Toxicity of targeted therapy: Implications for response and impact of genetic polymorphisms

Mechanisms of Pharmaceutical Therapy and Drug Resistance in Esophageal Cancer

Pharmaceutical therapies are essential for esophageal cancer (EC). For the advanced EC, the neoadjuvant therapy regimen, including chemotherapy plus radiotherapy and/or immunotherapy, is effective to achieve clinical benefit, even pathological complete response. For the unresectable, recurrent, and metastatic EC, the pharmaceutical therapy is the limited effective regimen to alleviate the disease and prolong the progression-free survival and overall survival. In this review, we focus on the pharmaceutical applications in EC treatment including cytotoxic agents, molecular targeted antibodies, and immune checkpoint inhibitors (ICIs). The chemotherapy regimen is based on cytotoxic agents such as platinum-based complexes, fluorinated pyrimidines and taxenes. Although the cytotoxic agents have been developed in past decades, the standard chemotherapy regimen is still the cisplatin and 5-FU or paclitaxel because the derived drugs have no significant advantages of overcoming the shortcomings of side effects and drug resistance. The targeted molecular therapy is an essential supplement for chemotherapy; however, there are only a few targeted therapies available in clinical practice. Trastuzumab and ramucirumab are the only two molecular therapy drugs which are approved by the US Food and Drug Administration to treat advanced and/or metastatic EC. Although the targeted therapy usually achieves effective benefits in the early stage therapy of EC, the patients will always develop drug resistance during treatment. ICIs have had a significant impact on routine clinical practice in cancer treatment. The anti-programmed cell death-1 monoclonal antibodies pembrolizumab and nivolumab, as the ICIs, are recommended for advanced EC by several clinical trials. However, the significant issues of pharmaceutical treatment are still the dose-limiting side effects and primary or secondary drug resistance. These defects of pharmaceutical therapy restrain the clinical application and diminish the effectiveness of treatment.

Is Structure-Based Drug Design Ready for Selectivity Optimization?

Alchemical free-energy calculations are now widely used to drive or maintain potency in small-molecule lead optimization with a roughly 1 kcal/mol accuracy. Despite this, the potential to use free-energy calculations to drive optimization of compound selectivity among two similar targets has been relatively unexplored in published studies. In the most optimistic scenario, the similarity of binding sites might lead to a fortuitous cancellation of errors and allow selectivity to be predicted more accurately than affinity. Here, we assess the accuracy with which selectivity can be predicted in the context of small-molecule kinase inhibitors, considering the very similar binding sites of human kinases CDK2 and CDK9 as well as another series of ligands attempting to achieve selectivity between the more distantly related kinases CDK2 and ERK2. Using a Bayesian analysis approach, we separate systematic from statistical errors and quantify the correlation in systematic errors between selectivity targets. We find that, in the CDK2/CDK9 case, a high correlation in systematic errors suggests that free-energy calculations can have significant impact in aiding chemists in achieving selectivity, while in more distantly related kinases (CDK2/ERK2), the correlation in systematic error suggests that fortuitous cancellation may even occur between systems that are not as closely related. In both cases, the correlation in systematic error suggests that longer simulations are beneficial to properly balance statistical error with systematic error to take full advantage of the increase in apparent free-energy calculation accuracy in selectivity prediction.

An Aptamer for Broad Cancer Targeting and Therapy

Simple Summary

Recent efforts to improve chemotherapy’s antitumor effects have increasingly focused on targeted therapies, where the drug is modified with an agent able to specifically deliver it to the tumor while limiting its accumulation in normal tissue. Aptamers, comprised of short pieces of RNA or DNA, are ideal for this type of drug targeting due in part to their ease of chemical synthesis. The E3 aptamer was previously conjugated to highly toxic chemotherapeutics and shown to target and treat prostate tumors. Here, we show that E3 is not limited to prostate cancer targeting but appears to broadly target cancer cells. E3 highly toxic drug conjugates also efficiently kill a broad range of cancer types, and E3 targets tumors that closely model patient tumors. Thus, the E3 aptamer appears to be a general agent for specific delivery of chemotherapy to tumors and should improve antitumor treatment while reducing unwanted toxicities in other tissues.

Abstract

Recent advances in chemotherapy treatments are increasingly targeted therapies, with the drug conjugated to an antibody able to deliver it directly to the tumor. As high-affinity chemical ligands that are much smaller in size, aptamers are ideal for this type of drug targeting. Aptamer-highly toxic drug conjugates (ApTDCs) based on the E3 aptamer, selected on prostate cancer cells, target and inhibit prostate tumor growth in vivo. Here, we observe that E3 also broadly targets numerous other cancer types, apparently representing a universal aptamer for cancer targeting. Accordingly, ApTDCs formed by conjugation of E3 to the drugs monomethyl auristatin E (MMAE) or monomethyl auristatin F (MMAF) efficiently target and kill a range of different cancer cells. Notably, this targeting extends to both patient-derived explant (PDX) cancer cell lines and tumors, with the E3 MMAE and MMAF conjugates inhibiting PDX cell growth in vitro and with the E3 aptamer targeting PDX colorectal tumors in vivo.

A Review of the Mechanisms and Clinical Implications of Precision Cancer Therapy-Related Toxicity: A Primer for the Radiologist

OBJECTIVE. The purpose of this review is to elucidate the mechanisms, types, and clinical significance of molecular targeted therapy (MTT) and immune checkpoint inhibitors (ICIs) and their related toxicity, emphasizing the radiologic manifestations. CONCLUSION. The related toxicities of MTT and ICIs can have acute, recurrent, chronic, and delayed presentations. These toxicities may serve as markers of response and survival. By understanding the clinical significance of drug toxicities, radiologists can play an important role in personalized cancer therapy.

Constructing cancer patient-specific and group-specific gene networks with multi-omics data

Background

Cancer is a complex and heterogeneous disease with many possible genetic and environmental causes. The same treatment for patients of the same cancer type often results in different outcomes in terms of efficacy and side effects of the treatment. Thus, the molecular characterization of individual cancer patients is increasingly important to find an effective treatment. Recently a few methods have been developed to construct cancer sample-specific gene networks based on the difference in the mRNA expression levels between the cancer sample and reference samples.

Methods

We constructed a patient-specific network with multi-omics data based on the difference between a reference network and a perturbed reference network by the patient. A network specific to a group of patients was obtained using the average change in correlation coefficients and node degree of patient-specific networks of the group.

Results

In this paper, we present a new method for constructing cancer patient-specific and group-specific gene networks with multi-omics data. The main differences of our method from previous ones are as follows: (1) networks are constructed with multi-omics (mRNA expression, copy number variation, DNA methylation and microRNA expression) data rather than with mRNA expression data alone, (2) background networks are constructed with both normal samples and cancer samples of the specified type to extract cancer-specific gene correlations, and (3) both patient individual-specific networks and patient group-specific networks can be constructed. The results of evaluating our method with several types of cancer show that it constructs more informative and accurate gene networks than previous methods.

Conclusions

The results of evaluating our method with extensive data of seven cancer types show that the difference of gene correlations between the reference samples and a patient sample is a more predictive feature than mRNA expression levels and that gene networks constructed with multi-omics data show a better performance than those with single omics data in predicting cancer for most cancer types. Our approach will be useful for finding genes and gene pairs to tailor treatments to individual characteristics.

Design, Synthesis, and Biological Investigation of Novel Classes of 3-Carene-Derived Potent Inhibitors of TDP1

Two novel structural types of tyrosyl-DNA phosphodiesterase 1 (TDP1) inhibitors with hexahydroisobenzofuran 11 and 3-oxabicyclo [3.3.1]nonane 12 scaffolds were discovered. These monoterpene-derived compounds were synthesized through preliminary isomerization of (+)-3-carene to (+)-2-carene followed by reaction with heteroaromatic aldehydes. All the compounds inhibit the TDP1 enzyme at micro- and submicromolar levels, with the most potent compound having an IC₅₀ value of 0.65 μM. TDP1 is an important DNA repair enzyme and a promising target for the development of new chemosensitizing agents. A panel of isogenic clones of the HEK293FT cell line knockout for the TDP1 gene was created using the CRISPR-Cas9 system. Cytotoxic effects of topotecan (Tpc) and non-cytotoxic compounds of the new structures were investigated separately and jointly in the TDP1 gene knockout cells. For two TDP1 inhibitors, 11h and 12k, a synergistic effect was observed with Tpc in the HEK293FT cells but was not found in TDP1 −/− cells. Thus, it is likely that the synergistic effect is caused by inhibition of TDP1. Synergy was also found for 11h in other cancer cell lines. Thus, sensitizing cancer cells using a non-cytotoxic drug can enhance the efficacy of currently used pharmaceuticals and, concomitantly, reduce toxic side effects.

