Phase I Trial of Sorafenib in Combination with Gefitinib in Patients with Refractory or Recurrent Non–Small Cell Lung Cancer

Efficacy and Safety of Habitual Consumption of a Food Supplement Containing Miraculin in Malnourished Cancer Patients: The CLINMIR Pilot Study

Taste disorders (TDs) are common among systemically treated cancer patients and negatively impact their nutritional status and quality of life. The novel food approved by the European Commission (EFSA), dried miracle berries (DMB), contains the natural taste-modifying protein miraculin. DMB, also available as a supplement, has emerged as a possible alternative treatment for TDs. The present study aimed to evaluate the efficacy and safety of habitual DMB consumption in malnourished cancer patients undergoing active treatment. An exploratory clinical trial was carried out in which 31 cancer patients were randomized into three arms [standard dose of DMB (150 mg DMB/tablet), high dose of DMB (300 mg DMB/tablet) or placebo (300 mg freeze-dried strawberry)] for three months. Patients consumed a DMB tablet or placebo daily before each main meal (breakfast, lunch, and dinner). Throughout the five main visits, electrochemical taste perception, nutritional status, dietary intake, quality of life and the fatty acid profile of erythrocytes were evaluated. Patients consuming a standard dose of DMB exhibited improved taste acuity over time (% change right/left side: -52.8 ± 38.5/-58.7 ± 69.2%) and salty taste perception (2.29 ± 1.25 vs. high dose: 2.17 ± 1.84 vs. placebo: 1.57 ± 1.51 points, p < 0.05). They also had higher energy intake (p = 0.075) and covered better energy expenditure (107 ± 19%). The quality of life evaluated by symptom scales improved in patients receiving the standard dose of DMB (constipation, p = 0.048). The levels of arachidonic (13.1 ± 1.8; 14.0 ± 2.8, 12.0 ± 2.0%; p = 0.004) and docosahexaenoic (4.4 ± 1.7; 4.1 ± 1.0; 3.9 ± 1.6%; p = 0.014) acids in erythrocytes increased over time after DMB intake. The standard dose of DMB increased fat-free mass vs. placebo (47.4 ± 9.3 vs. 44.1 ± 4.7 kg, p = 0.007). Importantly, habitual patients with DMB did not experience any adverse events, and metabolic parameters remained stable and within normal ranges. In conclusion, habitual consumption of a standard 150 mg dose of DMB improves electrochemical food perception, nutritional status (energy intake, fat quantity and quality, fat-free mass), and quality of life in malnourished cancer patients receiving antineoplastic treatment. Additionally, DMB consumption appears to be safe, with no changes in major biochemical parameters associated with health status. Clinical trial registered (NCT05486260).

Pharmacokinetics, safety, tolerability, and feasibility of apatinib in combination with gefitinib in stage IIIB-IV EGFR-mutated non-squamous NSCLC: a drug-drug interaction study

PURPOSE

Apatinib combined with gefitinib was proven to benefit advanced EGFR-mutant NSCLC patients in first-line treatment. This study aimed to evaluate the drug-drug interaction of gefitinib and apatinib when coadministered in EGFR-mutated NSCLC patients.

METHODS

In this phase 1b, multi-center, open-label, fixed-sequence study, the drug-drug interaction of gefitinib and apatinib was evaluated when coadministered in EGFR-mutated NSCLC patients. Patients received single-agent apatinib 500 mg QD on days 1-4. Gefitinib 250 mg QD was given on days 5-15 and combined with apatinib 500 mg QD on days 12-15. Serial blood samples were drawn on days 4 and 15. The plasma concentrations and other pharmacokinetics parameters were measured for apatinib with and without gefitinib.

RESULTS

The study enrolled 22 patients and 20 were analyzed for pharmacokinetics. There were no distinct differences in apatinib Cmax and AUC0-τ with versus without gefitinib (geometric LSM ratio, 0.96 [90% CI 0.84-1.10] for Cmax and 1.12 [90% CI 0.96-1.30] for AUC0-τ). Similar PFS and grade of treatment-emergent adverse events (TEAEs) were found between different Cmax and AUC0-τ of apatinib and gefitinib at 500 mg apatinib and 250 mg gefitinib dose levels.

CONCLUSIONS

Apatinib pharmacokinetics parameters were not significantly changed when coadministered with gefitinib. All TEAEs were manageable, and there was no need to change the dose level when combining apatinib and gefitinib (ClinicalTrials.gov identifier: NCT04390984, May 18, 2020).

Title: Chemotherapy-Induced Oral Complications and Prophylaxis Strategies

Cancer is currently a significant therapeutic challenge and is frequently connected with numerous adverse effects. Despite many improvements in chemotherapy, oral complications are common, leading to poor quality of life and chemotherapeutic dose reduction, which impair survival. This review summarizes the most common dental complications in patients receiving chemotherapy. We mainly focus on oral mucositis as it is a major cause of dose-limiting toxicity. Furthermore, oral candidiasis, viral infections, and xerostomia will be discussed. Conclusions: preventing complications is significantly more important than treating them. All patients beginning systemic anticancer treatment should undergo a thorough oral examination and get appropriate prophylaxis.

ERK5 signalling pathway is a novel target of sorafenib: Implication in EGF biology

Sorafenib is a multikinase inhibitor widely used in cancer therapy with an antitumour effect related to biological processes as proliferation, migration or invasion, among others. Initially designed as a Raf inhibitor, Sorafenib was later shown to also block key molecules in tumour progression such as VEGFR and PDGFR. In addition, sorafenib has been connected with key signalling pathways in cancer such as EGFR/EGF. However, no definitive clue about the molecular mechanism linking sorafenib and EGF signalling pathway has been established so far. Our data in HeLa, U2OS, A549 and HEK293T cells, based on in silico, chemical and genetic approaches demonstrate that the MEK5/ERK5 signalling pathway is a novel target of sorafenib. In addition, our data show how sorafenib is able to block MEK5-dependent phosphorylation of ERK5 in the Ser218/Tyr220, affecting the transcriptional activation associated with ERK5. Moreover, we demonstrate that some of the effects of this kinase inhibitor onto EGF biological responses, such as progression through cell cycle or migration, are mediated through the effect exerted onto ERK5 signalling pathway. Therefore, our observations describe a novel target of sorafenib, the ERK5 signalling pathway, and establish new mechanistic insights for the antitumour effect of this multikinase inhibitor.

Chemotherapy and dysphagia: the good, the bad, the ugly

PURPOSE OF REVIEW

Dysphagia is a debilitating, depressing and potentially life-threatening complication in cancer patients that is likely underreported. The purpose of this review is to critically synthesize the current knowledge regarding the impact of chemotherapeutic regimens on swallowing function.

RECENT FINDINGS

Those patients with cancers involving the aerodigestive tract, head and neck cancer and oesophageal cancer are at highest risk of developing dysphagia. The most common dysphagia causing toxicity of chemotherapeutic agents is mucositis/stomatitis. The use of cisplatin is correlated with increased incidence of mucositis. Similarly, the addition of melphalan is also associated with worsening mucositis and dysphagia. In some cases of oesophageal cancer, thyroid cancer, metastatic lung or breast cancer the use of chemotherapy can improve swallow function as obstructive lesions are reduced.

