bioactive Phytocompounds

Lung cancer is a heterogeneous group of malignancies with high incidence worldwide. It is the most frequently occurring cancer in men and the second most common in women. Due to its frequent diagnosis and variable response to treatment, lung cancer was reported as the top cause of cancer-related deaths worldwide in 2020. Many aberrant signaling cascades are implicated in the pathogenesis of lung cancer, including those involved in apoptosis (B cell lymphoma protein, Bcl-2-associated X protein, first apoptosis signal ligand), growth inhibition (tumor suppressor protein or gene and serine/threonine kinase 11), and growth promotion (epidermal growth factor receptor/proto-oncogenes/phosphatidylinositol-3 kinase). Accordingly, these pathways and their signaling molecules have become promising targets for chemopreventive and chemotherapeutic agents. Recent research provides compelling evidence for the use of plant-based compounds, known collectively as phytochemicals, as anticancer agents. This review discusses major contributing signaling pathways involved in the pathophysiology of lung cancer, as well as currently available treatments and prospective drug candidates. The anticancer potential of naturally occurring bioactive compounds in the context of lung cancer is also discussed, with critical analysis of their mechanistic actions presented by preclinical and clinical studies.

CircRNA ANXA2 Promotes Lung Cancer Proliferation and Metastasis by Upregulating PDPK1 Expression

Lung cancer is a common malignant tumor that seriously threatens human health. It has become the top malignant tumor in terms of morbidity and mortality. In recent years, circRNA, a special noncoding RNA molecule, has attracted considerable interest. This study focused on the role of circRNA ANXA2 (circANXA2) in lung cancer and the molecular mechanism of cancer promotion. Real-time quantitative PCR (RT-PCR) was used in detecting the expression abundance of circANXA2 in different lung cancer cells and tissues. The subcellular localization of circANXA2 was detected through fluorescence in situ hybridization. circANXA2 expression was knocked down through siRNA. CCK-8, clone formation assay, and TUNEL assay were used in evaluating the effects of circANXA2 on cell proliferation, clone formation ability, and apoptosis. The role of circANXA2 in tumor proliferation was further verified in vivo using the tumor transplantation model in nude mice. The molecular mechanism of circANXA2 was investigated with luciferase activity assay and RT-PCR. The expression abundance of circANXA2 is high in lung cancer cell lines and tissues. Knocking down of circANXA2 inhibits the proliferation and clonogenesis of the lung cancer cells. Knocking down circANXA2 promotes apoptosis. circANXA2 further affects downstream PDPK1 expression by regulating miR-33a-5p and thereby affecting the malignancy of the lung cancer cells. circANXA2 inhibits miR-33a-5p activity by directly interacting with miR-33a-5p. circANXA2 regulates the transcription of the miR-33a-5p downstream target gene PDPK1 and affects the malignant progression of lung cancer.

Optimized Dosing: The Next Step in Precision Medicine in Non-Small-Cell Lung Cancer

In oncology, and especially in the treatment of non-small-cell lung cancer (NSCLC), dose optimization is often a neglected part of precision medicine. Many drugs are still being administered in "one dose fits all" regimens or based on parameters that are often only minor determinants for systemic exposure. These dosing approaches often introduce additional pharmacokinetic variability and do not add to treatment outcomes. Fortunately, pharmacological knowledge is increasing, providing valuable information regarding the potential of, for example, therapeutic drug monitoring. This article focuses on the evidence for the most promising and easily implemented optimized dosing approaches for the small-molecule inhibitors, chemotherapeutic agents, and monoclonal antibodies as treatment options currently approved for NSCLC. Despite limitations such as investigations having been conducted in oncological diseases other than NSCLC or the retrospective origin of many analyses, an alternative dosing regimen could be beneficial for treatment outcomes, prescriber convenience, or financial burden on healthcare systems. This review of the literature provides recommendations on the implementation of dose optimization and advice regarding promising strategies that deserve further research in NSCLC.

Evaluating the utility of therapeutic drug monitoring in the clinical use of small molecule kinase inhibitors: a review of the literature

Introduction: Orally administered small molecule kinase inhibitors (KI) are a key class of targeted anti-cancer medicines that have contributed substantially to improved survival outcomes in patients with advanced disease. Since the introduction of KIs in 2001, there has been a building body of evidence that the benefit derived from these drugs may be further enhanced by individualizing dosing on the basis of concentration.Areas covered: This review considers the rationale for individualized KI dosing and the requirements for robust therapeutic drug monitoring (TDM). Current evidence supporting TDM-guided KI dosing is presented and critically evaluated, and finally potential approaches to address translational challenges for TDM-guided KI dosing and alternate approaches to support individualization of KI dosing are discussed.Expert opinion: Intuitively, the individualization of KI dosing through an approach such as TDM-guided dosing has great potential to enhance the effectiveness and tolerability of these drugs. However, based on current literature evidence it is unrealistic to propose that TDM-guided KI dosing should be routinely implemented into clinical practice.

The Influence of Intervening on the Pharmaceutical Consultation Targeting Outpatients with Advanced Non-small Cell Lung Cancer Receiving Erlotinib Treatment

Erlotinib is used to treat advanced non-small-cell lung cancer (NSCLC), the common serious adverse events are skin disorders. The dose intensity of erlotinib should be maintained as much as possible by an appropriate control of adverse events in order to maintain its efficacy. Therefore, the management of these adverse events related to skin disorders would enable a continuous erlotinib treatment without interruption and dose reduction. This study assessed the effect of pharmaceutical consultation in outpatients who received erlotinib. Participants included patients with NSCLC who received erlotinib therapy for more than 6 months between December 2007 and March 2019. The participants were divided into two groups: the intervention group that included patients who received pharmaceutical consultation targeting outpatients by a pharmacist and the nonintervention group that included patients who did not. We retrospectively investigated patient characteristics, treatment regimens, and treatment efficacy. We included a total of 33 patients (18 and 15 patients in the nonintervention and intervention groups, respectively) in this study. The intervention group had a significantly higher median relative dose intensity (RDI) of erlotinib than the nonintervention group (p = 0.0437). In addition, the pharmaceutical consultation targeting outpatients was identified as a factor contributing to the maintenance of RDI ≥90% (p = 0.0269). The present study indicated that there was improvement in RDI with pharmaceutical consultation targeting outpatients with advanced NSCLC.

The Pharmacokinetics of Gefitinib in a Chinese Cancer Population Group: A Virtual Clinical Trials Population Study

Gefitinib, a selective inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, is used to treat non-small-cell lung cancer (NSCLC). Lung cancer rates are high in China and are expected to increase over the next decade. CYP 2D6 intermediate metaboliser (IM) phenotypes are more prevalent in the Chinese population compared to Caucasians; the increased risk of drug-drug interactions (DDI) with chemotherapy polypharmacy may lead to different clinical pharmacokinetics outcomes for Chinese patients. This study developed and validated a virtual Chinese cancer population for the pragmatic assessment of gefitinib DDI as a victim drug in Chinese and Caucasian cancer populations. When assessing the impact of 2D6 phenotypes on bupropion mediated CYP 2D6 DDI in Chinese cancer population, we found that AUC increased by at least 60% in extensive metabolizers (EM) and 30% in IM. As a result, fmCYP2D6 was reduced by 15% in IM in the presence of bupropion, translating into > 70% of EM subjects and > 48% of IM subjects with trough concentrations at steady state (Ctrough,ss) below the gefitinib target trough level. The PBPK model predicted that a 500 mg once daily dose in both EM and IM subjects successfully reduced the percent of subjects below the Ctrough,ss. Such changes in Ctrough,ss warrant further investigation and highlight the ability of pharmacokinetic modelling to investigate populations that may be difficult to recruit for traditional clinical studies.

