Afatinib: An overview of its clinical development in non-small-cell lung cancer and other tumors

Possibilities of Overcoming Resistance to Osimertinib in NSCLC Patients with Mutations in the EGFR Gene

The advancement of genetic research has changed the treatment management of non-small cell lung cancer (NSCLC) and opened the era of personalized medicine. Currently, three generations of EGFR tyrosine kinase inhibitors (TKIs) are used in the treatment of NSCLC patients with activating mutations in the EGFR gene, and ongoing clinical trials examine the safety and effectiveness of new third and fourth generations. Osimertinib, a third generation of TKIs that binds irreversibly to abnormal tyrosine kinase, may be applied in various indications in patients with NSCLC: (i) in the second and subsequent lines of therapy in patients with resistance to first-generation or second-generation EGFR TKIs, (ii) in the first line of treatment in monotherapy in NSCLC patients with frequent or rare EGFR mutations, (iii) in combination with chemotherapy in patients with locally advanced or metastatic NSCLC with frequent EGFR mutations, (iv) in consolidation therapy in patients with locally advanced NSCLC who had previously received chemoradiotherapy, (v) in adjuvant treatment of NSCLC patients with stage IB-IIIA undergoing radical surgical resection. Despite the high efficacy of osimertinib in NSCLC patients harboring EGFR mutations, resistance driven in EGFR-dependent or EGFR-independent mechanisms may occur. Since resistance to osimertinib is poorly understood, the following review presents the overview of resistance mechanisms to osimertinib, methodological approaches for the resistance diagnosis, and the up-to-date treatment possibilities for overcoming the resistance process.

Symptom-based drug prediction of lifestyle-related chronic diseases using unsupervised machine learning techniques

BACKGROUND AND OBJECTIVES

Lifestyle-related diseases (LSDs) impose a substantial economic burden on patients and health care services. LSDs are chronic in nature and can directly affect the heart and lungs. Therapeutic interventions only based on symptoms can be crucial for prompt treatment initiation in LSDs, as symptoms are the first information available to clinicians. So, this work aims to apply unsupervised machine learning (ML) techniques for developing models to predict drugs from symptoms for LSDs, with a specific focus on pulmonary and heart diseases.

METHODS

The drug-disease and disease-symptom associations of 143 LSDs, 1271 drugs, and 305 symptoms were used to compute direct associations between drugs and symptoms. ML models with four different algorithms - K-Means, Bisecting K-Means, Mean Shift, and Balanced Iterative Reducing and Clustering using Hierarchies (BIRCH) - were developed to cluster the drugs using symptoms as features. The optimal model was saved in a server for the development of a web application. A web application was developed to perform the prediction based on the optimal model.

RESULTS

The Bisecting K-means model showed the best performance with a silhouette coefficient of 0.647 and generated 138 drug clusters. The drugs within the optimal clusters showed good similarity based on i) gene ontology annotations of the gene targets, ii) chemical ontology annotations, and iii) maximum common substructure of the drugs. In the web application, the model also provides a confidence score for each predicted drug while predicting from a new set of input symptoms.

CONCLUSION

In summary, direct associations between drugs and symptoms were computed, and those were used to develop a symptom-based drug prediction tool for LSDs with unsupervised ML models. The ML-based prediction can provide a second opinion to clinicians to aid their decision-making for early treatment of LSD patients. The web application (URL - http://bicresources.jcbose.ac.in/ssaha4/sdldpred) can provide a simple interface for all end-users to perform the ML-based prediction.

