A phase I/II study of erlotinib in combination with the anti-insulin-like growth factor-1 receptor monoclonal antibody IMC-A12 (cixutumumab) in patients with advanced non-small cell lung cancer

Role of Insulin-like Growth Factor-1 Receptor in Tobacco Smoking-Associated Lung Cancer Development

Cancer remains a significant global health concern, with lung cancer consistently leading as one of the most common malignancies. Genetic aberrations involving receptor tyrosine kinases (RTKs) are known to be associated with cancer initiation and development, but RTK involvement in smoking-associated lung cancer cases is not well understood. The Insulin-like Growth Factor 1 Receptor (IGF-1R) is a receptor that plays a critical role in lung cancer development. Its signaling pathway affects the growth and survival of cancer cells, and high expression is linked to poor prognosis and resistance to treatment. Several reports have shown that by activating IGF-1R, tobacco smoke-related carcinogens promote lung cancer and chemotherapy resistance. However, the relationship between IGF-1R and cancer is complex and can vary depending on the type of cancer. Ongoing investigations are focused on developing therapeutic strategies to target IGF-1R and overcome chemotherapy resistance. Overall, this review explores the intricate connections between tobacco smoke-specific carcinogens and the IGF-1R pathway in lung carcinogenesis. This review further highlights the challenges in using IGF-1R inhibitors as targeted therapy for lung cancer due to structural similarities with insulin receptors. Overcoming these obstacles may require a comprehensive approach combining IGF-1R inhibition with other selective agents for successful cancer treatment.

Challenges in the Use of Targeted Therapies in NSCLC

Precision oncology has fundamentally changed how we diagnose and treat cancer. In recent years, there has been a significant change in the management of patients with oncogene-addicted advanced-stage non–small cell lung cancer (NSCLC). Increasing amounts of identifiable oncogene drivers have led to the development of molecularly targeted drugs. Undoubtedly, the future of thoracic oncology is shifting toward increased molecular testing and the use of targeted therapies. For the most part, these novel drugs have proven to be safe and effective. As with all great innovations, targeted therapies pose unique challenges. Drug toxicities, resistance, access, and costs are some of the expected obstacles that will need to be addressed. This review highlights some of the major challenges in the use of targeted therapies in NSCLC and provides guidance for the future strategies.

Randomized phase II trial of cixutumumab alone or with cetuximab for refractory recurrent/metastatic head and neck squamous cell carcinoma

OBJECTIVES

Cixutumumab (CIX) and cetuximab (CET) monoclonal antibodies block ligand-binding to insulin-like growth factor-1 receptor (IGF-1R) and epidermal growth factor receptor (EGFR) respectively. The objective of this study was to assess the efficacy of CIX alone or combined with CET in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) patients.

METHODS

In this open-label phase II trial, 91 R/M HNSCC patients who progressed within 90 days of platinum-based chemotherapy, were randomized to CIX 10 mg/kg alone or with CET 500 mg/m² every 2 weeks. Patients were stratified by prior CET use. The primary endpoint was median progression-free survival (PFS). Exploratory biomarker assessments included relevant markers on archival tumor and serial cytokine/angiogenic-factor profiles in blood.

RESULTS

Forty-seven patients were treated with CIX monotherapy and 44 with combination. The median PFS was 1.9 and 2.0 months and clinical benefit rate (complete or partial responses and stable disease) was 5.9% and 15.3%, respectively. There was no exacerbation of CET toxicity by concurrent CIX exposure. Higher tumor expression of IGF-1 was associated with improved PFS in the CIX + CET arm while increased p-EGFR expression correlated with shorter PFS in patients receiving single agent CIX. Higher serum baseline levels of IGF-1 and IGFBP-3 correlated with improved PFS and overall survival (OS) in the CIX arm. Neither regimen resulted in improved PFS or OS compared to historical data with CET alone.

CONCLUSION

The results of this study do not support the use of cixutumumab alone or with cetuximab in unselected patients with R/M HNSCC.

Insulin-Like Growth Factor (IGF) Pathway Targeting in Cancer: Role of the IGF Axis and Opportunities for Future Combination Studies

Despite a strong preclinical rationale for targeting the insulin-like growth factor (IGF) axis in cancer, clinical studies of IGF-1 receptor (IGF-1R)-targeted monotherapies have been largely disappointing, and any potential success has been limited by the lack of validated predictive biomarkers for patient enrichment. A large body of preclinical evidence suggests that the key role of the IGF axis in cancer is in driving treatment resistance, via general proliferative/survival mechanisms, interactions with other mitogenic signaling networks, and class-specific mechanisms such as DNA damage repair. Consequently, combining IGF-targeted agents with standard cytotoxic agents, other targeted agents, endocrine therapies, or immunotherapies represents an attractive therapeutic approach. Anti-IGF-1R monoclonal antibodies (mAbs) do not inhibit IGF ligand 2 (IGF-2) activation of the insulin receptor isoform-A (INSR-A), which may limit their anti-proliferative activity. In addition, due to their lack of specificity, IGF-1R tyrosine kinase inhibitors are associated with hyperglycemia as a result of interference with signaling through the classical metabolic INSR-B isoform; this may preclude their use at clinically effective doses. Conversely, IGF-1/IGF-2 ligand-neutralizing mAbs inhibit proliferative/anti-apoptotic signaling via IGF-1R and INSR-A, without compromising the metabolic function of INSR-B. Therefore, combination regimens that include these agents may be more efficacious and tolerable versus IGF-1R-targeted combinations. Herein, we review the preclinical and clinical experience with IGF-targeted therapies to-date, and discuss the rationale for future combination approaches as a means to overcome treatment resistance.

Randomised Phase 2 study of maintenance linsitinib (OSI-906) in combination with erlotinib compared with placebo plus erlotinib after platinum-based chemotherapy in patients with advanced non-small cell lung cancer

Background:

Maintenance therapy is important in advanced/metastatic non-small cell lung cancer (NSCLC). Erlotinib as switch maintenance following platinum-based chemotherapy increases survival. Cross-talk between the epidermal growth factor receptor and insulin-like growth factor receptor (IGFR) pathways mediate resistance to individual receptor blockade. This study compared maintenance linsitinib plus erlotinib vs erlotinib plus placebo in patients with NSCLC.