Efficacy and Tolerability of Erlotinib 100 mg/d vs. Gefitinib 250 mg/d in EGFR-Mutated Advanced Non-small Cell Lung Cancer (E100VG250): An Open-Label, Randomized, Phase 2 Study

Background: Erlotinib-based combination therapy leads to increased efficacy but also toxicity for EGFR-mutated NSCLC. Reducing the dose of erlotinib could improve treatment tolerability, but few evidences are available regarding its efficacy at reduced dose. This randomized phase-2 study intends to compare the efficacy and tolerability between lower dose erlotinib (100 mg/d) and standard dose gefitinib (250 mg/d) in EGFR-mutated NSCLC. Methods: Patients with EGFR-mutated advanced NSCLC were randomized at 1:1 ratio to receive erlotinib 100 mg/d or gefitinib 250 mg/d until disease progression or unacceptable toxicity. The primary endpoint was disease control rate (DCR). Results: Between April 2013 and September 2018, 171 patients were randomized to receive erlotinib (n = 85) and gefitinib (n = 86); 74 in the erlotinib group and 83 in the gefitinib group were include in analysis. DCR with erlotinib and gefitinib were 91% [95% CI 81.7-95.3] and 93% [85.1-96.6], respectively (P = 0.613). Response rate was 62% [50.8-72.4] in the erlotinib group and 53% [42.4-63.4] in the gefitinib group (P = 0.247). No significant difference was observed between erlotinib and gefitinib in median progression-free survival [10.1 vs. 11.3 months, HR = 1.295 [0.893-1.879], P = 0.171] and median overall survival [26.6 vs. 28.7 months, HR = 0.999 [0.637-1.569], P = 0.998]. Subgroup analyses by line of treatment, EGFR subtypes and status of central nervous system (CNS) metastasis found similar results. More toxicity [any-grade, 80 [96%] vs. 66 [89]; grade 3-4, 11 [13%] vs. 4 [5%]] and toxicity-related discontinuation [10 [12%] vs. 3 [4%]] occurred with gefitinib compared with erlotinib. But no significant difference was observed. Conclusion: Lower dose erlotinib (100 mg/d) achieved comparable efficacy compared with standard dose gefitinib (250 mg/d) in EGFR-mutated NSCLC. Clinical Trial Registration: https://clinicaltrials.gov, identifier: NCT01955421.

Optimizing the Therapeutic Window of Targeted Drugs in Oncology: Potency-Guided First-in-Human Studies

Many targeted therapies are administered at or near the maximum tolerated dose (MTD). With the advent of precision medicine, a larger therapeutic window is expected. Therefore, dose optimization will require a new approach to early clinical trial design. We analyzed publicly available data for 21 therapies targeting six kinases, and four poly (ADP‐ribose) polymerase inhibitors, focusing on potency and exposure to gain insight into dose selection. The free average steady‐state concentration (C_ss) at the approved dose was compared to the in vitro cell potency (half‐maximal inhibitory concentration (IC₅₀)). Average steady‐state area under the plasma concentration‐time curve, the fraction unbound drug in plasma, and the cell potency were taken from the US drug labels, US and European regulatory reviews, and peer‐reviewed journal articles. The C_ss was remarkably similar to the IC₅₀. The median C_ss/IC₅₀ value was 1.2, and 76% of the values were within 3‐fold of unity. However, three drugs (encorafenib, erlotinib, and ribociclib) had a C_ss/IC₅₀ value > 25. Seven other therapies targeting the same 3 kinases had much lower C_ss/IC₅₀ values ranging from 0.5 to 4. These data suggest that these kinase inhibitors have a large therapeutic window that is not fully exploited; lower doses may be similarly efficacious with improved tolerability. We propose a revised first‐in‐human trial design in which dose cohort expansion is initiated at doses less than the MTD when there is evidence of clinical activity and C_ss exceeds a potency threshold. This potency‐guided approach is expected to maximize the therapeutic window thereby improving patient outcomes.

Impact of pharmacist's intervention on decreasing erlotinib interactions in the treatment of lung cancer patients in low resource settings

BACKGROUND

This study aimed to demonstrate that having clinical pharmacist as a member of oncology team in low and middle income countries might lead to significant reduction in the number of erlotinib interactions in the treatment of non-small cell lung cancer patients.

METHODS

A group of 44 patients was labeled as intervention group and they were analyzed prospectively in the period from 1 January 2017 to 1 May 2018 during clinical pharmacist's participation in regular weekly multidisciplinary oncology team meetings. The control group consisted of 44 out of 110 patients treated with erlotinib before the involvement of a clinical pharmacist in oncology team, match paired with 44 patients in intervention group.

RESULTS

Clinically significant interactions were identified in two-thirds of studied patients (57 out of 88). Most drug interactions, 38%, potentially result in decrease of serum concentration of erlotinib. Clinical pharmacist provided therapy modification suggestions for 32 out of 44 (72.72%) patients in the intervention group, most of which were accepted by doctors. In the intervention group, there were significantly less clinically significant interactions compared to the control group (10 versus 24, p = 0.002). Progression-free survival was significantly longer in the pharmacist's intervention group (p = 0.001).

CONCLUSIONS

Clinical pharmacist's intervention led to significant decrease in erlotinib interactions which may result in treatment optimization of lung cancer patients.

Phase I/II Study of Erlotinib to Determine the Optimal Dose in Patients With Non-Small Cell Lung Cancer Harboring Only EGFR Mutations

The recommended daily dose of erlotinib was determined for patients with all types of non‐small cell lung cancer (NSCLC). We determined the optimal dose (OD) in patients with NSCLC harboring only epidermal growth factor receptor (EGFR) sensitizing mutations. EGFR‐tyrosine kinase inhibitor‐naïve patients with sensitizing mutations were eligible. Clinical OD was determined in a phase I/II study based on the continual re‐assessment method (CRM) of both disease control and dose‐limiting toxicity, defined as any toxicity of grade 2 (G2) or higher within 8 weeks. We also determined the pharmacologic OD via a pharmacokinetic (PK) study. Thirty‐eight patients were enrolled. Clinical OD was 25 mg/day by the CRM. Median progression‐free survival (mPFS) was 9.3 months. In receiver operating characteristic (ROC) analysis of mPFS, the trough concentration ( Cminss) was ≥ 0.30 μg/mL. The area under the curve (AUC) and Cminss were predicted via population PK (PopPK) or a bootstrap of 100 iterations (PopPK₁₀₀). TOX20 was defined as < 20% duration of any toxicity ≥ G2 during the PFS period. In ROC analysis of mPFS and TOX20 in the PopPK₁₀₀ study, Cminss was ≥ 0.17 and < 0.32 μg/mL, respectively. In ROC analysis of mPFS and TOX20 in the PopPK₁₀₀ study, Cminss was ≥ 0.15 and < 0.31 μg/mL, AUC was ≥ 14.4 and < 14.5 μg/mL•hour, and the dosage was ≥ 58.4 and < 58.8 mg/day, respectively. Clinical and pharmacologic ODs were 25 by CRM and 50–60 mg/day by PK, respectively. The proposed starting OD is 50–60 mg/day, with personalized adjustment of 0.15–0.31 μg/mL based on Cminss as determined by PopPK monitoring.

Annexin A6 improves anti-migratory and anti-invasive properties of tyrosine kinase inhibitors in EGFR overexpressing human squamous epithelial cells

Annexin A6 (AnxA6), a member of the calcium (Ca²⁺ ) and membrane binding annexins, is known to stabilize and establish the formation of multifactorial signaling complexes. At the plasma membrane, AnxA6 is a scaffold for protein kinase Cα (PKCα) and GTPase-activating protein p120GAP to promote downregulation of epidermal growth factor receptor (EGFR) and Ras/mitogen-activated protein kinase (MAPK) signaling. In human squamous A431 epithelial carcinoma cells, which overexpress EGFR, but lack endogenous AnxA6, restoration of AnxA6 expression (A431-A6) promotes PKCα-mediated threonine 654 (T654)-EGFR phosphorylation, which inhibits EGFR tyrosine kinase activity. This is associated with reduced A431-A6 cell growth, but also decreased migration and invasion in wound healing, matrigel, and organotypic matrices. Here, we show that A431-A6 cells display reduced EGFR activity in vivo, with xenograft analysis identifying increased pT654-EGFR levels, but reduced tyrosine EGFR phosphorylation compared to controls. In contrast, PKCα depletion in A431-A6 tumors is associated with strongly reduced pT654 EGFR levels, yet increased EGFR tyrosine phosphorylation and MAPK activity. Moreover, tyrosine kinase inhibitors (TKIs; gefitinib, erlotinib) more effectively inhibit cell viability, clonogenic growth, and wound healing of A431-A6 cells compared to controls. Likewise, the ability of AnxA6 to inhibit A431 motility and invasiveness strongly improves TKI efficacy in matrigel invasion assays. This correlates with a greatly reduced invasion of the surrounding matrix of TKI-treated A431-A6 when cultured in 3D spheroids. Altogether, these findings implicate that elevated AnxA6 scaffold levels contribute to improve TKI-mediated inhibition of growth and migration, but also invasive properties in EGFR overexpressing human squamous epithelial carcinoma.