Receptor tyrosine kinases: biological functions and anticancer targeted therapy

Receptor tyrosine kinases (RTKs) are a class of protein kinases that play crucial roles in various cellular processes, including cell migration, morphological differentiation, cell growth, and angiogenesis. In humans, 58 RTKs have been identified and categorized into 20 distinct families based on the composition of their extracellular regions. RTKs are primarily activated by specific ligands that bind to their extracellular region. They not only regulate tumor transformation, proliferation, metastasis, drug resistance, and angiogenesis, but also initiate and maintain the self-renewal and cloning ability of cancer stem cells. Accurate diagnosis and grading of tumors with dysregulated RTKs are essential in clinical practice. There is a growing body of evidence supporting the benefits of RTKs-targeted therapies for cancer patients, and researchers are actively exploring new targets and developing targeted agents. However, further optimization of RTK inhibitors is necessary to effectively target the diverse RTK alterations observed in human cancers. This review provides insights into the classification, structure, activation mechanisms, and expression of RTKs in tumors. It also highlights the research advances in RTKs targeted anticancer therapy and emphasizes their significance in optimizing cancer diagnosis and treatment strategies.

Afatinib for the Treatment of NSCLC with Uncommon EGFR Mutations: A Narrative Review

Afatinib, the world's first irreversible ErbB family (containing four different cancer cell epidermal growth factor receptors, including EGFR, HER2, ErbB3, and ErbB4) inhibitor, is a second-generation oral epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). It can be used as a first-line treatment for locally advanced or metastatic non-small-cell lung cancer (NSCLC) with an EGFR-sensitive mutation or for patients with locally advanced or metastatic squamous lung cancer whose disease progresses during or after platinum-containing chemotherapy. Currently, with the use of third-generation EGFR-TKIs, afatinib is no longer clinically indicated as the first choice for patients with NSCLC who have EGFR-sensitive mutations. However, afatinib showed a considerable inhibitory effect in NSCLC patients with uncommon EGFR mutations (G719X, S768I, and L861Q) according to a combined post hoc analysis of the LUX-Lung2/3/6 trials. With the development of genetic testing technology, the detection rate of uncommon EGFR mutations is increasing. The aim of this paper is to describe in detail the sensitivity of rare EGFR mutations to afatinib and to provide information and a reference for those suffering from advanced NSCLC who have uncommon EGFR mutations.

The multi-kinase inhibitor afatinib serves as a novel candidate for the treatment of human uveal melanoma

PURPOSE

Uveal melanoma (UM) is the most common intraocular malignancy in adults with a poor prognosis and a high recurrence rate. Currently there is no effective treatment for UM. Multi-kinase inhibitors targeting dysregulated pro-tumorigenic signalling pathways have revolutionised anti-cancer treatment but, as yet, their efficacy in UM has not been established. Here, we identified the multi-kinase inhibitor afatinib as a highly effective agent that exerts anti-UM effects in in vitro, ex vivo and in vivo models.

METHODS

We assessed the anti-cancer effects of afatinib using cell viability, cell death and cell cycle assays in in vitro and ex vivo UM models. The signaling pathways involved in the anti-UM effects of afatinib were evaluated by Western blotting. The in vivo activity of afatinib was evaluated in UM xenograft models using tumour mass measurement, PET scan, immunohistochemical staining and TUNEL assays.

RESULTS

We found that afatinib reduced cell viability and activated apoptosis and cell cycle arrest in multiple established UM cell lines and in patient tumour-derived primary cell lines. Afatinib impaired cell migration and enhanced reproductive death in these UM cell models. Afatinib-induced cell death was accompanied by activation of STAT1 expression and downregulation of Bcl-xL and cyclin D1 expression, which control cell survival and cell cycle progression. Afatinib attenuated HER2-AKT/ERK/PI3K signalling in UM cell lines. Consistent with these observations, we found that afatinib suppressed tumour growth in UM xenografted mice.

CONCLUSION

Our data indicate that afatinib activates UM cell death and targets the HER2-mediated cascade, which modulates STAT1-Bcl-xL/cyclin D1 signalling. Thus, targeting HER2 with agents like afatinib may be a novel therapeutic strategy to treat UM and to prevent metastasis.

