An update on molecularly targeted therapies in second- and third-line treatment in non-small cell lung cancer: focus on EGFR inhibitors and anti-angiogenic agents

National trends in the use of oral chemotherapy over 13 years

Background: Systemic cancer therapy has traditionally been administered using an intravenous (IV) route, implying patients’ frequent visits to hospitals to access to their therapy. If we consider the actual pipeline in oncology, oral chemotherapy will be the main component of cancer treatment in the next few years. This shift in the administration route requires different care models in order to guarantee treatment efficacy and safety.

Objective: To analyze time trends in oral chemotherapy consumption in Portugal.

Method: Oral chemotherapy consumption over a 13-year period (2008–2020) was analyzed, considering dispensed units by the administration route with respective costs, resorting to the drug regulatory agency (INFARMED I.P.) database. Oral consumption patterns were further explored using common daily doses (CDD) for three conditions, including chronic myeloid leukemia (CML), non-small-cell lung cancer (NSCLC), and breast cancer (BC), to adjust for the effect of varying doses. Data were analyzed descriptively resorting to Microsoft Office Excel 2010.

Results: Overall chemotherapy consumption increased +Δ54.7%, with the highest contribution in units observed in oral forms (+Δ58.8%). The total expenditure increased +Δ96.5%, and despite the increase in oral forms (+Δ221.6%), intravenous forms continued to be the major cost driver, with an important contribution from immunotherapy. Much of the increase was led by the approval of 40 new IV and 48 new oral cancer medications with higher costs introduced in the market. Using CDD as an alternative metric to units had varying impacts by indication. The observed increases seemed to focus on specific cancer sites with varying effect; in CML, there was a 2.39-fold increase, compared to 4.41 for NSCLC and 1.86 for BC. However, for BC, two distinct sub-patterns were observed for hormone therapy (increasing 1.83) and for the novel tyrosine kinase inhibitors (increasing 40.8).

Conclusion: The growing use of oral chemotherapy is obvious and calls for investments in supporting patients in managing medication adherence and adverse events. The shifts in the healthcare system are complex and need to be prioritized. Our data suggest that priority could be attributed to cancer sites driving innovation, namely, advanced breast cancer.

Efficacy and safety of apatinib in advanced sarcoma: an open-label, nonrandomized, single-center study of 45 patients

Sarcoma is a rare tumor with more than 50 histologic subtypes. Patients with advanced sarcoma have a poor prognosis. The aim of this study was to evaluate the efficacy and safety of apatinib, an oral vascular endothelial growth factor receptor-2 inhibitor, as salvage treatment for advanced bone and soft tissue sarcomas. From May 2017 to July 2018, a prospective, open-label, nonrandomized, clinical trial of apatinib was carried out in selected patients with advanced sarcoma. After apatinib dosing, progression-free survival (PFS), overall survival (OS), objective response rate, disease control rate, and treatment-related adverse events (AEs) were reviewed and evaluated. Patients were administered apatinib for at least 1 month. Median follow-up time was 6.00 months (1-13 months). The median PFS was 7.88 months, with the longest PFS of 13 months observed in a patient with epithelial sarcoma. The 3-month PFS rate was 66.44%. The median OS was 11.64 months with significant differences observed based on disease subtypes. Four patients achieved a partial response, and 36 patients achieved stable disease. The objective response rate was 8.88% (4/45), and the disease control rate was 88.89% (40/45). The most common grade 3/4 treatment-related AEs were hypertension (12.50%), hand-foot syndrome (6.67%), diarrhea (12.50%), fatigue (6.25%), and proteinuria (14.29%). One drug-related severe AE of thrombocytopenia (21×10/l) occurred 2 months after therapy. Apatinib treatment in our study exhibited objective efficacy in PFS, OS, and manageable toxicity in patients with advanced sarcoma. This result supports future randomized controlled trials to further define apatinib activity in stage IV sarcomas.

