Phase III, randomized, placebo-controlled study of docetaxel in combination with zibotentan in patients with metastatic castration-resistant prostate cancer

BSA Binding and Aggregate Formation of a Synthetic Amino Acid with Potential for Promoting Fibroblast Proliferation: An In Silico, CD Spectroscopic, DLS, and Cellular Study

This study presents the chemical synthesis, purification, and characterization of a novel non-natural synthetic amino acid. The compound was synthesized in solution, purified, and characterized using NMR spectroscopy, polarimetry, and melting point determination. Dynamic Light Scattering (DLS) analysis demonstrated its ability to form aggregates with an average size of 391 nm, extending to the low micrometric size range. Furthermore, cellular biological assays revealed its ability to enhance fibroblast cell growth, highlighting its potential for tissue regenerative applications. Circular dichroism (CD) spectroscopy showed the ability of the synthetic amino acid to bind serum albumins (using bovine serum albumin (BSA) as a model), and CD deconvolution provided insights into the changes in the secondary structures of BSA upon interaction with the amino acid ligand. Additionally, molecular docking using HDOCK software elucidated the most likely binding mode of the ligand inside the BSA structure. We also performed in silico oligomerization of the synthetic compound in order to obtain a model of aggregate to investigate computationally. In more detail, the dimer formation achieved by molecular self-docking showed two distinct poses, corresponding to the lowest and comparable energies, with one pose exhibiting a quasi-coplanar arrangement characterized by a close alignment of two aromatic rings from the synthetic amino acids within the dimer, suggesting the presence of π-π stacking interactions. In contrast, the second pose displayed a non-coplanar configuration, with the aromatic rings oriented in a staggered arrangement, indicating distinct modes of interaction. Both poses were further utilized in the self-docking procedure. Notably, iterative molecular docking of amino acid structures resulted in the formation of higher-order aggregates, with a model of a 512-mer aggregate obtained through self-docking procedures. This model of aggregate presented a cavity capable of hosting therapeutic cargoes and biomolecules, rendering it a potential scaffold for cell adhesion and growth in tissue regenerative applications. Overall, our findings highlight the potential of this synthetic amino acid for tissue regenerative therapeutics and provide valuable insights into its molecular interactions and aggregation behavior.

A comprehensive analysis of liver safety across zibotentan oncology trials: knowledge of the past offers new perspectives on the present

BACKGROUND

Endothelin receptor antagonists (ERAs) are associated with liver injury. We used data from previous oncology clinical trials to determine the liver safety profile of zibotentan, which is currently in clinical development (in combination with dapagliflozin) for chronic kidney disease and cirrhosis.

RESEARCH DESIGN AND METHODS

Six global, double-blinded, phase 2b and 3 clinical trials from the zibotentan oncology development program were pooled to analyze liver safety. Descriptive statistics, proportion of liver-related adverse events, liver biochemistry parameter elevation, and shifts from baseline were analyzed, with individual case assessment.

RESULTS

A total of 1532 patients received zibotentan for 285 days (mean), and 1486 patients received placebo for 320 days (mean). The frequency of any hepatic disorder preferred term was similar across zibotentan monotherapy (22/947 patients, 2.3%) and placebo monotherapy arms (30/881 patients, 3.4%). A total of 4 (0.4%) patients receiving zibotentan monotherapy experienced ALT elevations >5× ULN versus 8 (0.9%) receiving placebo. Of the seven patients receiving zibotentan who met criteria for potential Hy's Law, there were no cases of drug-induced liver injury.

CONCLUSIONS

We found no evidence of zibotentan-related liver biochemistry changes among cancer-treated patients, suggesting that hepatotoxicity of ERAs is molecule-dependent, and allowing exploration of zibotentan for new indications.

New thiophene-1,3,4-oxadiazole-thiazolidine-2,4-dione hybrids: Synthesis, MCF-7 inhibition and binding studies

Two synthetic methods were proposed for the preparation of a new series of thiophene-1,3,4-oxadiazole-thiazolidine-2,4-dione hybrids (TOT-1 to 15) and their structures were elucidated based on spectral data. Studies on cytotoxicity, ROS, cellular uptake and interactions of TOT-14 with calf thymus DNA were carried out. Anticancer activity of compounds, TOT-1 to 15 on breast cancer (MCF-7) cell lines was investigated. The IC50 values for the standard, epirubicin hydrochloride and TOT-12, 13, 14 and 15 were found to be 6.78, 5.52, 6.53, 4.83 and 5.57 µg/mL, respectively. Notably, TOT-14 exhibited a remarkable antiproliferative activity with a strikingly selective inhibitory effect compared to standard. This specific selectivity could be attributed to the synergistic effect of increased cellular uptake and generation of higher ROS in cancer cells after irradiation. The binding constant of 4.25 x 103 M-1 indicated the moderate interaction between TOT-14 and ct-DNA. The docking score of TOT derivativeswas substantially identical to the docking score of epirubicin hydrochloride. The designed molecules complied with the requirements for drug-likeness and ADME.

Progression-free survival, disease-free survival and other composite end points in oncology: improved reporting is needed

Composite outcome measures such as progression-free survival and disease-free survival are increasingly used as surrogate end points in oncology research, frequently serving as the primary end point of pivotal trials that form the basis for FDA and EMA approvals. Such outcome measures combine two or more distinct events (for example, tumour (re)growth, new lesions and/or death) into a single, time-to-event end point. The use of a composite end point can increase the statistical power of a clinical trial and decrease the follow-up period required to demonstrate efficacy, thus lowering costs; however, these end points have a number of limitations. Composite outcomes are often vaguely defined, with definitions that vary greatly between studies, complicating comparisons of results across trials. Altering the makeup of events included in a composite outcome can alter study conclusions, including whether treatment effects are statistically significant. Moreover, the events included in a composite outcome often vary in clinical significance, reflect distinct biological pathways and/or are affected differently by treatment. Therefore, knowing the precise breakdown of the component events is essential to accurately interpret trial results and gauge the true benefit of an intervention. In oncology clinical trials, however, such information is rarely provided. In this Perspective, we emphasize this deficiency through a review of 50 studies with progression-free survival as an outcome published in five top oncology journals, discuss the advantages and challenges of using composite end points, and highlight the need for transparent reporting of the component events.

Synthesis of new 3-acetyl-1,3,4-oxadiazolines combined with pyrimidines as antileishmanial and antiviral agents

A new series of 3-acetyl-1,3,4-oxadiazoline hybrid molecules was designed and synthesized using a condensation between acyclonucleosides and substituted phenylhydrazone. All intermediates and final products were screened against Leishmania donovani, a Protozoan parasite and against three viruses SARS-CoV-2, HCMV and VZV. While no significant activity was observed against the viruses, the intermediate with 6-azatymine as thymine and 5-azathymine-3-acetyl-1,3,4-oxadiazoline hybrid exhibited a significant antileishmanial activity. The later compound was the most promising, exhibiting an IC50 value at 8.98 µM on L. donovani intramacrophage amastigotes and a moderate selectivity index value at 2.4.

Recent advances and future perspectives in the therapeutics of prostate cancer

Prostate cancer (PC) is one of the most common cancers in males and the fifth leading reason of death. Age, ethnicity, family history, and genetic defects are major factors that determine the aggressiveness and lethality of PC. The African population is at the highest risk of developing high-grade PC. It can be challenging to distinguish between low-risk and high-risk patients due to the slow progression of PC. Prostate-specific antigen (PSA) is a revolutionary discovery for the identification of PC. However, it has led to an increase in over diagnosis and over treatment of PC in the past few decades. Even if modifications are made to the standard PSA testing, the specificity has not been found to be significant. Our understanding of PC genetics and proteomics has improved due to advances in different fields. New serum, urine, and tissue biomarkers, such as PC antigen 3 (PCA3), have led to various new diagnostic tests, such as the prostate health index, 4K score, and PCA3. These tests significantly reduce the number of unnecessary and repeat biopsies performed. Chemotherapy, radiotherapy, and prostatectomy are standard treatment options. However, newer novel hormone therapy drugs with a better response have been identified. Androgen deprivation and hormonal therapy are evolving as new and better options for managing hormone-sensitive and castration-resistant PC. This review aimed to highlight and discuss epidemiology, various risk factors, and developments in PC diagnosis and treatment regimens.

Conditional survival does not improve over time in metastatic castration-resistant prostate cancer patients undergoing docetaxel

PURPOSE

To investigate the conditional overall survival (OS) of metastatic castration-resistant prostate cancer (mCRPC) patients receiving docetaxel chemotherapy.