β-radiating radionuclides in cancer treatment, novel insight into promising approach

Targeted radionuclide therapy, known as molecular radiotherapy is a novel therapeutic module in cancer medicine. β-radiating radionuclides have definite impact on target cells via interference in cell cycle and particular signalings that can lead to tumor regression with minimal off-target effects on the surrounding tissues. Radionuclides play a remarkable role not only in apoptosis induction and cell cycle arrest, but also in the amelioration of other characteristics of cancer cells. Recently, application of novel β-radiating radionuclides in cancer therapy has been emerged as a promising therapeutic modality. Several investigations are ongoing to understand the underlying molecular mechanisms of β-radiating elements in cancer medicine. Based on the radiation dose, exposure time and type of the β-radiating element, different results could be achieved in cancer cells. It has been shown that β-radiating radioisotopes block cancer cell proliferation by inducing apoptosis and cell cycle arrest. However, physical characteristics of the β-radiating element (half-life, tissue penetration range, and maximum energy) and treatment protocol determine whether tumor cells undergo cell cycle arrest, apoptosis or both and to which extent. In this review, we highlighted novel therapeutic effects of β-radiating radionuclides on cancer cells, particularly apoptosis induction and cell cycle arrest.

Association between single nucleotide polymorphisms of DNA damage response pathway genes and increased risk in breast cancer

Aim: We aimed to evaluate the role of selected single nucleotide polymorphisms of DNA damage response pathway genes in breast cancer (BC). Materials & methods: In present study, 500 BC patients and 500 controls was used to estimate the frequency of single nucleotide polymorphisms of DNA damage response pathway genes. Tetra-amplification refractory mutation system-PCR technique was used for screening of the six selected polymorphisms. Results: Logistic regression analysis showed that heterozygous mutant genotype of rs1800057 (p < 0.0001) and homozygous mutant genotype of rs1801516 (p < 0.0001) was associated with significant increased risk of BC. In the ATR gene, heterozygous mutant genotype of rs2227931 (p < 0.0001) was associated with significant increased risk of BC. However, significant decreased risk of BC was found associated with heterozygous mutant genotype of rs2227928 (p < 0.0002) and homozygous mutant genotype of rs2229032 (p < 0.0001) in patients compared with controls. Conclusion: The present results showed that alteration in DNA damage response pathway gene (ATM & ATR) results in increased BC risk.

Development of thrombocytopenia is associated with improved survival in patients treated with immunotherapy

Background:

Immune-related adverse events are associated with efficacy of immune checkpoint inhibitors (ICIs). We hypothesize that immune-mediated thrombocytopenia could be a biomarker for response to ICIs.

Materials & methods:

This retrospective study included 215 patients with metastatic malignancies treated with ICIs. Patients were stratified by nadir platelet count. Outcomes of interest were progression-free survival and overall survival.

Results:

On multivariate analysis, grade 1 thrombocytopenia was positively associated with overall survival compared with patients who did not develop thrombocytopenia (hazard ratio [HR]= 0.28 [95% CI: 0.13–0.60]; p = 0.001), while grade 2–4 thrombocytopenia was not (HR= 0.36 [95% CI: 0.13–1.04]; p = 0.060). There was no association between degree of thrombocytopenia and progression-free survival.

Conclusion:

Follow-up studies are warranted to substantiate the predictive significance of thrombocytopenia in patients receiving ICIs.

Immune checkpoint inhibitors (ICIs) are a class of drug that are increasingly being used in different cancers. The extent of response to treatment with ICIs differs among individuals. There is a lack of biomarkers, which would help clinicians predict response to ICIs. In our study, we aimed to explore the development of low platelets as a potential biomarker. Our findings suggest that cancer patients receiving ICIs who develop a mild decrease in platelet count tend to live longer than those who do not. However, this was not true for those who developed a severe decrease in platelet count. The mechanism of how ICIs affect platelets may be related to the interaction between the immune system and platelets. More studies are needed to validate our results and better understand the role of platelets in cancer biology.

A review of the imaging manifestations of immune check point inhibitor toxicities

The past decade has witnessed a paradigm shift in cancer therapy owing to the introduction of immune checkpoint inhibitors (ICIs) and it is now commonplace for radiologists to image patients on therapy with these agents. The purpose of this review is to detail the mechanism, radiological manifestations and clinical significance of ICI related toxicities, according to the organ system involved. ICI related toxicities that have known imaging manifestations include colitis, enterocolitis, pancreatitis, hepatitis, endocrine toxicities, pneumonitis, cardiovascular toxicity and musculoskeletal toxicity. These toxicities may be acute, recurrent or chronic in nature. Radiologists must be aware of the imaging features and clinical significance of these toxicities in order to effectively participate in personalized cancer therapy.

Finding prognostic gene pairs for cancer from patient-specific gene networks

BACKGROUND

Molecular characterization of individual cancer patients is important because cancer is a complex and heterogeneous disease with many possible genetic and environmental causes. Many studies have been conducted to identify diagnostic or prognostic gene signatures for cancer from gene expression profiles. However, some gene signatures may fail to serve as diagnostic or prognostic biomarkers and gene signatures may not be found in gene expression profiles.

METHODS

In this study, we developed a general method for constructing patient-specific gene correlation networks and for identifying prognostic gene pairs from the networks. A patient-specific gene correlation network was constructed by comparing a reference gene correlation network from normal samples to a network perturbed by a single patient sample. The main difference of our method from previous ones includes (1) it is focused on finding prognostic gene pairs rather than prognostic genes and (2) it can identify prognostic gene pairs from gene expression profiles even when no significant prognostic genes exist.

RESULTS

Evaluation of our method with extensive data sets of three cancer types (breast invasive carcinoma, colon adenocarcinoma, and lung adenocarcinoma) showed that our approach is general and that gene pairs can serve as more reliable prognostic signatures for cancer than genes.

CONCLUSIONS

Our study revealed that prognosis of individual cancer patients is associated with the existence of prognostic gene pairs in the patient-specific network and the size of a subnetwork of the prognostic gene pairs in the patient-specific network. Although preliminary, our approach will be useful for finding gene pairs to predict survival time of patients and to tailor treatments to individual characteristics. The program for dynamically constructing patient-specific gene networks and for finding prognostic gene pairs is available at http://bclab.inha.ac.kr/pancancer.

Generation of hepatic spheroids using human hepatocyte-derived liver progenitor-like cells for hepatotoxicity screening

Rationale: The idiosyncratic drug-induced liver injury (iDILI) is a major cause of acute liver injury and a key challenge in late-stage drug development. Individual heterogeneity is considered to be an essential factor of iDILI. However, few in vitro model can predict heterogeneity in iDILI. We have previously shown that mouse and human hepatocytes can be converted to expandable liver progenitor-like cells in vitro (HepLPCs). However, the limited proliferation potential of human HepLPCs confines its industrial application. Here, we reported the generation of a novel hepatocyte model not only to provide unlimited cell sources for human hepatocytes but also to establish a tool for studying iDILI in vitro.

Methods: Human primary hepatocytes were isolated by modified two-step perfusion technique. The chemical reprogramming culture condition together with gene-transfer were then used to generate the immortalized HepLPC cell lines (iHepLPCs). Growth curve, doubling time, and karyotype were analyzed to evaluate the proliferation characteristics of iHepLPCs. Modified Hepatocyte Maturation Medium and 3D spheroid culture were applied to re-differentiate iHepLPCs.