Bifunctional Duocarmycin Analogues as Inhibitors of Protein Tyrosine Kinases

Bifunctional duocarmycin analogues are highly cytotoxic compounds that have been shown to be irreversible aldehyde dehydrogenase 1 inhibitors. Interestingly, cells with low aldehyde dehydrogenase 1 expression are also sensitive to bifunctional duocarmycin analogues, suggesting the existence of another target. Through in silico approaches, including principal component analysis, structure-similarity search, and docking calculations, protein tyrosine kinases, and especially the vascular endothelial growth factor receptor 2 (VEGFR-2), were predicted as targets of bifunctional duocarmycin analogues. Biochemical validation was performed in vitro, confirming the in silico results. Structural optimization was performed to mainly target VEGFR-2, but not aldehyde dehydrogenase 1. The optimized bifunctional duocarmycin analogue was synthesized. In vitro assays revealed this bifunctional duocarmycin analogue as a strong inhibitor of VEGFR-2, with low residual aldehyde dehydrogenase 1 activity. Altogether, studies revealed bifunctional duocarmycin analogues as a new class of naturally derived compounds that express a very high cytotoxicity to cancer cells overexpressing aldehyde dehydrogenase 1 as well as VEGFR-2.

Suppressors for Human Epidermal Growth Factor Receptor 2/4 (HER2/4): A New Family of Anti-Toxoplasmic Agents in ARPE-19 Cells

The effects of tyrosine kinase inhibitors (TKIs) were evaluated on growth inhibition of intracellular Toxoplasma gondii in host ARPE-19 cells. The number of tachyzoites per parasitophorous vacuolar membrane (PVM) was counted after treatment with TKIs. T. gondii protein expression was assessed by western blot. Immunofluorescence assay was performed using Programmed Cell Death 4 (PDCD4) and T. gondii GRA3 antibodies. The TKIs were divided into 3 groups; non-epidermal growth factor receptor (non-EGFR), anti-human EGFR 2 (anti-HER2), and anti-HER2/4 TKIs, respectively. Group I TKIs (nintedanib, AZD9291, and sunitinib) were unable to inhibit proliferation without destroying host cells. Group II TKIs (lapatinib, gefitinib, erlotinib, and AG1478) inhibited proliferation up to 98% equivalent to control pyrimethamine (5 μM) at 20 μM and higher, without affecting host cells. Group III TKIs (neratinib, dacomitinib, afatinib, and pelitinib) inhibited proliferation up to 98% equivalent to pyrimethamine at 1–5 μM, but host cells were destroyed at 10–20 μM. In Group I, TgHSP90 and SAG1 inhibitions were weak, and GRA3 expression was moderately inhibited. In Group II, TgHSP90 and SAG1 expressions seemed to be slightly enhanced, while GRA3 showed none to mild inhibition; however, AG1478 inhibited all proteins moderately. Protein expression was blocked in Group III, comparable to pyrimethamine. PDCD4 and GRA3 were well localized inside the nuclei in Group I, mildly disrupted in Group II, and were completely disrupted in Group III. This study suggests the possibility of a vital T. gondii TK having potential HER2/4 properties, thus anti-HER2/4 TKIs may inhibit intracellular parasite proliferation with minimal adverse effects on host cells.

Interleukin-27 re-educates intratumoral myeloid cells and down-regulates stemness genes in non-small cell lung cancer

Current therapies for Non-Small Cell Lung Cancer (NSCLC) still fail to significantly increase its survival rate. Here we asked whether Interleukin(IL)-27, which has revealed powerful antitumor activity and is toxicity-free in humans, is a promising therapeutic choice for NSCLC patients.

IL-27's effects were tested on Adenocarcinoma (AC) and Squamous Cell Carcinoma (SCC) cell lines and xenograft models. IL-27Receptor(R) expression was assessed in lung tissues from 78 NSCLC patients.

