Pharmacodynamic biomarkers: falling short of the mark?

Noninvasive radiomic biomarkers for predicting pseudoprogression and hyperprogression in patients with non-small cell lung cancer treated with immune checkpoint inhibition

This study aimed to develop a computed tomography (CT)-based radiomics model capable of precisely predicting hyperprogression and pseudoprogression (PP) in patients with non-small cell lung cancer (NSCLC) treated with immunotherapy. We retrospectively analyzed 105 patients with NSCLC, from three institutions, treated with immune checkpoint inhibitors (ICIs) and categorized them into training and independent testing set. Subsequently, we processed CT scans with a series of image-preprocessing techniques, and 6008 radiomic features capturing intra- and peritumoral texture patterns were extracted. We used the least absolute shrinkage and selection operator logistic regression model to select radiomic features and construct machine learning models. To further differentiate between progressive disease (PD) and hyperprogressive disease (HPD), we developed a new radiomics model. The logistic regression (LR) model showed optimal performance in distinguishing PP from HPD, with areas under the receiver operating characteristic curve (AUC) of 0.95 (95% confidence interval [CI]: 0.91-0.99) and 0.88 (95% CI: 0.66-1) in the training and testing sets, respectively. Additionally, the support vector machine model showed optimal performance in distinguishing PD from HPD, with AUC of 0.97 (95% CI: 0.93-1) and 0.87 (95% CI: 0.72-1) in the training and testing sets, respectively. Kaplan‒Meier survival curves showed clear stratification between PP predicted by the radiomics model and true progression (HPD and PD) (hazard ratio = 0.337, 95% CI: 0.200-0.568, p < 0.01) in overall survival. Our study demonstrates that radiomic features extracted from baseline CT scans are effective in predicting PP and HPD in patients with NSCLC treated with ICIs.

Tumor response assessment on imaging following immunotherapy

In recent years, various systemic immunotherapies have been developed for cancer treatment, such as monoclonal antibodies (mABs) directed against immune checkpoints (immune checkpoint inhibitors, ICIs), oncolytic viruses, cytokines, cancer vaccines, and adoptive cell transfer. While being estimated to be eligible in 38.5% of patients with metastatic solid or hematological tumors, ICIs, in particular, demonstrate durable disease control across many oncologic diseases (e.g., in melanoma, lung, bladder, renal, head, and neck cancers) and overall survival benefits. Due to their unique mechanisms of action based on T-cell activation, response to immunotherapies is characterized by different patterns, such as progression prior to treatment response (pseudoprogression), hyperprogression, and dissociated responses following treatment. Because these features are not encountered in the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), which is the standard for response assessment in oncology, new criteria were defined for immunotherapies. The most important changes in these new morphologic criteria are, firstly, the requirement for confirmatory imaging examinations in case of progression, and secondly, the appearance of new lesions is not necessarily considered a progressive disease. Until today, five morphologic (immune-related response criteria (irRC), immune-related RECIST (irRECIST), immune RECIST (iRECIST), immune-modified RECIST (imRECIST), and intra-tumoral RECIST (itRECIST)) criteria have been developed to accurately assess changes in target lesion sizes, taking into account the specific response patterns after immunotherapy. In addition to morphologic response criteria, 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) is a promising option for metabolic response assessment and four metabolic criteria are used (PET/CT Criteria for Early Prediction of Response to Immune Checkpoint Inhibitor Therapy (PECRIT), PET Response Evaluation Criteria for Immunotherapy (PERCIMT), immunotherapy-modified PET Response Criteria in Solid Tumors (imPERCIST5), and immune PERCIST (iPERCIST)). Besides, there is evidence that parameters on 18F-FDG-PET/CT, such as the standardized uptake value (SUV)max and several radiotracers, e.g., directed against PD-L1, may be potential imaging biomarkers of response. Moreover, the emerge of human intratumoral immunotherapy (HIT-IT), characterized by the direct injection of immunostimulatory agents into a tumor lesion, has given new importance to imaging assessment. This article reviews the specific imaging patterns of tumor response and progression and available imaging response criteria following immunotherapy.