SUMMARY

There is limited literature regarding the role of chemotherapy in the development or treatment of dysphagia. Most dysphagia that occurs during cancer treatment is attributable to radiation or the synergistic effect of radiation and chemotherapy. Patients with disordered swallowing prior to treatment have the greatest risk of developing posttreatment dysphagia. Studies are needed to determine whether acute inflammation associated with oropharyngeal mucositis predisposes for late dysphagia.

Phase I/II study of sorafenib in combination with erlotinib for recurrent glioblastoma as part of a 3-arm sequential accrual clinical trial: NABTC 05-02

Background

Receptor tyrosine kinases such as epidermal growth factor receptors (EGFRs) and their downstream signaling pathways such as the Ras-Raf-mitogen-activated protein kinase (MAPK) pathway play important roles in glioblastoma (GBM). This study investigated the safety, pharmacokinetics, and efficacy of sorafenib (Ras/Raf/MAPK inhibitor) in combination with erlotinib (EGFR inhibitor) for treatment of recurrent GBMs.

Methods

Patients with recurrent GBM were eligible. A novel sequential accrual trial design was used, where patients were sequentially accrued into separate treatment arms in phase I and phase II investigations to optimize recruitment efficiency. In phase I, a standard 3 + 3 format was used to identify dose-limiting toxicities (DLTs), determine maximum tolerated dose (MTD), and investigate pharmacokinetics. Phase II followed a 2-stage design with the primary endpoint being 6-month progression-free survival (PFS6).

Results

Sixteen patients were recruited for phase I, and the MTD was determined to be sorafenib 200 mg twice daily and erlotinib 100 mg once daily. DLTs include Grade 3 hypertension, Grade 3 elevated liver transaminases, and Grade 4 elevated lipase. While erlotinib did not affect sorafenib levels, sorafenib reduced erlotinib levels. In phase II, 3 of 19 stage 1 participants were progression free at 6 months. This did not meet the predetermined efficacy endpoint, and the trial was terminated.

Conclusion

This study identified the MTD and DLTs for sorafenib and erlotinib combination therapy for recurrent GBMs; however, efficacy data did not meet the primary endpoint. This study also demonstrates the feasibility of a novel sequential accrual clinical trial design that optimizes patient recruitment for multiarm studies, which is particularly effective for multicenter clinical trials.

Clinical Pharmacokinetics and Pharmacodynamics of Transarterial Chemoembolization and Targeted Therapies in Hepatocellular Carcinoma

The management of hepatocellular carcinoma (HCC) is based on a multidisciplinary decision tree. Treatment includes loco-regional therapy, mainly transarterial chemoembolization, for intermediate-stage HCC and systemic therapy with oral tyrosine kinase inhibitors (TKIs) for advanced HCC. Transarterial chemoembolization involves hepatic intra-arterial infusion with either conventional procedure or drug-eluting-beads. The aim of the loco-regional procedure is to deliver treatment as close as possible to the tumor both to embolize the tumor area and to enhance efficacy and minimize systemic toxicity of the anticancer drug. Pharmacokinetic studies applied to transarterial chemoembolization are rare and pharmacodynamic studies even rarer. However, all available studies lead to the same conclusions: use of the transarterial route lowers systemic exposure to the cytotoxic drug and leads to much higher tumor drug concentrations than does a similar dose via the intravenous route. However, reproducibility of the procedure remains a major problem, and no consensus exists regarding the choice of anticancer drug and its dosage. Systemic therapy with TKIs is based on sorafenib and lenvatinib as first-line treatment and regorafenib and cabozantinib as second-line treatment. Clinical use of TKIs is challenging because of their complex pharmacokinetics, with high liver metabolism yielding both active metabolites and their common toxicities. Changes in liver function over time with the progression of HCC adds further complexity to the use of TKIs. The challenges posed by TKIs and the HCC disease process means monitoring of TKIs is required to improve clinical management. To date, only partial data supporting sorafenib monitoring is available. Results from further pharmacokinetic/pharmacodynamic studies of these four TKIs are eagerly awaited and are expected to permit such monitoring and the development of consensus guidelines.

Comparative review of drug-drug interactions with epidermal growth factor receptor tyrosine kinase inhibitors for the treatment of non-small-cell lung cancer

The development of small-molecule tyrosine kinase inhibitors (TKIs) that target the epidermal growth factor receptor (EGFR) has revolutionized the management of non-small-cell lung cancer (NSCLC). Because these drugs are commonly used in combination with other types of medication, the risk of clinically significant drug–drug interactions (DDIs) is an important consideration, especially for patients using multiple drugs for coexisting medical conditions. Clinicians need to be aware of the potential for clinically important DDIs when considering therapeutic options for individual patients. In this article, we describe the main mechanisms underlying DDIs with the EGFR-TKIs that are currently approved for the treatment of NSCLC, and, specifically, the potential for interactions mediated via effects on gastrointestinal pH, cytochrome P450-dependent metabolism, uridine diphosphate-glucuronosyltransferase, and transporter proteins. We review evidence of such DDIs with the currently approved EGFR-TKIs (gefitinib, erlotinib, afatinib, osimertinib, and icotinib) and discuss several information sources that are available online to aid clinical decision-making. We conclude by summarizing the most clinically relevant DDIs with these EFGR-TKIs and provide recommendations for managing, minimizing, or avoiding DDIs with the different agents.

The Evaluation of Animal Models in the Development of Anticancer Agents: From Preclinical to Clinical Tests

BACKGROUND

One of the main reasons for most of the anticancer drugs to fail in the late preclinical testing and early clinical trials is the differences in drug effects observed from animals and patients, and the challenge has been to find a balance to reduce the inherent differences from species.

OBJECTIVE

Predicting safe starting doses and dosing schedules for human clinical trials is the main purpose of toxicological studies of anticancer drugs.

METHODS

Relevant information and data were assimilated from manuscripts, congress publications, and online sources.

RESULTS

We systematically overview the cons and pros of animal models and briefed the ways to determine human clinical starting doses derived from animal toxicological studies for anticancer drugs.

CONCLUSION

This information helps smart select the suitable predictive model for anti-cancer drugs with the different mechanisms and emphasized the pharmaceutical challenges behind and ahead.

Human serum albumin binding and synergistic effects of gefitinib in combination with regorafenib on colorectal cancer cell lines

This study aimed to evaluate the combination effect of gefitinib (GEF) and regorafenib (REG) against HCT116, CT26 and SW948 colorectal cancer cell lines. Results showed synergistic effects on HCT116 and CT26 cells, while the additive effect was observed on SW948 cells. Combination of GEF and REG induced sub-G1 peak as the apoptotic population on HCT116 cells, through flow cytometry histogram. Downregulation of AKT1 and TGFB2 and upregulation of CASP3 were observed in the combination of GEF and REG in HCT116 cells, using quantitative real-time PCR analysis. HSA binding properties exhibit that the first drug increased binding affinity between the second drug and HSA; as a result, HSA could transport both drugs. Thus, we hope this study creates a promising strategy to treat colorectal cancer.