Methods:

In this Phase II randomised trial, patients without progression following four cycles of first-line platinum-based chemotherapy (N=205) received continuous schedule maintenance oral linsitinib 150 mg or placebo BID combined with erlotinib 150 mg QD for 21-day cycles. The primary endpoint was progression-free survival (PFS).

Results:

The study was unblinded early due to linsitinib non-superiority. No difference was found between the two treatment groups in median PFS of 125 days linsitinib vs 129 days placebo (P=0.601); no difference in overall survival (OS) was observed. Tolerability was similar, although in the linsitinib group, treatment-related adverse events and discontinuations were more frequent. No drug–drug interaction was implicated.

Conclusions:

Linsitinib maintenance therapy added to erlotinib did not improve PFS or OS in non-progressing NSCLC patients. This highlights the need for robust biomarkers of response for combinations that incorporate IGFR-targeted therapies in maintenance or other therapeutic settings.

Adverse Events and Efficacy of Cixutumumab in Phase II Clinical Trials: A systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Cixutumumab is a monoclonal antibody targeting insulin-like growth factor 1 receptor (IGF1R). We sought to evaluate the efficacy of cixutumumab in the treatment of cancer, and to comprehensively assess the associated adverse events in phase II clinical trials.

METHODS

Data were collected from PubMed, Embase, and Clinicaltrials.gov. The improvement on progression-free survival (PFS) was evaluated by hazard ratio (HR) and 95% confidence intervals (95% CIs). We also carried a meta-analysis to comprehensively evaluate the incidence of adverse events.

RESULTS

The adverse events that were mentioned most frequently were hyperglycemia, anemia, nausea, fatigue, and thrombocytopenia. The most frequent adverse events were hyponatremia (40.28%), fatigue (35.18%), and skin rash (35.11%). Results showed that cixutumumab treatments did not benefit PFS (HR 1.03, 95% CI 0.83-1.26, p = 0.979). The complete response (CR) was rarely seen in phase II trials.

CONCLUSIONS

Cixutumumab was well tolerated when used alone and in combination therapies, but its antitumor activity was low in the existing phase II clinical trials. An acceptable incidence of adverse effects supports further investigation of this drug, provided that it shows antitumor activity in combination with other drugs.

Phase 2 Study of Erlotinib in Combination With Linsitinib (OSI-906) or Placebo in Chemotherapy-Naive Patients With Non-Small-Cell Lung Cancer and Activating Epidermal Growth Factor Receptor Mutations

INTRODUCTION

First-line epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment of advanced non-small-cell lung cancer with EGFR-activating mutations improves outcomes compared with chemotherapy, but resistance develops in most patients. Compensatory signaling through type 1 insulin-like growth factor 1 receptor (IGF-1R) may contribute to resistance; dual blockade of IGF-1R and EGFR may improve outcomes.

PATIENTS AND METHODS

We performed a randomized, double-blind, placebo-controlled phase II study of linsitinib, a dual IGF-1R and insulin receptor tyrosine kinase inhibitor, plus erlotinib versus placebo plus erlotinib in chemotherapy-naive patients with EGFR-mutation positive, advanced non-small-cell lung cancer. Patients received linsitinib 150 mg twice daily or placebo plus erlotinib 150 mg once daily on continuous 21-day cycles. The primary end point was progression-free survival.

RESULTS

After randomization of 88 patients (44 each arm), the trial was unblinded early owing to inferiority in the linsitinib arm. The median progression-free survival for the linsitinib versus the placebo group was 8.4 months versus 12.4 months (hazard ratio, 1.37; P = .29). Overall response rate (47.7% vs. 75.0%; P = .02) and disease control rate (77.3% vs. 95.5%; P = .03) were also inferior. Whereas most adverse events were ≤ grade 2, linsitinib plus erlotinib was associated with increased adverse events that led to decreased erlotinib exposure (median days, 228 vs. 305). No drug-drug interaction was suggested by pharmacokinetic and pharmacodynamic results.

CONCLUSION

Adding linsitinib to erlotinib resulted in inferior outcomes compared with erlotinib alone. Further understanding of the signaling pathways and a biomarker that can predict efficacy is needed prior to further clinical development of IGF-1R inhibitors in lung cancer.

Approaches to modernize the combination drug development paradigm

Recent advances in genomic sequencing and omics-based capabilities are uncovering tremendous therapeutic opportunities and rapidly transforming the field of cancer medicine. Molecularly targeted agents aim to exploit key tumor-specific vulnerabilities such as oncogenic or non-oncogenic addiction and synthetic lethality. Additionally, immunotherapies targeting the host immune system are proving to be another promising and complementary approach. Owing to substantial tumor genomic and immunologic complexities, combination strategies are likely to be required to adequately disrupt intricate molecular interactions and provide meaningful long-term benefit to patients. To optimize the therapeutic success and application of combination therapies, systematic scientific discovery will need to be coupled with novel and efficient clinical trial approaches. Indeed, a paradigm shift is required to drive precision medicine forward, from the traditional "drug-centric" model of clinical development in pursuit of small incremental benefits in large heterogeneous groups of patients, to a "strategy-centric" model to provide customized transformative treatments in molecularly stratified subsets of patients or even in individual patients. Crucially, to combat the numerous challenges facing combination drug development-including our growing but incomplete understanding of tumor biology, technical and informatics limitations, and escalating financial costs-aligned goals and multidisciplinary collaboration are imperative to collectively harness knowledge and fuel continual innovation.

Clinical studies in humans targeting the various components of the IGF system show lack of efficacy in the treatment of cancer

The insulin-like growth factors (IGFs) system regulates cell growth, differentiation and energy metabolism and plays crucial role in the regulation of key aspects of tumor biology, such as cancer cell growth, survival, transformation and invasion. The current focus for cancer therapeutic approaches have shifted from the conventional treatments towards the targeted therapies and the IGF system has gained a great interest as anti-cancer therapy. The proliferative, anti-apoptotic and transformation effects of IGFs are mainly triggered by the ligation of the type I IGF receptor (IGF-IR). Thus, aiming at developing novel and effective cancer therapies, different strategies have been employed to target IGF system in human malignancies, including but not limited to ligand or receptor neutralizing antibodies and IGF-IR signaling inhibitors. In this review, we have focused on the clinical studies that have been conducted targeting the various components of the IGF system for the treatment of different types of cancer, providing a description and the challenges of each targeting strategy and the degree of success.