A Ras destabilizer KYA1797K overcomes the resistance of EGFR tyrosine kinase inhibitor in KRAS-mutated non-small cell lung cancer

The epidermal growth factor receptor (EGFR) inhibitors such as erlotinib and gefitinib are widely used for treatment of non-small cell lung cancer (NSCLC), but they have shown limited efficacy in an unselected population of patients. The KRAS mutations, which are identified in approximately 20% of NSCLC patients, have shown to be associated with the resistance to the EGFR tyrosine kinase inhibitors (TKIs). Currently, there is no clinically available targeted therapy which can effectively inhibit NSCLC tumors harboring KRAS mutations. This study aims to show the effectiveness of KYA1797K, a small molecule which revealed anti-cancer effect in colorectal cancer by destabilizing Ras via inhibiting the Wnt/β-catenin pathway, for the treatment of KRAS-mutated NSCLC. While erlotinib fail to have anti-transforming effect in NSCLC cell lines harboring KRAS mutations, KYA1797K effectively inhibited the Ras-ERK pathway in KRAS-mutant NSCLC cell lines. As a result, KYA1797K treatment suppressed the growth and transformation of KRAS mutant NSCLC cells and also induced apoptosis. Furthermore, KYA1797K effectively inhibited Kras-driven tumorigenesis in the Kras^LA2 mouse model by suppressing the Ras-ERK pathway. The destabilization of Ras via inhibition of the Wnt/β-catenin pathway is a potential therapeutic strategy for KRAS-mutated NSCLC that is resistant to EGFR TKI.

Markers of MEK inhibitor resistance in low-grade serous ovarian cancer: EGFR is a potential therapeutic target

BACKGROUND

Although low-grade serous ovarian cancer (LGSC) is rare, case-fatality rates are high as most patients present with advanced disease and current cytotoxic therapies are not overly effective. Recognizing that these cancers may be driven by MAPK pathway activation, MEK inhibitors (MEKi) are being tested in clinical trials. LGSC respond to MEKi only in a subgroup of patients, so predictive biomarkers and better therapies will be needed.

METHODS

We evaluated a number of patient-derived LGSC cell lines, previously classified according to their MEKi sensitivity. Two cell lines were genomically compared against their matching tumors samples. MEKi-sensitive and MEKi-resistant lines were compared using whole exome sequencing and reverse phase protein array. Two treatment combinations targeting MEKi resistance markers were also evaluated using cell proliferation, cell viability, cell signaling, and drug synergism assays.

RESULTS

Low-grade serous ovarian cancer cell lines recapitulated the genomic aberrations from their matching tumor samples. We identified three potential predictive biomarkers that distinguish MEKi sensitive and resistant lines: KRAS mutation status, and EGFR and PKC-alpha protein expression. The biomarkers were validated in three newly developed LGSC cell lines. Sub-lethal combination of MEK and EGFR inhibition showed drug synergy and caused complete cell death in two of four MEKi-resistant cell lines tested.

CONCLUSIONS

KRAS mutations and the protein expression of EGFR and PKC-alpha should be evaluated as predictive biomarkers in patients with LGSC treated with MEKi. Combination therapy using a MEKi with EGFR inhibition may represent a promising new therapy for patients with MEKi-resistant LGSC.

Markers of MEK inhibitor resistance in low-grade serous ovarian cancer: EGFR is a potential therapeutic target

Background

Although low-grade serous ovarian cancer (LGSC) is rare, case-fatality rates are high as most patients present with advanced disease and current cytotoxic therapies are not overly effective. Recognizing that these cancers may be driven by MAPK pathway activation, MEK inhibitors (MEKi) are being tested in clinical trials. LGSC respond to MEKi only in a subgroup of patients, so predictive biomarkers and better therapies will be needed.

Methods

We evaluated a number of patient-derived LGSC cell lines, previously classified according to their MEKi sensitivity. Two cell lines were genomically compared against their matching tumors samples. MEKi-sensitive and MEKi-resistant lines were compared using whole exome sequencing and reverse phase protein array. Two treatment combinations targeting MEKi resistance markers were also evaluated using cell proliferation, cell viability, cell signaling, and drug synergism assays.

Results

Low-grade serous ovarian cancer cell lines recapitulated the genomic aberrations from their matching tumor samples. We identified three potential predictive biomarkers that distinguish MEKi sensitive and resistant lines: KRAS mutation status, and EGFR and PKC-alpha protein expression. The biomarkers were validated in three newly developed LGSC cell lines. Sub-lethal combination of MEK and EGFR inhibition showed drug synergy and caused complete cell death in two of four MEKi-resistant cell lines tested.

Conclusions

KRAS mutations and the protein expression of EGFR and PKC-alpha should be evaluated as predictive biomarkers in patients with LGSC treated with MEKi. Combination therapy using a MEKi with EGFR inhibition may represent a promising new therapy for patients with MEKi-resistant LGSC.

Markers of MEK inhibitor resistance in low-grade serous ovarian cancer: EGFR is a potential therapeutic target

Background

Although low-grade serous ovarian cancer (LGSC) is rare, case-fatality rates are high as most patients present with advanced disease and current cytotoxic therapies are not overly effective. Recognizing that these cancers may be driven by MAPK pathway activation, MEK inhibitors (MEKi) are being tested in clinical trials. LGSC respond to MEKi only in a subgroup of patients, so predictive biomarkers and better therapies will be needed.

Methods

We evaluated a number of patient-derived LGSC cell lines, previously classified according to their MEKi sensitivity. Two cell lines were genomically compared against their matching tumors samples. MEKi-sensitive and MEKi-resistant lines were compared using whole exome sequencing and reverse phase protein array. Two treatment combinations targeting MEKi resistance markers were also evaluated using cell proliferation, cell viability, cell signaling, and drug synergism assays.

Results

Low-grade serous ovarian cancer cell lines recapitulated the genomic aberrations from their matching tumor samples. We identified three potential predictive biomarkers that distinguish MEKi sensitive and resistant lines: KRAS mutation status, and EGFR and PKC-alpha protein expression. The biomarkers were validated in three newly developed LGSC cell lines. Sub-lethal combination of MEK and EGFR inhibition showed drug synergy and caused complete cell death in two of four MEKi-resistant cell lines tested.

Conclusions

KRAS mutations and the protein expression of EGFR and PKC-alpha should be evaluated as predictive biomarkers in patients with LGSC treated with MEKi. Combination therapy using a MEKi with EGFR inhibition may represent a promising new therapy for patients with MEKi-resistant LGSC.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0725-1) contains supplementary material, which is available to authorized users.

A case report of metastatic lung adenocarcinoma with long-term survival for over 11 years

RATIONALE

This is the first known report in the English literature to describe a case of metastatic non-small cell lung cancer that has been controlled for >11 years.

PATIENT CONCERNS

A 71-year-old man visited our hospital because of dry cough.

DIAGNOSIS

Chest computed tomography revealed a tumor on the left lower lobe with pleural effusion, and thoracic puncture cytology indicated lung adenocarcinoma.

INTERVENTIONS

Four cycles of carboplatin and docetaxel chemotherapy reduced the size of the tumor; however, it increased in size after 8 months, and re-challenge chemotherapy (RC) with the same drugs was performed. Repeated RC controlled disease activity for 6 years. After the patient failed to respond to RC, erlotinib was administered for 3 years while repeating a treatment holiday to reduce side effects. The disease progressed, and epidermal growth factor receptor (EGFR) gene mutation analysis of cells from the pleural effusion detected the T790 M mutation. Therefore, osimertinib was administered, which has been effective for >1 year.

OUTCOMES

The patient has survived for >11 years since the diagnosis of lung cancer.

LESSONS

Long-term survival may be implemented by actively repeating cytotoxic chemotherapy and EGFR-tyrosine kinase inhibitor administration.

Gefitinib provides similar effectiveness and improved safety than erlotinib for east Asian populations with advanced non-small cell lung cancer: a meta-analysis

BACKGROUND

The first-generation epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib have both been proven effective for treating advanced non-small cell lung cancer (NSCLC), especially in East Asian patients. We conducted this meta-analysis to compare their efficacy and safety in treating advanced NSCLC in this population.

