Targeting the EGFR T790M mutation in non-small-cell lung cancer

Introduction: The presence of activating mutations of the epidermal growth factor receptor (EGFR) is predictive of response to first- and second-generation tyrosine kinase inhibitors (TKIs) in patients with advanced non-small-cell lung cancer (NSCLC). However, patients that initially respond to these drugs inexorably become resistant. The T790M mutation in the exon 20 of the EGFR is the main mechanism of resistance to EGFR TKIs occurring in over 50% of the cases. Third generation EGFR TKIs have been shown to be active in patients who progressed after TKI treatment and carry the T790M mutation.

Areas covered: This review is focused on the implications of tumor heterogeneity for targeting the T790M in patients with NSCLC.

Expert opinion: Pre-clinical and clinical data suggest that the T790M is heterogeneously expressed in tumors that become resistant to first- and second-generation EGFR TKIs. These findings have important implications for the molecular diagnostic of the T790M mutation. Indeed, the analysis of both the circulating free tumor DNA (ctDNA) isolated from plasma and the tumor tissue might provide complimentary information to identify patients carrying the T790M mutation. However, further studies are needed to better understand the influence of tumor heterogeneity on the activity of drugs targeting the T790M.     

Pharmacokinetic drug evaluation of osimertinib for the treatment of non-small cell lung cancer

Introduction: First- and second-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, erlotinib, icotinib, and afatinib are the standard-of-care for first-line therapy of non-small-cell lung cancer (NSCLC) harboring activating EGFR mutations. Unfortunately, after initial activity of an average 9–13 months, disease progression has been reported in the majority of patients. In about 50% of cases the progression is due to the onset of the T790M mutation in exon 20 of the EGFR gene. Third-generation EGFR-TKIs targeting this mutation were investigated, with osimertinib the only reaching clinical practice.

Areas covered: A structured search of bibliographic databases for peer-reviewed research literature and of main meetings using a focused review question addressing osimertinib, was undertaken.

Expert opinion: Osimertinib is the standard-of-care for EGFR-mutated patients progressing to first-line EGFR-TKIs due to the acquired EGFR T790M mutation. Results from the head-to-head first-line trial comparing osimertinib versus gefitinib or erlotinib in activating EGFR mutations might change the front-line approach. Osimertinib in combination regimens, such as immunotherapy, and in adjuvant setting are ongoing. Thus, the strategic approach for the management of EGFR-mutated NSCLC patients will change further in the next few years.     

EGFR TKI combination with immunotherapy in non-small cell lung cancer

Introduction: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) has significantly improved clinical outcomes compared with chemotherapy in non-small cell lung cancer (NSCLC) patients with sensitizing EGFR gene mutation.

Areas covered: Almost all patients treated with EGFR TKIs eventually develop acquired resistance. It has been reported that activation of the oncogenic EGFR pathway enhances susceptibility of the lung tumors to PD-1 blockade in mouse model, suggesting combination of PD1 blockade with EGFR TKIs may be a promising therapeutic strategy. Nivolumab combined with erlotinib was associated with 19% of grade 3 toxicities. The combination of osimertinib plus durvalumab in pretreated or chemo naïve NSCLC patients showed encouraging clinical activity, however, this combination was associated with high incidence of interstitial lung disease (38%), leading to termination of further enrollment. The combination of gefitinib plus durvalumab demonstrated encouraging activity but higher incidence of grade 3/4 liver enzyme elevation (40–70%). The treatment related Grade 3–4 adverse events were observed in 39% of patients when treated with atezolizumab plus erlotinib.

Expert opinion: Given the relatively high incidence of treatment-related toxicities associated with combination of EGFR TKI and immunotherapy, further development of this approach remains controversial. Until now, the combination of EGFR TKI and immunotherapy should be investigational.     

Class act: safety comparison of approved tyrosine kinase inhibitors for non-small-cell lung carcinoma

Introduction: The past decade has seen the development and widespread use of tyrosine kinase inhibitors (TKIs) targeting a mutated EGFR (mEGFR) for the treatment of metastatic NSCLC. We discuss the main properties of the TKIs currently recommended for the treatment of mEGFR NSCLC: gefitinib, erlotinib and afatinib.