Results: iHepLPCs exhibited efficient expansion for at least 40 population doublings, with a stable proliferative ability. They could easily differentiate back into metabolically functional hepatocytes in vitro within 10 days. Furthermore, under three-dimensional culture conditions, the formed hepatic spheroids showed multiple liver functions and toxicity profiles close to those of primary human hepatocytes. Importantly, we established a hepatocyte bank by generating a specific number of such cell lines. Screening for population heterogeneity allowed us to analyze the in vitro heterogeneous responses to hepatotoxicity induced by molecular targeted drugs.

Conclusions: In light of the proliferative capacity and the heterogeneity they represented, these iHepLPCs cell lines may offer assistance in studying xenobiotic metabolism as well as liver diseases in vitro.

The Role of the Pharmacist in Optimizing Cancer Immunotherapy: A Retrospective Study of Nivolumab Adverse Events

BACKGROUND

Immune checkpoint inhibitors (ICIs) are an emerging treatment in cancer therapy for prolonging life, minimizing symptoms, and selectively targeting cancer. Program death 1 (PD-1) inhibitors, such as nivolumab, fall within this class, enabling the patient's immune system to detect and destroy cancer. The introduction of ICIs is changing cancer therapy, with new drugs and new toxicities-an evolving area encountered by pharmacists.

OBJECTIVE

This study aims to compare the pattern of nivolumab-induced adverse events observed in practice, when compared with clinical trial and literature data. The secondary aim of the study is to identify the presentation and treatment modalities initiated in practice.

METHODS

We performed a retrospective case note review across 2 South Australian hospitals to identify the common toxicities and symptomatic treatments experienced by patients receiving nivolumab. Results were compared with clinical trial data from product innovator Bristol-Myer Squib and other published literature.

RESULTS

Seventy patients were included in the study; of these, 60 (86%) experienced any grade adverse event(s). A total of 59 (84%) of 70 experienced mild to moderate grade 1 to grade 2 adverse events and 10 (14%) of 70 patients experienced severe grade 3 to grade 4 adverse events, displaying some consistencies with clinical trial and published literature data. Together, the prevalence of adverse events with details on presentation and treatments illustrates possible pharmacy practice strategies and areas for intervention.

CONCLUSIONS

The listed prevalence of adverse events and practice strategies identified throughout this study highlights how pharmacists may assist in the identification of predictable ICI toxicities associated with gastrointestinal, endocrine, dermatological toxicities, and fatigue.

Sustained complete response to erlotinib in squamous cell carcinoma of the head and neck: A case report

BACKGROUND

Squamous cell carcinoma of head and neck (SCCHN) is the fifth most common cancer worldwide. Inhibition of epidermal growth factor receptor signaling has been shown to be a critical component of therapeutic option. Herein, we report a case of durable complete response to erlotinib.

CASE SUMMARY

An 81-year-old Caucasian male who presented with metastatic poorly differentiated squamous cell carcinoma of right cervical lymph nodes (levels 2 and 3). Imaging studies including (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (CT) and contrast-enhanced CT scan of neck and chest did not reveal any other disease elsewhere. Panendoscopic examination with random biopsy did not reveal malignant lesion in nasopharynx, oropharynx, and larynx. He underwent modified neck dissection and postoperative radiation. Within 2 mo after completion of radiation, he developed local recurrence at right neck, which was surgically removed. Two mo after the salvage surgery, he developed a second recurrence at right neck. Due to suboptimal performance status and his preference, he started erlotinib treatment. He achieved partial response after first 2 mo of erlotinib treatment, then complete response after total 6 mo of erlotinib treatment. He developed sever skin rash and diarrhea including Clostridium difficile infection during the course of erlotinib treatment requiring dose reduction and eventual discontinuation. He remained in complete remission for more than two years after discontinuation of erlotinib.

CONCLUSION

We report a case of metastatic SCCHN achieving durable complete response from erlotinib. Patient experienced skin rash and diarrhea toxicities which were likely predictors of his treatment response.

Controlling methacryloyl substitution of chondroitin sulfate: injectable hydrogels with tunable long-term drug release profiles

Drug delivery systems capable of local sustained release of small molecule therapeutics remain a critical need in many fields, including oncology. Here, a system to create tunable hydrogels capable of modulating the loading and release of cationic small molecule therapeutics was developed. Chondroitin sulfate (CS) is a sulfated glycosaminoglycan that has many promising properties, including biocompatibility, biodegradation and chemically modifiable groups for both covalent and non-covalent bonding. CS was covalently modified with photocrosslinkable methacryloyl groups (CSMA) to develop an injectable hydrogel fabrication. Utilizing anionic groups, cationic drugs can be adsorbed and released from the hydrogels. This study demonstrates the synthesis of CSMA with a varying degree of substitution (DS) to generate hydrogels with varying swelling properties, maximum injection force, and drug release kinetics. The DS of the synthesized CSMA ranged from 0.05 ± 0.02 (2 h reaction) to 0.28 ± 0.02 (24 h reaction) with a DS of 1 representing 100% modification. The altered DS resulted in changes in hydrogel properties with the swelling of 20% CSMA hydrogels ranging from 42 (2 h reaction) to 13 (24 h reaction) and injection forces ranging from 18 N (2 h reaction) to 94 N (24 h reaction). The release of sunitinib, an oncology therapeutic that inhibits intracellular signaling by targeting multiple receptor tyrosine kinases, ranged from 18 μg per day (2 h reaction) to 9 μg per day (24 h reaction). While decreasing the DS increased the hydrogel swelling and rate of therapeutic release, it also limited the hydrogel fabrication range to only those containing 10% or higher CSMA. Blended polymer systems with poly(vinyl alcohol)-methacrylate (PVAMA) were fabricated to stabilize the resulting hydrogels via attenuating the swelling properties. Release profiles previously unattainable with the pure CSMA hydrogels were achieved with the blended hydrogel formulations. Overall, these studies identify a method to formulate tunable CSMA and blended CSMA/PVAMA hydrogels capable of sustained release of cationic therapeutics over six weeks with applications in oncology therapeutics.

MicroRNA-143-3p inhibits colorectal cancer metastases by targeting ITGA6 and ASAP3

MicroRNAs, which regulate mRNAs, operate through a variety of signaling pathways to participate in the development of colorectal cancer (CRC). In this study, we found that microRNA (miR)‐143‐3p expression was significantly lower in both CRC and liver metastatic CRC tissues from liver compared with normal colonic tissues. Functional assays showed that miR‐143‐3p inhibited CRC cell invasion and migration in vitro. Using a bioinformatics approach, we identified miR‐143‐3p target mRNAs. Among the candidate targets, only the expression of integrin alpha 6 (ITGA6) and ArfGAP with the SH3 domain and ankyrin repeat and PH domain 3 (ASAP3) were significantly reduced by miR‐143‐3p mimics as examined by western blot, and the metastasis potential of CRC cells was attenuated by endogenous ITGA6 and ASAP3 knockdown, determined by migration and invasion assays. Both ITGA6 and ASAP3 were upregulated in CRC tissues compared to normal tissues. Analysis of the relationship between clinicopathological features and ITGA6/ASAP3 protein expression in 200 patients with CRC showed a significant difference in positive ITGA6 expression between the early stage (I + II) and the advanced stage (III + IV), and ASAP3 expression levels positively correlated with metastasis in the lymph nodes. These results indicate that miR‐143‐3p acts as an anti‐oncogene by downregulating ITGA6/ASAP3 protein expression and could offer new insight into potential therapeutic targets for CRC.