METHODS

We used deidentified patient-level data from the Prostate Cancer DREAM Challenge database and the control arm of the ENTHUSE 14 trial. We identified 2158 chemonaïve mCRPC patients undergoing docetaxel chemotherapy in the five randomized clinical trials. The 6-month conditional OS was calculated at times 0, 6, 12, 18, and 24 months from randomization. Survival curves of each group were compared using the log-rank test. Patients were then stratified into low- and high-risk groups based on the median predicted value of our recently published nomogram predicting OS in mCRPC patients.

RESULTS

Nearly half (45%) of the study population was aged between 65 and 74 years. Median interquartile range prostate-specific antigen for the overall cohort was 83.2 (29.6-243) ng/mL, and 59% of patients had bone metastasis with or without lymph node involvement. The 6-month conditional survival rates at 0, 6, 12, 18, and 24 months for the entire cohort were 93% (95% confidence interval [CI]: 92-94), 82% (95% CI: 81-84), 76% (95% CI: 73-78), 75% (95% CI: 71-78), and 71% (95% CI: 65-76). These rates were, respectively, 96% (95% CI: 95-97), 92% (95% CI: 90-93), 84% (95% CI: 81-87), 81% (95% CI: 77-85), and 79% (95% CI: 72-84) in the low-risk group and 89% (95% CI: 87-91), 73% (95% CI: 70-76), 65% (95% CI: 60-69), 64% (95% CI: 58-70), and 58% (95% CI: 47-67) in the high-risk group.

CONCLUSION

The conditional OS for patients undergoing docetaxel chemotherapy tends to plateau over time, with the main drop in conditional OS happening during the first year from initiating docetaxel treatment. That is the longer a patient survives, the more likely they are to survive further. This prognostic information could be a useful tool for a more accurate tailoring of both follow-up and therapies.

PATIENT SUMMARY

In this report, we looked at the future survival in months of patients with metastatic castration resistant prostate cancer on chemotherapy who have already survived a certain period. We found that the longer time that a patient survives, the more likely they will continue to survive. We conclude that this information will help physicians tailor follow-ups and treatments for patients for a more accurate personalized medicine.

External Validation of a Prognostic Model of Overall Survival in Men With Chemotherapy-Naïve Metastatic Castration-Resistant Prostate Cancer

PURPOSE

We have previously developed and externally validated a prognostic model of overall survival (OS) in men with metastatic, castration-resistant prostate cancer (mCRPC) treated with docetaxel. We sought to externally validate this model in a broader group of men with docetaxel-naïve mCRPC and in specific subgroups (White, Black, Asian patients, different age groups, and specific treatments) and to classify patients into validated two and three prognostic risk groupings on the basis of the model.

METHODS

Data from 8,083 docetaxel-naïve mCRPC men randomly assigned on seven phase III trials were used to validate the prognostic model of OS. We assessed the predictive performance of the model by computing the time-dependent area under the receiver operating characteristic curve (tAUC) and validated the two-risk (low and high) and three-risk prognostic groups (low, intermediate, and high).

RESULTS

The tAUC was 0.74 (95% CI, 0.73 to 0.75), and when adjusting for the first-line androgen receptor (AR) inhibitor trial status, the tAUC was 0.75 (95% CI, 0.74 to 0.76). Similar results were observed by the different racial, age, and treatment subgroups. In patients enrolled on first-line AR inhibitor trials, the median OS (months) in the low-, intermediate-, and high-prognostic risk groups were 43.3 (95% CI, 40.7 to 45.8), 27.7 (95% CI, 25.8 to 31.3), and 15.4 (95% CI, 14.0 to 17.9), respectively. Compared with the low-risk prognostic group, the hazard ratios for the high- and intermediate-risk groups were 4.3 (95% CI, 3.6 to 5.1; P < .0001) and 1.9 (95% CI, 1.7 to 2.1; P < .0001).

CONCLUSION

This prognostic model for OS in docetaxel-naïve men with mCRPC has been validated using data from seven trials and yields similar results overall and across race, age, and different treatment classes. The prognostic risk groups are robust and can be used to identify groups of patients for enrichment designs and for stratification in randomized clinical trials.

Exploring Probenecid Derived 1,3,4-Oxadiazole-Phthalimide Hybrid as α-Amylase Inhibitor: Synthesis, Structural Investigation, and Molecular Modeling

1,3,4-Oxadiazole moiety is a crucial pharmacophore in many biologically active compounds. In a typical synthesis, probenecid was subjected to a sequence of reactions to obtain a 1,3,4-oxadiazole–phthalimide hybrid (PESMP) in high yields. The NMR (1H and 13C) spectroscopic analysis initially confirmed the structure of PESMP. Further spectral aspects were validated based on a single-crystal XRD analysis. Experimental findings were confirmed afterwards by executing a Hirshfeld surface (HS) analysis and quantum mechanical computations. The HS analysis showed the role of the π⋯π stacking interactions in PESMP. PESMP was found to have a high stability and lower reactivity in terms of global reactivity parameters. α-Amylase inhibition studies revealed that the PESMP was a good inhibitor of α-amylase with an s value of 10.60 ± 0.16 μg/mL compared with that of standard acarbose (IC50 = 8.80 ± 0.21 μg/mL). Molecular docking was also utilized to reveal the binding pose and features of PESMP against the α-amylase enzyme. Via docking computations, the high potency of PESMP and acarbose towards the α-amylase enzyme was unveiled and confirmed by docking scores of −7.4 and −9.4 kcal/mol, respectively. These findings shine a new light on the potential of PESMP compounds as α-amylase inhibitors.

Should personalised dosing have a role in cancer treatment?

Almost all pharmaceutical products are approved on the basis of their effect in patients representing the "average" of the population studied in registrational trials, with most drug labels allowing, at most, for empirical dose reduction in the case of toxicity. In this perspective article we explore some of the evidence that supports the use of personalised dosing in cancer treatment and show how we have been able to build on existing models linking dose, exposure and toxicity to demonstrate how dose optimisation, including increasing the dose, has the potential to significantly improve efficacy outcomes. We also explore, through the lens of our own experience of developing a personalised dosing platform, some of the hurdles that stand in the way of implementing a personalised approach to dosing in real world settings. In particular, our experience is illustrated by the application of a dosing platform for docetaxel treatment in prostate cancer.

Synthesis and Evaluation of Novel S-alkyl Phthalimide- and S-benzyl-oxadiazole-quinoline Hybrids as Inhibitors of Monoamine Oxidase and Acetylcholinesterase

New S-alkyl phthalimide 5a-f and S-benzyl 6a-d analogs of 5-(2-phenylquinolin-4-yl)-1,3,4-oxadiazole-2-thiol (4) were prepared by reacting 4 with N-bromoalkylphthalimide and CF₃-substituted benzyl bromides in excellent yields. Spectroscopic techniques were employed to elucidate the structures of the synthesized molecules. The inhibition activity of newly synthesized molecules toward MAO-A, MAO-B, and AChE enzymes, was also assessed. All these compounds showed activity in the submicromolar range against all enzymes. Compounds 5a and 5f were found to be the most potent compounds against MAO-A (IC₅₀ = 0.91 ± 0.15 nM) and MAO-B (IC₅₀ = 0.84 ± 0.06 nM), while compound 5c showed the most efficient acetylcholinesterase inhibition (IC₅₀ = 1.02± 0.65 μM). Docking predictions disclosed the docking poses of the synthesized molecules with all enzymes and demonstrated the outstanding potency of compounds 5a, 5f, and 5c (docking scores = -11.6, -15.3, and -14.0 kcal/mol against MAO-A, MAO-B, and AChE, respectively). These newly synthesized analogs act as up-and-coming candidates for the creation of safer curative use against Alzheimer's illness.

Prostate Cancer Tumor Stroma: Responsibility in Tumor Biology, Diagnosis and Treatment

Simple Summary

The crosstalk between prostate stroma and its epithelium is essential to tissue homeostasis. Likewise, reciprocal signaling between tumor cells and the stromal compartment is required in tumor progression to facilitate or stimulate key processes such as cell proliferation and invasion. The aim of the present work was to review the current state of knowledge on the significance of tumor stroma in the genesis, progression and therapeutic response of prostate carcinoma. Additionally, we addressed the future therapeutic opportunities.

Abstract

Prostate cancer (PCa) is a common cancer among males globally, and its occurrence is growing worldwide. Clinical decisions about the combination of therapies are becoming highly relevant. However, this is a heterogeneous disease, ranging widely in prognosis. Therefore, new approaches are needed based on tumor biology, from which further prognostic assessments can be established and complementary strategies can be identified. The knowledge of both the morphological structure and functional biology of the PCa stroma compartment can provide new diagnostic, prognostic or therapeutic possibilities. In the present review, we analyzed the aspects related to the tumor stromal component (both acellular and cellular) in PCa, their influence on tumor behavior and the therapeutic response and their consideration as a new therapeutic target.