Impact of pharmacodynamic biomarkers in immuno-oncology phase 1 clinical trials

BACKGROUND

Phase 1 immuno-oncology (IO) trials frequently involve pharmacodynamic (PD) biomarker assessments involving tumour biopsies and/or blood collection, with increasing use of molecular imaging. PD biomarkers are set to play a fundamental role in early drug development of immuno-oncology (IO) agents. In the IO era, the impact of PD biomarkers for confirmation of biologic activity and their role in subsequent drug development have not been investigated.

METHODS

Phase 1 studies published between January 2014 and December 2020 were reviewed. Studies that reported on-treatment PD biomarkers [tissue-derived (tissue-PD), blood-based (blood-PD) and imaging-based (imaging-PD)] were analysed. PD biomarker results and their correlation with clinical activity endpoints were evaluated. Authors' statements on the influence of PD biomarkers on further drug development decisions, and subsequent citations of PD biomarker study results were recorded.

RESULTS

Among 386 trials, the most frequent IO agent classes evaluated were vaccines (32%) and PD-(L)1 inhibitors (25%). No PD biomarker assessments were reported in 100 trials (26%). Of the remaining 286, blood-PD, tissue-PD, and imaging-PD data were reported in 270 (94%), 94 (33%), and 12 (4%) trials, respectively. Assessments of more than one PD biomarker type were reported in 82 studies (29%). Similar proportions of blood-PD (9%), tissue-PD (7%), and imaging-PD studies (8%) had positive results that correlated with clinical activity. Results of 22 PD biomarker studies (8%) were referenced in subsequent clinical trials.

CONCLUSIONS

Most phase 1 IO studies performed PD biomarker assessments. Overall, positive PD biomarker results were infrequently correlated with clinical activity or cited in subsequent trials, suggesting a limited impact on subsequent drug development. With emerging health regulatory emphasis on optimal dose selection based on PD activity, more informative and integrative multiplexed assays that capture the complexity of tumour-host immunity interactions are warranted to improve phase 1 IO trial methodology.

Independent Drug Action in Combination Therapy: Implications for Precision Oncology

Combination therapies are superior to monotherapy for many cancers. This advantage was historically ascribed to the ability of combinations to address tumor heterogeneity, but synergistic interaction is now a common explanation as well as a design criterion for new combinations. We review evidence that independent drug action, described in 1961, explains the efficacy of many practice-changing combination therapies: it provides populations of patients with heterogeneous drug sensitivities multiple chances of benefit from at least one drug. Understanding response heterogeneity could reveal predictive or pharmacodynamic biomarkers for more precise use of existing drugs and realize the benefits of additivity or synergy.

Pseudoprogression in lung cancer patients treated with immunotherapy

Lung cancer has attracted much attention because of its high morbidity and mortality worldwide. The advent of immunotherapy approaches, especially the application of immune checkpoint inhibitors (ICIs) has dramatically changed the treatment of lung cancer, but a novel and unexpected pattern of treatment response-- pseudoprogression, has been observed simultaneously which complicates the routine clinical evaluation and management. However, manifestations of pseudoprogression vary and there are many disputes on immune-related response assessment and corresponding treatments for lung cancer. Therefore, we summarized the possible mechanisms, clinical manifestations and corresponding treatment measures of pseudoprogression in lung cancer, as well as potential methods to differentiate pseudoprogression from true tumor progression.

Integrating Molecular Biomarker Inputs Into Development and Use of Clinical Cancer Therapeutics

Biomarkers can contribute to clinical cancer therapeutics at multiple points along the patient’s diagnostic and treatment course. Diagnostic biomarkers can screen or classify patients, while prognostic biomarkers predict their survival. Biomarkers can also predict treatment efficacy or toxicity and are increasingly important in development of novel cancer therapeutics. Strategies for biomarker identification have involved large-scale genomic and proteomic analyses. Pathway-specific biomarkers are already in use to assess the potential efficacy of immunotherapy and targeted cancer therapies. Judicious application of machine learning techniques can identify disease-relevant features from large data sets and improve predictive models. The future of biomarkers likely involves increasing utilization of liquid biopsy and multiple samplings to better understand tumor heterogeneity and identify drug resistance.