Modulating Aptamer Specificity with pH-Responsive DNA Bonds

Aptamers that recognize specific cells in a complex environment have emerged as invaluable molecular tools in bioanalysis and in the development of targeted therapeutics. The selective recognition of aptamers, however, can be compromised by the coexistence of target receptors on both target cells and other cells. To address this problem, we constructed a structure-switchable aptamer (SW-Apt) with reconfigurable binding affinity in accordance with the microenvironment of target cells. The SW-Apt makes use of i-motifs, which are quadruplex structures that form in sequences rich in cytosine. More specifically, we report the design of single-stranded, pH-responsive i-motif-modified aptamers able to bind specifically with target cells by exploiting their pH. Here, the i-motif serves as a structural domain to either facilitate the binding ability of aptamers to target cells or suppress the binding ability of aptamers to nontarget cell based on the pH of the cellular microenvironment. SW-Apt exhibited high binding ability with target cells at acidic pH, while no obvious binding was observed at physiological pH. The i-motif-induced structure-switching was verified with Förster resonance energy transfer and circular dichroism spectroscopy. Notably, SW-Apt exhibits high specificity in serum and excellent stability, likely attributed to the folded quadruplex i-motif structure. This study provides a simple and efficient strategy to chemically modulate aptamer binding ability and thus improve aptamer binding specificity to target cells, irrespective of the coexistence of identical receptors on target and nontarget cells.

Role of Cytochrome P450 Enzymes in the Metabolic Activation of Tyrosine Kinase Inhibitors

Tyrosine kinase inhibitors are a rapidly expanding class of molecular targeted therapies for the treatment of various types of cancer and other diseases. An increasing number of clinically important small molecule tyrosine kinase inhibitors have been shown to undergo cytochrome P450-mediated bioactivation to form chemically reactive, potentially toxic products. Metabolic activation of tyrosine kinase inhibitors is proposed to contribute to the development of serious adverse reactions, including idiosyncratic hepatotoxicity. This article will review recent findings and ongoing studies to elucidate the link between drug metabolism and tyrosine kinase inhibitor-associated hepatotoxicity.

Research progress on common adverse events caused by targeted therapy for colorectal cancer

As targeted drug therapy is increasingly applied in the treatment of colon cancer, understanding and managing the adverse reactions of patients is becoming increasingly important. The present review examines the mechanisms of and adverse reactions to the most commonly used targeted drugs for colon cancer, and discusses methods of coping with these adverse reactions. Approved targeted drugs for metastatic colon cancer include monoclonal antibodies targeting vascular endothelial growth factor (VEGF), including bevacizumab, ziv-aflibercept and regorafenib, and monoclonal antibodies targeting epithelial growth factor receptor (EGFR), including cetuximab and panitumumab. The present review assesses the major adverse effects of these drugs and methods of dealing with reactions to them. VEGF inhibitors primarily result in cardiovascular and kidney problems. Meanwhile, EGFR receptor inhibitors are frequently reported to cause rashes, diarrhea and hypertension, and are reviewed from the point of view of resulting electrolyte disturbances.

Tunable cytotoxic aptamer-drug conjugates for the treatment of prostate cancer

Therapies that can eliminate both local and metastatic prostate tumor lesions while sparing normal organ tissue are desperately needed. With the goal of developing an improved drug-targeting strategy, we turned to a new class of targeted anticancer therapeutics: aptamers conjugated to highly toxic chemotherapeutics. Cell selection for aptamers with prostate cancer specificity yielded the E3 aptamer, which internalizes into prostate cancer cells without targeting normal prostate cells. Chemical conjugation of E3 to the drugs monomethyl auristatin E (MMAE) and monomethyl auristatin F (MMAF) yields a potent cytotoxic agent that efficiently kills prostate cancer cells in vitro but does not affect normal prostate epithelial cells. Importantly, the E3 aptamer targets tumors in vivo and treatment with the MMAF-E3 conjugate significantly inhibits prostate cancer growth in mice, demonstrating the in vivo utility of aptamer-drug conjugates. Additionally, we report the use of antidotes to block E3 aptamer-drug conjugate cytotoxicity, providing a safety switch in the unexpected event of normal cell killing in vivo.

Developing transmission line equations of oxygen transport for predicting oxygen distribution in the arterial system

The oxygen content in the arterial system plays a significant role in determining the physiological status of a human body. Understanding the oxygen concentration distribution in the arterial system is beneficial for the prevention and intervention of vascular disease. However, the oxygen concentration in the arteries could not be noninvasively monitored in clinical research. Although the oxygen concentration distribution in a vessel could be obtained from a three-dimensional (3D) numerical simulation of blood flow coupled with oxygen transport, a 3D numerical simulation of the systemic arterial tree is complicated and requires considerable computational resources and time. However, the lumped parameter model of oxygen transport derived from transmission line equations of oxygen transport requires fewer computational resources and less time to numerically predict the oxygen concentration distribution in the systemic arterial tree. In this study, transmission line equations of oxygen transport are developed according to the theory of oxygen transport in the vessel, and fluid transmission line equations are used as the theoretical reference for the development. The transmission line equations of oxygen transport could also be regarded as the theoretical basis for developing lumped parameter models of other substances in blood.

Priming the body to receive the therapeutic agent to redefine treatment benefit/risk profile

Many therapeutic agents offer a low useful dose (dose responsible for efficacy)/useless dose (dose eliminated or responsible for toxicity) ratio, mainly due to the fact that therapeutic agents must ensure in one single object all the functions required to deliver the treatment, which leads to compromises in their physico-chemical design. Here we introduce the concept of priming the body to receive the treatment by uncorrelating these functions into two distinct objects sequentially administered: a nanoprimer occupying transiently the main pathway responsible for therapeutic agent limited benefit/risk ratio followed by the therapeutic agent. The concept was evaluated for different nature of therapeutic agents: For nanomedicines we designed a liposomal nanoprimer presenting preferential hepatic accumulation without sign of acute toxicity. This nanoprimer was able to increase the blood bioavailability of nanomedicine correlated with a lower hepatic accumulation. Finally this nanoprimer markedly enhanced anti-tumor efficacy of irinotecan loaded liposomes in the HT-29 tumor model when compared to the nanomedicine alone. Then, for small molecules we demonstrated the ability of a cytochrome inhibitor loaded nanoprimer to increase efficacy of docetaxel treatment. These results shown that specific nanoprimers could be designed for each family of therapeutic agents to answer to their specific needs.

ADAM17 activation and regulation of profibrotic responses by high glucose requires its C-terminus and FAK kinase

Glomerular matrix accumulation is the hallmark of diabetic nephropathy. The metalloprotease ADAM17 mediates high glucose (HG)-induced matrix production by kidney mesangial cells through release of ligands for the epidermal growth factor receptor. Here we study the mechanism by which HG activates ADAM17. We find that the C-terminus is essential for ADAM17 activation and the profibrotic response to HG. In the C-terminus, Src-mediated Y702 phosphorylation and PI3K/MEK/Erk-mediated T735 phosphorylation are critical to ADAM17 activation, but play divergent roles in ADAM17 trafficking in response to HG. While T735 phosphorylation is required for the HG-induced increase in cell surface mature ADAM17, Y702 phosphorylation is dispensable. Src, however, enables trafficking independently of its phosphorylation of ADAM17. The nonreceptor tyrosine kinase FAK is a central mediator of these processes. These data not only support a critical role for the C-terminus in ADAM17 activation and downstream profibrotic responses to HG, but also highlight FAK as a potential alternate therapeutic target for diabetic nephropathy.

Targeted Therapies: Immunologic Effects and Potential Applications Outside of Cancer

Two pharmacologic approaches that are currently at the forefront of treating advanced cancer are those that center on disrupting critical growth/survival signaling pathways within tumor cells (commonly referred to as "targeted therapies") and those that center on enhancing the capacity of a patient's immune system to mount an antitumor response (immunotherapy). Maximizing responses to both of these approaches requires an understanding of the oncogenic events present in a given patient's tumor and the nature of the tumor-immune microenvironment. Although these 2 modalities were developed and initially used independently, combination regimens are now being tested in clinical trials, underscoring the need to understand how targeted therapies influence immunologic events. Translational studies and preclinical models have demonstrated that targeted therapies can influence immune cell trafficking, the production of and response to chemokines and cytokines, antigen presentation, and other processes relevant to antitumor immunity and immune homeostasis. Moreover, because these and other effects of targeted therapies occur in nonmalignant cells, targeted therapies are being evaluated for use in applications outside of oncology.