A novel prognostic model predicting overall survival in patients with metastatic castration-resistant prostate cancer receiving standard chemotherapy: A multi-trial cohort analysis

PURPOSE

Generalizable, updated, and easy-to-use prognostic models for patients with metastatic castration-resistant prostate cancer (mCRPC) are lacking. We developed a nomogram predicting the overall survival (OS) of mCRPC patients receiving standard chemotherapy using data from five randomized clinical trials (RCTs).

METHODS

Patients enrolled in the control arm of five RCTs (ASCENT 2, VENICE, CELGENE/MAINSAIL, ENTHUSE 14, and ENTHUSE 33) were randomly split between training (n = 1636, 70%) and validation cohorts (n = 700, 30%). In the training cohort, Cox regression tested the prognostic significance of all available variables as a predictor of OS. Independent predictors of OS on multivariable analysis were used to construct a novel multivariable model (nomogram). The accuracy of this model was tested in the validation cohort using time-dependent area under the curve (tAUC) and calibration curves.

RESULTS

Most of the patients were aged 65-74 years (44.5%) and the median (interquartile range) follow-up time was 13.9 (8.9-20.2) months. At multivariable analysis, the following were independent predictors of OS in mCRPC patients: sites of metastasis (visceral vs. bone metastasis, hazard ratio [HR]: 1.24), prostate-specific antigen (HR: 1.00), aspartate transaminase (HR: 1.01), alkaline phosphatase (HR: 1.00), body mass index (HR: 0.97), and hemoglobin (≥13 g/dl vs. <11 g/dl, HR: 0.41; all p < 0.05). A nomogram based on these variables was developed and showed favorable discrimination (tAUC at 12 and 24 months: 73% and 72%, respectively) and calibration characteristics on external validation.

CONCLUSION

A new prognostic model to predict OS of patients with mCRPC undergoing first line chemotherapy was developed. This can help urologists/oncologists in counseling patients and might be useful to better stratify patients for future clinical trials.

Translation of Prognostic and Pharmacodynamic Biomarkers from Trial to Non-trial Patients with Metastatic Castration-resistant Prostate Cancer Treated with Docetaxel

AIMS

We conducted a pooled analysis of four randomised controlled trials and a non-trial retrospective dataset to study the changes in serum prostate-specific antigen (PSA) concentrations during treatment and its impact on survival in men treated with docetaxel for metastatic castration-resistant prostate cancer. We also compared the outcomes and pre-treatment prognostic factors between trial and non-trial patients.

MATERIALS AND METHODS

Data were obtained from four randomised controlled trials and a non-trial cohort from a tertiary cancer centre. The PSA kinetics covariates chosen were absolute value (PSAT), best percentage change (BPCH) and tumour growth rate (K). The association between the covariates collected and overall survival was assessed within a Cox proportional hazards model. How well a covariate captured the difference between trial and non-trial patients was assessed by reporting on models with or without trial status as a covariate.

RESULTS

We reviewed individual datasets of 2282 patients. The median overall survival for trial patients was 20.4 (95% confidence interval 19.6-22.2) months and for the non-trial cohort was 12.4 (10.7-14.7) months (P < 0.001). Of the pre-treatment factors, we found that only lactate dehydrogenase fully captured the difference in prognosis between the trial and non-trial cohorts. All PSA kinetic metrics appeared to be prognostic in both the trial and non-trial patients. However, the effect size was reduced in non-trial versus trial patients (interaction P < 0.001). Of the time-dependent covariates, we found that BPCH best captured the difference between trial and non-trial patient prognosis.

CONCLUSIONS

The analysis presented here highlights how data from open-source trial databases can be combined with emerging clinical practice databases to assess differences between trial versus non-trial patients for particular treatments. These results highlight the importance of developing prognostic models using both pre-treatment and time-dependent biomarkers of new treatments.

Targeting signaling pathways in prostate cancer: mechanisms and clinical trials

Prostate cancer (PCa) affects millions of men globally. Due to advances in understanding genomic landscapes and biological functions, the treatment of PCa continues to improve. Recently, various new classes of agents, which include next-generation androgen receptor (AR) signaling inhibitors (abiraterone, enzalutamide, apalutamide, and darolutamide), bone-targeting agents (radium-223 chloride, zoledronic acid), and poly(ADP-ribose) polymerase (PARP) inhibitors (olaparib, rucaparib, and talazoparib) have been developed to treat PCa. Agents targeting other signaling pathways, including cyclin-dependent kinase (CDK)4/6, Ak strain transforming (AKT), wingless-type protein (WNT), and epigenetic marks, have successively entered clinical trials. Furthermore, prostate-specific membrane antigen (PSMA) targeting agents such as ¹⁷⁷Lu-PSMA-617 are promising theranostics that could improve both diagnostic accuracy and therapeutic efficacy. Advanced clinical studies with immune checkpoint inhibitors (ICIs) have shown limited benefits in PCa, whereas subgroups of PCa with mismatch repair (MMR) or CDK12 inactivation may benefit from ICIs treatment. In this review, we summarized the targeted agents of PCa in clinical trials and their underlying mechanisms, and further discussed their limitations and future directions.

Differential effect of body mass index (BMI) on outcomes of patients treated with docetaxel in prostate cancer - An exploratory analysis

OBJECTIVE

There are contradictory data on differential effect of docetaxel based on BMI in patients with breast and prostate cancer. We performed an exploratory analysis to determine if the benefit of docetaxel in patients with metastatic castration-resistant prostate cancer (mCRPC) is modified by BMI.

METHODS

We performed a post hoc analysis of the data retrieved from the ENTHUSE M1C study. BMI (kg/m²) was categorized as: 18.5 to <25 as lean; 25 to <30 as overweight; and ≥30 as obese. Cox regression models were constructed to determine the impact of BMI on progression-free survival (PFS) and overall survival (OS).

RESULTS

A total of 466 patients were eligible for the current analysis. The median PFS was 7.3, 7.7 and 8.4 months (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.81 to 1.06; P = 0.261) in lean, overweight and obese patients. The median OS was 16.6, 20.1 and 21.4 months (HR, 0.75; 95% CI, 0.63 to 0.89; P = 0.002) for lean, overweight and obese patients. After adjusting for baseline and tumor characteristics, there was no association of BMI with PFS (overweight, HR, 0.89; 95% CI, 0.71 to 1.13; P = 0.353; obese, HR, 0.86; 95% CI, 0.66 to 1.13; P = 0.277) while overweight (HR, 0.68; 95% CI, 0.51 to 0.89; P = 0.006) and obese (HR, 0.59; 95% CI, 0.41 to 0.83; P = 0.003) patients had significantly better OS compared with lean patients.

CONCLUSIONS

There was no effect of BMI on PFS in patients with mCRPC receiving docetaxel. Interestingly, overweight and obese patients had a longer OS compared with lean patients, which is in contradiction to a recent study in breast cancer; and warrants further investigation.

Inhibition of Janus Kinase 1 synergizes docetaxel sensitivity in prostate cancer cells

Prostate cancer (PCa) is the second most common malignancy and is the fifth leading cause of cancer mortality among men globally. Docetaxel-based therapy remains the first-line treatment for metastatic castration-resistant prostate cancer. However, dose-limiting toxicity including neutropenia, myelosuppression and neurotoxicity is the major reason for docetaxel dose reductions and fewer cycles administered, despite a recent study showing a clear survival benefit with increased total number of docetaxel cycles in PCa patients. Although previous studies have attempted to improve the efficacy and reduce docetaxel toxicity through drug combination, no drug has yet demonstrated improved overall survival in clinical trial, highlighting the challenges of improving the activity of docetaxel monotherapy in PCa. Herein, we identified 15 lethality hits for which inhibition could enhance docetaxel sensitivity in PCa cells via a high-throughput kinome-wide loss-of-function screen. Further drug-gene interactions analyses identified Janus kinase 1 (JAK1) as a viable druggable target with existing experimental inhibitors and FDA-approved drugs. We demonstrated that depletion of endogenous JAK1 enhanced docetaxel-induced apoptosis in PCa cells. Furthermore, inhibition of JAK1/2 by baricitinib and ruxolitinib synergizes docetaxel sensitivity in both androgen receptor (AR)-negative DU145 and PC3 cells, but not in the AR-positive LNCaP cells. In contrast, no synergistic effects were observed in cells treated with JAK2-specific inhibitor, fedratinib, suggesting that the synergistic effects are mainly mediated through JAK1 inhibition. In conclusion, the combination therapy with JAK1 inhibitors and docetaxel could be a useful therapeutic strategy in the treatment of prostate cancers.