Covalent allosteric modulation: An emerging strategy for GPCRs drug discovery

Designing covalent allosteric modulators brings new opportunities to the field of drug discovery towards G-protein-coupled receptors (GPCRs). Targeting an allosteric binding pocket can allow a modulator to have protein subtype selectivity and low drug resistance. Utilizing covalent warheads further enables the modulator to increase the binding potency and extend the duration of action. This review starts with GPCR allosteric modulation to discuss the structural biology of allosteric binding pockets, the different types of allosteric modulators, as well as the advantages of employing allosteric modulation. This is followed by a discussion on covalent modulators to clarify how covalent ligands can benefit the receptor modulation and to illustrate moieties that can commonly be used as covalent warheads. Finally, case studies are presented on designing class A, B, and C GPCR covalent allosteric modulators to demonstrate successful stories on combining allosteric modulation and covalent binding. Limitations and future perspectives are also covered.

Natural tyrosine kinase inhibitors acting on the epidermal growth factor receptor: Their relevance for cancer therapy

Epidermal growth factor receptor (EGFR), also known as ErbB-1/HER-1, plays a key role in the regulation of the cell proliferation, migration, differentiation, and survival. Since the constitutive activation or overexpression of EGFR is nearly found in various cancers, the applications focused on EGFR are the most widely used in the clinical level, including the therapeutic drugs of targeting EGFR, monoclonal antibodies (mAbs) and tyrosine kinase inhibitors (TKIs).Over the past decades, the compounds from natural sources have been a productive source of novel drugs, especially in both discovery and development of anti-tumor drugs by targeting the EGFR pathways as the TKIs. This work presents a review of the compounds from natural sources as potential EGFR-TKIs involved in the regulation of cancer. Moreover, high-throughput drug screening of EGFR-TKIs from the natural compounds has also been summarized.

Current Strategies for Treating NSCLC: From Biological Mechanisms to Clinical Treatment

The identification of specific epidermal growth factor receptor (EGFR)-activating mutations heralded a breakthrough in non-small-cell lung cancer (NSCLC) treatments, with the subsequent development of EGFR-tyrosine kinase inhibitor (TKIs) becoming the first-line therapy for patients harboring EGFR mutations. However, acquired resistance to EGFR-TKIs inevitably occurs in patients following initial TKI treatment, leading to disease progression. Various mechanisms are behind the acquired resistance, and mainly include (1) target gene modification, (2) alternative parallel pathway activation, (3) downstream pathway activation, and (4) histological/phenotypic transformation. Approaches to combat the acquired resistance have been investigated according to these mechanisms. Newer generations of TKIs have been developed to target the secondary/tertiary EGFR mutations in patients with acquired resistance. In addition, combination therapies have been developed as another promising strategy to overcome acquired resistance through the activation of other signaling pathways. Thus, in this review, we summarize the mechanisms for acquired resistance and focus on the potential corresponding therapeutic strategies for acquired resistance.

Advances in covalent kinase inhibitors

This comprehensive review details recent advances, challenges and innovations in covalent kinase inhibition within a 10 year period (2007–2018).

Afatinib in locally advanced/metastatic NSCLC harboring common EGFR mutations, after chemotherapy: a Phase IV study

Aim

The current study evaluated the efficacy and tolerability of second-line afatinib in patients with EGFR mutation-positive (EGFRm+) non-small-cell lung cancer (NSCLC) following chemotherapy.

Patients & methods

In this open-label, single-arm Phase IV study, patients with EGFRm+ (Del19/L858R) NSCLC who had progressed following platinum-based chemotherapy received afatinib (starting dose 40 mg/day). The primary end point was confirmed objective response.

Results

60 patients received afatinib for a median duration of 11.5 months. 50% of patients had a confirmed objective response, of median duration 13.8 months. Median progression-free survival was 10.9 months. The most common treatment-related adverse events were diarrhea (72%), rash (28%) and paronychia (23%).

Conclusion

Our data support the use of afatinib (40 mg/day) as an effective and well-tolerated second-line treatment in EGFRm+ NSCLC.