In vitro, IL-27 was ineffective on cancer cell proliferation or apoptosis, but fostered CXCL3/GROγ/MIP2β expression. In vitro and in vivo, IL-27 down-regulated stemness-related genes, namely SONIC HEDGEHOG in AC cells, and OCT4A, SOX2, NOTCH1, KLF4 along with Nestin, SNAI1/SNAIL, SNAI2/SLUG and ZEB1, in SCC cells. In vivo, IL-27 hampered both AC and SCC tumor growth in association with a prominent granulocyte- and macrophage-driven colliquative necrosis, CXCL3 production, and a reduced pluripotency- and EMT-related gene expression. Myeloablation of tumor-bearing hosts mostly abolished IL-27's antitumor effects. In clinical samples, IL-27R expression was found in AC, SCC, pre-cancerous lesions and tumor infiltrating myeloid cells, and correlated with advanced stages of disease.

Our data suggest that even immunocompromised or advancer NSCLC patients may benefit from IL-27's antitumor properties based on its ability to drive myeloid cells towards antitumor activities, and down-regulate stemness- and EMT-related genes in cancer cells.

Structure-Activity Relationship of Indole-Tethered Pyrimidine Derivatives that Concurrently Inhibit Epidermal Growth Factor Receptor and Other Angiokinases

Antiangiogenic agents have been widely investigated in combination with standard chemotherapy or targeted cancer agents for better management of advanced cancers. Therapeutic agents that concurrently inhibit epidermal growth factor receptor and other angiokinases could be useful alternatives to combination therapies for epidermal growth factor receptor-dependent cancers. Here, we report the synthesis of an indole derivative of pazopanib using a bioisosteric replacement strategy, which was designated MKP101. MKP101 inhibited not only the epidermal growth factor receptor with an IC₅₀ value of 43 nM but also inhibited angiokinases as potently as pazopanib. In addition, MKP101 effectively inhibited vascular endothelial growth factor-induced endothelial proliferation, tube formation, migration of human umbilical vein endothelial cells and proliferation of HCC827, an epidermal growth factor receptor-addicted cancer cell line. A docking model of MKP101 and the kinase domain of the epidermal growth factor receptor was generated to predict its binding mode, and validated by synthesizing and evaluating MKP101 derivatives. Additionally, a study of structure-activity relationships of indolylamino or indolyloxy pyrimidine analogues derived from MKP101 demonstrated that selectivity for epidermal growth factor receptor and other angiokinases, especially vascular endothelial growth factor receptor 2 depends on the position of substituents on pyrimidine and the type of link between pyrimidine and the indole moiety. We believe that this study could provide a basis for developing angiokinase inhibitors having high affinity for the epidermal growth factor receptor, from the pyrimidine scaffold.

Anti-angiogenic drugs for second-line treatment of NSCLC patients: just new pawns on the chessboard?

Tumor angiogenesis is one of the main pathways targeted to treat cancer. Bevacizumab added survival benefit when combined with platinum-based chemotherapy in NSCLC. Recently, Phase III trials showed survival benefit when anti-angiogenic drugs are added to docetaxel as second-line treatment for NSCLC. These anti-angiogenic agents include nintedanib and ramucirumab, a tyrosine-kinase inhibitor and a monoclonal antibody, respectively, which target receptors involved in angiogenesis. These studies have some similarities and differences. We propose a new algorithm for treatment sequences in performance status 0-1 patients with non-oncogene-addicted NSCLC type adenocarcinoma. Indeed clearer scientific evidences are available for this subgroup of patients.

Response to alectinib after one year of discontinuation of crizotinib in anaplastic lymphoma kinase-positive non-small-cell lung cancer: A case report

Therapy with crizotinib achieves prolonged progression-free and overall survival in non-small-cell lung cancer (NSCLC) patients with echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK). It was demonstrated that ALK-positive NSCLCs exhibit a high response rate to the ALK inhibitor, crizotinib. However, a proportion of the patients discontinue crizotinib treatment due to adverse events. This is the case report of a NSCLC patient with EML4-ALK rearrangement, who, following crizotinib discontinuation for one year due to adverse events, exhibited a marked response to alectinib. Even if the incidence is not high, clinicians should not overlook the most common crizotinib-related adverse events. Furthermore, certain patients may continue to benefit from alectinib following long-term discontinuation of crizotinib therapy.