KEYNOTE-921: Phase III study of pembrolizumab plus docetaxel for metastatic castration-resistant prostate cancer

Despite recent advances, treatment options for men with metastatic castration-resistant prostate cancer (mCRPC) progressing after next-generation hormonal agents (NHAs) are limited and provide only modest survival benefit. Thus, an unmet need remains for mCRPC patients after treatment with targeted endocrine therapy or NHA therapy. Pembrolizumab, a humanized monoclonal antibody for PD-1, has been found to have activity as monotherapy in patients with mCRPC and as combination therapy in a Phase Ib/II study with docetaxel and prednisone/prednisolone for patients previously treated with enzalutamide or abiraterone acetate. The aim of the randomized, double-blind, Phase III KEYNOTE-921 study is to evaluate the efficacy and safety of pembrolizumab plus docetaxel in patients with mCRPC who were previously treated with an NHA. Clinical trial registration: NCT03834506 (ClinicalTrials.gov).

Drug resistant cells with very large proliferative potential grow exponentially in metastatic prostate cancer

Most metastatic cancers develop drug resistance during treatment and continue to grow, driven by a subpopulation of cancer cells unresponsive to the therapy being administered. There is evidence that metastases are formed by phenotypically plastic cancer cells with stem-cell like properties. Currently the population structure and growth dynamics of the resulting metastatic tumors is unknown. Here, using scaling analysis of clinical data of tumor burden in patients with metastatic prostate cancer, we show that the drug resistant, metastasis-causing cells (MCC) are capable of producing drug resistant, exponentially growing tumors, responsible for tumor growth as a patient receives different treatments.

Novel 3-Acetyl-2,5-disubstituted-1,3,4-oxadiazolines: Synthesis and Biological Activity

The aim of our study was the two-stage synthesis of 1,3,4-oxadiazole derivatives. The first step was the synthesis of hydrazide-hydrazones from 3-methyl-4-nitrobenzhydrazide and the corresponding substituted aromatic aldehydes. Then, the synthesized hydrazide-hydrazones were cyclized with acetic anhydride to obtain new 3-acetyl-2,3-disubstituted-1,3,4-oxadiazolines. All of obtained compounds were tested in in vitro assays to establish their potential antimicrobial activity and cytotoxicity. Our results indicated that few of the newly synthesized compounds had some antimicrobial activity, mainly compounds 20 and 37 towards all used reference bacterial strains (except Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa) and fungi. These substances showed a strong or powerful bactericidal effect, especially against Staphylococcus spp. belonging to Gram-positive bacteria. Compound 37 was active against Staphylococcus epidermidis at minimal inhibitory concentration (MIC) = 0.48 µg/mL and was characterized by low cytotoxicity. This compound possessed quinolin-4-yl substituent in the second position of 1,3,4-oxadiazole ring and 3-methyl-4-nitrophenyl in position 5. High effectiveness and safety of these derivatives make them promising candidates as antimicrobial agents. Whereas the compound 20 with the 5-iodofurane substituent in position 2 of the 1,3,4-oxadiazole ring showed the greatest activity against S. epidermidis at MIC = 1.95 µg/mL.

Rationale and design of the Medical Research Council's Precision Medicine with Zibotentan in Microvascular Angina (PRIZE) trial

Microvascular angina is caused by cardiac small vessel disease, and dysregulation of the endothelin system is implicated. The minor G allele of the non-coding single nucleotide polymorphism (SNP) rs9349379 enhances expression of the endothelin 1 gene in human vascular cells, increasing circulating concentrations of ET-1. The prevalence of this allele is higher in patients with ischemic heart disease. Zibotentan is a potent, selective inhibitor of the ETA receptor. We have identified zibotentan as a potential disease-modifying therapy for patients with microvascular angina. METHODS: We will assess the efficacy and safety of adjunctive treatment with oral zibotentan (10 mg daily) in patients with microvascular angina and assess whether rs9349379 (minor G allele; population prevalence ~36%) acts as a theragnostic biomarker of the response to treatment with zibotentan. The PRIZE trial is a prospective, randomized, double-blind, placebo-controlled, sequential cross-over trial. The study population will be enriched to ensure a G-allele frequency of 50% for the rs9349379 SNP. The participants will receive a single-blind placebo run-in followed by treatment with either 10 mg of zibotentan daily for 12 weeks then placebo for 12 weeks, or vice versa, in random order. The primary outcome is treadmill exercise duration using the Bruce protocol. The primary analysis will assess the within-subject difference in exercise duration following treatment with zibotentan versus placebo. CONCLUSION: PRIZE invokes precision medicine in microvascular angina. Should our hypotheses be confirmed, this developmental trial will inform the rationale and design for undertaking a larger multicenter trial.

Endothelin-1-Mediated Drug Resistance in EGFR-Mutant Non-Small Cell Lung Carcinoma

Progression on therapy in non-small cell lung carcinoma (NSCLC) is often evaluated radiographically, however, image-based evaluation of said therapies may not distinguish disease progression due to intrinsic tumor drug resistance or inefficient tumor penetration of the drugs. Here we report that the inhibition of mutated EGFR promotes the secretion of a potent vasoconstrictor, endothelin-1 (EDN1), which continues to increase as the cells become resistant with a mesenchymal phenotype. As EDN1 and its receptor (EDNR) is linked to cancer progression, EDNR-antagonists have been evaluated in several clinical trials with disappointing results. These trials were based on a hypothesis that the EDN1-EDNR axis activates the MAPK-ERK signaling pathway that is vital to the cancer cell survival; the trials were not designed to evaluate the impact of tumor-derived EDN1 in modifying tumor microenvironment or contributing to drug resistance. Ectopic overexpression of EDN1 in cells with mutated EGFR resulted in poor drug delivery and retarded growth in vivo but not in vitro. Intratumoral injection of recombinant EDN significantly reduced blood flow and subsequent gefitinib accumulation in xenografted EGFR-mutant tumors. Furthermore, depletion of EDN1 or the use of endothelin receptor inhibitors bosentan and ambrisentan improved drug penetration into tumors and restored blood flow in tumor-associated vasculature. Correlatively, these results describe a simplistic endogenous yet previously unrealized resistance mechanism inherent to a subset of EGFR-mutant NSCLC to attenuate tyrosine kinase inhibitor delivery to the tumors by limiting drug-carrying blood flow and the drug concentration in tumors. SIGNIFICANCE: EDNR antagonists can be repurposed to improve drug delivery in VEGFA-secreting tumors, which normally respond to TKI treatment by secreting EDN1, promoting vasoconstriction, and limiting blood and drug delivery.

Cellular growth factors as prospective therapeutic targets for combination therapy in androgen independent prostate cancer (AIPC)

Cancer is the second leading cause of death worldwide, with prostate cancer, the second most commonly diagnosed cancer among men. Prostate cancer develops in the peripheral zone of the prostate gland, and the initial progression largely depends on androgens, the male reproductive hormone that regulates the growth and development of the prostate gland and testis. The currently available treatments for androgen dependent prostate cancer are, however, effective for a limited period, where the patients show disease relapse, and develop androgen-independent prostate cancer (AIPC). Studies have shown various intricate cellular processes such as, deregulation in multiple biochemical and signaling pathways, intra-tumoral androgen synthesis; AR over-expression and mutations and AR activation via alternative growth pathways are involved in progression of AIPC. The currently approved treatment strategies target a single cellular protein or pathway, where the cells slowly develop resistance and adapt to proliferate via other cellular pathways over a period of time. Therefore, an increased research aims to understand the efficacy of combination therapy, which targets multiple interlinked pathways responsible for acquisition of resistance and survival. The combination therapy is also shown to enhance efficacy as well as reduce toxicity of the drugs. Thus, the present review focuses on the signaling pathways involved in the progression of AIPC, comprising a heterogeneous population of cells and the advantages of combination therapy. Several clinical and pre-clinical studies on a variety of combination treatments have shown beneficial outcomes, yet further research is needed to understand the potential of combination therapy and its diverse strategies.

Risk Assessment and Considerations for Proper Management of Elderly Men with Advanced Prostate Cancer: A Systematic Review

CONTEXT

Treatment decisions for elderly men with prostate cancer are complicated by the intersection of competing risks of cancer, potential complications of treatment, and individual patients' comorbidities.

OBJECTIVE

To perform a systematic review of data guiding the assessment of elderly prostate cancer patients that addresses the risk from cancer and treatment, and to discuss a patient-centered approach to incorporating these factors into decision making.

EVIDENCE ACQUISITION

Evidence was gathered via a systematic review of the current literature. The search strategy used the terms prostate cancer, elderly, geriatric, >75 yr of age, risk assessment, and treatment in several combinations, and was limited to phase ≥ II clinical trials published between January 2008 and November 2018. Additional supporting literature for the discussion was pulled by hand search.