An Open-Label, Multicenter, Randomized, Phase II Study of Cisplatin and Pemetrexed With or Without Cixutumumab (IMC-A12) as a First-Line Therapy in Patients With Advanced Nonsquamous Non-Small Cell Lung Cancer

INTRODUCTION

Type 1 insulin-like growth factor receptor is deregulated in solid tumors. Cixutumumab, a monoclonal antibody that inhibits the activity of type 1 insulin-like growth factor receptor, was investigated in combination with pemetrexed/cisplatin in the frontline setting.

METHODS

In this open-label, phase II study, patients with stage IV nonsquamous NSCLC and a performance status of 0 to 1 were randomized (1:1) to receive 20 mg/kg cixutumumab, 500 mg/m² pemetrexed, and 75 mg/m² cisplatin (cixutumumab [n = 87]) or pemetrexed and cisplatin (control [n = 85]). Eligible patients received pemetrexed-based maintenance therapy with cixutumumab (cixutumumab arm) or without it (control arm). The primary end point was progression-free survival. Secondary end points assessed overall survival, objective response rate, and safety. Survival was analyzed by the Kaplan-Meier method and Cox proportional hazard model. Exploratory correlative analyses were also performed.

RESULTS

The mean age of the intent-to-treat population (n = 172) was 59 years (range 32-83). Median progression-free survival was 5.45 months with cixutumumab versus 5.22 months in the control (hazard ratio = 1.15, 95% confidence interval: 0.81-1.61; p = 0.44). Median overall survival was 11.33 months with cixutumumab versus 10.38 months in the control (hazard ratio = 0.93, 95% confidence interval: 0.64-1.36). Objective response rate did not differ between treatments (p = 0.338). Grade 3 or 4 hyperglycemia occurred at a higher rate with cixutumumab than in the control (9.4% versus 1.2%). One death possibly related to cixutumumab occurred.

CONCLUSIONS

Efficacy was not improved in patients with nonsquamous NSCLC when cixutumumab was added to pemetrexed/cisplatin. Combination therapy was well tolerated and no new safety concerns were reported.

Implications of Insulin-like Growth Factor 1 Receptor Activation in Lung Cancer

Insulin-like growth factor 1 receptor (IGF1R) has been intensively investigated in many preclinical studies using cell lines and animal models, and the results have provided important knowledge to help improve the understanding of cancer biology. IGF1R is highly expressed in patients with lung cancer, and high levels of circulating insulin-like growth factor 1 (IGF1), the main ligand for IGF1R, increases the risk of developing lung malignancy in the future. Several phase I clinical trials have supported the potential use of an IGF1R-targeted strategy for cancer, including lung cancer. However, the negative results from phase III studies need further attention, especially in selecting patients with specific molecular signatures, who will gain benefits from IGF1R inhibitors with minimal side effects. This review will discuss the basic concept of IGF1R in lung cancer biology, such as epithelial-mesenchymal transition (EMT) induction and cancer stem cell (CSC) maintenance, and also the clinical implications of IGF1R for lung cancer patients, such as prognostic value and cancer therapy resistance.

XGFR*, a novel affinity-matured bispecific antibody targeting IGF-1R and EGFR with combined signaling inhibition and enhanced immune activation for the treatment of pancreatic cancer

The epidermal growth factor receptor (EGFR) and the insulin-like growth factor-1 receptor (IGF-1R) play critical roles in tumor growth, providing a strong rationale for the combined inhibition of IGF-1R and EGFR signaling in cancer therapy. We describe the design, affinity maturation, in vitro and in vivo characterization of the bispecific anti-IGF-1R/EGFR antibody XGFR*. XGFR* is based on the bispecific IgG antibody XGFR, which enabled heterodimerization of an IGF-1R binding scFab heavy chain with an EGFR-binding light and heavy chain by the "knobs-into-holes" technology. XGFR* is optimized for monovalent binding of human EGFR and IGF-1R with increased binding affinity for IGF-1R due to affinity maturation and highly improved protein stability to oxidative and thermal stress. It bears an afucosylated Fc-portion for optimal induction of antibody-dependent cell-mediated cytotoxicity (ADCC). Stable Chinese hamster ovary cell clones with production yields of 2-3 g/L were generated, allowing for large scale production of the bispecific antibody. XGFR* potently inhibits EGFR- and IGF-1R-dependent receptor phosphorylation, reduces tumor cell proliferation in cells with heterogeneous levels of IGF-1R and EGFR receptor expression and induces strong ADCC in vitro. A comparison of pancreatic and colorectal cancer lines demonstrated superior responsiveness to XGFR*-mediated signaling and tumor growth inhibition in pancreatic cancers that frequently show a high degree of IGF-1R/EGFR co-expression. XGFR* showed potent anti-tumoral efficacy in the orthotopic MiaPaCa-2 pancreatic xenograft model, resulting in nearly complete tumor growth inhibition with significant number of tumor remissions. In summary, the bispecific anti-IGF-1R/EGFR antibody XGFR* combines potent signaling and tumor growth inhibition with enhanced ADCC induction and represents a clinical development candidate for the treatment of pancreatic cancer.

Phase I Dose-Escalation Study of Linsitinib (OSI-906) and Erlotinib in Patients with Advanced Solid Tumors

PURPOSE

Cross-talk between type I IGF receptor (IGF1R), insulin receptor (INSR), and epidermal growth factor receptor (EGFR) mediates resistance to individual receptor blockade. This study aimed to determine the MTD, safety, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of linsitinib, a potent oral IGF1R/INSR inhibitor, with EGFR inhibitor erlotinib.

EXPERIMENTAL DESIGN

This open-label, dose-escalation study investigated linsitinib schedules S1: once daily intermittent (days 1-3 weekly); S2, once daily continuous; S3, twice-daily continuous; each with erlotinib 100-150 mg once daily; and a non-small cell lung cancer (NSCLC) expansion cohort.