Areas covered: The mechanism of action, pharmacodynamics and pharmacokinetics of these drugs, with emphasis on the historical context of their preclinical and clinical development, will be covered, including potential resistance mechanisms to these first-generation TKIs that has driven the trial design for second and third generations of EGFR inhibitors. Six Phase III clinical trials comparing these three TKIs with cisplatin-based chemotherapy upfront for mEGFR NSCLC provide the basis for the comparative safety and toxicity analysis between these agents. Class-related toxicity of these EGFR inhibitors, including life-threatening effects, will be discussed.

Expert opinion: Toxicity and safety analysis from the Phase III trials of these agents in mEGFR populations suggests that afatinib has more frequent and severe side effects. Given that an efficacy advantage has not yet been demonstrated for afatinib over erlotinib and gefitinib, the consistent class toxicity profile of these agents means that gefitinib and erlotinib are a safer first-line treatment recommendation.     

Anaplastic lymphoma kinase inhibitors in phase I and phase II clinical trials for non-small cell lung cancer

Introduction: Crizotinib is a first-in-class ALK tyrosine kinase inhibitor (TKI), which has proven its superiority over standard platinum-based chemotherapy for the first-line therapy of ALK-rearranged non-small cell lung cancer (NSCLC) patients. The development of acquired resistance to crizotinib represents an ongoing challenge with the central nervous system being one of the most common sites of relapse. Ceritinib and alectinib are approved second-generation ALK TKIs. Several novel ALK inhibitors, more potent and with different selectivity compared to crizotinib, are currently in development.

Areas covered: This review will focus on new ALK inhibitors, currently in phase 1 or 2 clinical studies. We will also comment on the mechanisms of resistance to ALK inhibition and the strategies to delay or overcome resistance.

Expert opinion: The therapeutic management of ALK-rearranged NSCLC has been greatly improved. Next-generation ALK inhibitors have shown differential potency against ALK rearrangements and ALK resistance mutations. The molecular profile of the tumor at the time of disease progression to crizotinib is crucial for the sequencing of novel ALK TKIs. Ongoing clinical studies will address key issues, including the optimal therapeutic algorithm and whether combinational approaches are more effective than single ALK inhibition for the outcome of ALK-rearranged NSCLC patients.     

Tyrosine kinase inhibitors: potential use and safety considerations in HIV-1 infection

Introduction: Infection caused by HIV-1 is nowadays a chronic disease due to a highly efficient antiretroviral treatment that is nevertheless, unable to eliminate the virus from the organism. New strategies are necessary in order to impede the formation of the viral reservoirs, responsible for the failure of the antiretroviral treatment to cure the infection.

Areas covered: The purpose of this review is to discuss the possibility of using tyrosine kinase inhibitors (TKIs) for the treatment of HIV-1 infection. These inhibitors are successfully used in patients with distinct cancers such as chronic myeloid leukemia. The most relevant papers have been selected and commented.

Expert opinion: The family of TKIs are directed against the activation of tyrosine kinases from the Src family. Some of these kinases are essential for the activation of CD4 + T cells, the major target of HIV-1. During acute or primary infection the CD4 + T cells are massively activated, which is mostly responsible for the generation of the reservoirs, the spread of the infection and the destruction of activated CD4 + T cells, infected or not. Consequently, we discuss the possibility of using TKIs as adjuvant of the antiretroviral treatment against HIV-1 infection mostly, but not exclusively, during the acute/recent phase.     

Investigational drugs targeting fibroblast growth factor receptor in the treatment of non-small cell lung cancer

Introduction: Fibroblast growth factor receptor (FGFR) due to its central role in regulating cell survival, is a promising target for cancer therapeutics. Dysregulation of the FGFR pathway has been observed in several malignancies, including non-small cell lung cancer (NSCLC) particularly in patients with squamous histology.