BET Proteins as Attractive Targets for Cancer Therapeutics

Transcriptional dysregulation is a hallmark of cancer and can be an essential driver of cancer initiation and progression. Loss of transcriptional control can cause cancer cells to become dependent on certain regulators of gene expression. Bromodomain and extraterminal domain (BET) proteins are epigenetic readers that regulate the expression of multiple genes involved in carcinogenesis. BET inhibitors (BETis) disrupt BET protein binding to acetylated lysine residues of chromatin and suppress the transcription of various genes, including oncogenic transcription factors. Phase I and II clinical trials demonstrated BETis’ potential as anticancer drugs against solid tumours and haematological malignancies; however, their clinical success was limited as monotherapies. Emerging treatment-associated toxicities, drug resistance and a lack of predictive biomarkers limited BETis’ clinical progress. The preclinical evaluation demonstrated that BETis synergised with different classes of compounds, including DNA repair inhibitors, thus supporting further clinical development of BETis. The combination of BET and PARP inhibitors triggered synthetic lethality in cells with proficient homologous recombination. Mechanistic studies revealed that BETis targeted multiple essential homologous recombination pathway proteins, including RAD51, BRCA1 and CtIP. The exact mechanism of BETis’ anticancer action remains poorly understood; nevertheless, these agents provide a novel approach to epigenome and transcriptome anticancer therapy.

Pharmacodynamic and pharmacokinetic profiles of a neurotensin receptor type 2 (NTS2) analgesic macrocyclic analog

The current opioid crisis highlights the urgent need to develop safe and effective pain medications. Thus, neurotensin (NT) compounds represent a promising approach, as the antinociceptive effects of NT are mediated by activation of the two G protein-coupled receptor subtypes (i.e., NTS1 and NTS2) and produce potent opioid-independent analgesia. Here, we describe the synthesis and pharmacodynamic and pharmacokinetic properties of the first constrained NTS2 macrocyclic NT(8-13) analog. The Tyr¹¹ residue of NT(8-13) was replaced with a Trp residue to achieve NTS2 selectivity, and a rationally designed side-chain to side-chain macrocyclization reaction was applied between Lys⁸ and Trp¹¹ to constrain the peptide in an active binding conformation and limit its recognition by proteolytic enzymes. The resulting macrocyclic peptide, CR-01-64, exhibited high-affinity for NTS2 (K_i 7.0 nM), with a more than 125-fold selectivity over NTS1, as well as an improved plasma stability profile (t_1/2 > 24 h) compared with NT (t_1/2 ~ 2 min). Following intrathecal administration, CR-01-64 exerted dose-dependent and long-lasting analgesic effects in acute (ED₅₀ = 4.6 µg/kg) and tonic (ED₅₀ = 7.1 µg/kg) pain models as well as strong mechanical anti-allodynic effects in the CFA-induced chronic inflammatory pain model. Of particular importance, this constrained NTS2 analog exerted potent nonopioid antinociceptive effects and potentiated opioid-induced analgesia when combined with morphine. At high doses, CR-01-64 did not cause hypothermia or ileum relaxation, although it did induce mild and short-term hypotension, all of which are physiological effects associated with NTS1 activation. Overall, these results demonstrate the strong therapeutic potential of NTS2-selective analogs for the management of pain.

From the Broad Phase II Trial to Precision Oncology: A Perspective on the Origins of Basket and Umbrella Clinical Trial Designs in Cancer Drug Development

Oncologic phase II trials that evaluate the activity of new therapeutic agents have evolved dramatically over the past 50 years. The standard approach beginning in the late 1960s focused on individual studies that evaluated new anticancer agents against a wide range of both solid and hematopoietic malignancies often in a single "broad phase II trial" that included hundreds of patients; such studies efficiently established the landscape for subsequent development of a specific drug with respect to likely disease focus, toxicity, dose, and schedule. In the 1980s and 1990s, emphasis on histological context drove an explosion in the number of individual phase II trials conducted; despite this increase in trial activity, investigations based on histology per se failed to improve the success rate of new agents brought to the clinic. Over the past 20 years, evolution toward a molecular drug development paradigm has demonstrably improved our ability to select patients more likely to benefit from systemic treatment; simultaneously, technological advances have permitted initial attempts at the rapid assignment of therapy based on predefined molecular characteristics of tumor or germline in broad-based master protocols that are inclusive of many diseases and molecularly characterized disease subsets, akin to but much more sophisticated scientifically than the broad phase II platforms of the past.