EVIDENCE SYNTHESIS

The benefits of treatment identified for systemic therapies commonly used to treat men with prostate in general extend to elderly patients. Evidence supports a multifaceted assessment of the risks of cancer and aging, and an understanding of the side effects of treatment to optimally guide therapeutic decision making for elderly patients. There is little evidence defining a geriatric risk stratification system specific to prostate cancer, and recommendations are predominantly based on adapted geriatric oncology approaches and expert consensus.

CONCLUSIONS

The care of elderly men with prostate cancer should incorporate a review of cancer risk, an assessment of aging, and an understanding of the effects of treatment to provide the patient with thorough and personalized guidance for treatment decisions. Future studies of elderly men with prostate cancer can define and validate ideal risk stratification methods as well as management approaches that may be distinct from those for younger populations.

PATIENT SUMMARY

Treatment decisions for elderly men with prostate cancer require consideration of the risk posed by the cancer coupled with an understanding of the patient's general health status.

Comparative Survival of Asian and White Metastatic Castration-Resistant Prostate Cancer Men Treated With Docetaxel

There are few data regarding disparities in overall survival (OS) between Asian and white men with metastatic castration-resistant prostate cancer (mCRPC). We compared OS of Asian and white mCRPC men treated in phase III clinical trials with docetaxel and prednisone (DP) or a DP-containing regimen. Individual participant data from 8820 men with mCRPC randomly assigned on nine phase III trials to receive DP or a DP-containing regimen were combined. Men enrolled in these trials had a diagnosis of prostate adenocarcinoma. The median overall survival was 18.8 months (95% confidence interval [CI] = 17.4 to 22.1 months) and 21.2 months (95% CI = 20.8 to 21.7 months) for Asian and white men, respectively. The pooled hazard ratio for death for Asian men compared with white men, adjusted for baseline prognostic factors, was 0.95 (95% CI = 0.84 to 1.09), indicating that Asian men were not at increased risk of death. This large analysis showed that Asian men did not have shorter OS duration than white men treated with docetaxel.

Response and outcome of liver metastases in patients with metastatic castration-resistant prostate cancer (mCRPC) undergoing 177Lu-PSMA-617 radioligand therapy

PURPOSE

Little is known about the efficacy of prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) against liver metastases of metastatic castration-resistant prostate cancer (mCRPC). We retrospectively analyzed efficacy-related outcomes of ¹⁷⁷Lu-PSMA-617 RLT in this setting and potential predictors of those outcomes.

METHODS

Twenty-eight consecutive mCRPC patients with liver metastases given ¹⁷⁷Lu-PSMA-617 RLT were analyzed retrospectively. Their planned regimen was 4-6 cycles at 6 ± 2-week intervals; the mean activity/cycle was 6.5 ± 0.5 GBq. Hepatic response was determined by modified positron emission tomography response criteria in solid tumors; association of such response with overall survival (OS) was tested, as were relationships of the selected patient, disease, and treatment characteristics with hepatic progression-free survival (PFS_hep) and OS. Survival analyses used Kaplan-Meier curves, log-rank test at p < 0.05 significance, and Cox proportional-hazards modeling.

RESULTS

Median (minimum-maximum) follow-up was 37.5 (2.3-50.6) months. In liver metastases, complete or partial response was observed in 6 patients (21%) each, and stable disease in 1 (4%), for hepatic disease control in 46%. Overall, median (95% confidence interval) PFS_hep was 5.7 (2.2-9.2) months, and OS, 11.7 (3.0-20.4) months. Patients with hepatic disease control did not reach the median OS, while those with hepatic progressive disease had median OS (95% confidence interval) of 6.4 (1.6-11.1) months. In multivariate analysis, hepatic disease control by ¹⁷⁷Lu-PSMA-617 RLT was significantly independently associated with OS, as was a prostate-specific antigen decline of ≥ 50% after 2 RLT cycles, and good baseline performance status (Eastern Cooperative Oncology Group 0-1). Hepatic tumor burden (≤ 25% vs. > 25% of liver volume) had no apparent relationship with hepatic tumor response, PFS_hep, or OS.

CONCLUSION

¹⁷⁷Lu-PSMA-617 RLT frequently controlled liver metastases, resulting in long PFS_hep and significantly improved OS. Hepatic tumor burden appeared to lack any relationship with treatment efficacy, supporting ¹⁷⁷Lu-PSMA-617 RLT of late-stage/end-stage mCRPC with liver metastases.

Clinical outcomes in men of diverse ethnic backgrounds with metastatic castration-resistant prostate cancer

BACKGROUND

We have shown previously in multivariable analysis that black men had 19% lower risk of death than white men with metastatic castration-resistant prostate cancer (mCRPC) treated with a docetaxel and prednisone (DP)-based regimen. The primary goal of this analysis was to compare progression-free survival (PFS), biochemical PFS, ≥50% decline in prostate-specific antigen (PSA) from baseline and objective response rate (ORR) in white, black and Asian men with mCRPC treated with a DP-based regimen.

PATIENTS AND METHODS

Individual patient data from 8820 mCRPC men randomized on nine phase III trials to a DP-containing regimen were combined. Race used in the analysis was based on self-report. End points were PFS, biochemical PSA, ≥50% decline in PSA from baseline and ORR. The proportional hazards and the logistic regression models were employed to assess the prognostic importance of race in predicting outcomes adjusting for established prognostic factors.

RESULTS

Of 8820 patients, 7528 (85%) were white, 500 (6%) were black, 424 were Asian (5%) and 368 (4%) had race unspecified. Median PFS were 8.3 [95% confidence interval (CI) 8.2-8.5], 8.2 (95% CI 7.4-8.8) and 8.3 (95% CI 7.6-8.8) months in white, black and Asian men, respectively. Median PSA PFS were 9.9 (95% CI 9.7-10.4), 8.5 (95% CI 8.0-10.3) and 11.1 (95% CI 9.9-12.5) months in white, black and Asian men, respectively.

CONCLUSIONS

We observed no differences in clinical outcomes by race and ethnic groups in men with mCRPC enrolled on these phase III clinical trials with DP.

Endothelin Receptor Antagonists: Status Quo and Future Perspectives for Targeted Therapy

The endothelin axis, recognized for its vasoconstrictive action, plays a central role in the pathology of pulmonary arterial hypertension (PAH). Treatment with approved endothelin receptor antagonists (ERAs), such as bosentan, ambrisentan, or macitentan, slow down PAH progression and relieves symptoms. Several findings have indicated that endothelin is further involved in the pathogenesis of certain other diseases, making ERAs potentially beneficial in the treatment of various conditions. In addition to PAH, this review summarizes the use and perspectives of ERAs in cancer, renal disease, fibrotic disorders, systemic scleroderma, vasospasm, and pain management. Bosentan has proven to be effective in systemic sclerosis PAH and in decreasing the development of vasospasm-related digital ulcers. The selective ERA clazosentan has been shown to be effective in preventing cerebral vasospasm and delaying ischemic neurological deficits and new infarcts. Furthermore, in the SONAR (Study Of Diabetic Nephropathy With Atrasentan) trial, the selective ERA atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease. These data suggest atrasentan as a new therapy in the treatment of diabetic nephropathy and possibly other renal diseases. Preclinical studies regarding heart failure, cancer, and fibrotic diseases have demonstrated promising effects, but clinical trials have not yet produced measurable results. Nevertheless, the potential benefits of ERAs may not be fully realized.

Treatment Stratification of Patients with Metastatic Castration-Resistant Prostate Cancer by Machine Learning

Prostate cancer is the most common cancer in men in the Western world. One-third of the patients with prostate cancer will develop resistance to hormonal therapy and progress into metastatic castration-resistant prostate cancer (mCRPC). Currently, docetaxel is a preferred treatment for mCRPC. However, about 20% of the patients will undergo early therapeutic failure owing to adverse events induced by docetaxel-based chemotherapy. There is an emergent need for a computational model that can accurately stratify patients into docetaxel-tolerable and docetaxel-intolerable groups. Here we present the best-performing algorithm in the Prostate Cancer DREAM Challenge for predicting adverse events caused by docetaxel treatment. We integrated the survival status and severity of adverse events into our model, which is an innovative way to complement and stratify the treatment discontinuation information. Critical stratification biomarkers were further identified in determining the treatment discontinuation. Our model has the potential to improve future personalized treatment in mCRPC.