Targeting BCL-2 and ABL/LYN in Philadelphia chromosome-positive acute lymphoblastic leukemia

Treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+)ALL) remains a challenge. Although the addition of targeted tyrosine kinase inhibitors (TKIs) to standard cytotoxic therapy has greatly improved upfront treatment, treatment-related morbidity and mortality remain high. TKI monotherapy provides only temporary responses and renders patients susceptible to the development of TKI resistance. Thus, identifying agents that could enhance the activity of TKIs is urgently needed. Recently, a selective inhibitor of B cell lymphoma 2 (BCL-2), ABT-199 (venetoclax), has shown impressive activity against hematologic malignancies. We demonstrate that the combination of TKIs with venetoclax is highly synergistic in vitro, decreasing cell viability and inducing apoptosis in Ph(+)ALL. Furthermore, the multikinase inhibitors dasatinib and ponatinib appear to have the added advantage of inducing Lck/Yes novel tyrosine kinase (LYN)-mediated proapoptotic BCL-2-like protein 11 (BIM) expression and inhibiting up-regulation of antiapoptotic myeloid cell leukemia 1 (MCL-1), thereby potentially overcoming the development of venetoclax resistance. Evaluation of the dasatinib-venetoclax combination for the treatment of primary Ph(+)ALL patient samples in xenografted immunodeficient mice confirmed the tolerability of this drug combination and demonstrated its superior antileukemic efficacy compared to either agent alone. These data suggest that the combination of dasatinib and venetoclax has the potential to improve the treatment of Ph(+)ALL and should be further evaluated for patient care.

Dosing de novo combinations of two targeted drugs: Towards a customized precision medicine approach to advanced cancers

Metastatic cancers harbor complex genomic alterations. Thus, monotherapies are often suboptimal. Individualized combinations are needed in order to attenuate resistance. To help inform selection of safe starting doses for novel, two-agent, targeted drug combinations, we identified clinical trials in adult oncology patients who received targeted drug doublets (PubMed, January 1, 2010 through December 31, 2013). The dose percentage was calculated for each drug: (safe dose in combination divided by single agent full dose) X 100. Additive dose percentage represented the sum of the dose percentage for each drug. A total of 144 studies (N = 8568 patients; 95 combinations) were analyzed. In 51% of trials, each of the two drugs could be administered at 100% of their full dose. The lowest safe additive dose percentage was 60% if targets and/or class of drugs overlapped, or in the presence of mTor inhibitors, which sometimes compromised the combination dose. If neither class nor target overlapped and if mTor inhibitors were absent, the lowest safe additive dose percentage was 143%. The current observations contribute to the knowledge base that informs safe starting doses for new combinations of targeted drugs in the context of clinical trials or practice, hence facilitating customized combination therapies.

Targetable Clinical Nanoparticles for Precision Cancer Therapy Based on Disease-Specific Molecular Inflection Points

Novel translational approaches based on clinical modular nanoplatforms are needed in order to treat solid cancers according to their discrete molecular features. In the present study, we show that the clinical nanopharmaceutical Ferumoxytol, which consists of a glucose-based coat surrounding an iron oxide core, could identify molecular characteristics of prostate cancer, corresponding to unique phases of the disease continuum. By affixing a targeting probe for the prostate-specific membrane antigen on its surface, the nanopharmaceutical was able to assess the functional state of the androgen receptor pathway via MRI, guiding therapy and delivering it with the same clinical nanoparticle. In order to simultaneously inhibit signaling from key oncogenic pathways of more advanced forms of prostate cancer, a single-agent therapy for early stage disease to inhibit DNA replication, as well as combination therapy with two drugs co-retained within the nanopharmaceutical's polymeric coating, were tested and resulted in complete tumor ablation. Recalcitrant and terminal forms of the disease were effectively treated with a nanopharmaceutical delivering a combination that upregulates endoplasmic reticulum stress and inhibits metastasis, thereby showing that this multifunctional nanoplatform can be used in the clinic for patient stratification, as well as precision treatment based on the individual's unique disease features.

Molecular and Clinical Approach to Intra-abdominal Adverse Effects of Targeted Cancer Therapies

Targeted cancer therapies encompass an exponentially growing number of agents that involve a myriad of molecular pathways. To excel within this rapidly changing field of clinical oncology, radiologists must eschew traditional organ system-based approaches of cataloging adverse effects in favor of a conceptual framework that incorporates molecular mechanisms and associated clinical outcomes. Understanding molecular mechanisms that underlie imaging manifestations of adverse effects and known associations with treatment response allows radiologists to more effectively recognize adverse effects and differentiate them from tumor progression. Radiologists can therefore more effectively guide oncologists in the management of adverse effects and treatment decisions regarding continuation or cessation of drug therapy. Adverse effects from targeted cancer therapies can be classified into four categories: (a) category 1, on-target adverse effects associated with treatment response; (b) category 2, on-target adverse effects without associated treatment response; (c) category 3, off-target adverse effects; and (d) category 4, tumor necrosis-related adverse effects. This review focuses on adverse effects primarily within the abdomen and pelvis classified according to established or hypothesized molecular mechanisms and illustrated with images of classic examples and several potential emerging toxic effects. ^©RSNA, 2017.

PSMA-Targeted Theranostic Nanocarrier for Prostate Cancer

Herein, we report the use of a theranostic nanocarrier (Folate-HBPE(CT20p)) to deliver a therapeutic peptide to prostate cancer tumors that express PSMA (folate hydrolase 1). The therapeutic peptide (CT20p) targets and inhibits the chaperonin-containing TCP-1 (CCT) protein-folding complex, is selectively cytotoxic to cancer cells, and is non-toxic to normal tissue. With the delivery of CT20p to prostate cancer cells via PSMA, a dual level of cancer specificity is achieved: (1) selective targeting to PSMA-expressing prostate tumors, and (2) specific cytotoxicity to cancer cells with minimal toxicity to normal cells. The PSMA-targeting theranostic nanocarrier can image PSMA-expressing cells and tumors when a near infrared dye is used as cargo. Meanwhile, it can be used to treat PSMA-expressing tumors when a therapeutic, such as the CT20p peptide, is encapsulated within the nanocarrier. Even when these PSMA-targeting nanocarriers are taken up by macrophages, minimal cell death is observed in these cells, in contrast with doxorubicin-based therapeutics that result in significant macrophage death. Incubation of PSMA-expressing prostate cancer cells with the Folate-HBPE(CT20p) nanocarriers induces considerable changes in cell morphology, reduction in the levels of integrin β1, and lower cell adhesion, eventually resulting in cell death. These results are relevant as integrin β1 plays a key role in prostate cancer invasion and metastatic potential. In addition, the use of the developed PSMA-targeting nanocarrier facilitates the selective in vivo delivery of CT20p to PSMA-positive tumor, inducing significant reduction in tumor size.

Hepatocellular Toxicity Associated with Tyrosine Kinase Inhibitors: Mitochondrial Damage and Inhibition of Glycolysis

Tyrosine kinase inhibitors (TKIs) are anticancer drugs with a lesser toxicity than classical chemotherapeutic agents but still with a narrow therapeutic window. While hepatotoxicity is known for most TKIs, underlying mechanisms remain mostly unclear. We therefore aimed at investigating mechanisms of hepatotoxicity for imatinib, sunitinib, lapatinib and erlotinib in vitro. We treated HepG2 cells, HepaRG cells and mouse liver mitochondria with TKIs (concentrations 1–100 μM) for different periods of time and assessed toxicity. In HepG2 cells maintained with glucose (favoring glycolysis), all TKIs showed a time- and concentration-dependent cytotoxicity and, except erlotinib, a drop in intracellular ATP. In the presence of galactose (favoring mitochondrial metabolism), imatinib, sunitinib and erlotinib showed a similar toxicity profile as for glucose whereas lapatinib was less toxic. For imatinib, lapatinib and sunitinib, cytotoxicity increased in HepaRG cells induced with rifampicin, suggesting formation of toxic metabolites. In contrast, erlotinib was more toxic in HepaRG cells under basal than CYP-induced conditions. Imatinib, sunitinib and lapatinib reduced the mitochondrial membrane potential in HepG2 cells and in mouse liver mitochondria. In HepG2 cells, these compounds increased reactive oxygen species production, impaired glycolysis, and induced apoptosis. In addition, imatinib and sunitinib impaired oxygen consumption and activities of complex I and III (only imatinib), and reduced the cellular GSH pool. In conclusion, imatinib and sunitinib are mitochondrial toxicants after acute and long-term exposure and inhibit glycolysis. Lapatinib affected mitochondria only weakly and inhibited glycolysis, whereas the cytotoxicity of erlotinib could not be explained by a mitochondrial mechanism.