Use of a physiologically based pharmacokinetic model to simulate drug-drug interactions between antineoplastic and antiretroviral drugs

Background

Co-administration of antineoplastics with ART is challenging due to potential drug-drug interactions (DDIs). However, trials specifically assessing such DDIs are lacking. Our objective was to simulate DDIs between the antineoplastics erlotinib and gefitinib with key antiretroviral drugs and to predict dose adjustments using a physiologically based pharmacokinetic (PBPK) model.

Methods

In vitro data describing chemical properties and pharmacokinetic processes of each drug and their effect on cytochrome P450 isoforms were obtained from the literature. Plasma drug-concentration profiles were simulated in a virtual population of 50 individuals receiving erlotinib or gefitinib alone or with darunavir/ritonavir, efavirenz or etravirine. Simulated pharmacokinetic parameters and the magnitude of DDIs with probe drugs (midazolam, maraviroc) were compared with literature values. Erlotinib and gefitinib pharmacokinetics with and without antiretrovirals were compared and dose-adjustment strategies were evaluated.

Results

Simulated parameters of each drug and the magnitude of DDIs with probe drugs were in agreement with reference values. Darunavir/ritonavir increased erlotinib and gefitinib exposure, while efavirenz and etravirine decreased erlotinib and gefitinib concentrations. Based on our predictions, dose-adjustment strategies may consist of once-daily dosing erlotinib at 25 mg and gefitinib at 125 mg with darunavir/ritonavir; or erlotinib at 200 mg and gefitinib at 375 mg with etravirine. The interaction with efavirenz was not overcome even after doubling erlotinib or gefitinib doses.

Conclusions

PBPK models predicted the in vivo pharmacokinetics of erlotinib, gefitinib and the antiretrovirals darunavir/ritonavir, efavirenz and etravirine, and the DDIs between them. The simulated dose-adjustments may represent valuable strategies to optimize antineoplastic therapy in HIV-infected patients.

Synergistic activity of sorafenib and betulinic acid against clonogenic activity of non-small cell lung cancer cells

The highly selective multi‐targeted agent sorafenib is an inhibitor of a number of intracellular signaling kinases with anti‐proliferative, anti‐angiogenic and pro‐apoptotic effects in various types of tumors, including human non‐small cell lung cancer (NSCLC). Betulin displays a broad spectrum of biological and pharmacological properties, including anticancer and chemopreventive activity. Combination of drugs with different targets is a logical approach to overcome multilevel cross‐stimulation among key signaling pathways in NSCLC progression. NSCLC cell lines, A549, H358 and A427, with different KRAS mutations, and normal human peripheral blood lymphocyte cells, were treated with sorafenib and betulinic acid alone and in combination. We examined the effect of different combined treatments on viability (MTS test), proliferation and apoptotic susceptibility based on flow cytometry, alterations in signaling pathways by western blotting and colony‐forming ability. The combination of sorafenib with betulinic acid had a strong effect on the induction of apoptosis of different NSCLC cell lines. In addition, this combination was not toxic for human peripheral blood lymphocytes. Combination treatment changed the expression of proteins involved in the mitochondrial apoptosis pathway and induced apoptotic death by caspase activation. Importantly, combination treatment with low drug concentrations tremendously reduced the colony‐forming ability of A549, H358 and A427 cells, as compared to both compounds alone. In this study, we showed that combination therapy with low concentrations of sorafenib and betulinic acid had the capacity to induce high levels of cell death and abolish clonogenic activity in some NSCLC cell lines regardless of KRAS mutations.

Inefficiencies and Patient Burdens in the Development of the Targeted Cancer Drug Sorafenib: A Systematic Review

Failure in cancer drug development exacts heavy burdens on patients and research systems. To investigate inefficiencies and burdens in targeted drug development in cancer, we conducted a systematic review of all prelicensure trials for the anticancer drug, sorafenib (Bayer/Onyx Pharmaceuticals). We searched Embase and MEDLINE databases on October 14, 2014, for prelicensure clinical trials testing sorafenib against cancers. We measured risk by serious adverse event rates, benefit by objective response rates and survival, and trial success by prespecified primary endpoint attainment with acceptable toxicity. The first two clinically useful applications of sorafenib were discovered in the first 2 efficacy trials, after five drug-related deaths (4.6% of 108 total) and 93 total patient-years of involvement (2.4% of 3,928 total). Thereafter, sorafenib was tested in 26 indications and 67 drug combinations, leading to one additional licensure. Drug developers tested 5 indications in over 5 trials each, comprising 56 drug-related deaths (51.8% of 108 total) and 1,155 patient-years (29.4% of 3,928 total) of burden in unsuccessful attempts to discover utility against these malignancies. Overall, 32 Phase II trials (26% of Phase II activity) were duplicative, lacked appropriate follow-up, or were uninformative because of accrual failure, constituting 1,773 patients (15.6% of 11,355 total) participating in prelicensure sorafenib trials. The clinical utility of sorafenib was established early in development, with low burden on patients and resources. However, these early successes were followed by rapid and exhaustive testing against various malignancies and combination regimens, leading to excess patient burden. Our evaluation of sorafenib development suggests many opportunities for reducing costs and unnecessary patient burden in cancer drug development.

Pharmacokinetic Aspects of Vascular Endothelial Growth Factor Tyrosine Kinase Inhibitors

Scientists have identified the impact of angiogenesis on tumor growth and survival. Among other efficient drugs, several small-molecule tyrosine kinase inhibitors (TKIs) targeting the vascular endothelial growth factor receptor (VEGFR) have been developed and have already been integrated into the treatment of various advanced malignancies. This review provides a compilation of current knowledge on the pharmacokinetic aspects of all VEGFR-TKIs already approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) and of those still under investigation. Additional information on substance metabolism, potential for drug-drug interactions (DDIs), and the need for dose adaptation in patients with predominant renal and/or hepatic impairment has been included. All TKIs introduced in this review were administered orally, allowing for easy drug handling for healthcare professionals and patients. For almost all substances, the maximum plasma concentrations were reached within a short period of time. The majority of the substances showed a high plasma protein binding and their excretion occurred via the feces and, to a lesser extent, via the urine. In most cases, dose adaptation in patients with mild to moderate renal or hepatic impairment is not recommended. Cytochrome P450 (CYP) 3A4 was found to play a crucial role in the drug metabolic processes of many compounds. In order to prevent unwanted DDIs, co-administration of VEGFR TKIs together with CYP3A4 inhibitors or inducers should be avoided. Throughout all TKIs, the data indicate high inter-individual variability. The causes of this are still unclear and require further research to allow for individualization of treatment regimens.