Synthesis of Thiazolium-Labeled 1,3,4-Oxadiazole Thioethers as Prospective Antimicrobials: In Vitro and in Vivo Bioactivity and Mechanism of Action

In this study, a type of thiazolium-labeled 1,3,4-oxadiazole thioether bridged by diverse alkyl chain lengths was constructed. The antimicrobial activity of the fabricated thioether toward plant pathogenic bacteria and fungi was then screened. Antibacterial evaluation indicated that title compounds possess specific characteristics that enable them to severely attack three phytopathogens, namely, Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Xanthomonas axonopodis pv. citri with minimal EC₅₀ values of 0.10, 3.27, and 3.50 μg/mL, respectively. Three-dimensional quantitative structure-activity relationship models were established to direct the following excogitation for exploring higher active drugs. The in vivo study against plant bacterial diseases further identified the prospective application of title compounds as alternative antibacterial agents. The proteomic technique, scanning electron microscopy patterns, and fluorescence spectrometry were exploited to investigate the antibacterial mechanism. Additionally, some target compounds performed superior inhibitory actions against three tested fungal strains. In view of their simple molecular architecture and highly efficient bioactivity, these substrates could be further explored as promising surrogates for fighting against plant microbial infections.

Developing and Validating Risk Assessment Models of Clinical Outcomes in Modern Oncology

The identification of prognostic factors and building of risk assessment prognostic models will continue to play a major role in 21st century medicine in patient management and decision making. Investigators are often interested in examining the relationship between host, tumor-related, and environmental variables in predicting clinical outcomes. We make a distinction between static and dynamic prediction models. In static prediction modelling, typically variables collected at baseline are utilized in building models. On the other hand, dynamic predictive models leverage the longitudinal data of covariates collected during treatment or follow-up, and hence provide accurate predictions of patients prognoses. To date, most risk assessment models in oncology have been based on static models. In this article, we cover topics that are related to the analysis of prognostic factors, centering on factors that are both relevant at the time of diagnosis or initial treatment and during treatment. We describe the types of risk prediction and then provide a brief description of the penalized regression methods. We then review the state-of-the art methods for dynamic prediction and compare the strengths and the limitations of these methods. While static models will continue to play an important role in oncology, developing and validating dynamic models of clinical outcomes need to take a higher priority. It is apparent that a framework for developing and validating dynamic tools in oncology is still needed. One of the limitations in oncology that modelers may be constrained by the lack of access to the longitudinal biomarker data. It is highly recommended that the next generation of risk assessments consider the longitudinal biomarker data and outcomes so that prediction can be continually updated.

Loss of Fibroblast-Dependent Androgen Receptor Activation in Prostate Cancer Cells is Involved in the Mechanism of Acquired Resistance to Castration

Loss of androgen receptor (AR) dependency in prostate cancer (PCa) cells is associated with progression to castration-resistant prostate cancer (CRPC). The tumor stroma is enriched in fibroblasts that secrete AR-activating factors. To investigate the roles of fibroblasts in AR activation under androgen deprivation, we used three sublines of androgen-sensitive LNCaP cells (E9 and F10 cells: low androgen sensitivity; and AIDL cells: androgen insensitivity) and original fibroblasts derived from patients with PCa. We performed in vivo experiments using three sublines of LNCaP cells and original fibroblasts to form homotypic tumors. The volume of tumors derived from E9 cells plus fibroblasts was reduced following androgen deprivation therapy (ADT), whereas that of F10 or AIDL cells plus fibroblasts was increased even after ADT. In tumors derived from E9 cells plus fibroblasts, serum prostate-specific antigen (PSA) decreased rapidly after ADT, but was still detectable. In contrast, serum PSA was increased even in F10 cells inoculated alone. In indirect cocultures with fibroblasts, PSA production was increased in E9 cells. Epidermal growth factor treatment stimulated Akt and p44/42 mitogen-activated protein kinase phosphorylation in E9 cells. Notably, AR splice variant 7 was detected in F10 cells. Overall, we found that fibroblast-secreted AR-activating factors modulated AR signaling in E9 cells after ADT and loss of fibroblast-dependent AR activation in F10 cells may be responsible for CRPC progression.

Bone-targeted therapy in castration-resistant prostate cancer: where do we stand?

INTRODUCTION

In the last years, there have been significant developments in the therapeutic armamentarium of metastatic castration-resistant prostate cancer (mCRPC). New evidence shows that the addition of bone-targeted agents (BTA) to "life-prolonging agents" result in improved clinical benefit. This review aims to give an overview of data for the use of BTAs in a new era of mCRPC where new agents are used in daily practice.

EVIDENCE ACQUISITION

A non-systematic review of the literature was performed combining the keywords: "castration-resistant prostate cancer" and "bone-targeted therapy". The primary objective was to provide a critical assessment of data for the use of BTAs in mCRPC, and the secondary objective was to assess novel targeted therapy.

EVIDENCE SYNTHESIS

Zoledronic acid and denosumab have shown to be effective in reducing the risk of SREs in patients with mCRPC. The point at which treatment with bisphosphonates or denosumab should be initiated during PCa evolution has yet to be determined. The EMA has restricted the usage of Ra-223 to patients who have had two previous treatments for mCRPC to the bone or who cannot receive other treatments. Ra-223 should only be used as monotherapy or in combination with ADT for the treatment of mCRPC, symptomatic bone metastases and without visceral metastases. With recent developments in PSMA-targeted radiopharmaceuticals, PSMA RLT agents are now under investigation for the treatment of mCRPC.

CONCLUSIONS

Reducing skeletal-related morbidity remains a crucial goal of palliative life-extending therapy in mCRPC. New data about dosing schedules and combinations of different treatments will continue to refine the optimal strategy for incorporating BTAs into the new treatment paradigms for PCa. Novel molecules such as PSMA-targeted small molecules promise theranostic agents in the management of PCa patients.

Quality-of-Life Assessment and Reporting in Prostate Cancer: Systematic Review of Phase 3 Trials Testing Anticancer Drugs Published Between 2012 and 2018

Quality of life (QoL) is not included among the end points in many studies, and QoL results are underreported in many phase 3 oncology trials. We performed a systematic review to describe QoL prevalence and heterogeneity in QoL reporting in recently published prostate cancer phase 3 trials. A PubMed search was performed to identify primary publications of randomized phase 3 trials testing anticancer drugs in prostate cancer, issued between 2012 and 2018. We analyzed QoL inclusion among end points, presence of QoL results, and methodology of QoL analysis. Seventy-two publications were identified (15 early-stage, 20 advanced hormone-sensitive, and 37 castration-resistant prostate cancer [CRPC]). QoL was not listed among study end points in 23 studies (31.9%) (40.0% early stage, 40.0% advanced hormone sensitive, and 24.3% CRPC). QoL results were absent in 15 (30.6%) of 49 primary publications of trials that included QoL among end points. Overall, as a result of absent end point or unpublished results, QoL data were lacking in 38 (52.8%) primary publications (53.3% early stage, 55.0% in advanced hormone sensitive, and 51.4% in CRPC). The most commonly used QoL tools were Functional Assessment of Cancer Therapy-Prostate (FACT-P) (21, 53.8%) and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) (14, 35.9%); most common methods of analysis were mean changes or mean scores (28, 71.8%), time to deterioration (14, 35.9%), and proportion of patients with response (10, 25.6%). In conclusion, QoL data are lacking in a not negligible proportion of recently published phase 3 trials in prostate cancer, although the presence of QoL results is better in positive trials, especially in CRPC. The methodology of QoL analysis is heterogeneous for type of instruments, analysis, and presentation of results.

A DREAM Challenge to Build Prediction Models for Short-Term Discontinuation of Docetaxel in Metastatic Castration-Resistant Prostate Cancer

Purpose

Docetaxel has a demonstrated survival benefit for patients with metastatic castration-resistant prostate cancer (mCRPC); however, 10% to 20% of patients discontinue docetaxel prematurely because of toxicity-induced adverse events, and the management of risk factors for toxicity remains a challenge.

Patients and Methods

The comparator arms of four phase III clinical trials in first-line mCRPC were collected, annotated, and compiled, with a total of 2,070 patients. Early discontinuation was defined as treatment stoppage within 3 months as a result of adverse treatment effects; 10% of patients discontinued treatment. We designed an open-data, crowd-sourced DREAM Challenge for developing models with which to predict early discontinuation of docetaxel treatment. Clinical features for all four trials and outcomes for three of the four trials were made publicly available, with the outcomes of the fourth trial held back for unbiased model evaluation. Challenge participants from around the world trained models and submitted their predictions. Area under the precision-recall curve was the primary metric used for performance assessment.

Results

In total, 34 separate teams submitted predictions. Seven models with statistically similar area under precision-recall curves (Bayes factor ≤ 3) outperformed all other models. A postchallenge analysis of risk prediction using these seven models revealed three patient subgroups: high risk, low risk, or discordant risk. Early discontinuation events were two times higher in the high-risk subgroup compared with the low-risk subgroup. Simulation studies demonstrated that use of patient discontinuation prediction models could reduce patient enrollment in clinical trials without the loss of statistical power.