Conditional internalization of PEGylated nanomedicines by PEG engagers for triple negative breast cancer therapy

Triple-negative breast cancer (TNBC) lacks effective treatment options due to the absence of traditional therapeutic targets. The epidermal growth factor receptor (EGFR) has emerged as a promising target for TNBC therapy because it is overexpressed in about 50% of TNBC patients. Here we describe a PEG engager that simultaneously binds polyethylene glycol and EGFR to deliver PEGylated nanomedicines to EGFR⁺ TNBC. The PEG engager displays conditional internalization by remaining on the surface of TNBC cells until contact with PEGylated nanocarriers triggers rapid engulfment of nanocargos. PEG engager enhances the anti-proliferative activity of PEG-liposomal doxorubicin to EGFR⁺ TNBC cells by up to 100-fold with potency dependent on EGFR expression levels. The PEG engager significantly increases retention of fluorescent PEG probes and enhances the antitumour activity of PEGylated liposomal doxorubicin in human TNBC xenografts. PEG engagers with specificity for EGFR are promising for improved treatment of EGFR⁺ TNBC patients.

The majority of treatment options for cancers are ineffective due to limited therapeutic targeting. Here, the authors develop bispecific antibodies that effectively target nanomaterials to triple-negative breast cancer cell receptors and deliver therapeutics leading to inhibition of tumour growth.

Harnessing Solute Carrier Transporters for Precision Oncology

Solute Carrier (SLC) transporters are a large superfamily of transmembrane carriers involved in the regulated transport of metabolites, nutrients, ions and drugs across cellular membranes. A subset of these solute carriers play a significant role in the cellular uptake of many cancer therapeutics, ranging from chemotherapeutics such as antimetabolites, topoisomerase inhibitors, platinum-based drugs and taxanes to targeted therapies such as tyrosine kinase inhibitors. SLC transporters are co-expressed in groups and patterns across normal tissues, suggesting they may comprise a coordinated regulatory circuit serving to mediate normal tissue functions. In cancer however, there are dramatic changes in expression patterns of SLC transporters. This frequently serves to feed the increased metabolic demands of the tumor cell for amino acids, nucleotides and other metabolites, but also presents a therapeutic opportunity, as increased transporter expression may serve to increase intracellular concentrations of substrate drugs. In this review, we examine the regulation of drug transporters in cancer and how this impacts therapy response, and discuss novel approaches to targeting therapies to specific cancers via tumor-specific aberrations in transporter expression. We propose that among the oncogenic changes in SLC transporter expression there exist emergent vulnerabilities that can be exploited therapeutically, extending the application of precision medicine from tumor-specific drug targets to tumor-specific determinants of drug uptake.

Differences in symptom occurrence, severity, and distress ratings between patients with gastrointestinal cancers who received chemotherapy alone or chemotherapy with targeted therapy

BACKGROUND

Approximately 28% of patients with gastrointestinal (GI) cancers will receive targeted therapy (TT) because of the associated increases in survival. Only four studies have examined the symptom experience of these patients. To date, no studies have evaluated for differences in symptom occurrence, severity, and distress between patients who received chemotherapy (CTX) alone (n=304) or CTX with TT (n=93).

METHODS

Patients completed self-report questionnaires, approximately one week after they received CTX. A modified version of the Memorial Symptom Assessment Scale (MSAS) was used to obtain data on symptom occurrence, severity, and distress. Binary logistic regression analyses were used to test for differences in symptom occurrence rates between the two treatment groups. Ordinal logistic regression analyses were used to test for differences in severity and distress ratings between the two treatment groups.

RESULTS

Patients who received CTX with TT were significantly younger (P=0.009); were diagnosed with cancer longer (P=0.004); had a higher number of prior treatments (P=0.024); had metastatic disease, specifically to the liver (P<0.001); had a diagnosis of anal, colon, rectum, or colorectal cancer (CRC) (P<0.001); and were positive for detection of B-Raf proto-oncogene, serine/threonine kinase (BRAF) and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations (both P<0.001). In addition, CTX treatment regimens were significantly different between the two groups (P<0.001). After controlling for significant covariates, patients who received TT reported lower occurrence rates for lack of energy, cough, feeling drowsy, and difficulty sleeping (all, P<0.05). Patients who received TT reported lower severity scores for dry mouth (P=0.034) and change in the way food tastes (P=0.035). However, they reported higher severity scores for "I don't look like myself" (P=0.026). No differences in symptom distress scores were found between the two treatment groups.

CONCLUSIONS

This study is the first to evaluate for differences in the symptom experience of GI cancer patients who received CTX alone or CTX with TT using a multidimensional symptom assessment scale. While between group differences in patients' symptom experiences were identified, both treatment groups warrant ongoing assessments to optimally manage their symptoms.

Target Safety Assessment: Strategies and Resources

An in-depth evaluation of target safety is an invaluable resource throughout drug discovery and development. The goal of a target safety evaluation is to identify potential unintended adverse consequences of target modulation, and to propose a risk evaluation and mitigation strategy to shepherd compounds through the discovery and development pipeline, to confirm and characterize unavoidable on-target toxicities in a timely manner to assist in early program advancement decisions, and to anticipate, monitor, and manage potential clinical adverse events. The role of an experienced discovery toxicologist in synthesizing the available information into an actionable set of recommendations for a safety evaluation strategy is critical to its successful application in early discovery programs. This chapter presents a summary of some of the information types and sources that should be investigated, and approaches that can be taken to generate an early assessment of potential safety liabilities.

Protein-Protein Interactions (PPIs) as an Alternative to Targeting the ATP Binding Site of Kinase

Most of the developed kinase inhibitor drugs are ATP competitive and suffer from drawbacks such as off-target kinase activity, development of resistance due to mutation in the ATP binding pocket and unfavorable intellectual property situations. Besides the ATP binding pocket, protein kinases have binding sites that are involved in Protein-Protein Interactions (PPIs); these PPIs directly or indirectly regulate the protein kinase activity. Of recent, small molecule inhibitors of PPIs are emerging as an alternative to ATP competitive agents. Rational design of inhibitors for kinase PPIs could be carried out using molecular modeling techniques. In silico tools available for the prediction of hot spot residues and cavities at the PPI sites and the means to utilize this information for the identification of inhibitors are discussed. Moreover, in silico studies to target the Aurora B-INCENP PPI sites are discussed in context. Overall, this chapter provides detailed in silico strategies that are available to the researchers for carrying out structure-based drug design of PPI inhibitors.

The impact of DNA damage response gene polymorphisms on therapeutic outcomes in late stage ovarian cancer

Late stage epithelial ovarian cancer has a dismal prognosis. Identification of pharmacogenomic markers (i.e. polymorphisms) to stratify patients to optimize individual therapy is of paramount importance. We here report the retrospective analysis of polymorphisms in 5 genes (ATM, ATR, Chk1, Chk2 and CDK12) involved in the cellular response to platinum in a cohort of 240 cancer patients with late stage ovarian cancer. The aim of the present study was to evaluate associations between the above mentioned SNPs and patients’ clinical outcomes: overall survival (OS) and progression free survival (PFS). None of the ATM, ATR, Chk1 and Chk2 polymorphisms was found to significantly affect OS nor PFS in this cohort of patients. Genotype G/G of CDK12 polymorphism (rs1054488) predicted worse OS and PFS than the genotype A/A-A/G in univariate analysis. The predictive value was lost in the multivariate analysis. The positive correlation observed between this polymorphism and age, grade and residual tumor may explain why the CDK12 variant was not confirmed as an independent prognostic factor in multivariate analysis.The importance of CDK12 polymorphism as possible prognostic biomarker need to be confirmed in larger ovarian cancer cohorts, and possibly in other cancer population responsive to platinum agents.