Third- and further-line therapy in advanced non-small-cell lung cancer patients: an overview

Non-small-cell lung cancer (NSCLC) treatment has led to improved efficacy and compliance due to individual tailoring of the therapeutic options and the use of strategies based on both clinical characteristics and histological and biological features of the disease. In nonsquamous NSCLC, novel agents, such as pemetrexed and bevacizumab, have improved survival in the first-line setting. Maintenance therapy with pemetrexed and erlotinib resulted in improved progression-free survival compared with second-line therapy at disease progression. In the second-line setting, pemetrexed improves survival in nonsquamous NSCLC compared with docetaxel, and erlotinib has shown a survival benefit compared with best supportive care in patients who did not previously receive an EGF receptor inhibitor. Although the benefit of first- and second-line treatment over best supportive care alone has been firmly established, the role of further-line treatment remains controversial. This article summarizes the state-of-the-art treatments in this setting.

Drug-drug interactions with tyrosine-kinase inhibitors: a clinical perspective

In the past decade, many tyrosine-kinase inhibitors have been introduced in oncology and haemato-oncology. Because this new class of drugs is extensively used, serious drug-drug interactions are an increasing risk. In this Review, we give a comprehensive overview of known or suspected drug-drug interactions between tyrosine-kinase inhibitors and other drugs. We discuss all haemato-oncological and oncological tyrosine-kinase inhibitors that had been approved by Aug 1, 2013, by the US Food and Drug Administration or the European Medicines Agency. Various clinically relevant drug interactions with tyrosine-kinase inhibitors have been identified. Most interactions concern altered bioavailability due to altered stomach pH, metabolism by cytochrome P450 isoenzymes, and prolongation of the QTc interval. To guarantee the safe use of tyrosine-kinase inhibitors, a drugs review for each patient is needed. This Review provides specific recommendations to guide haemato-oncologists, oncologists, and clinical pharmacists, through the process of managing drug-drug interactions during treatment with tyrosine-kinase inhibitors in daily clinical practice.

EGFR and KRAS mutations, and ALK fusions: current developments and personalized therapies for patients with advanced non-small-cell lung cancer

Personalized therapy has significantly developed in lung cancer treatment over recent years. VEGF and EGF play a major role in non-small-cell lung cancer (NSCLC) tumor angiogenesis and aggressiveness. EGFR mutation as well as KRAS and ALK rearrangements are important biomarkers in the field owing to potential targeted therapies involved in clinical practice: erlotinib, geftinib, cetuximab and crizotinib. More recently, regulation of tumor immunity through CTLA4 and PD1/L1 has emerged as a promising field in NSCLC management. This review will focus on the current and future biomarkers in the advanced NSCLC field and also address potential related targeted therapies for these patients.

Clinical pharmacokinetics of tyrosine kinase inhibitors: implications for therapeutic drug monitoring

The treatment of many malignancies has been improved in recent years by the introduction of molecular targeted therapies. These drugs interact preferentially with specific targets that are mutated and/or overexpressed in malignant cells. A group of such targets are the tyrosine kinases, against which a number of inhibitors (tyrosine kinase inhibitors, TKIs) have been developed. Imatinib, a TKI with targets that include the breakpoint cluster region-Abelson (bcr-abl) fusion protein kinase and mast/stem cell growth factor receptor kinase (c-Kit), was the first clinically successful drug of this type and revolutionized the treatment and prognosis of chronic myeloid leukemia and gastrointestinal stromal tumors. This success paved the way for the development of other TKIs for the treatment of a range of hematological malignancies and solid tumors. To date, 14 TKIs have been approved for clinical use and many more are under investigation. All these agents are given orally and are substrates of a range of drug transporters and metabolizing enzymes. In addition, some TKIs are capable of inhibiting their own transporters and metabolizing enzymes, making their disposition and metabolism at steady-state unpredictable. A given dose can therefore give rise to markedly different plasma concentrations in different patients, favoring the selection of resistant clones in the case of subtherapeutic exposure, and increasing the risk of toxicity if dosage is excessive. The aim of this review was to summarize current knowledge of the clinical pharmacokinetics and known adverse effects of the TKIs that are available for clinical use and to provide practical guidance on the implications of these data in patient management, in particular with respect to therapeutic drug monitoring.

Sorafenib: targeting multiple tyrosine kinases in cancer

Sorafenib (BAY 43-9006, Nexavar®) is an oral multiple tyrosine kinase inhibitor. Main targets are receptor tyrosine kinase pathways frequently deregulated in cancer such as the Raf-Ras pathway, vascular endothelial growth factor (VEGF) pathway, and FMS-like tyrosine kinase 3 (FLT3). Sorafenib was approved by the FDA in fast track for advanced renal cell cancer and hepatocellular cancer and shows good clinical activity in thyroid cancer. Multiple clinical trials are undertaken to further investigate the role of sorafenib alone or in combination for the treatment of various tumor entities.

BCRP/ABCG2 inhibition sensitizes hepatocellular carcinoma cells to sorafenib

The multikinase inhibitor, sorafenib (Nexavar®, BAY43-9006), which inhibits both the Raf/MEK/ERK pathway and several receptor tyrosine kinases (RTKs), has shown significantly therapeutic benefits in advanced hepatocellular carcinoma (HCC). However, not all HCC patients respond to sorafenib well and new therapeutic strategies to optimize the efficacy of sorafenib are urgently required. Overexpression of breast cancer resistance protein (BCRP/ABCG2) mediates the drug-efflux of several tyrosine kinase inhibitors (TKIs) to attenuate their efficacy. This study aimed to investigate the role of BCRP/ABCG2 in the sensitivity of HCC to sorafenib. Our data showed that BCRP/ABCG2 mediated the efflux of sorafenib. Co-treatment with a BCRP/ABCG2 inhibitor greatly augmented the cytotoxicity of sorafenib in HCC cells. Similar results were also achieved by the competitive inhibitor of BCRP/ABCG2, gefitinib, in combination with sorafenib. These results suggest not only that BCRP/ABCG2 is a potential predictor for the sorafenib sensitivity in HCC, but also that blockage of BCRP/ABCG2 may be a potential strategy to increase the response of HCC cells to sorafenib.

Drug interactions with solid tumour-targeted therapies

Drug interactions are an on-going concern in the treatment of cancer, especially when targeted therapies, such as tyrosine kinase inhibitors (TKI) or mammalian target of rapamycin (mTOR) inhibitors, are being used. The emergence of elderly patients and/or patients with both cancer and other chronic co-morbidities leads to polypharmacy. Therefore, the risk of drug-drug interactions (DDI) becomes a clinically relevant issue, all the more so as TKIs and mTOR inhibitors are essentially metabolised by cytochrome P450 enzymes. These DDIs can result in variability in anticancer drug exposure, thus favouring the selection of resistant cellular clones or the occurrence of toxicity. This review provides a comprehensive overview of DDIs that involve targeted therapies approved by the FDA for the treatment of solid tumours for more than 3 years (sorafenib, sunitinib, erlotinib, gefitinib, imatinib, lapatinib, everolimus, temsirolimus) and medicinal herb or drugs. This review also provides some guidelines to help oncologists and pharmacists in their clinical practice.