RESULTS

Ninety-five patients were enrolled (S1, 44; S2, 24; S3, 12; expansion cohort, 15) and 91 treated. Seven experienced dose-limiting toxicities: QTc prolongation (3), abnormal liver function (2), hyperglycemia (1), and anorexia (1). Common adverse events included drug eruption (84%), diarrhea (73%), fatigue (68%), nausea (58%), vomiting (40%). MTDs for linsitinib/erlotinib were 450/150 mg (S1), 400/100 mg (S2). On the basis of prior monotherapy data, S3 dosing at 150 mg twice daily/150 mg once daily was the recommended phase II dose for the expansion cohort. There was no evidence of drug-drug interaction. Pharmacodynamic data showed IGF-1 elevation and reduced IGF1R/INSR phosphorylation, suggesting pathway inhibition. Across schedules, 5/75 (7%) evaluable patients experienced partial responses: spinal chordoma (268+ weeks), rectal cancer (36 weeks), three NSCLCs including 2 adenocarcinomas (16, 72 weeks), 1 squamous wild-type EGFR NSCLC (36 weeks). Disease control (CR+PR+SD) occurred in 38 of 75 (51%), and 28 of 91 (31%) patients were on study >12 weeks.

CONCLUSIONS

The linsitinib/erlotinib combination was tolerable with preliminary evidence of activity, including durable responses in cases unlikely to respond to erlotinib monotherapy. Clin Cancer Res; 22(12); 2897-907. ©2016 AACR.

Instability of IGF-IGFBP complex as a cause of the different performance of serum and EDTA-plasma after storage: EDTA-plasma is preferable for evaluating bioactive IGF especially in the mouse

OBJECTIVE

The insulin-like growth factor (IGF) signaling pathway is recognized as a potential target for treating several cancers, and strategies targeting the IGF type 1 receptor (IGF-1R) have been evaluated in many clinical trials. These suggested that the pretreatment level of circulating free IGF gives an estimate of IGF bioactivity and might be a predictive biomarker of the response to anti-IGF-1R antibodies. However, there is no defined protocol for measuring free and bioactive IGF concentrations, partly because the measurement procedures, including sample collection and handling, have not been standardized. We investigated the effects of sample collection methods and storage conditions on bioactive IGF measurement using a modified kinase receptor activation (KIRA) assay in human and mouse samples.

DESIGN

Blood samples were obtained from healthy men and women, and from healthy male and female wild-type BALB/c mice. Serum and ethylenediaminetetraacetic acid (EDTA)-plasma samples were collected and used immediately or stored in small quantities at 4 °C or -80 °C for 3, 7, or 14 days. A bioassay directed against the phosphorylated IGF-1R using western blot analysis was developed as a modification of the KIRA assay, in which the level of phosphorylation of IGF-1R represented the IGF bioactivity in blood samples.

RESULTS

The levels of bioactive IGFs in mouse serum stored at 4 °C increased markedly in a time-dependent manner; the increase was slightly reduced in samples stored at -80 °C. Analysis of mouse EDTA-plasma stored at 4 °C showed a similar pattern, but the time-dependent increase was less than in the serum samples. By contrast, the levels of bioactive IGFs in EDTA-plasma stored at -80 °C were stable over 14 days. The levels of human bioactive IGFs in both serum and EDTA-plasma stored at 4 °C increased slightly with time, but the increases were much smaller than in mouse samples. The levels of human bioactive IGF in both serum and EDTA-plasma stored at -80 °C were stable over 14 days.

CONCLUSIONS

The use of EDTA-plasma avoids the problems with long-term storage. Therefore, EDTA-plasma should be used when measuring circulating IGF bioactivity, especially in mouse samples. All samples should be stored at -80 °C when long-term storage is unavoidable. Because of the large difference in the stability of the IGF-IGF-binding protein complex between the human and mouse in vitro, all samples should be handled carefully to ensure the accurate evaluation of IGF bioactivity, especially in mouse samples.

Anthropometric, metabolic and molecular determinants of human epidermal growth factor receptor 2 expression in luminal B breast cancer

Genomic and trascriptomic profiling has recently contributed details to the characterization of luminal B breast cancer. We explored the contribution of anthropometric, metabolic, and molecular determinants to the multifaceted heterogeneity of this breast cancer subtype, with a specific focus on the association between body mass index (BMI), pre-treatment fasting glucose, hormone receptors, and expression of human epidermal growth factor receptor 2 (HER2). Extensively annotated specimens were obtained from 154 women with luminal B breast cancer diagnosed at two Italian comprehensive cancer centres. Participants' characteristics were descriptively analyzed overall and by HER2 status (positive vs. negative). BMI (<25 vs ≥25), pre-treatment fasting glucose (<median value of 94 mg/dl vs. ≥94) and percentage of hormone receptors were tested for association with HER2 expression in regression models. In univariate models, BMI, fasting glucose and, at a lesser extent, percentage of estrogen receptors (ER) were significantly and inversely associated with HER2 expression (OR: 0.32, 95% CI: 0.16-0.66; 0.43, 0.23-0.82; 0.96, 0.94-0.97, respectively). The multivariate models confirmed the protective role of BMI and ER on HER2 expression, with luminal B HER2 positive patients being significantly less frequent among women within the highest category of BMI and percentage expression of ER compared with their counterparts (OR: 0.22, 95% CI: 0.09-0.53; 0.95, 0.93-0.97). In conclusions, BMI and percentage of ER representation are inversely associated with HER2 expression in luminal B breast cancers. Upon confirmatory findings, this might help identify patient subgroups who may best benefit from the use of interventions targeting insulin resistance in well depicted breast cancer scenarios.

Three-arm, randomized, phase 2 study of carboplatin and paclitaxel in combination with cetuximab, cixutumumab, or both for advanced non-small cell lung cancer (NSCLC) patients who will not receive bevacizumab-based therapy: An Eastern Cooperative Oncology Group (ECOG) study (E4508)

BACKGROUND

Preclinical evidence supports the clinical investigation of inhibitors to the insulin-like growth factor receptor (IGFR) and the epidermal growth factor receptor (EGFR) either alone or in combination as treatment for patients with non-small cell lung cancer (NSCLC).

METHODS

Patients with chemotherapy-naïve, advanced NSCLC who had an Eastern Cooperative Oncology Group performance status of 0 or 1 were eligible. Patients were randomized to receive carboplatin intravenously at an area under the plasma drug concentration-time curve of 6.0 plus paclitaxel 200 mg/m(2) intravenously on day 1 every 3 weeks combined with either intravenous cetuximab weekly (arm A), intravenous cixutumumab every 2 weeks (arm B), or both (arm C). Patients who had nonprogessing disease after 12 weeks of therapy were permitted to continue on maintenance antibody therapy until they developed progressive disease. The primary endpoint was progression-free survival (PFS). The study design required 180 eligible patients and had 88% power to detect a 60% increase in median PFS for either comparison (arm A vs arm C or arm B vs arm C) using the log-rank test.