Prediction of active human dose: learnings from 20 years of Merck KGaA experience, illustrated by case studies

High-quality dose predictions based on a good understanding of target engagement is one of the main translational goals in drug development. Here, we systematically evaluate active human dose predictions for 15 Merck KGaA/EMD Serono assets spanning several modalities and therapeutic areas. Using case studies, we illustrate the value of adhering to the translational best practices of having an exposure-response relationship in an appropriate animal model; having validated, translatable pharmacodynamic (PD) biomarkers measurable in Phase I populations in the right tissue; having a deeper understanding of biology; and capturing uncertainties in predictions. Given the gap in publications on the subject, we believe that the learnings from this unique diverse data set, which are generic to the industry, will trigger actions to improve future predictions.

A window-of-opportunity trial of the CXCR1/2 inhibitor reparixin in operable HER-2-negative breast cancer

Background

Cancer stem cells (CSCs) are purported to be responsible for tumor initiation, treatment resistance, disease recurrence, and metastasis. CXCR1, one of the receptors for CXCL8, was identified on breast cancer (BC) CSCs. Reparixin, an investigational allosteric inhibitor of CXCR1, reduced the CSC content of human BC xenograft in mice.

Methods

In this multicenter, single-arm trial, women with HER-2-negative operable BC received reparixin oral tablets 1000 mg three times daily for 21 days before surgery. Primary objectives evaluated the safety of reparixin and the effects of reparixin on CSC and tumor microenvironment in core biopsies taken at baseline and at treatment completion. Signal of activity was defined as a reduction of ≥ 20% in ALDH⁺ or CD24⁻/CD44⁺ CSC by flow cytometry, with consistent reduction by immunohistochemistry.

Results

Twenty patients were enrolled and completed the study. There were no serious adverse reactions. CSC markers ALDH⁺ and CD24⁻/CD44⁺ measured by flow cytometry decreased by ≥ 20% in 4/17 and 9/17 evaluable patients, respectively. However, these results could not be confirmed by immunofluorescence due to the very low number of CSC.

Conclusions

Reparixin appeared safe and well-tolerated. CSCs were reduced in several patients as measured by flow cytometry, suggesting targeting of CXCR1 on CSC.

Clinical trial registration

Clinicaltrials.gov, NCT01861054. Registered on April 18, 2013.

Imaging of tumour response to immunotherapy

A wide range of cancer immunotherapy approaches has been developed including non-specific immune-stimulants such as cytokines, cancer vaccines, immune checkpoint inhibitors (ICIs), and adoptive T cell therapy. Among them, ICIs are the most commonly used and intensively studied. Since 2011, these drugs have received marketing authorisation for melanoma, lung, bladder, renal, and head and neck cancers, with remarkable and long-lasting treatment response in some patients. The novel mechanism of action of ICIs, with immune and T cell activation, leads to unusual patterns of response on imaging, with the advent of so-called pseudoprogression being more pronounced and frequently observed when compared to other anticancer therapies. Pseudoprogression, described in about 2–10% of patients treated with ICIs, corresponds to an increase of tumour burden and/or the appearance of new lesions due to infiltration by activated T cells before the disease responds to therapy. To overcome the limitation of response evaluation criteria in solid tumors (RECIST) to assess these specific changes, new imaging criteria—so-called immune-related response criteria and then immune-related RECIST (irRECIST)—were proposed. The major modification involved the inclusion of the measurements of new target lesions into disease assessments and the need for a 4-week re-assessment to confirm or not confirm progression. The RECIST working group introduced the new concept of “unconfirmed progression”, into the irRECIST. This paper reviews current immunotherapeutic approaches and summarises radiologic criteria to evaluate new patterns of response to immunotherapy. Furthermore, imaging features of immunotherapy-related adverse events and available predictive biomarkers of response are presented.

Genomics and the History of Precision Oncology

Progress toward the implementation of a molecular characterization paradigm in cancer drug development over the past 20 years has markedly enhanced our capability to select patients who are more likely to benefit from cancer therapy. Improvements in genomic and related diagnostic testing platforms have permitted evaluation of the efficacy of treatment assignment based on predefined biologic features of a patient's tumor or germline using master protocols that may include many malignancies and their molecularly characterized subsets. With this approach, a wide range of new targeted and immunologic treatment approaches have been defined for patients who, heretofore, lacked effective therapeutic options.