Canertinib induces ototoxicity in three preclinical models

Neuregulin-1 (NRG1) ligand and its epidermal growth factor receptor (EGFR)/ERBB family regulate normal cellular proliferation and differentiation in many tissues including the cochlea. Aberrant NRG1 and ERBB signaling cause significant hearing impairment in mice. Dysregulation of the same signaling pathway in humans is involved in certain types of cancers such as breast cancer or non-small cell lung cancer (NSCLC). A new irreversible pan-ERBB inhibitor, canertinib, has been tested in clinical trials for the treatment of refractory NSCLC. Its possible ototoxicity was unknown. In this study, a significant dose-dependent canertinib ototoxicity was observed in a zebrafish model. Canertinib ototoxicity was further confirmed in two mouse models with different genetic backgrounds. The data strongly suggested an evolutionally preserved ERBB molecular mechanism underlying canertinib ototoxicity. Thus, these results imply that clinical monitoring of hearing loss should be considered for clinical testing of canertinib or other pan-ERBB inhibitors.

Tumor heterogeneity: evolution through space and time in EGFR mutant non small cell lung cancer patients

NSCLC patients with mutations in epidermal growth factor receptor (EGFR) gene have dramatic responses with the EGFR tyrosine kinase inhibitors (TKI) in the majority of patients. However, all patients will eventually present progression of disease because of both primary and acquired resistance to EGFR TKI. In the recent years several studies have identified mechanisms involved in primary and secondary resistance to EGFR TKI treatment that can also be potential therapeutic strategies, although up to 30% of cases of acquired resistance to EGFR TKI are still unexplained. In this review we describe the mechanisms of resistance to EGFR TKIs in NSCLC patients that have been discovered and potential therapeutic strategies to overcome EGFR TKI resistance. Additionally we highlight the importance of performing additional biopsies not only at time of acquired resistance to EGFR TKI but also immediately after initiation of therapy to discover the remaining unknown mechanisms of acquired resistance to EGFR TKI as well as the underlying molecular basis of the heterogeneity in response to EGFR TKI.

[Reflections on the limits of specific treatments in thoracic oncology]

The modest impact of specific treatments is a major problem in oncology and particularly for metastatic lung cancer patients. Therapeutic progress achieved by some targeted therapies is, in fact, only relevant for a small proportion of patients. The vast majority of people with this condition are rapidly confronted by the limits of specific therapies and management is or becomes entirely palliative. This article addresses therapeutic limitations in the management of metastatic lung cancer, as well as legislative aspects and guidelines for practitioners when discussing these issues with patients, together with a discussion of the psychological consequences for patients.

Pazopanib for Non-small Cell Lung Cancer: The First Case Report in Korea

Pazopanib is a potent multitargeted tyrosine kinase inhibitor that has been shown to have good efficacy in patients with renal cell carcinoma. A previous phase II trial demonstrated that short-term pazopanib administration was generally well tolerated and showed antitumor activity in patients with early-stage non-small cell lung cancer. Herein, we report on the case of a 66-year-old man with simultaneous metastatic squamous cell carcinoma of the lung and renal cell carcinoma who was treated with pazopanib. The patient showed an unexpected partial response and experienced a 10-month progression-free survival without significant toxicity. To the best of the authors’ knowledge, this is the first report of pazopanib treatment in a non-small cell lung cancer patient in Korea. The results in this patient suggest that pazopanib may be a valid treatment option for advanced non-small cell lung cancer.

Fluorescence in situ hybridization, immunohistochemistry, and next-generation sequencing for detection of EML4-ALK rearrangement in lung cancer

BACKGROUND

The U.S. Food and Drug Administration-approved method for detecting EML4-ALK rearrangement is fluorescence in situ hybridization (FISH); however, data supporting the use of immunohistochemistry (IHC) for that purpose are accumulating. Previous studies that compared FISH and IHC considered FISH the gold standard, but none compared data with the results of next-generation sequencing (NGS) analysis.