Areas covered: The aim of this article is to review the most relevant findings of clinical trials investigating drugs targeting FGFR pathway: such as FGFR tyrosine kinase inhibitors (TKIs), FGFR monoclonal antibodies and FGF ligand traps in NSCLC patients.

Expert opinion: At present, clinical activity of drugs targeting FGFR in NSCLC is disappointing. Further studies are needed in order to better identify patients who might benefit from these drugs and to clarify the mechanisms of resistance to these compounds.     

Pharmacokinetic/pharmacodynamic drug evaluation of enzalutamide for treating prostate cancer

Introduction: Enzalutamide is the first approved second-generation androgen receptor (AR) antagonist in the treatment of metastatic castration-resistant prostate cancer (mCRPC) with or without docetaxel-based chemotherapy. Over the past 5 years, a number of attempts were made to determine the efficacy of enzalutamide in the different clinical settings.

Areas covered: A literature search was performed at the PubMed, Embase, and Web of Science database to collect the most relevant and impactful studies, including basic science investigations, clinical trials, and reviews. This article focuses on the pharmacology, efficacy, tolerability, and future perspective of enzalutamide.

Expert opinion: The treatment paradigm of CRPC has been dramatically challenged of late. Enzalutamide are in wide use because of its favorable efficacy and safety, but primary or acquired resistance to the drug will eventually develop. Further studies are thus necessary to identify appropriate patients who can achieve apparent benefits from enzalutamide alone or in combination with other drugs.     

Role of osteopontin as a predictive biomarker for anti-EGFR therapy in triple-negative breast cancer

Objective: Effective targeted therapies for patients with triple-negative breast cancer (TNBC) present an unmet clinical need. There is evidence that TNBCs often have increased expression of the epidermal growth factor receptor (EGFR) and of osteopontin (OPN). OPN-mediated signaling can activate EGFR-dependent signaling pathways. Here, we assessed OPN as a potential predictive biomarker for response to anti-EGFR therapy in TNBC.

Research design and methods: Using two different TNBC cell lines, MDA-MB-468 and MDA-MB-231, we investigated the impact of stable expression of OPN on efficacy of the EGFR inhibitor erlotinib in vitro.

Results: We observed that breast cancer cells engineered to overexpress OPN are more sensitive to growth inhibition by erlotinib than control cells. The level of response was related to the level of OPN expression, possibly due to increased phosphorylation status of EGFR Tyr1068.

Conclusions: These results indicate that OPN expression levels are related to sensitivity of TNBC cells to growth inhibition by erlotinib. OPN thus is a promising predictive biomarker for anti-EGFR therapy in breast cancer.     

Predictors of skeletal-related events among cancer patients with bone metastases treated with zoledronic acid: a secondary analysis of a randomized study

Background: The purpose of the current study is to assess the predictors of skeletal-related events (SREs) among advanced cancer patients with bone metastases treated with zoledronic acid within a randomized study.

Research design and methods: This is a secondary analysis of patient-level data of advanced cancer patients with bone metastases who were treated with monthly zoledronic acid in the NCT00330759 clinical trial.

Results: A total of 702 patients were included in the current analysis. In univariate logistic regression analysis, higher body mass index (P = 0.034) and lytic nature of bone metastasis (P = 0.008) were found to be predictive of a higher probability of SREs. When the two factors were included in a multivariate logistic regression model, both of them were predictive of the later development of SREs (P value for higher body mass index = 0.015; P value for lytic bone lesions = 0.005).

Conclusion: Among advanced cancer patients with bone metastases, lytic nature of metastases, as well as higher body mass index, are associated with a higher probability of SREs.

Trial registration number: this clinical trial was registered at clinicaltrials.gov with the number: nct0033     

Early clinical development of epidermal growth factor receptor targeted therapy in breast cancer

Introduction: Epidermal growth factor receptor (EGFR) targeted treatment has been evaluated but has not shown a clear clinical benefit for breast cancer. This review article aims to consider the knowledge of the biological background of EGFR pathways in dissecting clinical studies of EGFR targeted treatment in breast cancer.