FLT PET/CT imaging of metastatic prostate cancer patients treated with pTVG-HP DNA vaccine and pembrolizumab

Background

Immunotherapy has demonstrated remarkable success in treating different cancers. Nonetheless, a large number of patients do not respond, many respond without immediate changes detectable with conventional imaging, and many have unusual immune-related adverse events that cannot be predicted in advance. In this exploratory study, we investigate how 3′-Deoxy-3’-¹⁸F-fluorothymidine (FLT) positron emission tomography (PET) measurements of tumor and immune cell proliferation might be utilized as biomarkers in immunotherapy.

Methods

Seventeen patients with metastatic castrate resistant prostate cancer were treated with combination pTVG-HP DNA vaccine and pembrolizumab. Patients underwent baseline and 12-week FLT PET/CT scans. FLT PET standardized uptake values (SUVs) were extracted from tumors, non-metastatic lymph nodes, spleen, bone marrow, pancreas, and thyroid to quantify cell proliferation in these tissues. Regional immune cell responses to pTVG-HP DNA vaccine were assessed by comparing FLT uptake changes in vaccine draining and non-draining lymph nodes. Cox proportional hazards regression was utilized to relate FLT uptake and other clinical markers (PSA and tumor size) to progression-free survival. Area under receiver operating characteristic (AUC) curves and concordance indices were used to assess the predictive capabilities of FLT uptake.

Results

Changes in FLT uptake in vaccine draining lymph nodes were significantly greater than changes in non-draining lymph nodes (P = 0.02), suggesting a regional immune response to vaccination. However, the changes in FLT uptake in lymph nodes were not significantly predictive of progression-free survival. Increases in tumor FLT uptake were significantly predictive of shorter progression-free survival (concordance index = 0.83, P < 0.01). Baseline FLT uptake in the thyroid was significantly predictive of whether or not a patient would subsequently experience a thyroid-related adverse event (AUC = 0.97, P < 0.01).

Conclusions

FLT PET uptake was significantly predictive of progression-free survival and the occurrence of adverse events relating to thyroid function. The results suggest FLT PET imaging has potential as a biomarker in immunotherapy, providing a marker of tumor and immune responses, and as a possible means of anticipating specific immune-related adverse events.

Trial registration

NCT02499835.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0516-1) contains supplementary material, which is available to authorized users.

How scientific literature analysis yields innovative therapeutic hypothesis through integrative iterations

It is becoming generally accepted that the current diagnostic system often guarantees, rather than diminishes, disease heterogeneity. In effects, syndrome-dominated conceptual thinking has become a barrier to understanding the biological causes of complex, multifactorial diseases characterized by clinical and therapeutic heterogeneity. Furthermore, not only is the flood of currently available medical and biological information highly heterogeneous, it is also often conflicting. Together with the entire absence of functional models of pathogenesis and pathological evolution of complex diseases, this leads to a situation where illness activity cannot be coherently approached and where therapeutic developments become highly problematic. Acquisition of the necessary knowledge can be obtained, in parts, using in silico models produced through analytical approaches and processes collectively known as `Systems Biology'. However, without analytical approaches that specifically incorporate the facts that all that is called `information' is not necessarily useful nor utilisable and that all information should be considered as a priori suspect, modelling attempts will fail because of the much too numerous conflicting and, although correct in molecular terms, physiologically invalid reports. In the present essay, we suggest means whereby this body of problems could be functionally attacked and describe new analytical approaches that have demonstrated their efficacy in alleviating these difficulties.

Clinical decision making in cancer care: a review of current and future roles of patient age

Background

Patient age is among the most controversial patient characteristics in clinical decision making. In personalized cancer medicine it is important to understand how individual characteristics do affect practice and how to appropriately incorporate such factors into decision making. Some argue that using age in decision making is unethical, and how patient age should guide cancer care is unsettled. This article provides an overview of the use of age in clinical decision making and discusses how age can be relevant in the context of personalized medicine.