METHODS

We systematically searched PubMed, ScienceDirect, The Cochrane Library, Scopus, Ovid MEDLINE, Embase, Web of Science, and Google Scholar for the relevant studies. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and adverse effects (AEs) were analyzed as primary endpoints.

RESULTS

We identified 5829 articles, among which 31 were included in the final analysis. Both gefitinib and erlotinib were effective for treating advanced NSCLC, with comparable PFS (95% confidence interval [CI]: 0.97-1.10, p = 0.26), OS (95% CI: 0.89-1.21, p = 0.61), ORR (95% CI: 1.00-1.18, p = 0.06), and DCR (95% CI: 0.93-1.05, p = 0.68). Erlotinib induced a significantly higher rate of dose reduction (95% CI: 0.13-0.65, p = 0.002) and grade 3-5 AEs (95% CI: 0.27-0.71, p = 0.0008). In subgroup analysis of AEs, the erlotinib group had a significantly higher rate and severity of skin rash, nausea/vomiting, diarrhea, fatigue and stomatitis.

CONCLUSIONS

With equal anti-tumor efficacy and fewer AEs compared with erlotinib, gefitinib is more suitable for treating advanced NSCLC in East Asian patients. Further large-scale, well-designed randomized controlled trials are warranted to confirm our findings.

Gefitinib provides similar effectiveness and improved safety than erlotinib for advanced non-small cell lung cancer: A meta-analysis

BACKGROUND

The epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib are effective for advanced non-small cell lung cancer (NSCLC). This meta-analysis compared their effectiveness and safety.

METHODS

We searched systematically in PubMed, ScienceDirect, The Cochrane Library, Scopus, Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar for relevant clinical trials regarding gefitinib versus erlotinib for NSCLC. Antitumor effectiveness (overall survival [OS], progression-free survival [PFS], objective response rate [ORR] and disease control rate [DCR]) and adverse effects [AEs]) were assessed.

RESULTS

Forty studies comprising 9376 participants were included. The results suggested that gefitinib and erlotinib are effective for advanced NSCLC with comparable PFS (95% confidence intervals [CI]: 0.98-1.11, P = .15), OS (95% CI: 0.93-1.19, P = .45), ORR (95% CI: 0.99-1.16, P = .07), and DCR (95% CI: 0.92-1.03, P = .35). For erlotinib, dose reduction was significantly more frequent (95% CI: 0.10-0.57, P = .001) as were grade 3 to 5 AEs (95% CI: 0.36-0.79, P = .002). In the subgroup analysis, the erlotinib group had a significant higher rate and severity of skin rash, nausea/vomiting, fatigue, and stomatitis.

CONCLUSIONS

Gefitinib was proven to be the better choice for advanced NSCLC, with equal antitumor effectiveness and fewer AEs compared with erlotinib. Further large-scale, well-designed randomized controlled trials are warranted to confirm our validation.

EGFR kinase inhibitors and gastric acid suppressants in EGFR-mutant NSCLC: a retrospective database analysis of potential drug interaction

Background

Erlotinib and gefitinib are weak base drugs whose absorption and clinical efficacy may be impaired by concomitant gastric acid suppressive (AS) therapy, yet proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2As) are widely indicated in non-small cell lung cancer (NSCLC) patients for the prevention and treatment of erlotinib-induced gastrointestinal injury and corticosteroid-associated gastric irritation. We assessed the clinical relevance of this potential drug-drug interaction (DDI) in a retrospective cohort of EGFR-mutant NSCLC patients.

Results

The AS usage rate was 35%. In the overall cohort, AS users did not experience poorer OS (HR: 1.47, 95% CI: 0.92 – 2.35, P = 0.10; median, 11.4 versus 17.5 months) or PFS (HR = 1.37, 95% CI: 0.89 – 2.12, P = 0.16; median, 7.6 versus 8.7 months) compared with non-users in multivariate Cox regression analysis. However, subgroup analyses indicated that AS usage was associated with significantly poorer OS and PFS in patients who had fewer or milder comorbidities (Charlson comorbidity index ≤ 2), those with Karnofsky performance status < 90, and never-smokers.

Materials and Methods

A retrospective database analysis of 157 patients given erlotinib or gefitinib for EGFR-mutant advanced NSCLC from two institutions was conducted. Patients were classified as AS-users if the periods of AS and anti-EGFR therapy overlapped by ≥ 30%. Overall survival (OS) and progression-free survival (PFS) were assessed according to AS usage.

Conclusions

Concomitant AS therapy did not have an adverse impact on OS and/or PFS in the overall cohort. Our subgroup findings should be regarded exploratory and require replication in a large prospective cohort.

Downregulating Neuropilin-2 Triggers a Novel Mechanism Enabling EGFR-Dependent Resistance to Oncogene-Targeted Therapies

Neuropilins are a class of cell surface proteins implicated in cell migration and angiogenesis, with aberrant expression in human tumors. Here, we show that the expression of Neuropilin-2 (NRP2) controls EGFR protein levels, thereby impinging on intracellular signaling, viability, and response to targeted therapies of oncogene-addicted cells. Notably, increased NRP2 expression in EGFR-addicted tumor cells led to downregulation of EGFR protein and tumor cell growth inhibition. NRP2 also blunted upregulation of an EGFR "rescue" pathway induced by targeted therapy in Met-addicted carcinoma cells. Cancer cells acquiring resistance to MET oncogene-targeted drugs invariably underwent NRP2 loss, a step required for EGFR upregulation. Mechanistic investigations revealed that NRP2 loss activated NFkB and upregulated the EGFR-associated protein KIAA1199/CEMIP, which is known to oppose the degradation of activated EGFR kinase. Notably, KIAA1199 silencing in oncogene-addicted tumor cells improved therapeutic responses and counteracted acquired drug resistance. Our findings define NRP2 as the pivotal switch of a novel broad-acting and actionable pathway controlling EGFR signaling, and driving resistance to therapies targeting oncogene-addiction.Significance: These important findings identify the cell surface molecule Nrp2 as the pivotal switch of a novel, actionable pathway driving EGFR upregulation and resistance to oncogene- targeted therapies. Cancer Res; 78(4); 1058-68. ©2017 AACR.

Comparison of gefitinib, erlotinib and afatinib in non-small cell lung cancer: A meta-analysis

Gefitinib, erlotinib and afatinib are three widely used epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) for treating advanced non-small cell lung cancer (NSCLC) with proven efficacy. We undertook a systematic review and meta-analysis to synthesize existing studies with direct comparisons of EGFR TKIs in NSCLC in terms of both efficacy and safety. Eight randomized trials and 82 cohort studies with a total of 17,621 patients were included for analysis. Gefitinib and erlotinib demonstrated comparable effects on progression-free survival (hazard ratio [HR], 1.00; 95% confidence interval [CI], 0.95 to 1.04), overall survival (HR, 0.99; 95% CI, 0.93 to 1.06), overall response rate (risk ratio [RR], 1.05; 95% CI, 1.00 to 1.11), and disease control rate (RR, 0.98; 95% CI, 0.96 to 1.01), which did not vary considerably with EGFR mutation status, ethnicity, line of treatment, and baseline brain metastasis status. Gefitinib was associated with more grade 3/4 liver dysfunction, but tended to cause lower rates of dose reduction, treatment discontinuation, total grade 3/4 adverse events (RR, 0.78; 95% CI 0.65 to 0.94), and a number of specific adverse events such as rash and diarrhea. No solid evidence was found that afatinib had greater efficacy than gefitinib or erlotinib in first-line treatment of EGFR-mutant NSCLC. However, afatinib was more effective than erlotinib as second-line treatment of patients with advanced squamous cell carcinoma. The grade 3/4 adverse events rate of afatinib was comparable to that of erlotinib but higher than that of gefitinib.

Phase 1 study of twice weekly pulse dose and daily low-dose erlotinib as initial treatment for patients with EGFR-mutant lung cancers

Background

Patients with EGFR-mutant lung cancers treated with EGFR tyrosine kinase inhibitors (TKIs) develop clinical resistance, most commonly with acquisition of EGFR T790M. Evolutionary modeling suggests that a schedule of twice weekly pulse and daily low-dose erlotinib may delay emergence of EGFR T790M. Pulse dose erlotinib has superior central nervous system (CNS) penetration and may result in superior CNS disease control.

Methods

We evaluated toxicity, pharmacokinetics, and efficacy of twice weekly pulse and daily low-dose erlotinib. We assessed six escalating pulse doses of erlotinib.