The Impact of Afatinib on Survival in Advanced Non-Small Cell Lung Cancer: A Meta-Analysis of Randomized Controlled Trials

Background: Afatinib is a second-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) that has been approved by the Food and Drug Administration for the treatment of advanced non-small cell lung cancer (NSCLC) harboring EGFR mutations. We performed a meta-analysis to assess the efficacy and safety of afatinib in advanced NSCLC.

Methods: We searched PubMed, PMC database, EMBASE, Cochrane Library and Web of Science to obtain the relevant literature. The efficacy and safety of afatinib was assessed based on progression-free survival (PFS), overall survival (OS), overall response rate (ORR), primary grade 3/4 adverse events and fatal adverse events (FAEs). A subgroup analysis was performed according to control type for all end-points.

Results: Seven randomized controlled trials were included, with a total of 3093 patients. The meta-analysis showed that afatinib treatment significantly prolonged PFS in patients compared with control groups (HR = 0.57, 95% CI: 0.42-0.76; P = 0.00), increased OS (HR = 0.91, 95% CI: 0.83-0.99; P = 0.04) and ORR (RR = 1.82, 95% CI: 1.13-2.93; P = 0.01). In terms of safety, afatinib significantly increased the incidence of diarrhea (RR = 8.9, 95% CI: 5.33-14.93; P = 0.00), rash (RR = 7.31, 95% CI: 1.56-34.12; P = 0.01) and stomatitis (RR = 6.45, 95% CI: 1.27-32.78; P = 0.03), compared with the control group. However, there was no significant difference in FAEs (RR = 0.75, 95% CI: 0.38-1.49; P = 0.41).

Conclusions: This meta-analysis confirmed that afatinib extended survival, improved response rates and did not increase the risk of treatment-related mortality in advanced NSCLC. As a novel EGFR-TKI, afitinib has significant potential for clinical application.

Cost-effectiveness of afatinib, gefitinib, erlotinib and pemetrexed-based chemotherapy as first-line treatments for advanced non-small cell lung cancer in China

PURPOSE

Tyrosine kinase inhibitors (TKI) of the epidermal growth factor receptor (EGFR) are becoming the standard treatments for Chinese patients with advanced non-small cell lung cancer (NSCLC) harboring an EGFR mutation. However, the economic impact is unclear yet in China.

MATERIALS AND METHODS

A decision-analytic model was developed to simulate 1-month patient transitions in a 10-year time horizon from Chinese heath care system perspective. The health and economic outcomes of four first-line strategies (pemetrexed plus cisplatin [PC], gefitinib, erlotinib, and afatinib) among NSCLC patients harboring EGFR mutations were estimated and assessed via indirect comparisons. Costs in the Chinese setting were estimated by using local hospital data and literatures. A 5% annual discount rate was applied to both costs and outcomes. The primary outcome was the incremental cost-effectiveness ratio (ICER). Sensitivity analyses were performed.

RESULTS

Afatinib achieved additional 0.382, 0.216 and 0.174 quality-adjusted life-years (QALYs) with marginal $7930, $3680 and $2818 costs in comparison with PC, gefitinib and erlotinib, which resulted in the ICERs of $20,758, $17,693 and $16,197 per QALY gained, respectively. The hazard ratios (HR) of overall survival (OS) of afatinib against gefitinib, erlotinib and PC strategy had substantial influential parameters.

CONCLUSIONS

First-line afatinib is cost-effective compared with gefitinib, erlotinib and PC treatment for Chinese patients with EGFR mutation-positive NSCLC.

Second-line treatment for advanced NSCLC without actionable mutations: is immunotherapy the 'panacea' for all patients?