Methods

We conducted a scoping review, searching Pubmed for English references published between 1985 and May 2017. References concerning cancer, with patients above the age of 18 and that discussed age in relation to diagnostic or treatment decisions were included. References that were non-medical or concerning patients below the age of 18, and references that were case reports, ongoing studies or opinion pieces were excluded. Additional references were collected through snowballing and from selected reports, guidelines and articles.

Results

Three hundred and forty-seven relevant references were identified. Patient age can have many and diverse roles in clinical decision making: Contextual roles linked to access (age influences how fast patients are referred to specialized care) and incidence (association between increasing age and increasing incidence rates for cancer); patient-relevant roles linked to physiology (age-related changes in drug metabolism) and comorbidity (association between increasing age and increasing number of comorbidities); and roles related to interventions, such as treatment (older patients receive substandard care) and outcome (survival varies by age).

Conclusions

Patient age is integrated into cancer care decision making in a range of ways that makes it difficult to claim age-neutrality. Acknowledging this and being more transparent about the use of age in decision making are likely to promote better clinical decisions, irrespective of one’s normative viewpoint. This overview also provides a starting point for future discussions on the appropriate role of age in cancer care decision making, which we see as crucial for harnessing the full potential of personalized medicine.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4456-9) contains supplementary material, which is available to authorized users.

Monitoring Daily Dynamics of Early Tumor Response to Targeted Therapy by Detecting Circulating Tumor DNA in Urine

Purpose: Noninvasive drug biomarkers for the early assessment of tumor response can enable adaptive therapeutic decision-making and proof-of-concept studies for investigational drugs. Circulating tumor DNA (ctDNA) is released into the circulation by tumor cell turnover and has been shown to be detectable in urine.Experimental Design: We tested the hypothesis that dynamic changes in EGFR activating (exon 19del and L858R) and resistance (T790M) mutation levels detected in urine could inform tumor response within days of therapy for advanced non-small cell lung cancer (NSCLC) patients receiving osimertinib, a second-line third-generation anti-EGFR tyrosine kinase inhibitor.Results: Eight of nine evaluable NSCLC patients had detectable T790M-mutant DNA fragments in pretreatment baseline samples. Daily monitoring of mutations in urine indicated a pattern of intermittent spikes throughout week 1, suggesting apoptosis with an overall decrease in fragment numbers from baselines to day 7 preceding radiographic response assessed at 6 to 12 weeks.Conclusions: These findings suggest drug-induced tumor apoptosis within days of initial dosing. Daily sampling of ctDNA may enable early assessment of patient response and proof-of-concept studies for drug development. The modeling of tumor lysis through the day-to-day kinetics of ctDNA released into the blood and then into the urine is demonstrated in this proof-of-concept study in lung cancer patients receiving anti-EGFR tyrosine kinase inhibitors. This strategy may determine the specific clonal populations of cells which undergo apoptosis within the first week of therapy. This has important implications for developing combinational strategies to address inter- and intralesional heterogeneity and characterizing residual disease after initial drug exposure. Clin Cancer Res; 23(16); 4716-23. ©2017 AACR.

Accurate detection of low prevalence AKT1 E17K mutation in tissue or plasma from advanced cancer patients

Personalized healthcare relies on accurate companion diagnostic assays that enable the most appropriate treatment decision for cancer patients. Extensive assay validation prior to use in a clinical setting is essential for providing a reliable test result. This poses a challenge for low prevalence mutations with limited availability of appropriate clinical samples harboring the mutation. To enable prospective screening for the low prevalence AKT1 E17K mutation, we have developed and validated a competitive allele-specific TaqMan^® PCR (castPCR™) assay for mutation detection in formalin-fixed paraffin-embedded (FFPE) tumor tissue. Analysis parameters of the castPCR™ assay were established using an FFPE DNA reference standard and its analytical performance was assessed using 338 breast cancer and gynecological cancer FFPE samples. With recent technical advances for minimally invasive mutation detection in circulating tumor DNA (ctDNA), we subsequently also evaluated the OncoBEAM™ assay to enable plasma specimens as additional diagnostic opportunity for AKT1 E17K mutation testing. The analysis performance of the OncoBEAM™ test was evaluated using a novel AKT1 E17K ctDNA reference standard consisting of sheared genomic DNA spiked into human plasma. Both assays are employed at centralized testing laboratories operating according to quality standards for prospective identification of the AKT1 E17K mutation in ER+ breast cancer patients in the context of a clinical trial evaluating the AKT inhibitor AZD5363 in combination with endocrine (fulvestrant) therapy.