Areas covered: This review focuses on the role of the EGFR pathway and the investigational drugs that target EGFR for breast cancer.

Expert opinion: Recent studies have indicated that EGFR targeted therapy for breast cancer has some promising effects for patients with triple-negative breast cancer, basal-like breast cancer, and inflammatory breast cancer. However, predictive and prognostic biomarkers for EGFR targeted therapy have not been identified. The overexpression or amplification of EGFR itself may not be the true factor of induction of the canonical pathway as an oncogenic driver of breast cancer. Instead, downstream, non-canonical pathways related to EGFR may contribute to some aspects of the biological behavior of breast cancer; therefore, the blockade of the receptor could result in sufficient suppression of downstream pathways to inhibit the aggressive behavior of breast cancer. Mechanistic studies to investigate the dynamic interaction between the EGFR pathway and non-canonical pathways are warranted.     

Experience with Sunitinib in metastatic renal cell carcinoma (mRCC) patients: pooled analysis from 3 Spanish observational prospective studies

Background: A pivotal, randomized, phase III trial demonstrated a statistically significant superiority of sunitinib over interferon-α in metastatic renal cell carcinoma (mRCC) patients.

Objective: To evaluate the effectiveness and safety of sunitinib in patients with advanced or mRCC in routine clinical practice.

Methods: Retrospective pooled analysis of clinical data from three observational and prospective studies carried out between 2007 and 2011 in 33 Spanish hospitals. Tumor response, Progression-free survival (PFS) and overall survival (OS), and main sunitinib-related toxicities were registered.

Results: 224 patients were analyzed. Median PFS 10.6 months (95% CI: 9.02–12.25), median OS 21.9 months (95% CI: 17.2–26.6). Objective response rate (ORR) 43.8% (95% CI: 36.8–50.7). Median time to PR was 3.8 months (95% CI: 3.86–5.99) and to CR 8.2 months (95% CI: 4.75–9.77). The most common ≥ grade-3 AEs were asthenia/fatigue (18.7%), hand-foot syndrome (6.2%), hypertension (5.8%) and neutropenia (4.8%). Hand-foot syndrome, diarrhea and mucositis were confirmed as independent predictors for PFS and/or OS in a multivariate analysis (p < 0.05)

Conclusions: Outcomes with sunitinib in daily clinical practice resemble those obtained in clinical trials. Long-term benefit with sunitinib is possible in advanced RCC patients but the appropriate management of toxicities is mandatory to enable patients to remain on treatment.     

Clinical development of mTor inhibitors for renal cancer

Introduction: Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90–95% of neoplasms arising from the kidney. In the last 10 years, clinical trials have established multitargeted tyrosine kinase inhibitors (TKIs) as the standard first-line treatment in patients with metastatic disease. Multiple agents are now available for treatment in subsequent lines.The mammalian target of rapamycin (mTOR) inhibitors (e.g., everolimus alone or with lenvatinib) are among the most effective options.

Areas covered: This paper provides a complete and updated overview on mTOR inhibitors for the treatment of advanced RCC. The authors revised the results of the most recent completed clinical trials and provided information about ongoing trials.

Expert opinion: mTOR pathway still represents an important driver for RCC management. Combination of everolimus and lenvatinib is considered a category 1 choice with cabozantinib and nivolumab for subsequent therapy in metastatic RCC according to NCCN guidelines v2.2017. These three treatments (levantinib/everolimus, cabozantinib, and nivolumab) all resulted in a superior efficacy compared to everolimus alone. Moreover, mTOR inhibitors, and in particular temsirolimus for poor risk patients, are available choices for treatment in non-clear cell carcinomas together with TKIs.     

Pharmacotherapeutic options for treating brain metastases in non-small cell lung cancer

Introduction: Central nervous system (CNS) metastases represent an important cause of morbidity and mortality in non-small cell lung cancer (NSCLC) patients. Local approaches of neurosurgery (usually for single brain lesions), whole brain radiotherapy, and stereotactic radiosurgery are often withheld for the treatment of NSCLC-derived brain metastases (BMs). However, systemic treatment is consistently emerging as an option for patients with asymptomatic BMs, which could allow for delaying cranial radiotherapy at symptomatic/radiological progression.