RESULTS

From September 2009 to December 2010, 140 patients were accrued. The study was closed to accrual early because of an excessive number of grade 5 events reported on arms A and C. Thirteen patients died during treatment (6 patients on arm A, 2 patients on arm B, and 5 patients on arm C), including 9 within approximately 1 month of starting therapy. The estimated median PFS for arms A, B, and C were similar at 3.4 months, 4.2 months, and 4 months, respectively.

CONCLUSIONS

On the basis of the apparent lack of efficacy and excessive premature deaths, the current results do not support the continued investigation of carboplatin, paclitaxel, and cixutumumab either alone or in combination with cetuximab for patients with advanced NSCLC.

Strategies to overcome resistance to tyrosine kinase inhibitors in non-small-cell lung cancer

The use of molecularly targeted agents has dramatically improved the prognosis of defined subsets of patients with non-small-cell lung cancer harboring somatically activated oncogenes, such as mutant EGFR or rearranged ALK. However, after initial marked responses to EGFR or ALK tyrosine kinase inhibitors (TKIs), almost all patients inevitably progress due to development of acquired resistance. Multiple molecular mechanisms of resistance have been identified; the best characterized are secondary mutations in the tyrosine kinase domain of the oncogene, such as T790M in EGFR and L1196M in ALK, which prevent target inhibition by the corresponding TKI. Other mechanisms include copy number gain of the ALK fusion gene and the activation of bypass signaling pathways that can maintain downstream proliferation and survival signals despite inhibition of the original drug target. Here, the authors provide an overview of the known mechanisms of resistance to TKIs and outline the therapeutic strategies, including new investigational agents and targeted therapies combinations, that have been developed to overcome resistance.

Advances in phage display technology for drug discovery

INTRODUCTION

Over the past decade, several library-based methods have been developed to discover ligands with strong binding affinities for their targets. These methods mimic the natural evolution for screening and identifying ligand-target interactions with specific functional properties. Phage display technology is a well-established method that has been applied to many technological challenges including novel drug discovery.

AREAS COVERED

This review describes the recent advances in the use of phage display technology for discovering novel bioactive compounds. Furthermore, it discusses the application of this technology to produce proteins and peptides as well as minimize the use of antibodies, such as antigen-binding fragment, single-chain fragment variable or single-domain antibody fragments like VHHs.

EXPERT OPINION

Advances in screening, manufacturing and humanization technologies demonstrate that phage display derived products can play a significant role in the diagnosis and treatment of disease. The effects of this technology are inevitable in the development pipeline for bringing therapeutics into the market, and this number is expected to rise significantly in the future as new advances continue to take place in display methods. Furthermore, a widespread application of this methodology is predicted in different medical technological areas, including biosensing, monitoring, molecular imaging, gene therapy, vaccine development and nanotechnology.

The Role of the Insulin/IGF System in Cancer: Lessons Learned from Clinical Trials and the Energy Balance-Cancer Link

Numerous epidemiological and pre-clinical studies have demonstrated that the insulin/insulin-like growth factor (IGF) system plays a key role in the development and progression of several types of cancer. Insulin/IGF signaling, in cooperation with chronic low-grade inflammation, is also an important contributor to the cancer-promoting effects of obesity. However, clinical trials for drugs targeting different components of this system have produced largely disappointing results, possibly due to the lack of predictive biomarker use and problems with the design of combination therapy regimens. With careful attention to the identification of likely patient responders and optimal drug combinations, the outcome of future trials may be improved. Given that insulin/IGF signaling is known to contribute to obesity-associated cancer, further investigation regarding the efficacy of drugs targeting this system and its downstream effectors in the obese patient population is warranted.

Trial watch: Monoclonal antibodies in cancer therapy

During the past 20 years, dozens-if not hundreds-of monoclonal antibodies have been developed and characterized for their capacity to mediate antineoplastic effects, either as they activate/enhance tumor-specific immune responses, either as they interrupt cancer cell-intrinsic signal transduction cascades, either as they specifically delivery toxins to malignant cells or as they block the tumor-stroma interaction. Such an intense research effort has lead to the approval by FDA of no less than 14 distinct molecules for use in humans affected by hematological or solid malignancies. In the inaugural issue of OncoImmunology, we briefly described the scientific rationale behind the use of monoclonal antibodies in cancer therapy and discussed recent, ongoing clinical studies investigating the safety and efficacy of this approach in patients. Here, we summarize the latest developments in this exciting area of clinical research, focusing on high impact studies that have been published during the last 15 months and clinical trials launched in the same period to investigate the therapeutic profile of promising, yet hitherto investigational, monoclonal antibodies.

Can we unlock the potential of IGF-1R inhibition in cancer therapy?

IGF-1R inhibitors arrived in the clinic accompanied by optimism based on preclinical activity of IGF-1R targeting, and recognition that low IGF bioactivity protects from cancer. This was tempered by concerns about toxicity to normal tissue IGF-1R and cross-reactivity with insulin receptor (InsR). In fact, toxicity is not a show-stopper; the key issue is efficacy. While IGF-1R inhibition induces responses as monotherapy in sarcomas and with chemotherapy or targeted agents in common cancers, negative Phase 2/3 trials in unselected patients prompted the cessation of several Pharma programs. Here, we review completed and on-going trials of IGF-1R antibodies, kinase inhibitors and ligand antibodies. We assess candidate biomarkers for patient selection, highlighting the potential predictive value of circulating IGFs/IGFBPs, the need for standardized assays for IGF-1R, and preclinical evidence that variant InsRs mediate resistance to IGF-1R antibodies. We review hypothesis-led and unbiased approaches to evaluate IGF-1R inhibitors with other agents, and stress the need to consider sequencing with chemotherapy. The last few years were a tough time for IGF-1R therapeutics, but also brought progress in understanding IGF biology. Even failed studies include patients who derived benefit; they should be investigated to identify features distinguishing the tumors and host environment of responders from non-responders. We emphasize the importance of incorporating biospecimen collection into trial design, and wording patient consents to allow post hoc analysis of trial material as new data become available. Such information represents the key to unlocking the potential of this approach, to inform the next generation of trials of IGF signalling inhibitors.