Novel small molecule EGFR inhibitors as candidate drugs in non-small cell lung cancer

In the last decade, better understanding of the role of epidermal growth factor receptor in the pathogenesis and progression of non-small cell lung cancer has led to a revolution in the work-up of these neoplasms. Tyrosine kinase inhibitors, such as erlotinib and gefitinib, have been approved for the treatment of non-small cell lung cancer, demonstrating an improvement in progression-free and overall survival, particularly in patients harboring activating EGFR mutations. Nevertheless, despite initial responses and long-lasting remissions, resistance to tyrosine kinase inhibitors invariably develops, most commonly due to the emergence of secondary T790M mutations or to the amplification of mesenchymal-epithelial transition factor (c-Met), which inevitably leads to treatment failure. Several clinical studies are ongoing (http://www.clinicaltrials.gov), aimed to evaluate the efficacy and toxicity of combined approaches and to develop novel irreversible or multitargeted tyrosine kinase inhibitors and mutant-selective inhibitors to overcome such resistance. This review is an overview of ongoing Phase I, II, and III trials of novel small molecule epidermal growth factor receptor inhibitors and combinations in non-small cell lung cancer patients.

Safety and feasibility of targeted agent combinations in solid tumours

The plethora of novel molecular-targeted agents (MTAs) has provided an opportunity to selectively target pathways involved in carcinogenesis and tumour progression. Combination strategies of MTAs are being used to inhibit multiple aberrant pathways in the hope of optimizing antitumour efficacy and to prevent development of resistance. While the selection of specific agents in a given combination has been based on biological considerations (including the role of the putative targets in cancer) and the interactions of the agents used in combination, there has been little exploration of the possible enhanced toxicity of combinations resulting from alterations in multiple signalling pathways in normal cell biology. Owing to the complex networks and crosstalk that govern normal and tumour cell proliferation, inhibiting multiple pathways with MTA combinations can result in unpredictable disturbances in normal physiology. This Review focuses on the main toxicities and the lack of tolerability of some common MTA combinations, particularly where evidence of enhanced toxicity compared to either agent alone is documented or there is development of unexpected toxicity. Toxicities caused by MTA combinations highlight the need to introduce new preclinical testing paradigms early in the drug development process for the assessment of chronic toxicities resulting from such combinations.

NABTT 0502: a phase II and pharmacokinetic study of erlotinib and sorafenib for patients with progressive or recurrent glioblastoma multiforme

BACKGROUND

The signal transduction pathways of epidermal growth factor receptor and Ras are both important in the growth of glioblastoma multiforme (GBM). We hypothesized that inhibition of both pathways would improve the survival time of patients with recurrent GBM.

METHODS

Patients with recurrent/progressive GBM with 0-2 prior chemotherapy regimens received erlotinib 150 mg once daily and sorafenib 400 mg twice daily until progression. The primary endpoint was overall survival. Pharmacokinetic sampling was performed during cycle 1.

RESULTS

The median overall survival was 5.7 months. Progression-free survival at 6 months was 14%. Toxicity was manageable. Clearance of erlotinib was markedly enhanced by sorafenib.

CONCLUSION

The study did not meet its objective of a 30% increase in overall survival time compared with historical controls. Erlotinib and sorafenib have significant pharmacokinetic interactions that may negatively impact the efficacy of the combination regimen.

Phase III, randomized, double-blind, placebo-controlled trial of gemcitabine/cisplatin alone or with sorafenib for the first-line treatment of advanced, nonsquamous non-small-cell lung cancer

PURPOSE

This trial evaluated the efficacy and safety of sorafenib plus gemcitabine/cisplatin in chemotherapy-naive patients with unresectable stage IIIB to IV nonsquamous non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Between February 2007 and March 2009, 904 patients were randomly assigned to daily sorafenib (400 mg twice a day) or matching placebo plus gemcitabine (1,250 mg/m(2) per day on days 1 and 8) and cisplatin (75 mg/m(2) on day 1) for up to six 21-day cycles. Because of safety findings from the Evaluation of Sorafenib, Carboplatin and Paclitaxel Efficacy in NSCLC (ESCAPE) trial, patients with squamous cell histology were withdrawn from the trial in February 2008 and excluded from analysis. The primary end point was overall survival (OS), and secondary end points included progression-free survival (PFS) and time-to-progression (TTP).

RESULTS

The primary analysis population consisted of 772 patients (sorafenib, 385; placebo, 387); the two groups had similar demographic and baseline characteristics. Median OS was similar in the sorafenib and placebo groups (12.4 v 12.5 months; hazard ratio [HR], 0.98; P = .401). By investigator assessment, sorafenib improved median PFS (6.0 v 5.5 months; HR, 0.83; P = .008) and TTP (6.1 v 5.5 months; HR, 0.73; P < .001). Grade 3 to 4 drug-related adverse events more than two-fold higher in the sorafenib group included hand-foot skin reaction (8.6% v 0.3%), fatigue (7.3% v 3.6%), rash (5.7% v 0.5%), and hypertension (4.2% v 1.8%). No unexpected toxicities were observed.

CONCLUSION

This study did not meet its primary end point of improved OS when sorafenib was added to first-line gemcitabine/cisplatin in patients with advanced nonsquamous NSCLC. Identification of predictive biomarkers is warranted in future trials of sorafenib.

Sorafenib in non-small cell lung cancer

INTRODUCTION

Conventional chemotherapy has reached a plateau of effectiveness for the treatment of non-small cell lung cancer (NSCLC). Patients with EGFR mutation or ALK translocations will benefit significantly from agents targeting these pathways, however, only 20% of western NSCLC patients have these mutations. Anti-VEGF antibody bevacizumab was approved for advanced NSCLC, but the clinical benefits are modest and all patients eventually develop resistance. Multi-targeted tyrosine kinase inhibitors (TKI) may offer more efficient inhibition of angiogenesis by blocking overlapping pathways and they may also have direct anti-tumor effects. Sorafenib is approved in the treatment of renal cell carcinoma and hepatocellular carcinoma and is now under investigation in the treatment of NSCLC.

AREAS COVERED

This review summarizes recent studies evaluating sorafenib in the treatment of NSCLC.

EXPERT OPINION

Sorafenib has shown anti-tumor activity in NSCLC. However, because NSCLC is complex and molecularly heterogeneous, it is very likely that only a subset of NSCLC patients will benefit from sorafenib, and so it is imperative to discover biomarkers to select patients who will probably benefit from sorafenib. Combination with other agents targeting parallel and compensatory pathways, such as EGFR inhibitors, may offer broader coverage and better disease control.

[Anti-angiogenic agents in the treatment of lung cancer: indications and toxicities]

Lung cancer is the leading cause of cancer-related death. Targeting the vascular endothelial growth factor (VEGF) pathways in combination with standard chemotherapy can improve response rate and survival in non-small cell lung cancer. Since October 2006, a new class of drugs targeting angiogenesis has been introduced for the treatment of advanced lung cancer. Bevacizumab, an antibody directly targeting VEGF was the first agent to be approved. Other small molecule tyrosine kinase inhibitors targeting the VEGF receptor are also active in the treatment of advanced lung cancer and are currently under development. Most of these new drugs are well tolerated though potentially significant toxicities such as haemoptysis and hypertension have been observed. This article will review these new-targeted anti-angiogenic agents with a focus on their use in lung cancer and on their important side effects.