In vitro and in vivo antitumor activities of T-3764518, a novel and orally available small molecule stearoyl-CoA desaturase 1 inhibitor

Most cancer cells are characterized by elevated lipid biosynthesis. The rapid proliferation of cancer cells requires de novo synthesis of fatty acids. Stearoyl-CoA desaturase-1 (SCD1), a key enzyme for lipogenesis, is overexpressed in various types of cancer and plays an important role in cancer cell proliferation. Therefore, it has been studied as a candidate target for cancer therapy. In this study, we demonstrate the pharmacological properties of T-3764518, a novel and orally available small molecule inhibitor of SCD1. T-3764518 inhibited stearoyl-CoA desaturase-catalyzed conversion of stearoyl-CoA to oleoyl-CoA in colorectal cancer HCT-116 cells and their growth. Further, it slowed tumor growth in an HCT-116 and a mesothelioma MSTO-211H mouse xenograft model. Comprehensive lipidomic analyses revealed that T-3764518 increases the membrane ratio of saturated: unsaturated fatty acids in various lipid species such as phosphatidylcholines and diacylglycerols in both cultured cells and HCT-116 xenografts. Treatment-associated lipidomic changes were followed by activated endoplasmic reticulum (ER) stress responses such as increased immunoglobulin heavy chain-binding protein expression in HCT-116 cells. These T-3764518-induced changes led to an increase in cleaved poly (ADP-ribose) polymerase 1 (PARP1), a marker of apoptosis. Additionally, bovine serum albumin conjugated with oleic acid, an SCD1 product, prevented cell growth inhibition and ER stress responses by T-3764518, indicating that these outcomes were not attributable to off-target effects. These results indicate that T-3764518 is a promising new anticancer drug candidate.

Discovery and identification of potential biomarkers for alcohol-induced oxidative stress based on cellular metabolomics

Biomarkers involved in alcohol-induced oxidative stress play an important role in alcoholic liver disease prevention and diagnosis. Alcohol-induced oxidative stress in human liver L-02 cells was used to discover the potential biomarkers. Metabolites from L-02 cells induced by alcohol were measured by high-performance liquid chromatography and mass spectrometry. Fourteen metabolites that allowed discrimination between control and model groups were discovered by multivariate statistical data analysis (i.e. principal components analysis, orthogonal partial least-squares discriminate analysis). Based on the retention time, UV spectrum and LC-MS findings of the samples and compared with the authentic standards, eight biomarkers involved in alcohol-induced oxidative stress, namely, malic acid, oxidized glutathione, γ-glutamyl-cysteinyl-glycine, adenosine triphosphate, phenylalanine, adenosine monophosphate, nitrotyrosine and tryptophan, were identified. These biomarkers offered important targets for disease diagnosis and other researches.

Enhancing value of clinical pharmacodynamics in oncology drug development: An alliance between quantitative pharmacology and translational science

Clinical pharmacodynamic evaluation is a key component of the "pharmacologic audit trail" in oncology drug development. We posit that its value can and should be greatly enhanced via application of a robust quantitative pharmacology framework informed by biologically mechanistic considerations. Herein, we illustrate examples of intersectional blindspots across the disciplines of quantitative pharmacology and translational science and offer a roadmap aimed at enhancing the caliber of clinical pharmacodynamic research in the development of oncology therapeutics.

Novel pharmacodynamic biomarkers for MYCN protein and PI3K/AKT/mTOR pathway signaling in children with neuroblastoma