The therapeutic approach for the second-line treatment of patients with advanced non-small cell lung cancer (NSCLC) without actionable mutations has been revolutionized by the recent approval of new effective drugs with various mechanisms of action, including nintedanib, ramucirumab, nivolumab, pembrolizumab, atezolizumab, and afatinib. The recent network meta-analysis of Créquit et al. (BMC Medicine, 15:193, 2017) compared the effectiveness and tolerability of the second-line treatments for advanced NSCLC with wild-type or unknown status for EGFR. The authors found that immunotherapy might be more efficacious than the currently recommended treatments. However, their meta-analysis does not take into account the role of predictive biomarkers - this is indeed a crucial point in the decision-making process considering that only a fraction of advanced NSCLC patients might derive a long-term benefit from second-line immunotherapy. The identification of molecular biomarkers that can predict a response to immune checkpoints, angiogenesis, and EGFR inhibitors remains an important goal of clinical research in order to maximize the benefit of these agents and to aid clinicians in the decision-making process.Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-017-0954-x.

Afatinib in advanced NSCLC: a profile of its use

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

6,7-Dimorpholinoalkoxy quinazoline derivatives as potent EGFR inhibitors with enhanced antiproliferative activities against tumor cells

A series of novel 6,7-dimorpholinoalkoxy quinazoline derivatives was designed, synthesized and evaluated as potent EGFR inhibitors. Most of synthesized derivatives exhibited moderate to excellent antiproliferative activities against five human tumor cell lines. Compound 8d displayed the most remarkable inhibitory activities against tumor cells expressing wild type (A431, A549 and SW480 cells) or mutant (HCC827 and NCI-H1975 cells) epidermal growth factor receptor (EGFR) (with IC₅₀ values in the range of 0.37-4.87 μM), as well as more potent inhibitory effects against recombinant EGFR tyrosine kinase (EGFR-TK, wt or T790M) (with the IC₅₀ values of 7.0 and 9.3 nM, respectively). Molecular docking showed that 8d can form four hydrogen bonds with EGFR, and two of them were located in the Asp855-Phe856-Gly857 (DFG) motif of EGFR. Meanwhile, 8d can significantly block EGF-induced EGFR activation and the phosphorylation of its downstream proteins such as Akt and Erk1/2 in human NSCLC cells. Also, 8d mediated cell apoptosis and the prolongation of cell cycle progression in G0/G1-phase in A549 cells. The work would have remarkable implications for further design and development of more potent EGFR tyrosine kinase inhibitors (TKIs).

Development of a personalized therapeutic strategy for ERBB-gene-mutated cancers

Background:

The application of genomic technologies to patient tumor samples identified groups of signaling pathways which acquire activating mutations. Some cancers are dependent on these mutations and the aberrant proteins resulting from these mutations can be targeted by novel drugs which can eradicate the cancer.

Methods:

We used www.cbioportal.org to determine the frequency of ERBB mutations in solid tumors. We then determined the sensitivity of a panel of cell lines to clinically available PI3K inhibitors. Using proliferation and apoptosis assays as well as functional interrogation with reverse phase protein arrays we demonstrated the impact of targeting ERBB-mutant cancers with the combination of a PI3K inhibitor and the pan-HER family inhibitor afatinib.

Results:

In over 14,000 patients we found that 12% of their tumors have an ERBB family gene mutation (EGFR, ERBB2, ERBB3 and ERBB4). In cancers not commonly associated with HER family protein overexpression, such as ovarian, endometrial, melanoma and head and neck cancers (n = 2116), we found that ERBB family mutations are enriched, occurring at rates from 14% to 34% and commonly co-occur with PIK3CA mutations. Importantly, we demonstrate that ERBB family mutant cancers are sensitive to treatment with PI3K inhibitors. Finally we show that the combination of afatinib and copanlisib represents a novel therapeutic strategy for patients whose cancers harbor both ERBB family and PIK3CA mutation.

Conclusions:

We demonstrate that ERBB family mutations are common in cancers not associated with overexpression or amplification of HER family proteins. These ERBB family mutant cancers are sensitive to treatment with PI3K inhibitors, and when combined with pan-HER inhibitors have synergistic antiproliferative effects.