Areas covered: Chemotherapy, monoclonal antibodies, tyrosine-kinase inhibitors (TKIs) for molecularly selected NSCLCs, such as epidermal growth factor receptor (EGFR)-mutant and anaplastic lymphoma kinase (ALK)-rearranged diseases, and immune checkpoint inhibitors are all systemic treatments that have shown activity against NSCLC-derived CNS metastases. Among these, EGFR- and ALK-TKIs will be discussed more in detail owing to their superior efficacy in this context.

Expert opinion: Up-front systemic treatment should be considered for patients with asymptomatic, multiple BMs, as recently acknowledged by the European Society of Medical Oncology guidelines. Nevertheless, it must be emphasized that the best treatment strategy for NSCLC-derived BMs has to be defined within a multidisciplinary team.     

Dosing strategies to optimize currently available anti-MRSA treatment options (Part 2: PO options)

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a problematic pathogen in both outpatient and inpatient settings. Research to optimize the dosing of these agents is needed to slow the development of antimicrobial resistance and to decrease the likelihood of clinical failure.

Areas covered: This review summarizes the available data for orally administered antimicrobials routinely used as monotherapy for MRSA infections. We make recommendations and highlight the current gaps in the literature. A PubMed (1966 – Present) search was performed to identify relevant literature for this review.

Expert commentary: There is a vast divide in the amount of pharmacokinetic/pharmacodynamic data to guide dosing decisions for older MRSA agents compared with the oxazolidenones.

Five-year view: Additional retrospective data will become available for the older MRSA agents in severe MRSA infections.     

Pharmacological management of relapsed/refractory NSCLC with chemical drugs

Introduction: Lung cancer is the leading cause of cancer death in both genders. In the early stages the disease is asymptomatic and most patients appear with metastasis at the time of the diagnosis. The discovery of key oncogenic events mainly in lung adenocarcinoma, like EGFR mutations or ALK rearrangements has changed the treatment landscape and has improved the prognosis of lung cancer patients. Inevitably, all patients initially treated with either chemotherapy or targeted therapies develop resistance and require a second-line therapeutic approach.

Areas covered: In this review we are discussing the current treatment of relapsed or refractory lung cancer. We have thoroughly searched the literature (Pubmed) the last five years for studies or reviews published on the issue of second-line therapy in lung cancer using as key words, lung cancer, relapse, EGFR mutations, ALK rearrangements, chemotherapy and immunotherapy

Expert opinion: The prognosis of lung cancer has been radically improved. Due to the recent development of checkpoint inhibitors, this also occurs for patients whose tumor’s are not driven by a genetic alteration and who, until recently, derived only minimal benefit from chemotherapy.     

The safety of Bosutinib for the treatment of chronic myeloid leukemia

Introduction: Tyrosine kinase inhibitors (TKIs) are a potentially lifelong treatment for patients with chronic myeloid leukemia (CML). Adverse events (AEs) associated with TKIs are significant impediments in the daily life of patients that can impact compliance, and efficacy.

Areas covered: This is a review on safety of bosutinib in the treatment of chronic phase CML. Data is extracted from the latest updates of bosutinib phase I/II and III trials.

Expert opinion: Bosutinib is an effective agent against all phases of CML presently approved for the treatment in patients with resistance or intolerance to prior TKI therapy. Bosutinib has a unique toxicity profile characterized by early and transient diarrhea. Otherwise, the AE profile of bosutinib is comparable to other TKIs, with the exception of cardiovascular AEs that are infrequent in bosutinib-treated patients. Similar to other TKIs, the minimum effective dose of bosutinib remains unknown. Better definition of the optimal effective dose may spare, for those patients otherwise benefitting from treatment, unnecessary AEs.     