Results

We enrolled 34 patients; 11 patients (32%) had brain metastases at study entry. We observed 3 dose-limiting toxicities in dose escalation: transaminitis, mucositis, and rash. The MTD was erlotinib 1200 mg days 1-2 and 50 mg days 3-7 weekly. The most frequent toxicities (any grade) were rash, diarrhea, nausea, fatigue, and mucositis. 1 complete and 24 partial responses were observed (74%, 95% CI 60-84%). Median progression-free survival was 9.9 months (95% CI 5.8-15.4 months). No patient had progression of an untreated CNS metastasis or developed a new CNS lesion while on study (0%, 95% CI 0-13%). Of the 18 patients with biopsies at progression, EGFR T790M was identified in 78% (95% CI 54-91%).

Conclusion

This is the first clinical implementation of an anti-cancer TKI regimen combining pulse and daily low-dose administration. This evolutionary modeling-based dosing schedule was well-tolerated but did not improve progression-free survival or prevent emergence of EGFR T790M, likely due to insufficient peak serum concentrations of erlotinib. This dosing schedule prevented progression of untreated or any new central nervous system metastases in all patients.

Low-dose Epidermal Growth Factor Receptor (EGFR)- Tyrosine Kinase Inhibition of EGFR Mutation-positive Lung Cancer: Therapeutic Benefits and Associations Between Dosage, Efficacy and Body Surface Area

A key drug for treatment of EGFR mutation-positive non-small cell lung cancer is epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). While the dosage of many general anti-tumor drugs is adjusted according to the patient body surface area, one uniform dose of most TKIs is recommended regardless of body size. In many cases, dose reduction or drug cessation is necessary due to adverse effects. Disease control, however, is frequently still effective, even after dose reduction. In this study, we retrospectively reviewed the characteristics of 26 patients at Fukuoka University Hospital between January 2004 and January 2015 in whom the EGFR-TKI dose was reduced with respect to progression free survival and overall survival. There were 10 and 16 patients in the gefitinib group and the erlotinib group, respectively. The median progression-free survival in the gefitinib group and the erlotinib group was 22.4 months and 14.1 months, respectively, and the median overall survival was 30.5 months and 32.4 months, respectively. After stratification of patients by body surface area, the overall median progression-free survival was significantly more prolonged in the low body surface area (<1.45 m2) group (25.6 months) compared to the high body surface area (>1.45 m2) group (9.7 months) (p=0.0131). These results indicate that low-dose EGFR-TKI may sufficiently control disease without side effects in lung cancer patients with a small body size.

Targeted therapies for the treatment of non-small-cell lung cancer: Monoclonal antibodies and biological inhibitors

The usual treatments for patients with non-small-cell lung cancer (NSCLC), such as advanced lung adenocarcinoma, are unspecific and aggressive, and include lung resection, radiotherapy and chemotherapy. Recently, treatment with monoclonal antibodies and biological inhibitors has emerged as an effective alternative, generating effective results with few side effects. In recent years, several clinical trials using monoclonal antibodies presented potential benefits to NSCLC, and 4 of them are already approved for the treatment of NSCLC, such as cetuximab, bevacizumab, nivolumab and pembrolizumab. Also, biological inhibitors are attractive tolls for biological applications. Among the approved inhibitors are crizotinib, erlotinib, afatinib and gefitinib, and side effects are usually mild to intense. Nevertheless, biological molecule treatments are under development, and several new monoclonal antibodies and biological inhibitors are in trial to treat NSCLC. Also under trial study are as follows: anti-epidermal growth factor receptor (EGFR) antibodies (nimotuzumab and ficlatuzumab), anti-IGF 1 receptor (IGF-1R) monoclonal antibody (figitumumab), anti-NR-LU-10 monoclonal antibody (nofetumomab) as well as antibodies directly affecting the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) molecule (ipilimumab and tremelimumab), to receptor activator of nuclear factor-kappa B ligand (RANKL) (denosumab) or to polymerase enzyme (veliparib and olaparib). Among new inhibitors under investigation are poly-ADP ribose polymerase (PARP) inhibitors (veliparib and olaparib) and phosphatidylinositol 3-kinase (PI3K) inhibitor (buparlisib). However, the success of immunotherapies still requires extensive research and additional controlled trials to evaluate the long-term benefits and side effects.

Dermatologic events from EGFR inhibitors: the issue of the missing patient voice

Purpose

As epidermal growth factor receptor (EGFR) inhibitors are associated with a variety of dermatologic adverse events (dAEs), the purpose of this study was to develop an overview of current knowledge of dAEs associated with EGFR inhibitors and to identify knowledge gaps regarding incidence, treatment, impact on quality of life (QOL), and patient acceptance.

Method

A structured literature search was conducted using MEDLINE/PubMed (January 1983 to January 2014). In total, 71 publications published from 2004 to 2014 were identified for consideration in the final evidence review.

Results

The majority of published articles concentrate on the incidence of skin reactions, duration, treatment, and prevention strategies. Different grading systems based on the symptoms of skin rash or on health-related QOL (HRQOL) are used. An additional topic is the possible correlation between acneiform rash and efficacy of EGFR inhibitors. Knowledge gaps identified in the literature were how dAEs impact QOL compared with other AEs from a patient’s perspective, patients’ acceptance of dAEs (willingness to tolerate), and the impact of physician-patient communication on treatment decisions.

Conclusions

Research is needed on the impact of dAEs on patients’ acceptance of cancer treatments. Systematic studies are missing that compare the impact of dAEs with other toxicities on therapy decisions from both physician’s and patient’s view, and that investigate the balance between efficacy and avoidance of acneiform rash in treatment decisions. Such studies could provide deeper insights into the acceptance of the risk of untoward dermatologic events by both physicians and patients when treating advanced cancers.

Electronic supplementary material

The online version of this article (doi:10.1007/s00520-016-3419-4) contains supplementary material, which is available to authorized users.

Activity of erlotinib when dosed below the maximum tolerated dose for EGFR-mutant lung cancer: Implications for targeted therapy development

BACKGROUND

Erlotinib is a standard first-line therapy for patients who have metastatic nonsmall cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. The recommended dose of 150 mg daily is the maximum tolerated dose (MTD). Few clinical data are available regarding its efficacy at doses less than the MTD.

METHODS

An institutional database was queried for patients with advanced NSCLC who were positive for EGFR L858R mutations or exon 19 deletions and had received treatment with erlotinib. The treatment course, including the erlotinib dose at initiation of treatment, at 4 months into therapy, and at disease progression, was retrospectively studied. Progression-free survival (PFS) was compared between patients who received the MTD (150 mg) and those who received reduced-dose erlotinib (≤100 mg).

RESULTS

In total, 198 eligible patients were identified. Thirty-one patients (16%) were initiated on reduced-dose erlotinib; they were older (P = .001) and had lower performance status (P = .01) compared with those who were initiated on erlotinib at the MTD. The response rate to reduced-dose erlotinib was 77%. The median PFS of patients initiated on reduced-dose erlotinib was 9.6 months versus 11.4 months for those initiated at the MTD, a difference that was not statistically significant (hazard ratio, 0.81; 95% confidence interval, 0.54-1.21; P = .30). There was a nonsignificant trend toward higher rates of progression within the central nervous system with reduced-dose erlotinib.

CONCLUSIONS

At doses below the MTD, erlotinib treatment results in a high response rate and a prolonged median PFS. Review of the literature indicates that 15 of 30 small-molecule inhibitors that are approved or in late-stage development for cancer therapy have recommended doses below the MTD. When the toxicities of MTD dosing are a concern, an investigation of small-molecule inhibitors at doses below the MTD is warranted. Cancer 2016;122:3456-63. © 2016 American Cancer Society.