Growth inhibition of human lung cancer cells via down-regulation of epidermal growth factor receptor signaling by yuanhuadine, a daphnane diterpene from Daphne genkwa

The growth inhibition and antitumor activities of yuanhuadine (1), a daphnane diterpenoid from the flowers of Daphne genkwa, were investigated in human lung cancer cells. Compound 1 exhibited a relatively selective growth inhibition against human lung cancer cells compared to other solid human cancer cell lines. The potent antiproliferative activity by 1 was associated with cell-cycle arrest and modulation of cell-signaling pathways. Cell-cycle arrest in the G0/G1 and G2/M phase was induced by 1 in A549 human non-small-cell lung cancer cells, and these events were correlated with the expression of checkpoint proteins including the up-regulation of p21 and down-regulation of cyclins, cyclin-dependent kinases 2 (CDK2) and 4 (CDK4), and c-Myc. Compound 1 also suppressed the expression of the Akt/mammalian target of rapamycin (mTOR) and its downstream effector molecules including p70 S6 kinase (p70S6K) and eukaryotic initiation factor 4E-binding protein 1 (4EBP1). Ligand-induced epidermal growth factor receptor (EGFR) and c-Met signaling were also inhibited by 1. The oral administration of 1 (0.5 mg/kg body weight, daily) for 14 days significantly inhibited tumor growth in athymic xenograft nude mouse model bearing human lung A549 cells, without any overt toxicity. Synergistic antiproliferative effects of compound 1 were also found in combination with the EGFR inhibitor gefitinib. Cell-cycle arrest and suppression of Akt/mTOR and EGFR signaling pathways might be plausible mechanisms of actions for the antiproliferative and antitumor activity of 1 in human non-small-cell lung cancer cells.

Safety and pharmacokinetics of motesanib in combination with gemcitabine and erlotinib for the treatment of solid tumors: a phase 1b study

BACKGROUND

This phase 1b study assessed the maximum tolerated dose (MTD), safety, and pharmacokinetics of motesanib (a small-molecule antagonist of VEGF receptors 1, 2, and 3; platelet-derived growth factor receptor; and Kit) administered once daily (QD) or twice daily (BID) in combination with erlotinib and gemcitabine in patients with solid tumors.

METHODS

Patients received weekly intravenous gemcitabine (1000 mg/m2) and erlotinib (100 mg QD) alone (control cohort) or in combination with motesanib (50 mg QD, 75 mg BID, 125 mg QD, or 100 mg QD; cohorts 1-4); or erlotinib (150 mg QD) in combination with motesanib (100 or 125 mg QD; cohorts 5 and 6).

RESULTS

Fifty-six patients were enrolled and received protocol-specified treatment. Dose-limiting toxicities occurred in 11 patients in cohorts 1 (n = 2), 2 (n = 4), 3 (n = 3), and 6 (n = 2). The MTD of motesanib in combination with gemcitabine and erlotinib was 100 mg QD. Motesanib 125 mg QD was tolerable only in combination with erlotinib alone. Frequently occurring motesanib-related adverse events included diarrhea (n = 19), nausea (n = 18), vomiting (n = 13), and fatigue (n = 12), which were mostly of worst grade < 3. The pharmacokinetics of motesanib was not markedly affected by coadministration of gemcitabine and erlotinib, or erlotinib alone. Erlotinib exposure, however, appeared lower after coadministration with gemcitabine and/or motesanib. Of 49 evaluable patients, 1 had a confirmed partial response and 26 had stable disease.

CONCLUSIONS

Treatment with motesanib 100 mg QD plus erlotinib and gemcitabine was tolerable. Motesanib 125 mg QD was tolerable only in combination with erlotinib alone.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01235416.

Targeting Ras-RAF-ERK and its interactive pathways as a novel therapy for malignant gliomas

Malignant gliomas are the most common and the deadliest brain malignancies in adults. Despite the lack of a complete understanding of the biology of these tumors, significant advances have been made in the past decades. One of the key discoveries made in the area of malignant gliomas is that these tumors can be induced and maintained by aberrant signaling networks. In this context, the Ras pathway has been extensively exploited, from both basic and translational perspectives. Although somatic oncogenic mutations of Ras genes are frequent in several cancer types, early investigations on gliomas revealed disappointing facts that the Ras mutations are nearly absent in malignant gliomas and that the BRAF mutations are present in a very small percentage of gliomas. Therefore, the observed deregulation of the Ras-RAF-ERK signaling pathway in gliomas is attributed to its upstream positive regulators, including, EGFR and PDGFR known to be highly active in the majority of malignant gliomas. In contrast to the initial negative results on the somatic mutations of H-Ras, K-Ras and BRAF, recent breakthrough studies on pediatric low-grade astrocytomas uncovered genetic alterations of the BRAF gene involving copy number gains and rearrangements. The 7q34 rearrangements result in a novel in-frame KIAA1549:BRAF fusion gene that possesses constitutive BRAF kinase activity resembling oncogenic BRAF (V600E). In light of the earlier findings and recent breakthroughs, this review summarizes our current understanding of the Ras-RAF-ERK signaling pathway in gliomas and the outcome of preclinical and clinical studies that evaluated the efficacy of Ras-targeted therapy in malignant gliomas.

Long-term safety and tolerability of sorafenib in patients with advanced non-small-cell lung cancer: a case-based review

BACKGROUND

Sorafenib, a small-molecule inhibitor of multiple kinases involved in tumor growth and progression, is approved for the treatment of advanced renal-cell carcinoma and advanced hepatocellular carcinoma. Encouraging activity and good tolerability of daily oral sorafenib, either as a single agent or in combination with gefitinib, have been demonstrated in phase I-II trials in patients with advanced non-small-cell lung cancer (NSCLC). Currently, minimal data are available describing the long-term safety and tolerability of sorafenib in patients with NSCLC.

MATERIALS AND METHODS

We describe a series of 12 patients with advanced NSCLC (derived from 1 phase I and 2 phase II trials) who achieved long-term (ie, > 12 months) disease control and continued to receive sorafenib alone or in combination with gefitinib beyond the end of the study in which they were enrolled.

RESULTS

The safety profile of sorafenib administered on a long-term basis did not differ significantly from that seen previously in the shorter term. The majority of adverse events (AEs) were Grade 1-2 in severity. Five of the 12 patients experienced no ≥ Grade 3 AEs. There was no evidence of increased frequency or severity of AEs over time, or of late AEs, and no patient in this series discontinued study treatment because of AEs.

CONCLUSION

In patients with advanced NSCLC who achieve a prolonged response or stable disease with sorafenib given as a single agent or as part of a combination regimen, sorafenib treatment could be continued until disease progression without major long-term safety or tolerability problems.