Emerging drugs for EGFR-mutated non-small cell lung cancer

Introduction: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) represent the standard of care for patients with metastatic non-small-cell lung cancer (NSCLC) harboring sensitizing EGFR mutations. However, these agents are associated with inevitable treatment resistance. Newer generations of TKIs are under development that may prevent or overcome resistance and enhance intracranial activity.

Areas covered: In this review, we will discuss newer generations of EGFR TKIs for EGFR-mutated NSCLC. We will also address resistance mutations and escape pathways associated with these agents such as secondary mutations, downstream signaling, bypass pathways, phenotypic transformation, anti-apoptotic signaling, immune evasion, and angiogenesis. Furthermore, this article encompasses emerging data from combination trials with next-generation TKIs that are being pursued to delay or prevent the occurrence of resistance.

Expert opinion: The promise and challenge of precision oncology is encapsulated in the treatment of EGFR-mutated NSCLC with TKIs. Third generation TKIs have shown superior efficacy in the front-line setting and have become standard of care. A better understanding of mechanisms of treatment failure and disease relapse will be required to develop novel therapeutic strategies to further improve patient outcomes in the future.     

Effects of metformin on clinical outcome in diabetic patients with advanced HCC receiving sorafenib

Background and objective: Several studies have reported an association between type 2 diabetes mellitus and hepatocellular carcinoma (HCC). Data from several retrospective studies and meta-analyses have highlighted a reduction of about 50% in the risk of developing HCC in cirrhotic patients treated with metformin for diabetes. The aim of this study was to evaluate the different outcomes of patients who received or did not receive metformin during treatment with sorafenib.

Methods: We analyzed 93 patients consecutively treated with sorafenib. Forty-two (45.2%) patients were diabetic, of whom 31 were on metformin. Progression-free survival (PFS) and overall survival (OS) were estimated with the Kaplan-Meier method and compared with the log-rank test.

Results: The concomitant use of sorafenib and metformin was associated with a median PFS of 2.6 months (95% CI 1.9–3.3) compared to 5.0 months (95% CI 2.5–8.2) for patients receiving sorafenib alone (p = 0.029). The median OS of patients treated with the combination was 10.4 months (95% CI 3.9–14.4) compared to 15.1 months (95% CI 11.7–17.8) for those who were not given metformin (p = 0.014).

Conclusions: Our findings could be the result of increased tumor aggressiveness and resistance to sorafenib in metformin-treated patients.     

A noninterventional study evaluating the effectiveness of rotigotine and levodopa combination therapy in younger versus older patients with Parkinson’s disease

Background: PD0013 was a 6-month noninterventional study in clinical practice comparing effectiveness/tolerability of rotigotine+levodopa in younger (<70 years) vs. older (≥70 years) Parkinson’s disease (PD) patients.

Methods: Patients previously received levodopa for ≥6 months as monotherapy/in combination with another dopamine-agonist (DA). Primary variable: Unified PD Rating Scale (UPDRS) Part-II change from baseline to end-of-observation-period (EOP).

Results: 91 younger/99 older patients started rotigotine; 68 younger/62 older patients completed the study. Most switched from levodopa+another DA. Addition of rotigotine as first DA was more common in older patients (20.2% vs.15.4%). Mean ± SD rotigotine-exposure: 6.1 ± 3.4 mg/24h younger vs. 4.9 ± 2.4 mg/24h older. Eleven patients changed levodopa dose.

At EOP, improvement in mean UPDRS-II was greater in younger patients (p = 0.0289). UPDRS-II responder-rate (≥20% decrease in UPDRS-II score) was higher in younger patients (42.3% vs. 25.9%). Improvement across age groups was similar on PD Sleep Scale-2 and Clinical Global Impressions-Improvement Scale. Adverse drug reactions (ADRs), and discontinuations because of ADRs, were more common among older patients. There were no new safety signals.

Conclusions: Despite low rotigotine doses, when added to levodopa/switched from levodopa+another DA, rotigotine led to greater improvement in UPDRS-II in younger patients (<70 years). Individual patient data revealed clinically meaningful improvements in UPDRS-II in both groups.