Drug resistance to molecular targeted therapy and its consequences for treatment decisions in non-small-cell lung cancer

Our ability to detect and directly target the oncogenic alterations responsible for tumor proliferation has contributed significantly to the management of lung cancer in the last decade. The therapeutic efficacy of molecularly targeted therapy is, however, mainly limited to patients harboring certain genetic mutations and is generally short-lived. Herein, we review primary and secondary drug resistance using the most well-studied of the molecularly targeted agents, the tyrosine kinase inhibitors targeting the epidermal growth factor (EGF) receptor, and the anaplastic lymphoma kinase (ALK) rearrangement, the current limitations of targeted therapies and their consequences on the management of patients with lung cancer.

The adverse events profile of anti-IGF-1R monoclonal antibodies in cancer therapy

AIM(S)

Insulin-like growth factor-1 receptor (IGF-1R) targeted therapies have become one of the intriguing areas in anticancer drug development during the last decade. As one of these therapies, anti-IGF-1R monoclonal antibodies (mAbs) are also advancing further in development. Our purpose was to conduct a systematic review of the adverse events (AEs) caused by anti-IGF-1R monoclonal antibodies in cancer therapy.

METHODS

We searched the term'IGF-1R monoclonal antibody' in the Pubmed database and found 389 related articles. After elaborate selection, 15 clinical studies that satisfied our criteria were then adopted for further analysis. We extracted all the useful information about the AEs of mAbs from the enrolled studies. Every kind of reported AE as well as corresponding incidences were summed up and calculated. We compared AE incidence differences in two age groups, and analyzed toxicities of mAbs used as a single agent or combined with chemotherapies. Finally, the differences of AE profiles between individual mAbs were also valued.

RESULTS

AEs were more severe in the lower age group and 13 of 19 AE incidences in the single-agent group were significantly lower than in the combination group (P < 0.05). R1507 seemed to show a worse AE profile than cixutumumab and figitumumab.

CONCLUSIONS

When anti-IGF-1R mAbs are used for cancer therapy, it is essential to choose the proper drug and combined chemotherapies to reduce AE occurrences. Also, administration of these mAbs to younger patients should be more carefully supervised. Furthermore, some more frequently observed AEs for specific mAb should be paid adequate attention.

A novel glycoengineered bispecific antibody format for targeted inhibition of epidermal growth factor receptor (EGFR) and insulin-like growth factor receptor type I (IGF-1R) demonstrating unique molecular properties

In the present study, we have developed a novel one-arm single chain Fab heterodimeric bispecific IgG (OAscFab-IgG) antibody format targeting the insulin-like growth factor receptor type I (IGF-1R) and the epidermal growth factor receptor (EGFR) with one binding site for each target antigen. The bispecific antibody XGFR is based on the "knob-into-hole" technology for heavy chain heterodimerization with one heavy chain consisting of a single chain Fab to prevent wrong pairing of light chains. XGFR was produced with high expression yields and showed simultaneous binding to IGF-1R and EGFR with high affinity. Due to monovalent binding of XGFR to IGF-1R, IGF-1R internalization was strongly reduced compared with the bivalent parental antibody, leading to enhanced Fc-mediated cellular cytotoxicity. To further increase immune effector functions triggered by XGFR, the Fc portion of the bispecific antibody was glycoengineered, which resulted in strong antibody-dependent cell-mediated cytotoxicity activity. XGFR-mediated inhibition of IGF-1R and EGFR phosphorylation as well as A549 tumor cell proliferation was highly effective and was comparable with a combined treatment with EGFR (GA201) and IGF-1R (R1507) antibodies. XGFR also demonstrated potent anti-tumor efficacy in multiple mouse xenograft tumor models with a complete growth inhibition of AsPC1 human pancreatic tumors and improved survival of SCID beige mice carrying A549 human lung tumors compared with treatment with antibodies targeting either IGF-1R or EGFR. In summary, we have applied rational antibody engineering technology to develop a heterodimeric OAscFab-IgG bispecific antibody, which combines potent signaling inhibition with antibody-dependent cell-mediated cytotoxicity induction and results in superior molecular properties over two established tetravalent bispecific formats.

Targeting insulin-like growth factor-I and insulin-like growth factor-binding protein-3 signaling pathways. A novel therapeutic approach for asthma

Insulin-like growth factor (IGF)-I has been recognized to play critical roles in the pathogenesis of asthma, whereas IGF-binding protein (IGFBP)-3 blocks crucial physiologic manifestations of asthma. IGF-I enhances subepithelial fibrosis, airway inflammation, airway hyperresponsiveness, and airway smooth muscle hyperplasia by interacting with various inflammatory mediators and complex signaling pathways, such as intercellular adhesion molecule-1, and the hypoxia-inducible factor/vascular endothelial growth factor axis. On the other hand, IGFBP-3 decreases airway inflammation and airway hyperresponsiveness through IGFBP-3 receptor-mediated activation of caspases, which subsequently inhibits NF-κB signaling pathway. It also inhibits the IGF-I/hypoxia-inducible factor/vascular endothelial growth factor axis via IGF-I-dependent and/or IGF-I-independent mechanisms. This Translational Review summarizes the role of IGF-I and IGFBP-3 in the context of allergic airway disease, and discusses the therapeutic potential of various strategies targeting the IGF-I and IGFBP-3 signaling pathways for the management of asthma.

Diabetes and cancer

Diabetes is a worldwide health problem that has been increasingly associated with various types of cancers. Epidemiologic studies have shown an increased risk of cancer as well as a higher mortality rate in patients with type 2 diabetes (T2D). The biologic mechanisms driving the link between T2D and cancer are not well understood. In this review, various proposed mechanisms are addressed to explain the relationship between T2D and cancer. Understanding the precise mechanisms that link T2D, obesity, and the metabolic syndrome with cancer will aid in developing treatments that will reduce mortality in individuals with T2D and cancer.

Prognostic implications of tumoral expression of insulin like growth factors 1 and 2 in patients with non-small-cell lung cancer

INTRODUCTION

The currently available systemic therapies for non-small-cell lung cancer (NSCLC) have limited efficacy. Previous studies indicated an association of elevated insulinlike growth factor (IGF)-1 receptor (IGF-1R) and insulin receptor expression levels with poor survival in patients with NSCLC. To better understand the molecular biomarkers involved in the IGF signaling pathway in NSCLC, the expression levels of IGF-1 and IGF-2 are characterized and evaluated for their association with IGF-1R and phosphorylated IGF-1R (pIGF-1R) expression in NSCLC.