Effect of acid suppressants on the efficacy of tyrosine kinase inhibitors in patients with epidermal growth factor receptor-mutated non-small-cell lung cancer

This retrospective study was conducted to evaluate whether oral acid suppressant (AS) therapy is associated with decreased efficacy of gefitinib and erlotinib, particularly in patients with mutated epidermal growth factor receptor (EGFR). A total of 46 consecutive patients with pathologically confirmed non-small-cell lung cancer (NSCLC), who were treated with tyrosine kinase inhibitors (TKIs) in two tertiary hospitals between September, 2005 and May, 2013, were retrospectively analyzed. Of the 46 patients, 11 received AS treatment. As regards age, gender, smoking history, performance status, histology of lung cancer, clinical stage, body surface area (BSA) and type of EGFR mutation, there were no statistically significant differences between patients with and those without AS treatment. There was no statistically significant difference in progression-free survival (PFS) or overall survival (OS) between the two groups of patients (P=0.296 and 0.613, respectively). As regards the relative dose of TKI/BSA and survival in patients with and those without AS treatment, there were no statistically significant differences in PFS and OS between the two groups of patients. Our study indicates that AS treatment may not compromise TKI efficacy (gefitinib or erlotinib) in NSCLC patients with mutated EGFR. Prospective studies and large-scale confirmation studies investigating the effect of AS co-administration with TKIs in patients with mutated EGFR may be meaningful in clinical practice.

Spotlight on lenvatinib in the treatment of thyroid cancer: patient selection and perspectives

Thyroid cancer is the most common endocrine malignancy, with over 60,000 cases reported per year in the US alone. The incidence of thyroid cancer has increased in the last several years. Patients with metastatic differentiated thyroid cancer (DTC) generally have a good prognosis. Metastatic DTC can often be treated in a targeted manner with radioactive iodine, but the ability to accumulate iodine is lost with decreasing differentiation. Until recently, chemotherapy was the only treatment in patients with advanced thyroid cancer, which is no longer amenable to therapy with radioactive iodine. The modest efficacy and significant toxicity of chemotherapy necessitated the need for urgent advances in the medical field. New insights in thyroid cancer biology propelled the development of targeted therapies for this disease, including the tyrosine kinase inhibitor sorafenib as salvage treatment for DTC. In 2015, the US Food and Drug Administration approved a second tyrosine kinase inhibitor, lenvatinib, for the treatment of radioiodine-refractory thyroid cancer. Although associated with a significant progression-free survival improvement as compared to placebo in a large Phase III study (median progression-free survival 18.2 vs 3.6 months; hazard ratio 0.21; 99% confidence interval 0.14-0.31; P<0.001), the benefit of lenvatinib needs to be proved in the context of associated moderate to severe toxicities that require frequent dose reduction and delays. This article reviews the evidence supporting the use of lenvatinib as salvage therapy for radioactive iodine-refractory thyroid cancer, with a focus on the toxicity profile of this new therapy.

Adjuvant Erlotinib Versus Placebo in Patients With Stage IB-IIIA Non–Small-Cell Lung Cancer (RADIANT): A Randomized, Double-Blind, Phase III Trial

Purpose

Epidermal growth factor receptor (EGFR) –tyrosine kinase inhibitors have proven efficacy in advanced non–small-cell lung cancer (NSCLC). We hypothesized that erlotinib would be efficacious in the adjuvant setting.

Patients and Methods

An international randomized, double-blind, placebo-controlled study was conducted in patients with completely resected IB to IIIA NSCLC whose tumors expressed EGFR protein by immunohistochemistry or EGFR amplification by fluorescence in situ hybridization. Patients were assigned 2:1 to erlotinib 150 mg once per day or placebo for 2 years. Stratification factors were stage, histology, previous adjuvant chemotherapy, smoking status, EGFR amplification status, and country. The primary end point was disease-free survival (DFS); key secondary end points were overall survival (OS) and DFS and OS in patients whose tumors had EGFR-activating mutations (EGFRm-positive).

Results

A total of 973 patients were randomly assigned (November 26, 2007, to July 7, 2010). There was no statistically significant difference in DFS (median, 50.5 months for erlotinib and 48.2 months for placebo; hazard ratio, 0.90; 95% CI, 0.74 to 1.10; P = .324). Among the 161 patients (16.5%) in the EGFRm-positive subgroup, DFS favored erlotinib (median, 46.4 v 28.5 months; hazard ratio, 0.61; 95% CI, 0.38 to 0.98; P = .039), but this was not statistically significant because of the hierarchical testing procedure. OS data are immature. Rash and diarrhea were common adverse events occurring in 528 (86.4%) and 319 (52.2%) patients treated with erlotinib, respectively, versus 110 (32.1%) and 54 (15.7%) patients receiving placebo. The most common grade 3 adverse events in patients treated with erlotinib were rash (22.3%) and diarrhea (6.2%).

Conclusion

Adjuvant erlotinib did not prolong DFS in patients with EGFR-expressing NSCLC or in the EGFRm-positive subgroup. Further evaluation of erlotinib is warranted in the EGFRm-positive subgroup.

Management of advanced non-small cell lung cancers with known mutations or rearrangements: latest evidence and treatment approaches

Precision oncology is now the evidence-based standard of care for the management of many advanced non-small cell lung cancers (NSCLCs). Expert consensus has defined minimum requirements for routine testing and identification of epidermal growth factor (EGFR) mutations (15% of tumors harbor EGFR exon 19 deletions or exon 21 L858R substitutions) and anaplastic lymphoma kinase (ALK) rearrangements (5% of tumors) in advanced lung adenocarcinomas (ACs). Application of palliative targeted therapies with oral tyrosine kinase inhibitors (TKIs) in advanced/metastatic lung ACs harboring abnormalities in EGFR (gefitinib, erlotinib, afatinib) and ALK/ROS1/MET (crizotinib) has consistently led to more favorable outcomes compared with traditional cytotoxic agents. In addition, mutations leading to resistance to first-line EGFR and ALK TKIs can now be successfully inhibited by soon to be approved third-generation EGFR TKIs (osimertinib, rociletinib) and second-generation ALK TKIs (ceritinib, alectinib). Notably, increasing feasibility, accessibility, and application of molecular profiling technologies has permitted dynamic growth in the identification of actionable driver oncogenes. Emerging genomic aberrations for which TKIs have shown impressive results in clinical trials and expansion of drug labels for approved agents are awaited include ROS1 rearrangements (1-2% of tumors, drug: crizotinib) and BRAF-V600E mutations (1-3% of tumors, drugs: vemurafenib, dafrafenib + trametinib). Evolving genomic events in which TKI responses have been reported in smaller series include MET exon 14 skipping mutations (2-4% of tumors, drug: crizotinib); high-level MET amplification (1-2% of tumors, drug: crizotinib); RET rearrangements (1% of tumors, drug: cabozantinib); and ERBB2 mutations (2-3% of tumors, drug: afatinib), among others. Unfortunately, the most common genomic event in NSCLC, KRAS mutations (25-30% of tumors), is not targetable with approved or in development small molecule inhibitors. Here, we review currently approved, emerging, and evolving systemic precision therapies matched with their driver oncogenes for the management of advanced NSCLC.

Randomized, Multicenter Study of Gefitinib Dose-escalation in Advanced Non-small-cell Lung Cancer Patients Achieved Stable Disease after One-month Gefitinib Treatment

There is no consensus on the optimal treatment for patients with advanced non-small-cell lung cancer (NSCLC) and stable disease (SD) after gefitinib therapy. This randomized, open-label, multicenter study aimed to explore whether dose-escalation of gefitinib would improve response and survival in NSCLC patients who achieved SD after one-month of standard gefitinib dosage. Between May 2009 and January 2012, 466 patients were enrolled and 100 eligible patients were randomized (1:1) to receive either a higher dose (500 mg/d; H group) or to continue standard dose (250 mg/d; S group) of gefitinib. Objective response rate (ORR) was similar between the two groups (12.5% vs 12.5%, p = 1.000). There were no significant differences regarding progression-free survival (PFS) and overall survival (OS) between both arms (H group vs S group: median PFS, 5.30 months vs 6.23 months, p = 0.167; median OS, 13.70 months vs 18.87 months, p = 0.156). Therefore, dose-escalation of gefitinib does not confer a response or survival advantage in patients who achieve SD with one month of standard-dose gefitinib treatment.

A prospective, multicentre phase II trial of low-dose erlotinib in non-small cell lung cancer patients with EGFR mutations pretreated with chemotherapy: Thoracic Oncology Research Group 0911

BACKGROUND

Low-dose erlotinib may be as effective as gefitinib or erlotinib at full dose in non-small cell lung cancer (NSCLC) patients with activating mutations of the epidermal growth factor receptor (EGFR) gene.

METHODS

Patients with chemotherapy pretreated NSCLC harbouring EGFR mutations received erlotinib at 50 mg/d until disease progression or unacceptable toxicities. The dose was escalated to 150 mg/d in patients showing no response (i.e. without major tumour shrinkage according to Response Evaluation Criteria in Solid Tumours (RECIST)) to the initial dose during the first 4 weeks. The primary end-point was the objective response rate at the dose of 50 mg/d.