Tumor-suppressive miR-218-5p inhibits cancer cell proliferation and migration via EGFR in non-small cell lung cancer

Lung cancer remains the leading cause of cancer-related death worldwide, and non-small cell lung cancer (NSCLC) accounts for approximately 80% of lung cancer cases. Recently, microRNAs (miRNAs) have been consistently demonstrated to be involved in NSCLC and to act as either tumor oncogenes or tumor suppressors. In this study, we identified a specific binding site for miR-218-5p in the 3'-untranslated region of the epidermal growth factor receptor (EGFR). We further experimentally validated miR-218-5p as a direct regulator of EGFR. We also identified an inverse correlation between miR-218-5p and EGFR protein levels in NSCLC tissue samples. Moreover, we demonstrated that miR-218-5p plays a critical role in suppressing the proliferation and migration of lung cancer cells probably by binding to EGFR. Finally, we examined the function of miR-218-5p in vivo and revealed that miR-218-5p exerts an anti-tumor effect by negatively regulating EGFR in a xenograft mouse model. Taken together, the results of this study highlight an important role for miR-218-5p in the regulation of EGFR in NSCLC and may open new avenues for future lung cancer therapies.

Afatinib: A Review in Advanced Non-Small Cell Lung Cancer

Afatinib (Giotrif^®, Gilotrif^®) is an orally administered, irreversible inhibitor of the ErbB family of tyrosine kinases. In the first-line treatment of patients with advanced lung adenocarcinoma with activating epidermal growth factor receptor (EGFR) mutations, afatinib significantly prolonged progression-free survival (PFS) and time to treatment failure (TTF), but not overall survival (OS), compared with gefitinib (LUX-Lung 7 trial). In the overall population of patients receiving first-line treatment for advanced lung adenocarcinoma with activating EGFR mutations, afatinib significantly prolonged PFS, but not OS, compared with pemetrexed plus cisplatin (LUX-Lung 3 trial) or gemcitabine plus cisplatin (LUX-Lung 6 trial). However, in both LUX-Lung 3 and LUX-Lung 6, OS was significantly prolonged in the subgroup of patients with deletions in exon 19 receiving afatinib versus chemotherapy. In the second-line treatment of advanced squamous non-small cell lung cancer (NSCLC), afatinib significantly prolonged PFS and OS, compared with erlotinib, regardless of EGFR mutation status (LUX-Lung 8 trial). Afatinib had a predictable and manageable tolerability profile in patients with advanced NSCLC. In conclusion, afatinib is an important option for the first-line treatment of patients with advanced NSCLC and activating EGFR mutations, and provides an additional option for the treatment of patients with squamous NSCLC that has progressed following first-line platinum-based chemotherapy.

HDAC inhibitors enhance neratinib activity and when combined enhance the actions of an anti-PD-1 immunomodulatory antibody in vivo

Patients whose NSCLC tumors become afatinib resistant presently have few effective therapeutic options to extend their survival. Afatinib resistant NSCLC cells were sensitive to clinically relevant concentrations of the irreversible pan-HER inhibitor neratinib, but not by the first generation ERBB1/2/4 inhibitor lapatinib. In multiple afatinib resistant NSCLC clones, HDAC inhibitors reduced the expression of ERBB1/3/4, but activated c-SRC, which resulted in higher total levels of ERBB1/3 phosphorylation. Neratinib also rapidly reduced the expression of ERBB1/2/3/4, c-MET and of mutant K-/N-RAS; K-RAS co-localized with phosphorylated ATG13 and with cathepsin B in vesicles. Combined exposure of cells to [neratinib + HDAC inhibitors] caused inactivation of mTORC1 and mTORC2, enhanced autophagosome and subsequently autolysosome formation, and caused an additive to greater than additive induction of cell death. Knock down of Beclin1 or ATG5 prevented HDAC inhibitors or neratinib from reducing ERBB1/3/4 and K-/N-RAS expression and reduced [neratinib + HDAC inhibitor] lethality. Neratinib and HDAC inhibitors reduced the expression of multiple HDAC proteins via autophagy that was causal in the reduced expression of PD-L1, PD-L2 and ornithine decarboxylase, and increased expression of Class I MHCA. In vivo, neratinib and HDAC inhibitors interacted to suppress the growth of 4T1 mammary tumors, an effect that was enhanced by an anti-PD-1 antibody. Our data support the premises that neratinib lethality can be enhanced by HDAC inhibitors, that neratinib may be a useful therapeutic tool in afatinib resistant NSCLC, and that [neratinib + HDAC inhibitor] exposure facilitates anti-tumor immune responses.