MATERIALS AND METHODS

A total of 352 patients who underwent NSCLC resection with curative intent were studied. The expression patterns of the IGF-1, IGF-2, IGF-1R, and pIGF-1R proteins were assessed immunohistochemically using tissue microarrays.

RESULTS

The IGF-1 expression was higher in patients with adenocarcinoma (ADC) than in those with squamous cell carcinoma (SCC), whereas the IGF-2 score was higher in patients with SCC than those with ADC. Likewise, the IGF-1 score was higher in patients with mutated epidermal growth factor receptor (mtEGFR) than in those with wild type EGFR (wtEGFR), whereas the IGF-2 score was higher in patients with wtEGFR than in those with mtEGFR. Patients with low levels of IGF-1 expression had longer overall survival (OS) than those with high IGF-1 expression, and subgroup analyses found a significant difference in OS only in patients with ADC.

CONCLUSION

The overexpression of IGF-1 predicts poor survival among patients with NSCLC, especially those with ADC. These results might serve as a future guide for clinical trials involving IGF-1R-targeting agents.

Targeted therapies in development for non-small cell lung cancer

The iterative discovery in various malignancies during the past decades that a number of aberrant tumorigenic processes and signal transduction pathways are mediated by "druggable" protein kinases has led to a revolutionary change in drug development. In non-small cell lung cancer (NSCLC), the ErbB family of receptors (e.g., EGFR [epidermal growth factor receptor], HER2 [human epidermal growth factor receptor 2]), RAS (rat sarcoma gene), BRAF (v-raf murine sarcoma viral oncogene homolog B1), MAPK (mitogen-activated protein kinase) c-MET (c-mesenchymal-epithelial transition), FGFR (fibroblast growth factor receptor), DDR2 (discoidin domain receptor 2), PIK3CA (phosphatidylinositol-4,5-bisphosphate3-kinase, catalytic subunit alpha)), PTEN (phosphatase and tensin homolog), AKT (protein kinase B), ALK (anaplastic lym phoma kinase), RET (rearranged during transfection), ROS1 (reactive oxygen species 1) and EPH (erythropoietin-producing hepatoma) are key targets of various agents currently in clinical development. These oncogenic targets exert their selective growth advantage through various intercommunicating pathways, such as through RAS/RAF/MEK, phosphoinositide 3-kinase/AKT/mammalian target of rapamycin and SRC-signal transduction and transcription signaling. The recent clinical studies, EGFR tyrosine kinase inhibitors and crizotinib were considered as strongly effective targeted therapies in metastatic NSCLC. Currently, five molecular targeted agents were approved for treatment of advanced NSCLC: Gefitinib, erlotinib and afatinib for positive EGFR mutation, crizotinib for positive echinoderm microtubule-associated protein-like 4 (EML4)-ALK translocation and bevacizumab. Moreover, oncogenic mutant proteins are subject to regulation by protein trafficking pathways, specifically through the heat shock protein 90 system. Drug combinations affecting various nodes in these signaling and intracellular processes are predicted and demonstrated to be synergistic and advantageous in overcoming treatment resistance compared with monotherapy approaches. Understanding the role of the tumor microenvironment in the development and maintenance of the malignant phenotype provided additional therapeutic approaches as well. More recently, improved knowledge on tumor immunology has set the stage for promising immunotherapies in NSCLC. This review will focus on the rationale for the development of targeted therapies in NSCLC and the various strategies employed in preventing or overcoming the inevitable occurrence of treatment resistance.

Molecular Targeted Drugs and Biomarkers in NSCLC, the Evolving Role of Individualized Therapy

Lung cancer first line treatment has been directed from the non-specific cytotoxic doublet chemotherapy to the molecular targeted. The major limitation of the targeted therapies still remains the small number of patients positive to gene mutations. Furthermore, the differentiation between second line and maintenance therapy has not been fully clarified and differs in the clinical practice between cancer centers. The authors present a segregation between maintenance treatment and second line and present a possible definition for the term “maintenance” treatment. In addition, cancer cell evolution induces mutations and therefore either targeted therapies or non-specific chemotherapy drugs in many patients become ineffective. In the present work pathways such as epidermal growth factor, anaplastic lymphoma kinase, met proto-oncogene and PI3K are extensively presented and correlated with current chemotherapy treatment. Future, perspectives for targeted treatment are presented based on the current publications and ongoing clinical trials.

Targeted therapies in non-small cell lung carcinoma: what have we achieved so far?

The search for innovative therapeutic agents in non-small cell lung cancer (NSCLC) has witnessed a swift evolution. The number of targeted drugs that can improve patient outcomes with an acceptable safety profile is steadily increasing. In this review, we highlight current drugs that have already been approved or are under evaluation for the treatment of patients with NSCLC, either in monotherapy or combined therapy for both the first- and second-line settings. Experience with drugs targeting the vascular endothelial growth factor and its receptor, as well as the epidermal growth factor receptor is summarized. Moreover, we provide an overview of more novel targets in NSCLC and initial experience with the respective therapeutic agents.

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.

Non-small-cell lung cancer: molecular targeted therapy and personalized medicine - drug resistance, mechanisms, and strategies

Targeted therapies for cancer bring the hope of specific treatment, providing high efficacy and in some cases lower toxicity than conventional treatment. Although targeted therapeutics have helped immensely in the treatment of several cancers, like chronic myelogenous leukemia, colon cancer, and breast cancer, the benefit of these agents in the treatment of lung cancer remains limited, in part due to the development of drug resistance. In this review, we discuss the mechanisms of drug resistance and the current strategies used to treat lung cancer. A better understanding of these drug-resistance mechanisms could potentially benefit from the development of a more robust personalized medicine approach for the treatment of lung cancer.

Monoclonal antibodies in lung cancer

INTRODUCTION

Lung cancer is the leading cause of cancer death worldwide. As clinical benefits to conventional cancer therapies are still formidable, there is an urgent need for novel agents and approaches to improve the overall clinical outcomes for patients with lung cancer.