Novel angiogenesis inhibitors: addressing the issue of redundancy in the angiogenic signaling pathway

Angiogenesis, the formation of new blood vessels from established vasculature, is a fundamental process in the growth and metastasis of solid tumours. It is a complex, tightly regulated process that requires the coordinated action of antiangiogenic and proangiogenic factors, the balance of which becomes disturbed during tumour development. Vascular endothelial growth factor (VEGF) and its receptor are the key mediators of angiogenesis and targets for multiple pharmacologic agents. Many patients treated with VEGF inhibitors survive for a longer period; however, eventual resistance is associated with progressive disease and death. Multiple approaches to overcome resistance have been investigated with varying success, including the use of agents that target multiple angiogenic factors or co-administration of angiogenesis inhibitors with standard chemotherapy or radiotherapy. It would appear that the future of angiogenic inhibitors lies in the intelligent combination of multiple targeted agents with other angiogenic inhibitors, as well as more conventional therapies to maximise therapeutic effect.

Interaction of sorafenib and cytochrome P450 isoenzymes in patients with advanced melanoma: a phase I/II pharmacokinetic interaction study

BACKGROUND

In vitro data indicate that the sorafenib is a moderate inhibitor of cytochrome P450 (CYP) enzymes, including CYP3A4, CYP2C19, and CYP2D6. This phase I/II study in patients with advanced melanoma evaluated the potential effect of sorafenib on the pharmacokinetics of midazolam, omeprazole, and dextromethorphan, specific substrates of CYP3A4, CYP2C19, and CYP2D6, respectively.

METHODS

Twenty-one patients received sorafenib 400 mg twice daily for 28 consecutive days. On days 1 and 28, a cocktail containing midazolam 2 mg, omeprazole 20 mg, and dextromethorphan 30 mg was administered. Pharmacokinetic analyses were performed on day 1 without sorafenib and day 28 after steady-state sorafenib exposure; sorafenib pharmacokinetics were evaluated on day 28. We defined an interaction to be excluded if the 90% confidence interval of the ratio of all day 28:day 1 analyses fell within a range from 0.80 to 1.25.

RESULTS

In all, 18 patients were evaluable. On day 28, area under the plasma concentration-time curve from time 0 to 12 h (AUC(0-12)) and maximum plasma concentration (C(max)) for sorafenib were 38.1 mg h/l and 4.9 mg/l, respectively. Day 28:day 1 ratios for AUC from time 0 extrapolated to infinity (AUC(0-inf)) and C(max) for midazolam were 0.85 and 0.98, respectively. Day 28:day 1 ratio for 5-OH-omeprazole:omeprazole plasma concentration at 3 h postdose was 1.26, slightly outside of the 0.80-1.25 range. Thus, an interaction could not be excluded, but is considered unlikely to be clinically significant. Day 28:day 1 ratio for dextromethorphan:dextrorphan concentration in urine was 0.94. Sorafenib had an acceptable safety profile. The most frequently observed grade 3-4 toxicities in cycle 1 included elevated lipase (19%) and hypertension (10%).

CONCLUSIONS

In this patient population, our results demonstrate that exposures of probes of CYP3A4, CYP2D6, or CYP2C19 activity are potentially altered by administration of sorafenib at 400 mg twice daily. However, these differences are sufficiently small that a clinically significant inhibition or induction of these important drug metabolizing P450 isoenzymes is unlikely. Clinical and, where possible, drug level monitoring may still be appropriate for drugs of narrow therapeutic range co-administered with sorafenib.

Outcomes of patients with advanced non-small cell lung cancer treated in a phase I clinic

BACKGROUND

The outcomes of patients with advanced non-small cell lung cancer (NSCLC) treated in phase I clinical trials have not been systematically analyzed.

METHODS

We reviewed the records of consecutive patients with advanced/metastatic NSCLC who were treated in the Phase I Clinical Trials Program at MD Anderson from August 2004 to May 2009.

RESULTS

Eighty-five patients (51 men, 34 women) treated on various phase I protocols were identified. The median age was 62 years (range, 30-85). The median number of previous systemic therapies was two (range, 0-5). A partial response was observed in eight patients (9.5%) and stable disease lasting >4 months was observed in 16 patients (19%). The median overall survival time was 10.6 months and median progression-free survival (PFS) time was 2.8 months, which was 0.6 months shorter than the median PFS of 3.4 months following prior second-line therapy. Factors predicting longer survival in the univariate analysis were an Eastern Cooperative Oncology Group performance status (PS) score of 0-1, no prior smoking, two or fewer organ systems involved, a hemoglobin level ≥ 12 g/dL, liver metastases, a history of thromboembolism, and a platelets count > 440 × 10(9)/L. In the multivariate analysis, a PS score of 0-1 and history negative for smoking predicted longer survival. Sixty-two (73%) patients had grade ≤ 2 toxicity, and there were no treatment-related deaths.

CONCLUSION

Phase I clinical trials were well tolerated by selected patients with advanced NSCLC treated at M.D. Anderson. Nonsmokers and patients with a good PS survived longer. PFS in our population was shorter in smokers/ex-smokers and patients with a PS score of 2. It is reasonable to refer pretreated patients with a good PS to phase I clinical trials.

Pharmacokinetic results of a phase I trial of sorafenib in combination with dacarbazine in patients with advanced solid tumors

PURPOSE

Sorafenib, a multikinase inhibitor of Raf and several growth factor receptors, is under investigation in combination with dacarbazine, a commonly used chemotherapeutic agent for the treatment of many cancers. The current phase I study investigates the effects of sorafenib on the pharmacokinetic (PK) profile of dacarbazine and its metabolite 5-amino-imidazole-4-carboxamide (AIC). (AIC is formed in amounts equimolar to the active alkylating moiety, methane diazohydroxide, which is undetectable by known validated assays.)

METHODS

Patients with advanced solid tumors received intravenous dacarbazine 1,000 mg/m(2) on day 1 of a 21-day cycle to evaluate the PK of dacarbazine alone. Sorafenib 400 mg was administered twice daily continuously starting at day 2 of cycle 1. The PK of dacarbazine in the presence of sorafenib was assessed on day 1 of cycle 2. Sorafenib PK was also assessed at steady state.

RESULTS

PK data were available for 15 of 23 patients. With concomitant administration of sorafenib, the mean AUC and C (max) values of dacarbazine were reduced by 23 and 16%, respectively. Mean AUC and C (max) values of AIC were increased by 41 and 45%, respectively, with individual increases of up to 106 and 136%, respectively. The apparent terminal half-lives of the two compounds were not significantly influenced by sorafenib. Based on coefficients of variation, the AUC and C (max) values for sorafenib and its three metabolites were highly variable with dacarbazine coadministration.

CONCLUSIONS

Concomitant administration of sorafenib and dacarbazine as described above may result in decreased dacarbazine exposure but increased AIC exposure.