There is an urgent need for improved therapies for children with high-risk neuroblastoma where survival rates remain low. MYCN amplification is the most common genomic change associated with aggressive neuroblastoma and drugs targeting PI3K/AKT/mTOR, to activate MYCN oncoprotein degradation, are entering clinical evaluation. Our aim was to develop and validate pharmacodynamic (PD) biomarkers to evaluate both proof of mechanism and proof of concept for drugs that block PI3K/AKT/mTOR pathway activity in children with neuroblastoma. We have addressed the issue of limited access to tumor biopsies for quantitative detection of protein biomarkers by optimizing a three-color fluorescence activated cell sorting (FACS) method to purify CD45-/GD2+/CD56+ neuroblastoma cells from bone marrow. We then developed a novel quantitative measurement of MYCN protein in these isolated neuroblastoma cells, providing the potential to demonstrate proof of concept for drugs that inhibit PI3K/AKT/mTOR signaling in this disease. In addition we have established quantitative detection of three biomarkers for AKT pathway activity (phosphorylated and total AKT, GSK3β and P70S6K) in surrogate platelet-rich plasma (PRP) from pediatric patients. Together our new approach to neuroblastoma cell isolation for protein detection and suite of PD assays provides for the first time the opportunity for robust, quantitative measurement of protein-based PD biomarkers in this pediatric patient population. These will be ideal tools to support clinical evaluation of PI3K/AKT/mTOR pathway drugs and their ability to target MYCN oncoprotein in upcoming clinical trials in neuroblastoma.

Circulating tumor cells: a multifunctional biomarker

One of the most promising developments in translational cancer medicine has been the emergence of circulating tumor cells (CTC) as a minimally invasive multifunctional biomarker. CTCs in peripheral blood originate from solid tumors and are involved in the process of hematogenous metastatic spread to distant sites for the establishment of secondary foci of disease. The emergence of modern CTC technologies has enabled serial assessments to be undertaken at multiple time points along a patient's cancer journey for pharmacodynamic (PD), prognostic, predictive, and intermediate endpoint biomarker studies. Despite the promise of CTCs as multifunctional biomarkers, there are still numerous challenges that hinder their incorporation into standard clinical practice. This review discusses the key technical aspects of CTC technologies, including the importance of assay validation and clinical qualification, and compares existing and novel CTC enrichment platforms. This article discusses the utility of CTCs as a multifunctional biomarker and focuses on the potential of CTCs as PD endpoints either directly via the molecular characterization of specific markers or indirectly through CTC enumeration. We propose strategies for incorporating CTCs as PD biomarkers in translational clinical trials, such as the Pharmacological Audit Trail. We also discuss issues relating to intrapatient heterogeneity and the challenges associated with isolating CTCs undergoing epithelial-mesenchymal transition, as well as apoptotic and small CTCs. Finally, we envision the future promise of CTCs for the selection and monitoring of antitumor precision therapies, including applications in single CTC phenotypic and genomic profiling and CTC-derived xenografts, and discuss the promises and limitations of such approaches. See ALL articles in this CCR focus section, "Progress in pharmacodynamic endpoints."

Pharmacologic biomarkers in the development of stratified cancer medicine

Clinical pharmacologic research plays a vital role in cancer drug development. In recent years, biomarker studies have become integral to this process, specifically the use of pharmacologic biomarkers in the development of targeted therapies and their translation to clinical practice. In this overview, we discuss the validation of pharmacodynamics (PD) biomarkers and highlight the circulating tumor DNA as a promising cancer biomarker to illustrate how PD biomarkers can be powerful tools for guiding treatment strategies. We provide insights into PD biomarker approaches for future development of novel therapies and their role in cancer medicine. See all articles in this CCR focus section, "Progress in pharmacodynamic endpoints."

Translational research in oncology--10 years of progress and future prospects

International efforts to sequence the genomes of various human cancers have been broadly deployed in drug discovery programmes. Diagnostic tests that predict the value of the molecularly targeted anticancer agents used in such programmes are conceived and validated in parallel with new small-molecule treatments and immunotherapies. This approach has been aided by better preclinical cancer models; an enhanced appreciation of the complex interactions that exist between tumour cells and their microenvironment; the elucidation of interactions between many of the genetic drivers of cancer, including oncogenes and tumour suppressors; and recent insights into the genetic heterogeneity of human tumours made possible by extraordinary improvements in DNA-sequencing techniques. These advances are being employed in the first generation of genomic clinical trials that will examine the feasibility of matching a broad range of systemic therapies to specific molecular tumour characteristics. More-extensive molecular characterization of tumours and their supporting matrices are anticipated to become standard aspects of oncological practice, permitting continuous molecular re-evaluations of human malignancies on a patient-by-patient and treatment-by-treatment basis. We review selected developments in translational cancer biology, diagnostics, and therapeutics that have occurred over the past decade and offer our thoughts on future prospects for the next few years.