MATERIALS AND METHODS

We studied FISH and IHC (D5F3 antibody) systematically for EML4-ALK rearrangement in 51 lung adenocarcinoma patients, followed by NGS in case of discordance.

RESULTS

Of 51 patients, 4 were positive with FISH (7.8%), and 8 were positive with IHC (15.7%). Three were positive with both. NGS confirmed that four of the five patients who were positive with IHC and negative with FISH were positive for ALK. Two were treated by crizotinib, with progression-free survival of 18 and 6 months. Considering NGS as the most accurate test, the sensitivity and specificity were 42.9% and 97.7%, respectively, for FISH and 100% and 97.7%, respectively, for IHC.

CONCLUSION

The FISH-based method of detecting EML4-ALK rearrangement in lung cancer may miss a significant number of patients who could benefit from targeted ALK therapy. Screening for EML4-ALK rearrangement by IHC should be strongly considered, and NGS is recommended in borderline cases. Two patients who were negative with FISH and positive with IHC were treated with crizotinib and responded to therapy.

Efficacy of combining targeted therapy with pemetrexed or docetaxel as second-line treatment in patients with advanced non-small-cell lung cancer: a meta-analysis of 14 randomized controlled trials

OBJECTIVES

To compare the effects of adding targeted agents to standard second-line chemotherapy with a single agent (pemetrexed or docetaxel) in patients with advanced NSCLC, a meta-analysis of all relevant randomized controlled trials was performed and overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR) were assessed.

PATIENTS AND METHODS

The PubMed and Embase databases, and the Cochrane Central Register of Controlled Trials were searched for relevant publications reporting randomized controlled trials between January 2000 and December 2013. Hazard ratios (HRs) with their 95% confidence intervals (CIs), or data for calculating HRs with 95% CIs were derived.

RESULTS

Fourteen trials with a total of 6922 patients were included in this meta-analysis. Compared with chemotherapy, combination therapy did not improve OS (HR = 0.95; 95% CI, 0.90-1.01; P = 0.081) but improved PFS (HR = 0.83; 95% CI, 0.78-0.87; P = 0.000). Survival outcomes did not differ significantly among trials. Combination therapy significantly increased ORR (RR = 1.83; 95% CI, 1.59-2.127; P = 0.000) and DCR (RR = 1.18; 95% CI, 1.13-1.23, P = 0.000). Sub-analysis indicated that adding targeted therapy to chemotherapy significantly prolonged OS in patients with non-squamous NSCLC (HR = 0.87; 95% CI, 0.87-0.97; P = 0.009). Patients treated with combination therapy had an increased incidence of grade 3 or greater diarrhea (RR = 1.96; 95% CI, 1.37-2.81; P = 0.000), neutropenia (RR = 1.27, 95% CI, 1.14-1.61; P = 0.000) and thrombocytopenia (RR = 4.21, 95% CI, 1.87-9.51; P = 0.001). This meta-analysis has the limitations of heterogeneity among the included trials and not using individual patient data.

CONCLUSIONS

In the second-line treatment of advanced NSCLC, the combination of targeted therapy and chemotherapy significantly increased response rates and progression-free survival, but did not improve overall survival and was more toxic.

Multitarget inhibitors derived from crosstalk mechanism involving VEGFR2

Seven VEGFR small-molecule inhibitors have been approved by the US FDA as anticancer drugs, which confirms the therapeutic value of angiogenesis inhibitors. However, much more evidence indicates that VEGFR inhibition alone is usually not sufficient to block the tumor progress. The potential of some agents targeting VEGFR owes partially to the simultaneous inhibition of additional targets in other signaling pathways. In this review, the crosstalk between VEGFR2 and the additional targets in other signaling pathways, such as EGFR, MET, FGFR, PDGFR, c-Kit, Raf, PI3K and HDAC, and the synergistic effects derived from multitarget activities against these crosstalks are discussed. We also briefly describe the multitarget inhibitors in clinical trials or reported in the literature and patents under the different multitarget categories involving VEGFR2.