RESULTS

Thirty-four patients from seven institutes were enrolled. The study was closed early when no response was confirmed in 15 patients, excluding the possibility that the primary end-point would be met. The objective response and disease control rates at the dose of 50 mg/d as determined by an independent review committee were 54.5% and 84.8%, respectively. Four additional patients achieved partial response with increased 150 mg/d dose. Progression-free survival and median survival times during the entire period of the study were 9.5 and 28.5 months, respectively. Treatment-related toxicities were generally mild, the most common being skin disorders and diarrhoea. Only one case experienced grade 3 toxicity, which was transient increase of hepatic enzymes.

CONCLUSION

The primary end-point was not met; low-dose erlotinib is not recommended for fit patients with NSCLC harbouring EGFR mutations. However, it may merit further evaluation for elderly or frail patients.

Genetic modifiers of EGFR dependence in non-small cell lung cancer

Lung adenocarcinomas harboring activating mutations in the epidermal growth factor receptor (EGFR) represent a common molecular subset of non-small cell lung cancer (NSCLC) cases. EGFR mutations predict sensitivity to EGFR tyrosine kinase inhibitors (TKIs) and thus represent a dependency in NSCLCs harboring these alterations, but the genetic basis of EGFR dependence is not fully understood. Here, we applied an unbiased, ORF-based screen to identify genetic modifiers of EGFR dependence in EGFR-mutant NSCLC cells. This approach identified 18 kinase and kinase-related genes whose overexpression can substitute for EGFR in EGFR-dependent PC9 cells, and these genes include seven of nine Src family kinase genes, FGFR1, FGFR2, ITK, NTRK1, NTRK2, MOS, MST1R, and RAF1. A subset of these genes can complement loss of EGFR activity across multiple EGFR-dependent models. Unbiased gene-expression profiling of cells overexpressing EGFR bypass genes, together with targeted validation studies, reveals EGFR-independent activation of the MEK-ERK and phosphoinositide 3-kinase (PI3K)-AKT pathways. Combined inhibition of PI3K-mTOR and MEK restores EGFR dependence in cells expressing each of the 18 EGFR bypass genes. Together, these data uncover a broad spectrum of kinases capable of overcoming dependence on EGFR and underscore their convergence on the PI3K-AKT and MEK-ERK signaling axes in sustaining EGFR-independent survival.

Epidermal growth factor receptor (EGFR) mutations in lung cancer: preclinical and clinical data

Lung cancer leads cancer-related mortality worldwide. Non-small-cell lung cancer (NSCLC), the most prevalent subtype of this recalcitrant cancer, is usually diagnosed at advanced stages, and available systemic therapies are mostly palliative. The probing of the NSCLC kinome has identified numerous nonoverlapping driver genomic events, including epidermal growth factor receptor (EGFR) gene mutations. This review provides a synopsis of preclinical and clinical data on EGFR mutated NSCLC and EGFR tyrosine kinase inhibitors (TKIs). Classic somatic EGFR kinase domain mutations (such as L858R and exon 19 deletions) make tumors addicted to their signaling cascades and generate a therapeutic window for the use of ATP-mimetic EGFR TKIs. The latter inhibit these kinases and their downstream effectors, and induce apoptosis in preclinical models. The aforementioned EGFR mutations are stout predictors of response and augmentation of progression-free survival when gefitinib, erlotinib, and afatinib are used for patients with advanced NSCLC. The benefits associated with these EGFR TKIs are limited by the mechanisms of tumor resistance, such as the gatekeeper EGFR-T790M mutation, and bypass activation of signaling cascades. Ongoing preclinical efforts for treating resistance have started to translate into patient care (including clinical trials of the covalent EGFR-T790M TKIs AZD9291 and CO-1686) and hold promise to further boost the median survival of patients with EGFR mutated NSCLC.

Gastric Acid suppression is associated with decreased erlotinib efficacy in non-small-cell lung cancer

BACKGROUND

Erlotinib is a key therapy for advanced NSCLC. Concurrent AS therapy with TKIs might reduce TKI plasma levels. Because of gastroesophageal reflux disease prevalence, this retrospective analysis was undertaken to determine if coadministering erlotinib with AS therapy affected NSCLC outcomes.

PATIENTS AND METHODS

Records of advanced NSCLC patients who received erlotinib from 2007 to 2012 at a large, centralized, cancer institution were retrospectively reviewed. Pertinent demographic data were collected and concomitant AS treatment was defined as AS prescription dates overlapping with ≥ 20% of erlotinib treatment duration. Records of patients who received erlotinib for ≥ 1 week were analyzed for progression-free survival (PFS) and overall survival (OS).

RESULTS

Stage IIIB/IV NSCLC patients (n = 544) were identified and 507 had adequate data for review. The median age was 64 years and 272 were female. Adenocarcinoma (n = 318; 64%) and squamous (n = 106; 21%) were predominant subtypes; 124 patients received concomitant AS therapy. In this unselected population, median PFS and OS in AS versus no AS groups were 1.4 versus 2.3 months (P < .001) and 12.9 versus 16.8 months (P = .003), respectively. Factoring sex, subtype, and performance status in multivariate Cox proportional hazards ratios for PFS and OS between AS and no AS groups were 1.83 (95% confidence interval [CI], 1.48-2.25) and 1.37 (95% CI, 1.11-1.69), respectively.

CONCLUSION

This large population-based study suggests erlotinib efficacy might be linked with gastric pH and OS could be adversely affected. To our knowledge, this is the first study demonstrating a possible negative clinical effect of coadministration of erlotinib with AS therapy. Further prospective investigation is warranted.

Structural, biochemical, and clinical characterization of epidermal growth factor receptor (EGFR) exon 20 insertion mutations in lung cancer

Epidermal growth factor receptor (EGFR) gene mutations (G719X, exon 19 deletions/insertions, L858R, and L861Q) predict favorable responses to EGFR tyrosine kinase inhibitors (TKIs) in advanced non-small cell lung cancer (NSCLC). However, EGFR exon 20 insertion mutations (~10% of all EGFR mutations) are generally associated with insensitivity to available TKIs (gefitinib, erlotinib, and afatinib). The basis of this primary resistance is poorly understood. We studied a broad subset of exon 20 insertion mutations, comparing in vitro TKI sensitivity with responses to gefitinib and erlotinib in NSCLC patients, and found that most are resistant to EGFR TKIs. The crystal structure of a representative TKI-insensitive mutant (D770_N771insNPG) reveals an unaltered adenosine triphosphate-binding pocket, and the inserted residues form a wedge at the end of the C helix that promotes the active kinase conformation. Unlike EGFR-L858R, D770_N771insNPG activates EGFR without increasing its affinity for EGFR TKIs. Unexpectedly, we find that EGFR-A763_Y764insFQEA is highly sensitive to EGFR TKIs in vitro, and patients whose NSCLCs harbor this mutation respond to erlotinib. Analysis of the A763_Y764insFQEA mutant indicates that the inserted residues shift the register of the C helix in the N-terminal direction, altering the structure in the region that is also affected by the TKI-sensitive EGFR-L858R. Our studies reveal intricate differences between EGFR mutations, their biology, and their response to EGFR TKIs.

Effective ultra-low doses of erlotinib in patients with EGFR sensitising mutation

We describe three cases of patients with advanced adenocarcinoma of the lung and epidermal growth factor receptor (EGFR) mutation treated with erlotinib 25 mg/day and 25 mg every second day, being equal to one-sixth and one-twelfth of the recommended dose. The mean age of our patients was above 70 with a WHO performance status 1 before and during the treatment. The reasons for erlotinib dose reduction were rash, diarrhoea and fatigue. The decision was a result of lack of other treatment options and radiological response on standard doses. We did not observe any liver enzyme abnormalities. However, the post-treatment creatinine increased significantly. As of February 2014, our patients are still on treatment with tolerable side effects and improved quality of life. These findings indicate that some patients responding to erlotinib with noxious side effects could have clinical benefit in doses much lower than recommended.