Impact of the structures of macrocyclic Michael acceptors on covalent proteasome inhibition

A systematic analysis of the structure–activity relationship of a series of syringolin analogues, which are irreversible covalent inhibitors of proteasomes.

Molecules that have a reactive functional group within a macrocycle represent a class of covalent inhibitor. The relationship between reactivity and affinity for the target is cooperative and complicated. An understanding and characterization of this class of inhibitor are vital for the development of covalent inhibitors as drug candidates. Herein, we describe a systematic analysis of structure–activity relationships using a series of syringolin analogues, which are irreversible covalent inhibitors of proteasomes. We investigate the detailed mechanistic effects of the macrocycles on affinity and reaction rate.

Spotlight on afatinib and its potential in the treatment of squamous cell lung cancer: the evidence so far

Compared to adenocarcinoma, fewer effective treatment options are available for advanced or metastatic squamous cell carcinoma (SCC) of the lung. Afatinib is an orally administered, irreversible EGFR antagonist. As a second-generation tyrosine kinase inhibitor, it has been applied in the treatment of patients with EGFR-mutant non-small-cell lung cancer. Recently, several clinical trials have shown that afatinib leads to a significant improvement in progression-free survival and overall survival of patients with SCC. Moving forward, afatinib should be one of the options among tyrosine kinase inhibitors, monoclonal antibodies, and cytotoxicity chemotherapy drugs for SCC.

Afatinib in first-line setting for NSCLC harbouring common EGFR mutations: new light after the preliminary results of LUX-Lung 7?

The development of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) changed dramatically the history of non-small cell lung cancer (NSCLC) harboring EGFR sensitive mutations. Several randomized prospective trials confirmed the superiority of these target agents about survival and response rate when comparing with platinum-based chemotherapy. Knowledge about EGFR mutations increased gradually during the development of target agents and different clinical trials. EGFR mutations cannot be considered all equal, but different entities should be considered in our clinical practice: exon 19 deletions, exon 21 mutation (L858R) and uncommon mutation (exon 20, exon 18 and double mutation). Nowadays, we dispose of three different EGFR TKIs (afatinib, erlotinib and gefitinib) approved for the treatment for first-line treatment of patients di NSCLC carrying EGFR, that was compared only by indirect analysis, producing data not always clear and convincing. This research highlight is an overview of data about EGFR TKIs in first-line setting, focusing on differences about exon 19 deletions and L585R mutation in patients treated with different TKIs. In addition, we report the preliminary results of the first head-to-head randomized clinical trial between two different EGFR TKIs, the LUX-Lung 7 (LL7) that compared afatinib and gefitinib showing interesting results.

Development of epidermal growth factor receptor tyrosine kinase inhibitors against EGFR T790M. Mutation in non small-cell lung carcinoma

Individualized therapies targeting epidermal growth factor receptor (EGFR) mutations show promises for the treatment of non small-cell lung carcinoma (NSCLC). However, disease progression almost invariably occurs 1 year after tyrosine kinase inhibitor (TKI) treatment. The most prominent mechanism of acquired resistance involves the secondary EGFR mutation, namely EGFR T790M, which accounts for 50%-60% of resistant tumors. A large amount of studies have focused on the development of effective strategies to treat TKI-resistant EGFR T790M mutation in lung tumors. Novel generations of EGFR inhibitors are producing encouraging results in patients with acquired resistance against EGFR T790M mutation. This review will summarize the novel inhibitors, which might overcome resistance against EGFR T790M mutation.