ErbB/HER protein-tyrosine kinases: Structures and small molecule inhibitors

The epidermal growth factor receptor (EGFR) family consists of four members that belong to the ErbB lineage of proteins (ErbB1-4). These receptors consist of an extracellular domain, a single hydrophobic transmembrane segment, and an intracellular portion with a juxtamembrane segment, a protein kinase domain, and a carboxyterminal tail. The ErbB proteins function as homo and heterodimers. Growth factor binding to EGFR induces a large conformational change in the extracellular domain. Two ligand-EGFR complexes unite to form a back-to-back dimer in which the ligands are on opposite sides of the aggregate. Following ligand binding, EGFR intracellular kinase domains form an asymmetric dimer. The carboxyterminal lobe of the activator kinase of the dimer interacts with the amino-terminal lobe of the receiver kinase thereby leading to its allosteric stimulation. Several malignancies are associated with the mutation or increased expression of members of the ErbB family including lung, breast, stomach, colorectal, head and neck, and pancreatic carcinomas. Gefitinib, erlotinib, and afatinib are orally effective protein-kinase targeted quinazoline derivatives that are used in the treatment of ERBB1-mutant lung cancer and lapatinib is an orally effective quinazoline derivative used in the treatment of ErbB2-overexpressing breast cancer. Moreover, monoclonal antibodies that target the extracellular domain of ErbB2 are used for the treatment of ErbB2-positive breast cancer and monoclonal antibodies that target ErbB1 and are used for the treatment of colorectal cancer. Cancers treated with these targeted drugs eventually become resistant to them, and a current goal of research is to develop drugs that are effective against drug-resistant tumors.

Druggable oncogene fusions in invasive mucinous lung adenocarcinoma

PURPOSE

To identify druggable oncogenic fusions in invasive mucinous adenocarcinoma (IMA) of the lung, a malignant type of lung adenocarcinoma in which KRAS mutations frequently occur.

EXPERIMENTAL DESIGN

From an IMA cohort of 90 cases, consisting of 56 cases (62%) with KRAS mutations and 34 cases without (38%), we conducted whole-transcriptome sequencing of 32 IMAs, including 27 cases without KRAS mutations. We used the sequencing data to identify gene fusions, and then performed functional analyses of the fusion gene products.

RESULTS

We identified oncogenic fusions that occurred mutually exclusively with KRAS mutations: CD74-NRG1, SLC3A2-NRG1, EZR-ERBB4, TRIM24-BRAF, and KIAA1468-RET. NRG1 fusions were present in 17.6% (6/34) of KRAS-negative IMAs. The CD74-NRG1 fusion activated HER2:HER3 signaling, whereas the EZR-ERBB4 and TRIM24-BRAF fusions constitutively activated the ERBB4 and BRAF kinases, respectively. Signaling pathway activation and fusion-induced anchorage-independent growth/tumorigenicity of NIH3T3 cells expressing these fusions were suppressed by tyrosine kinase inhibitors approved for clinical use.

CONCLUSIONS

Oncogenic fusions act as driver mutations in IMAs without KRAS mutations, and thus represent promising therapeutic targets for the treatment of such IMAs.

Emerging combination therapies to overcome resistance in EGFR-driven tumors

The epidermal growth factor receptor (EGFR) is responsible for the growth and progression of tumor cells; its overexpression and deregulation of its downstream signaling pathway have been found in many different neoplasms. These characteristics make it an ideal target for cancer treatment. Two classes of EGFR inhibitors, which bind to different parts of this molecule, have been developed and studied: monoclonal antibodies, such as cetuximab and panitumumab and tyrosine kinase inhibitors, including erlotinib and gefitinib. The effectiveness of these new drugs is considerably reduced by a number of mechanisms of resistance developed by tumor cells. Hence, there is a clear need for better characterization of these processes and finding new therapeutic strategies to make the action of these drugs more incisive. Here, we describe some of the mechanisms of resistance to EGFR inhibitors and review the main innovations attempting to overcome these drawbacks.