Acquired resistance to TKIs in solid tumours: learning from lung cancer

The use of advanced molecular profiling to direct the use of targeted therapy, such as tyrosine kinase inhibitors (TKIs) for patients with advanced-stage non-small-cell lung cancer (NSCLC), has revolutionized the treatment of this disease. However, acquired resistance, defined as progression after initial benefit, to targeted therapies inevitably occurs. This Review explores breakthroughs in the understanding and treatment of acquired resistance in NSCLC, focusing on EGFR mutant and ALK rearrangement-positive disease, which may be relevant across multiple different solid malignancies with oncogene-addicted subtypes. Mechanisms of acquired resistance may be pharmacological (that is, failure of delivery of the drug to its target) or biological, resulting from evolutionary selection on molecularly diverse tumours. A number of clinical approaches can maintain control of the disease in the acquired resistance setting, including the use of radiation to treat isolated areas of progression and adding or switching to cytotoxic chemotherapy. Furthermore, novel approaches that have already proven successful include the development of second-generation and third-generation inhibitors and the combination of some of these inhibitors with antibodies directed against the same target. With our increased understanding of the spectrum of acquired resistance, major changes in how we conduct clinical research in this setting are now underway.

Determining the optimal dose in the development of anticancer agents

Identification of the optimal dose remains a key challenge in drug development. For cytotoxic drugs, the standard approach is based on identifying the maximum tolerated dose (MTD) in phase I trials and incorporating this to subsequent trials. However, this strategy does not take into account important aspects of clinical pharmacology. For targeted agents, the dose-effect relationships from preclinical studies are less obvious, and it is important to change the way these agents are developed to avoid recommending drug doses for different populations without evidence of differential antitumour effects in different diseases. The use of expanded cohorts in phase I trials to better define MTD and refine dose optimization should be further explored together with a focus on efficacy rather than toxicity-based predictions. Another key consideration in dose optimization is related to interindividual pharmacokinetic variability. High variability in intra-individual pharmacokinetics has been observed for many orally-administered drugs, especially those with low bioavailability, which might complicate identification of dose-effect relationships. End-organ dysfunction, interactions with other prescription drugs, herbal supplements, adherence, and food intake can influence pharmacokinetics. It is important these variables are identified during early clinical trials and considered in the development of further phase II and subsequent large-scale phase III studies.

Population pharmacokinetics/pharmacodynamics of erlotinib and pharmacogenomic analysis of plasma and cerebrospinal fluid drug concentrations in Japanese patients with non-small cell lung cancer

BACKGROUND

Erlotinib shows large inter-patient pharmacokinetic variability, but the impact of early drug exposure and genetic variations on the clinical outcomes of erlotinib remains fully investigated. The primary objective of this study was to clarify the population pharmacokinetics/pharmacodynamics of erlotinib in Japanese patients with non-small cell lung cancer (NSCLC). The secondary objective was to identify genetic determinant(s) for the cerebrospinal fluid (CSF) permeability of erlotinib and its active metabolite OSI-420.

METHODS

A total of 88 patients treated with erlotinib (150 mg/day) were enrolled, and CSF samples were available from 23 of these patients with leptomeningeal metastases. Plasma and CSF concentrations of erlotinib and OSI-420 were measured by high-performance liquid chromatography with UV detection. Population pharmacokinetic analysis was performed with the nonlinear mixed-effects modelling program NONMEM. Germline mutations including ABCB1 (1236C>T, 2677G>T/A, 3435C>T), ABCG2 (421C>A), and CYP3A5 (6986A>G) polymorphisms, as well as somatic EGFR activating mutations if available, were examined. Early exposure to erlotinib and its safety/efficacy relationship were evaluated.

RESULTS

The apparent clearance of erlotinib and OSI-420 were significantly decreased by 24 and 35 % in patients with the ABCG2 421A allele, respectively (p < 0.001), while ABCB1 and CYP3A5 polymorphisms did not affect their apparent clearance. The ABCG2 421A allele was significantly associated with increased CSF penetration for both erlotinib and OSI-420 (p < 0.05). Furthermore, the incidence of grade ≥2 diarrhea was significantly higher in patients harboring this mutant allele (p = 0.035). A multivariate logistic regression model showed that erlotinib trough (C0) levels on day 8 were an independent risk factor for the development of grade ≥2 diarrhea (p = 0.037) and skin rash (p = 0.031). Interstitial lung disease (ILD)-like events occurred in 3 patients (3.4 %), and the median value of erlotinib C0 levels adjacent to these events was approximately 3 times higher than that in patients who did not develop ILD (3253 versus 1107 ng/mL; p = 0.014). The objective response rate in the EGFR wild-type group was marginally higher in patients achieving higher erlotinib C0 levels (≥1711 ng/mL) than that in patients having lower erlotinib C0 levels (38 versus 5 %; p = 0.058), whereas no greater response was observed in the higher group (67 %) versus the lower group (77 %) within EGFR mutation-positive patients (p = 0.62).

CONCLUSIONS

ABCG2 can influence the apparent clearance of erlotinib and OSI-420, and their CSF permeabilities in patients with NSCLC. Our preliminary findings indicate that early exposure to erlotinib may be associated with the development of adverse events and that increased erlotinib exposure may be relevant to the antitumor effects in EGFR wild-type patients while having less of an impact on the tumor response in EGFR mutation-positive patients.

Compound EGFR mutations and response to EGFR tyrosine kinase inhibitors

BACKGROUND

Non-small-cell lung cancers (NSCLCs) containing EGFR mutations are exquisitely sensitive to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). This is the case of the most common EGFR mutations affecting exon 18 (G719X), 19 (inframe deletions), and 21 (L858R and L861Q). However, the frequency of compound (i.e., double or complex) EGFR mutations-where an EGFR TKI sensitizing or other mutation is identified together with a mutation of unknown clinical significance-and their pattern of response/resistance to EGFR TKIs are less well described.

METHODS

We analyzed the EGFR mutation pattern of 79 cases of NSCLC harboring EGFR mutations and compiled the genotype-response data for patients with NSCLCs with compound EGFR mutations treated with EGFR TKIs.

RESULTS

Of the 79 EGFR-mutated tumors identified, 11 (14%) had compound mutations. Most involved the EGFR TKI-sensitizing G719X (n = 3, plus S768I or E709A), L858R (n = 4, plus L747V, R776H, T790M, or A871G), L861Q (n = 1, plus E709V), and delL747_T751 (n = 1, plus R776H). Eight patients received an EGFR TKI: three cases with G719X plus another mutation had partial responses (PRs) to erlotinib; of three cases with L858R plus another mutation, two displayed PRs and one (with EGFR-L858R+A871G) progressive disease (PD) to erlotinib; one NSCLC with EGFR-L861Q+E709A and one with delL747_T751+R776S had PRs to EGFR TKIs.

CONCLUSION

Compound EGFR mutations comprised 14% of all mutations identified during routine sequencing of exons 18-21 of EGFR in our cohort. Most patients with an EGFR TKI-sensitizing mutation (G719X, exon 19 deletion, L858R, and L861Q) in addition to an atypical mutation responded to EGFR TKIs. Reporting of the genotype-response pattern of NSCLCs with EGFR compound and other rare mutations, and the addition of this information to searchable databases, will be helpful to select the appropriate therapy for EGFR-mutated NSCLC.

Effects of pharmacokinetic processes and varied dosing schedules on the dynamics of acquired resistance to erlotinib in EGFR-mutant lung cancer

INTRODUCTION

Erlotinib (Tarceva) is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, which effectively targets EGFR-mutant driven non-small-cell lung cancer. However, the evolution of acquired resistance because of a second-site mutation (T790M) within EGFR remains an obstacle to successful treatment.

METHODS

We used mathematical modeling and available clinical trial data to predict how different pharmacokinetic parameters (fast versus slow metabolism) and dosing schedules (low dose versus high dose; missed doses with and without make-up doses) might affect the evolution of T790M-mediated resistance in mixed populations of tumor cells.

RESULTS

We found that high-dose pulses with low-dose continuous therapy impede the development of resistance to the maximum extent, both pre- and post-emergence of resistance. The probability of resistance is greater in fast versus slow drug metabolizers, suggesting a potential mechanism, unappreciated to date, influencing acquired resistance in patients. In case of required dose modifications because of toxicity, little difference is observed in terms of efficacy and resistance dynamics between the standard daily dose (150 mg/d) and 150 mg/d alternating with 100 mg/d. Missed doses are expected to lead to resistance faster, even if make-up doses are attempted.

CONCLUSIONS

For existing and new kinase inhibitors, this novel framework can be used to rationally and rapidly design optimal dosing strategies to minimize the development of acquired resistance.