Conclusion

This work represents a successful collaboration between 34 international teams that leveraged open clinical trial data. Our results demonstrate that routinely collected clinical features can be used to identify patients with mCRPC who are likely to discontinue treatment because of adverse events and establishes a robust benchmark with implications for clinical trial design.

Bone-targeted therapies to reduce skeletal morbidity in prostate cancer

Bone metastases are the main driver of morbidity and mortality in advanced prostate cancer. Targeting the bone microenvironment, a key player in the pathogenesis of bone metastasis, has become one of the mainstays of therapy in men with advanced prostate cancer. This review will evaluate the data supporting the use of bone-targeted therapy, including (1) bisphosphonates such as zoledronic acid, which directly target osteoclasts, (2) denosumab, a receptor activator of nuclear factor-kappa B (RANK) ligand inhibitor, which targets a key component of bone stromal interaction, and (3) radium-223, an alpha-emitting calcium mimetic, which hones to the metabolically active areas of osteoblastic metastasis and induces double-strand breaks in the DNA. Denosumab has shown enhanced delay in skeletal-related events compared to zoledronic acid in patients with metastatic castration-resistant prostate cancer (mCRPC). Data are mixed with regard to pain control as a primary measure of efficacy. New data call into question dosing frequency, with quarterly dosing strategy potentially achieving similar effect compared to monthly dosing for zoledronic acid. In the case of radium-223, there are data for both pain palliation and improved overall survival in mCRPC. Further studies are needed to optimize timing and combination strategies for bone-targeted therapies. Ongoing studies will explore the impact of combining bone-targeted therapy with investigational therapeutic agents such as immunotherapy, for advanced prostate cancer. Future studies should strive to develop biomarkers of response, in order to improve efficacy and cost-effectiveness of these agents.

Phase II, Multicenter, Randomized Trial of Docetaxel plus Prednisone with or Without Cediranib in Men with Chemotherapy-Naive Metastatic Castrate-Resistant Prostate Cancer

Lessons Learned.

The negative results are consistent with the negative results of large phase III trials in which docetaxel plus antiangiogenic agents were used in patients with metastatic castrate‐resistant prostate cancer (mCRPC).

The negative data underscore that, despite a sound biological rationale and supportive early‐phase clinical results, adding antiangiogenic agents to docetaxel for mCRPC is a great challenge.

Background.

Inhibition of vascular endothelial growth factor (VEGF) signaling abrogates tumor‐induced angiogenesis to constrain tumor growth, and can be exploited therapeutically by using cediranib, an oral tyrosine kinase inhibitor of VEGF receptor signaling. Our preliminary phase I trial data showed that adding cediranib to docetaxel plus prednisone (DP) was safe and feasible, with early evidence for efficacy in patients with metastatic castrate‐resistant prostate cancer (mCRPC).

Methods.

This multicenter phase II trial assessed whether adding cediranib to DP improves efficacy of DP in patients with mCRPC. Chemotherapy‐naive patients with mCRPC were randomly assigned to receive either docetaxel (75 mg/m² intravenously every 3 weeks) with prednisone (5 mg twice daily) plus cediranib (30 mg once daily; the DP+C arm) or DP only (the DP arm). The primary endpoint was to compare 6‐month progression‐free survival (PFS) rate between the two arms. Secondary endpoints included 6‐month overall survival (OS), objective tumor and prostate‐specific antigen (PSA) response rates, biomarkers, and adverse events.

Results.

The 6‐month PFS rate in a total of 58 patients was only numerically higher in the DP+C arm (61%) compared with the DP arm (57%). Similarly, the 6‐month OS rate, objective tumor and PSA response rates, and biomarkers were not significantly different between the two arms. Increased baseline levels of interleukin 6 (IL‐6), however, were significantly associated with increased risk of progression. Neutropenia was the only grade 4 toxicity (38% in the DP+C arm vs. 18% in the DP arm).

Conclusion.

Combining cediranib with docetaxel + prednisone failed to demonstrate superior efficacy, compared with docetaxel + prednisone, and added toxicity. Our data do not support pursuing the combination further in patients with mCRPC.

Pirfenidone, an Anti-Fibrotic Drug, Suppresses the Growth of Human Prostate Cancer Cells by Inducing G₁ Cell Cycle Arrest

Pirfenidone (PFD) is an anti-fibrotic drug used to treat idiopathic pulmonary fibrosis by inducing G₁ cell cycle arrest in fibroblasts. We hypothesize that PFD can induce G₁ cell cycle arrest in different types of cells, including cancer cells. To investigate the effects of PFD treatment on the growth of human prostate cancer (PCa) cells, we used an androgen-sensitive human PCa cell line (LNCaP) and its sublines (androgen-low-sensitive E9 and F10 cells and androgen-insensitive AIDL cells), as well as an androgen-insensitive human PCa cell line (PC-3). PFD treatment suppressed the growth of all PCa cells. Transforming growth factor β1 secretion was significantly increased in PFD-treated PCa cells. In both LNCaP and PC-3 cells, PFD treatment increased the population of cells in the G₀/G₁ phase, which was accompanied by a decrease in the S/G₂ cell population. CDK2 protein expression was clearly decreased in PFD-treated LNCaP and PC-3 cells, whereas p21 protein expression was increased in only PFD-treated LNCaP cells. In conclusion, PFD may serve as a novel therapeutic drug that induces G₁ cell cycle arrest in human PCa cells independently of androgen sensitivity. Thus, in the tumor microenvironment, PFD might target not only fibroblasts, but also heterogeneous PCa cells of varying androgen-sensitivity levels.

Overall Survival of Black and White Men With Metastatic Castration-Resistant Prostate Cancer Treated With Docetaxel

PURPOSE

Several studies have reported that among patients with localized prostate cancer, black men have a shorter overall survival (OS) time than white men, but few data exist for men with advanced prostate cancer. The primary goal of this analysis was to compare the OS in black and white men with metastatic castration-resistant prostate cancer (mCRPC) who were treated in phase III clinical trials with docetaxel plus prednisone (DP) or a DP-containing regimen.

METHODS

Individual participant data from 8,820 men with mCRPC randomly assigned in nine phase III trials to DP or a DP-containing regimen were combined. Race was based on self-report. The primary end point was OS. The Cox proportional hazards regression model was used to assess the prognostic importance of race (black v white) adjusted for established risk factors common across the trials (age, prostate-specific antigen, performance status, alkaline phosphatase, hemoglobin, and sites of metastases).

RESULTS

Of 8,820 men, 7,528 (85%) were white, 500 (6%) were black, 424 (5%) were Asian, and 368 (4%) were of unknown race. Black men were younger and had worse performance status, higher testosterone and prostate-specific antigen, and lower hemoglobin than white men. Despite these differences, the median OS was 21.0 months (95% CI, 19.4 to 22.5 months) versus 21.2 months (95% CI, 20.8 to 21.7 months) in black and white men, respectively. The pooled multivariable hazard ratio of 0.81 (95% CI, 0.72 to 0.91) demonstrates that overall, black men have a statistically significant decreased risk of death compared with white men ( P < .001).

CONCLUSION

When adjusted for known prognostic factors, we observed a statistically significant increased OS in black versus white men with mCRPC who were enrolled in these clinical trials. The mechanism for these differences is not known.

The efficacy and safety comparison of docetaxel, cabazitaxel, estramustine, and mitoxantrone for castration-resistant prostate cancer: A network meta-analysis

AIMS

The aim of this study was to compare the efficacy and safety of docetaxel, cabazitaxel, docetaxel + estramustine, mitoxantrone in the management of castration-resistant prostate cancer (CRPC).

METHODS

Electronic databases including PubMed, Cochrance Library and Embase were searched for studies published from when the databases were established to January 1st, 2018. Randomized controlled trials (RCTs) that compared docetaxel + prednisone (DP), cabazitaxel + prednisone (CP), docetaxel + estramustine + prednisone (DEP), and mitoxantrone + cabazitaxel + prednisone (MP) for CRPC treatment were identified. The network meta-analysis was conducted with software R 3.3.2. We analyzed the main outcomes, including the overall survival (OS), progression-free survival (PFS), prostate-specific antigen (PSA) response, tumor response and severe adverse events (AEs). Ranking of the chemotherapeutic agents was based on probabilities of interventions for each of the outcomes that were performed. The consistency of direct and indirect evidence was assessed by node splitting.