AREAS COVERED

This article reviews the current understanding of targeted therapy for lung cancer with monoclonal antibodies (mAbs), mainly bevacizumab and cetuximab. The results from several key clinical trials validating the effectiveness and safety of bevacizumab and cetuximab, the relation of cancer biomarkers, the polymorphic correlation of targeted genes with the therapeutic outcome of mAb-based treatment, as well as the impact of Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) trial on personalised treatment of lung cancer are discussed.

EXPERT OPINION

The addition of bevacizumab or cetuximab to chemotherapy has shown promising benefits to the patients with non-small-cell lung cancer. However, the overall benefits of mAb-based targeted therapy to lung cancer patients vary among individuals. It is therefore necessary to define reliable predictive biomarkers in an effort to better identify patients who are most likely to benefit from treatment with these novel agents in lung cancer.

Inhibition of insulin-like growth factor receptor: end of a targeted therapy?

The Insulin-like Growth Factor 1 (IGF-1) signaling pathway activates several downstream signals important to lung cancer development and survival. IGF-1R activation has been linked to cancer risk in epidemiological studies and tumorigenesis in preclinical models. Several inhibitors of the insulin-like growth factor 1 receptor (IGF-1R) have been tested in clinical trials. Despite promising data in early phase studies, most studies of IGF-1R antagonists in combination with chemotherapy or with epidermal growth factor receptor (EGFR) inhibitors in non-small cell lung cancer (NSCLC) yielded disappointing results. Biomarker studies of clinical trials have identified IGF-1 levels as a potential marker of sensitivity to IGF-1R inhibition. Further study will need to focus on selection of NSCLC patients most likely to benefit from the addition of IGF-1R antagonists to standard therapy and the development of rational strategies for combination therapy in NSCLC.

Local ablative therapy of oligoprogressive disease prolongs disease control by tyrosine kinase inhibitors in oncogene-addicted non-small-cell lung cancer

INTRODUCTION

Many patients with oncogene-driven non-small-cell lung cancer (NSCLC) treated with tyrosine kinase inhibitors experience limited sites of disease progression. This study investigated retrospectively the benefits of local ablative therapy (LAT) to central nervous system (CNS) and/or limited systemic disease progression and continuation of crizotinib or erlotinib in patients with metastatic ALK gene rearrangement (ALK+) or EGFR-mutant (EGFR-MT) NSCLC, respectively.

METHODS

Patients with metastatic ALK+ NSCLC treated with crizotinib (n = 38) and EGFR-MT NSCLC treated with erlotinib (n = 27) were identified at a single institution. Initial response to the respective kinase inhibitors, median progression-free survival (PFS1), and site of first progression were recorded. A subset of patients with either nonleptomeningeal CNS and/or four sites or fewer of extra-CNS progression (oligoprogressive disease) suitable for LAT received either radiation or surgery to these sites and continued on the same tyrosine kinase inhibitors. The subsequent median progression-free survival from the time of first progression (PFS2) and pattern of progression were recorded.

RESULTS

Median progression-free survival in ALK+ patients on crizotinib was 9.0 months, and 13.8 months for EGFR-MT patients on erlotinib. Twenty-five of 51 patients (49%) who progressed were deemed suitable for local therapy (15 ALK+, 10 EGFR-MT; 24 with radiotherapy, one with surgery) and continuation of the same targeted therapy. Post-LAT, 19 of 25 patients progressed again, with median PFS2 of 6.2 months.

DISCUSSION

Oncogene-addicted NSCLC with CNS and/or limited systemic disease progression (oligoprogressive disease) on relevant targeted therapies is often suitable for LAT and continuation of the targeted agent, and is associated with more than 6 months of additional disease control.

The role of molecular pathology in non-small-cell lung carcinoma-now and in the future

In recent years, better understanding of the molecular biology of non-small-cell lung carcinoma (nsclc) has led to a revolution in the work-up of these neoplasms. As a pathology diagnosis, "nsclc" without further attempt at subclassification is no longer accepted as a standard of care; separating squamous cell carcinoma from adenocarcinoma and large-cell carcinoma carries implications for prognosis and treatment decisions. Currently, detection of the presence in nsclc of mutations involving the epidermal growth factor receptor (EGFR) gene and fusion of the N-terminal portion of the protein encoded by EML4 (echinoderm microtubule-associated protein-like 4 gene) with the intracellular signaling portion of the receptor tyrosine kinase encoded by ALK (anaplastic lymphoma kinase gene)-that is, EML4-ALK-and variants has become routine in many centres because patients having tumours harbouring such alterations might benefit from tyrosine kinase inhibitors as part of their treatment regimen.The purpose of the present review is to highlight important aspects of the screening for molecular derangements in nsclc and to briefly discuss the emergence of possible future biomarkers.

Deciphering the role of insulin-like growth factor-I receptor in trastuzumab resistance

Resistance to the HER2-targeted antibody trastuzumab is a major clinical concern in the treatment of HER2-overexpressing metastatic breast cancer. Increased expression or signaling of the insulin-like growth factor-I receptor (IGF-IR) has been reported in a subset of cell lines and clinical samples derived from trastuzumab-resistant breast cancers. Genetic and pharmacologic inhibition of IGF-IR signaling has been shown to improve response to trastuzumab in trastuzumab-naïve and trastuzumab-resistant models. In this paper, we will discuss the role of IGF-IR signaling in trastuzumab resistance. Further, we will discuss cotargeting IGF-IR and HER2 as a potential therapeutic strategy for HER2-over-expressing breast cancers that have progressed on trastuzumab treatment.

Antibody phage display libraries: contributions to oncology

Since the advent of phage display technology, dating back to 1985, antibody libraries displayed on filamentous phage surfaces have been used to identify specific binders for many different purposes, including the recognition of tumors. Phage display represents a high-throughput technique for screening billions of random fusion antibodies against virtually any target on the surface or inside cancer cells, or even soluble markers found in patient serum. Many phage display derived binders targeting important tumor markers have been identified. Selection directed to tumoral cells’ surfaces lead to the identification of unknown tumoral markers. Also the improvement of methods that require smaller amounts of cells has opened the possibility to use this approach on patient samples. Robust techniques combining an antibody library displayed on the phage surface and protein microarray allowed the identification of auto antibodies recognized by patient sera. Many Ab molecules directly or indirectly targeting angiogenesis have been identified, and one of them, ramucirumab, has been tested in 27 phase I–III clinical trials in a broad array of cancers. Examples of such antibodies will be discussed here with emphasis on those used as probes for molecular imaging and other clinical trials.