Targeted therapies for non-small cell lung cancer: an evolving landscape

Over the past decade, a multitude of targeted agents have been explored in the treatment of advanced non-small cell lung cancer (NSCLC). Thus far, two broad classes of agents have been implemented in clinical practice: (a) vascular endothelial growth factor (VEGF)-directed therapies and (b) antagonists of the epidermal growth factor receptor (EGFR). In the former category, the agent bevacizumab (a monoclonal antibody) has shown landmark improvements in survival when added to cytotoxic therapy. Small molecule tyrosine kinase inhibitors (TKI) targeting the VEGF receptor (i.e., sunitinib, sorafenib, and vandetanib) show activity in phase II clinical studies. With respect to EGFR-directed therapies, the TKIs gefitinib and erlotinib have shown significant benefit, and have uncovered valuable information about the biology of lung cancer. Outside of therapies directed specifically at VEGF- and EGFR-mediated signaling, trials evaluating insulin-like growth factor-1 receptor (IGF-IR)-targeting agents, cyclooxygenase-2 (COX-2) inhibitors, c-met inhibitors, irreversible pan-HER inhibitors, mammalian target of rapamycin (mTOR) inhibitors, and histone deacetylase (HDAC) inhibitors are ongoing. Inhibitors of ALK show great promise in patients with the relevant gene translocation. Herein, the clinical development of novel therapies for NSCLC is described, including some discussion of relevant biomarkers and determination of synergy with both cytotoxic therapy and other targeted agents.

Drug interactions among the epidermal growth factor receptor inhibitors, other biologics and cytotoxic agents

The epidermal growth factor receptor (EGFR) signalling pathway is a key element in the growth of several epithelial malignancies. Small molecules tyrosine kinase inhibitors (TKIs) and anti-EGFR monoclonal antibodies (mAbs) prevent the phosphorylation of the receptor, leading to cell cycle arrest at G(1) phase, apoptosis, inhibition of angiogenesis and metastasis. To increase the antitumoral effects of EGFR inhibitors (EGFRIs), a number of combinatory regimens have been evaluated and planned with standard cytotoxic drugs and/or inhibitors of EGFR complementary pathways such as mTOR, VEGF and Ras/Raf/ERK. Compared to EGFRI monotherapy, the combination approach is a promising strategy to improve tumor response and survival. However, pharmacokinetic (absorption, distribution, metabolism and excretion) and pharmacodynamic drug interactions can occur, affecting the outcome. Pharmacokinetics of TKIs can be affected by drugs used in combination: conversely, pharmacokinetic interactions have not been reported for EGFR mAbs. Potential pharmacokinetic interactions occur between EGFRIs and other factors such as food and hydrocarbons in tobacco smoke were also considered. EGFRIs are characterized by a number of pharmacodynamic interactions that must be taken into consideration to avoid adverse events, to increase antitumoral activity, and define potential new strategies for developing efficient combination regimens. In this context, treatment schedule and drug sequence appear to be particularly relevant for combination regimens with EGFRIs. Improved molecular characterisation of the EGFR pathway and its complementary pathways in tumor cells is required to better define predictive pharmacokinetic and pharmacodynamic biomarkers for optimum treatment outcome.

Standing the test of time in Europe? Gefitinib in the treatment of non-small-cell lung cancer

Lung cancer is the most common cancer worldwide, with 1.3 million new cases diagnosed every year. Non-small-cell lung carcinoma (NSCLC) has previously had a very poor prognosis with few effective therapies; however, research has identified that it is associated with a high rate of expression of epidermal growth factor receptor (EGFR) tyrosine kinase. This has led to discoveries in drug manipulation of this receptor, to provide effective new therapies against NSCLC. Gefitinib is a small molecule kinase inhibitor which inhibits the cytoplasmic domain of the EGFR; the evidence behind its use and future role is presented in this review.

A multicenter phase II study of erlotinib and sorafenib in chemotherapy-naive patients with advanced non-small cell lung cancer

PURPOSE

This multicenter, phase II study evaluates the efficacy and safety of erlotinib, an epidermal growth factor receptor (EGFR) inhibitor, plus sorafenib, a multityrosine kinase inhibitor against vascular endothelial growth factor receptors, in patients with previously untreated advanced non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Chemotherapy-naïve patients with stage IIIB/IV NSCLC received erlotinib (150 mg once a day) and sorafenib (400 mg twice a day) until disease progression or unacceptable toxicity. The primary end point was the rate of nonprogression at 6 weeks. Secondary end points included objective response rate (ORR), time to progression, overall survival, and adverse events. Exploratory end points included pretreatment EGFR and KRAS mutation status, pharmacokinetics, and cytochrome P450 polymorphisms.

RESULTS

Fifty patients initiated therapy. The nonprogression rate at 6 weeks was 74%: 12 (24%) partial response and 25 (50%) stable disease. Ultimately, the ORR was 28%. Median time to progression was 5.0 months [95% confidence interval (95% CI), 3.2-6.8 months]. Median overall survival was 10.9 months (95% CI, 3.8-18.1 months). Grade 3/4 adverse events included fatigue (16%), hand-foot skin reaction (16%), rash (16%), diarrhea (14%), and hypophosphatemia (42%). There was one treatment-related fatal pulmonary hemorrhage. Patients with wild-type EGFR had a higher ORR (19%) than previously reported for single-agent erlotinib/sorafenib. Erlotinib levels were lowered. This was associated with CYP3A4 polymorphism and was possibly due to sorafenib.

CONCLUSION

Despite a possible drug interaction, sorafenib plus erlotinib has promising clinical activity in patients with stage IIIB/IV NSCLC and has an acceptable safety profile. Further evaluation of this combination as potential salvage therapy in EGFR mutation-negative patients and the possible drug interaction is warranted.

Phase I combination of sorafenib and erlotinib therapy in solid tumors: safety, pharmacokinetic, and pharmacodynamic evaluation from an expansion cohort

The aims of this study were to further define the safety of sorafenib and erlotinib, given at their full approved monotherapy doses, and to correlate pharmacokinetic and pharmacodynamic markers with clinical outcome. In addition, a novel pharmacodynamic marker based on the real-time measurement of RAF signal transduction capacity (STC) is described. Sorafenib was administered alone for a 1-week run-in period, and then both drugs were given together continuously. RAF STC was assessed in peripheral blood monocytes prior to erlotinib initiation. Epidermal growth factor receptor (EGFR) expression and K-RAS mutations were measured in archival tumor samples. Changes in pERK and CD31 were determined in fresh tumor biopsies obtained pretreatment, prior to erlotinib dosing, and during the administration of both drugs. In addition, positron emission tomography-computed tomography scans and pharmacokinetic assessments were done. Eleven patients received a total of 57 cycles (median, 5; range, 1-10). Only four patients received full doses of both drugs for the entire study course, with elevation of liver enzymes being the main reason for dose reductions and delays. Among 10 patients evaluable for response, 8 experienced tumor stabilization of >or=4 cycles. Pharmacokinetic analysis revealed no significant interaction of erlotinib with sorafenib. Sorafenib-induced decrease in RAF-STC showed statistically significant correlation with time-to-progression in seven patients. Other pharmacodynamic markers did not correlate with clinical outcome. This drug combination resulted in promising clinical activity in solid tumor patients although significant toxicity warrants close monitoring. RAF-STC deserves further study as a predictive marker for sorafenib.