Sulforaphane, a natural component of broccoli, inhibits vestibular schwannoma growth in vitro and in vivo

Vestibular schwannoma (VS) is an intracranial tumor that causes significant morbidity, including hearing loss, tinnitus, dizziness, and possibly even death from brainstem compression. However, FDA-approved pharmacologic treatments for VS do not exist. Sulforaphane (SFN) is a naturally occurring isothiocyanate found in cruciferous vegetables, such as broccoli, with potent chemoprotective effects in several cell types. Our objective was to determine whether SFN is effective against VS in vitro and in vivo. Human primary VS cells, HEI-193 schwannoma cells, and SC4 Nf2^−/− Schwann cells were used to investigate the inhibitory effects of SFN in vitro. Cell proliferation was assessed by bromodeoxyuridine (BrdU) incorporation, and cell viability and metabolic activity was calculated by MTT assay. Apoptosis was measured by flow cytometry, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and Western blot for cleaved caspases. A mouse model with a murine schwannoma allograft was also used to examine the antitumor activity of SFN. SFN exhibited significant antiproliferative activity in schwannoma cells in vitro, via the inhibition of HDAC activity and the activation of ERK. SFN treatment induced apoptosis and cell cycle arrest at the G2/M phase. SFN also significantly inhibited schwannoma growth in vivo. Our preclinical studies motivate a future prospective clinical study of SFN for the treatment of VS.

Antineoplastic-related cardiotoxicity, morphofunctional aspects in a murine model: contribution of the new tool 2D-speckle tracking

OBJECTIVE

Considering that global left ventricular systolic radial strain is a sensitive technique for the early detection of left ventricular dysfunction due to antineoplastics and the analysis of segmental myocardial contractility, we evaluated this technique for early detection of trastuzumab-related cardiotoxicity by comparing it with cardiac structural damage.

METHODS

Groups of six mice were injected with trastuzumab or doxorubicin, used either as single agents or in combination. Cardiac function was evaluated by transthoracic echocardiography measurements before and after treatment for 2 or 7 days, by using a Vevo 2100 high-resolution imaging system. After echocardiography, mice were euthanized, and hearts were processed for histological evaluations, such as cardiac fibrosis, apoptosis, capillary density, and inflammatory response.

RESULTS

Trastuzumab-related cardiotoxicity was detected early by 2D strain imaging. Radial strain was reduced after 2 days in mice treated with trastuzumab alone (21.2%±8.0% vs 40.5%±4.8% sham; P<0.01). Similarly, trastuzumab was found to induce apoptosis, capillary density reduction, and inflammatory response in cardiac tissue after 2 days of treatment, in a fashion similar to doxorubicin. On the contrary, fractional shortening reduction and cardiac fibrosis were observed only after 7 days of trastuzumab treatment, in contrast to doxorubicin treatment which induced early fibrosis and fractional shortening reduction.

CONCLUSION

The reduction of left ventricular systolic strain after 2 days of trastuzumab treatment may indicate early myocardial functional damage before the reduction in left ventricular ejection fraction and this early dysfunction is well correlated with structural myocardial damage, such as apoptosis and inflammatory response. Fractional shortening reduction after 7 days of trastuzumab treatment is related to fibrosis in cardiac tissue.

Targeting angiogenesis in gastrointestinal tumors: current challenges

Colorectal cancer (CRC) is one of the few cancers where screening modalities are standardized, but it still remains the third leading cause of cancer related mortality. For more than a decade now, the approval of anti-angiogenic therapy has led to an increase in the rate of overall survival (OS) of patients with advanced colon cancer. The drawback of the anti-angiogenic therapy is that their effect is short-lived and many patients progress through these therapies. Various mechanisms of resistance have been hypothesized, but overcoming this has been challenging. Also, there are no standardized predictive biomarkers that could aid in selecting patients who responds to the therapy upfront. This review focuses on the basis of angiogenesis, describing the approved anti-angiogenic therapies, discusses the challenges in terms of resistance to anti-angiogenic therapy and also the role of biomarkers. In the future, hopefully newer targeted therapies, immunotherapy, combination therapies and the standardization of biomarkers may result in improved outcomes and cure rates.

Dosing targeted and cytotoxic two-drug combinations: Lessons learned from analysis of 24,326 patients reported 2010 through 2013

Combining agents has the potential to attenuate resistance in metastatic cancer. However, knowledge of appropriate starting doses for novel drug combinations in clinical trials and practice is lacking. Analysis of 372 published studies was used to ascertain safe starting doses for doublets involving a cytotoxic and targeted agent. Phase I–III adult oncology clinical trial publications (January 1, 2010 to December 31, 2013) were identified (PubMed). The dose of drug used in each combination was compared to the single agent recommended dose [FDA‐approved/recommended phase 2 dose (RP2D)/maximum tolerated dose (MTD)]. Dose percentages were calculated as: (safe dose of drug in combination/dose of drug as single agent at FDA/RP2D/MTD) × 100. Additive dose percentages were the sum of the dose percentage for each drug. A total of 24,326 patients (248 drug combinations) were analyzed. In 38% of studies, both drugs could be administered at 100% of their FDA‐approved/RP2D/MTD dose. The lowest safe additive dose percentage was 41% with poly‐ADP ribose polymerase (PARP) or histone deacetylase inhibitors as the targeted agents; 82%, in the absence of these agents; and 97%, with an antibody in the combination. If one drug was administered at 100% of the single agent dose, the lowest safe dose percentage for the second drug was 17% (cytotoxic at 100%) or 36% (targeted at 100%) of the FDA‐approved/RP2D/MTD dose. The current findings can help inform safe starting doses for novel two‐drug combinations (cytotoxic and targeted agents) in the context of clinical trials and practice.

What's new?

Cytotoxic and targeted cancer drugs act through distinct mechanisms, and when used in combination they can potentially augment therapeutic effectiveness while minimally impacting toxicity. However, whereas algorithms for safe starting doses for new single‐agent therapies are well established, there are few guidelines for combination therapies. Here, analyses of data from published Phase I–III clinical trials shows that about 38% of patients tolerated combinations in which both drugs were administered at full starting doses. In the majority of patients, significant dose reductions were required to guard against toxicity. Intrapatient dose escalation is possible, however, potentially allowing for increased efficacy.

Erlotinib and the Risk of Oral Cancer: The Erlotinib Prevention of Oral Cancer (EPOC) Randomized Clinical Trial

IMPORTANCE

Standard molecularly based strategies to predict and/or prevent oral cancer development in patients with oral premalignant lesions (OPLs) are lacking.

OBJECTIVE

To test if the epidermal growth factor receptor inhibitor erlotinib would reduce oral cancer development in patients with high-risk OPLs defined by specific loss of heterozygosity (LOH) profiles. Secondary objectives included prospective determination of LOH as a prognostic marker in OPLs.

DESIGN

The Erlotinib Prevention of Oral Cancer (EPOC) study was a randomized, placebo-controlled, double-bind trial. Accrual occurred from November 2006 through July 2012, with a median follow-up time of 35 months in an ambulatory care setting in 5 US academic referral institutions. Patients with OPLs were enrolled in the protocol, and each underwent LOH profiling (N = 379); they were classified as high-risk (LOH-positive) or low-risk (LOH-negative) patients based on their LOH profiles and oral cancer history. The randomized sample consisted of 150 LOH-positive patients.

INTERVENTIONS

Oral erlotinib treatment (150 mg/d) or placebo for 12 months.

MAIN OUTCOMES AND MEASURES

Oral cancer-free survival (CFS).

RESULTS

A total of 395 participants were classified with LOH profiles, and 254 were classified LOH positive. Of these, 150 (59%) were randomized, 75 each to the placebo and erlotinib groups. The 3-year CFS rates in placebo- and erlotinib-treated patients were 74% and 70%, respectively (hazard ratio [HR], 1.27; 95% CI, 0.68-2.38; P = .45). The 3-year CFS was significantly lower for LOH-positive compared with LOH-negative groups (74% vs 87%, HR, 2.19; 95% CI, 1.25-3.83; P = .01). Increased EGFR gene copy number correlated with LOH-positive status (P < .001) and lower CFS (P = .01). The EGFR gene copy number was not predictive of erlotinib efficacy. Erlotinib-induced skin rash was associated with improved CFS (P = .01).

CONCLUSIONS AND RELEVANCE

In this trial, LOH was validated as a marker of oral cancer risk and found to be associated with increased EGFR copy number (the target of the intervention). Erlotinib did not, however, improve CFS in high-risk patients with LOH-positive or high-EGFR-gene-copy-number OPLs. These results support incorporation of LOH testing as a prognostic tool in routine clinical practice but do not support erlotinib use in this setting.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00402779.

A simplified interventional mapping system (SIMS) for the selection of combinations of targeted treatments in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is a leading cause of death worldwide. Targeted monotherapies produce high regression rates, albeit for limited patient subgroups, who inevitably succumb. We present a novel strategy for identifying customized combinations of triplets of targeted agents, utilizing a simplified interventional mapping system (SIMS) that merges knowledge about existent drugs and their impact on the hallmarks of cancer. Based on interrogation of matched lung tumor and normal tissue using targeted genomic sequencing, copy number variation, transcriptomics, and miRNA expression, the activation status of 24 interventional nodes was elucidated. An algorithm was developed to create a scoring system that enables ranking of the activated interventional nodes for each patient. Based on the trends of co-activation at interventional points, combinations of drug triplets were defined in order to overcome resistance. This methodology will inform a prospective trial to be conducted by the WIN consortium, aiming to significantly impact survival in metastatic NSCLC and other malignancies.

Update on Cardiovascular Safety of Tyrosine Kinase Inhibitors: With a Special Focus on QT Interval, Left Ventricular Dysfunction and Overall Risk/Benefit

We previously reviewed the cardiovascular safety of 16 tyrosine kinase inhibitors (TKIs), approved for use in oncology as of 30 September 2012. Since then, the indications for some of them have been widened and an additional nine TKIs have also been approved as of 30 April 2015. Eight of these nine are indicated for use in oncology and one (nintedanib) for idiopathic pulmonary fibrosis. This report is an update on the cardiovascular safety of those 16 TKIs, including the post-marketing data concerning their pro-arrhythmic effects, and reviews the cardiovascular safety of the nine new TKIs approved since (afatinib, cabozantinib, ceritinib, dabrafenib, ibrutinib, lenvatinib, nintedanib, ponatinib, and trametinib). As before, we focus on specific aspects of cardiovascular safety, namely their potential to induce QT interval prolongation, left ventricular (LV) dysfunction and hypertension but now also summarise the risks of arterial thromboembolic events (ATEs) associated with these agents. Of the newer TKIs, cabozantinib and ceritinib have been shown to induce a mild to moderate degree of QTc interval prolongation while cardiac dysfunction has been reported with the use of afatinib, dabrafenib, lenvatinib, ponatinib and trametinib. The label for axitinib was revised to include a new association with cardiac dysfunction. Hypertension is associated with cabozantinib, lenvatinib, nintedanib, ponatinib and trametinib. Ponatinib, within 10 months of its approval in December 2012, required voluntary (temporary) suspension of its marketing until significant safety revisions (restricted indication, additional warnings and precautions about the risk of arterial occlusion and thromboembolic events and amended dose) were made to its label. Compared with the previous 16 TKIs, more of the recently introduced TKIs are associated with the risk of LV dysfunction, and fewer with QT prolongation. Available data on morbidity and mortality associated with TKIs, together with post-marketing experience with lapatinib and ponatinib, emphasise the need for effective pharmacovigilance and ongoing re-assessment of their risk/benefit after approval of these novel agents. If not adequately managed, these cardiovascular effects significantly decrease the quality of life and increase the morbidity and mortality in a population already at high risk. Evidence accumulated over the last decade suggests that their clinical benefit, although worthwhile, is modest and extends only to progression-free survival and complete response without any effect on overall survival. During uncontrolled use in routine clinical practice, their risk/benefit is likely to be inferior to that perceived from highly controlled clinical trials.

The steady progress of targeted therapies, promising advances for lung cancer

Lung cancer remains one of the most complex and challenging cancers, being responsible for almost a third of all cancer deaths. This grim picture seems however to be changing, for at least a subset of lung cancers. The number of patients who can benefit from targeted therapies is steadily increasing thanks to the progress made in identifying actionable driver lesions in lung tumours. The success of the latest generation of EGFR and ALK inhibitors in the clinic not only illustrates the value of targeted therapies, but also shows how almost inevitably drug resistance develops. Therefore, more sophisticated approaches are needed to achieve long-term remissions. Although there are still significant barriers to be overcome, technological advances in early detection of relevant mutations and the opportunity to test new drugs in predictive preclinical models justify the hope that we will overcome these obstacles.

Genetic Association of Curative and Adverse Reactions to Tyrosine Kinase Inhibitors in Chinese advanced Non-Small Cell Lung Cancer patients

Epidermal growth factor receptor (EGFR) Tyrosine kinase inhibitor (TKI) is an effective targeted therapy for advanced non-small cell lung cancer (NSCLC) but also causes adverse drug reactions (ADRs) e.g., skin rash and diarrhea. SNPs in the EGFR signal pathway, drug metabolism/ transport pathways and miRNA might contribute to the interpersonal difference in ADRs but biomarkers for therapeutic responses and ADRs to TKIs in Chinese population are yet to be fully investigated. We recruited 226 Chinese advanced NSCLC patients who received TKIs erlotinib, gefitinib and icotinib hydrochloride and systematically studied the genetic factors associated with therapeutic responses and ADRs. Rs884225 (T > C) in EGFR 3' UTR was significantly associated with lower risk of ADRs to erlotinib (p value = 0.0010, adjusted p value = 0.042). A multivariant interaction four-SNP model (rs884225 in EGFR 3'UTR, rs7787082 in ABCB1 intron, rs38845 in MET intron and rs3803300 in AKT1 5'UTR) was associated with ADRs in general and the more specific drug induced skin injury. The SNPs associated with both therapeutic responses and ADRs indicates they might share a common genetic basis. Our study provided potential biomarkers and clues for further research of biomarkers for therapeutic responses and ADRs in Chinese NSCLC patients.

Diagnosis, monitoring and management of immune-related adverse drug reactions of anti-PD-1 antibody therapy

PD-1 checkpoint inhibitors are associated with a specific spectrum of immune-related adverse events. This spectrum is different from toxicities known for kinase inhibitors or cytotoxic drugs. Since PD-1 directed therapies show effectivity in an increasing number of malignant diseases, their clinical usage will increase rapidly. Therefore clinicians from different specialities such as medical oncology, internal medicine, family doctors and emergency unit staff should be aware of the adverse effects of PD-1 checkpoint inhibitors to avoid delays in diagnosis and treatment. Based on pooled data from pivotal trials as reported by the European Medicines Agency, the present paper reviews incidences and kinetics of onset and resolution of immune-mediated "adverse events of specific interest" (AEOSI) of both approved PD-1 inhibitors nivolumab and pembrolizumab. In general, the severity of AEOSI is mild to moderate (grade 1-2); the frequency of immune-mediated but also idiopathic grade 3-4 adverse drug reactions is ⩽2% for any event term. Recommendations for the diagnosis, monitoring and management of the relevant dermatological, gastrointestinal, pulmonary, endocrine, renal and hepatic toxicities are convened by an expert panel that consolidated and clarified treatment recommendations after the onset of AEOSI. Although the time of onset is not predictable - the medians range from 1 to 6months - the huge majority of events is reversible, with no impact of the time of onset. By the systemic use of glucocorticoids, notably methylprednisolone or equivalents, most AEOSI are well manageable. Non-steroidal immunosuppressants may be used in certain cases of refractory/recalcitrant, long-lasting immune toxicities. With regard to the outstanding clinical activity of the anti-PD-1 antibodies, therapy restart is the principal therapeutic option after recovery of grade 2 AEOSI, or diminution of higher grade skin or endocrine events to mild severity. Early diagnosis and close clinical monitoring are essential for successful management of immune-related adverse events.