RESULTS

10 RCTs, with 3590 patients, were analyzed. The network meta-analysis results revealed that CP significantly increased OS, PFS, PSA response, tumor response, and severe AEs compared to MP. DP showed similar results with CP except for tumor response, where it showed slight inferiority in effectiveness. DEP was associated with clearly improved outcomes in PFS, PSA response and tumor response compared to those of MP, but this was not the case for OS benefit and severe AEs. No significant difference was detected in DP, CP and DEP except for the outcomes of severe AEs. MP was less effective in survival and clinical benefit, but much safer in safety outcomes than other chemotherapy agents. The probabilities of rank plots showed that CP ranked first in OS and tumor response; DEP ranked first in PFS time and PSA response; MP was the best treatment mode for safety.

CONCLUSIONS

DP and CP survival benefit (OS, PFS) and clinical benefit (PSA response and tumor response) were comparable, as well as their associated AEs. DEP was associated with less survival benefit, similar clinical improvement and more AEs than DP or CP. MP had the lowest survival and clinical benefit but excellent safety than other agents. Based on evidences of current results, we recommended CP as the most suitable chemotherapy agent for CRPC patients, followed by DP, MP as third, and DEP as the last choice. However, considering limitations of our network meta-analysis, additional high-quality studies are needed for further evaluation.

Can RECIST response predict success in phase 3 trials in men with metastatic castration-resistant prostate cancer?

BACKGROUND

Intermediate endpoints are needed in early phase studies of men with metastatic castration-resistant prostate cancer (mCRPC) that can reliably predict success in phase 3 trials. Among men with measurable disease, objective response may provide information as to whether a treatment is likely to be successful.

METHODS

We conducted a systematic review of systemic agents that have proceeded to phase 3 trials in men with mCRPC and examined the relationship between improvements in measurable disease response in phase 2 trials and successful phase 3 trials leading to regulatory approval. Only trials that included men with radiographically measurable disease were included.

RESULTS

We examined 31 eligible mCRPC phase 3 trials between 1992 and 2017 and 29 of the preceding phase 2 trials for RECIST responses. Measurable tumor responses in phase 2 trials were higher for successful therapies in phase 3 trials in chemotherapy-naive men with mCRPC, but were less correlated with success in trials investigating docetaxel combination regimens or the post chemotherapy mCRPC setting. Many failed agents did not produce higher than expected response rates over control arms; however, several agents such as anti-angiogenic therapies or orteronel produced higher than expected responses without survival benefit.

CONCLUSIONS

Objective responses in men with mCRPC may be associated with prolonged survival, but this association is mechanism dependent and inconsistent across trials or disease states. These data support considering RECIST response as a supportive but not sole endpoint in phase 2 trials to support launching phase 3 trials.

Effectiveness and tolerability of targeted drugs for the treatment of metastatic castration-resistant prostate cancer: a network meta-analysis of randomized controlled trials

PURPOSE

Castration-resistant prostate cancer (CRPC) refers to prostate cancer that has progressed after initial androgen deprivation therapy (ADT). Over the years, treatment strategies for metastatic CRPC (mCRPC) have undergone considerable changes. We performed a network meta-analysis to assess the effectiveness and tolerability of targeted agents for mCRPC.

METHODS

We search databases including MEDLINE, EMBASE, and the Cochrane Library through Sep 5, 2017. The major effectiveness outcomes were progression-free survival (PFS) and overall survival (OS). The tolerability outcome was severe adverse events (AEs) of grade ≥ 3.

RESULTS

Twenty-six articles assessing a total of 20,314 patients were included in this study. A random-effect analysis showed that targeted agents could significant prolong PFS in mCRPC patients (I² = 94.3%; hazard ratio (HR): 0.74; 95% confidence interval (CI): 0.65-0.84; p < 0.001). In addition, the surface under the cumulative ranking curve (SUCRA) ranking from the network analysis showed that enzalutamide was the most effective in improving the PFS of mCRPC patients (100%), followed by abiraterone (90.1%) and tasquinimod (84.2%). Additionally, targeted agents could clearly prolong OS in mCRPC patients (I² = 71.6%; HR: 0.91; 95% CI: 0.85-0.97; p < 0.001). Furthermore, based on SUCRA ranking, enzalutamide was the most effective in improving the OS of mCRPC patients (97.2%), followed by abiraterone (91.1%) and zibotentan (65.8%). Intetumumab was associated with the lowest incidence of severe AEs (94.9%), followed by atrasentan (85.1%) and placebo (79.3%).

CONCLUSION

In patients with mCRPC, enzalutamide, abiraterone and tasquinimod can prolong PFS, and enzalutamide and abiraterone can prolong OS. Additionally, enzalutamide and abiraterone can improve both PFS and OS with a low risk of causing severe AEs.

Laboratory-Based Biomarkers and Liver Metastases in Metastatic Castration-Resistant Prostate Cancer

BACKGROUND

Metastatic castrate-resistant prostate cancer (mCRPC) patients with liver metastases have a poor prognosis. No large studies have investigated the clinical and biochemical parameters associated with liver metastases in this population.

MATERIALS AND METHODS

Patient data made available via Project Data Sphere were collected from 1,281 men with mCRPC who were enrolled on to three phase III clinical trials for the treatment of their disease. Multiple logistic regression was performed on eight clinical and biochemical baseline variables to test their association with the presence of liver metastases on baseline radiographic imaging. Variables of interest included prior docetaxel exposure, Eastern Cooperative Oncology Group performance status, albumin, alkaline phosphatase, alanine transaminase, aspartate transaminase (AST), hemoglobin (HGB), lactate dehydrogenase (LDH), prostate-specific antigen, and total bilirubin. Final models were compared when treating the variables as either continuous or categorized.

RESULTS

Multiple variable analysis demonstrated that an increasing serum AST or LDH or a decreasing HGB was associated with an increased probability of having documented radiographic liver metastases (p < .0001). The area under the curve for the continuous model was 0.6842 and 0.6890 for the categorical one, with the latter model containing a dichotomized AST and LDH based on the upper limit of normal and tertile ranges of HGB based on the distribution of the outcome.

CONCLUSION

Our analysis demonstrated a significant association between the presence of liver metastases and laboratory levels of AST, LDH, and HGB. These have implications for patient management. More research is needed to validate these biomarkers and prospectively determine their application in the clinical setting.

IMPLICATIONS FOR PRACTICE

The purpose of this study was to evaluate biochemical and clinical biomarkers associated with the presence of liver metastases in men diagnosed with metastatic castrate-resistant prostate cancer. The results indicate that quantitative assessments of aspartate transaminase, lactate dehydrogenase, and hemoglobin are significantly associated with an increased probability of having documented radiographic liver metastases. Analysis of these simple variables can alert clinicians to those at high risk for prostate cancer that has spread to the liver, a finding of clear importance for clinical management.

Role of Stromal Paracrine Signals in Proliferative Diseases of the Aging Human Prostate

Androgens are essential for the development, differentiation, growth, and function of the prostate through epithelial–stromal interactions. However, androgen concentrations in the hypertrophic human prostate decrease significantly with age, suggesting an inverse correlation between androgen levels and proliferative diseases of the aging prostate. In elderly males, age- and/or androgen-related stromal remodeling is spontaneously induced, i.e., increased fibroblast and myofibroblast numbers, but decreased smooth muscle cell numbers in the prostatic stroma. These fibroblasts produce not only growth factors, cytokines, and extracellular matrix proteins, but also microRNAs as stromal paracrine signals that stimulate prostate epithelial cell proliferation. Surgical or chemical castration is the standard systemic therapy for patients with advanced prostate cancer. Androgen deprivation therapy induces temporary remission, but the majority of patients eventually progress to castration-resistant prostate cancer, which is associated with a high mortality rate. Androgen deprivation therapy-induced stromal remodeling may be involved in the development and progression of castration-resistant prostate cancer. In the tumor microenvironment, activated fibroblasts stimulating prostate cancer cell proliferation are called carcinoma-associated fibroblasts. In this review, we summarize the role of stromal paracrine signals in proliferative diseases of the aging human prostate and discuss the potential clinical applications of carcinoma-associated fibroblast-derived exosomal microRNAs as promising biomarkers.

A mini-review of quality of life as an outcome in prostate cancer trials: patient-centered approaches are needed to propose appropriate treatments on behalf of patients

Background

Patients with prostate cancer (PC) may be ready to make trade-offs between their quantity and their quality of life. For instance, elderly patients may prefer the absence of treatment if it is associated with a low-risk of disease progression, compared to treatments aiming at preventing disease progression but with a substantial deterioration of their Health-Related Quality of Life (HRQoL). Therefore, it seems relevant to compare the treatments by considering both survival and HRQoL. In this mini-review, the aim was to question whether the potential trade-offs between survival and HRQoL are considered in high impact factor journals.

Methods

The study was conducted from the PubMed database for recent papers published between May 01, 2013, and May 01, 2015. We also restricted our search to nine medical journals with 2013 impact factor > 15.

Results

Among the 30 selected studies, only six collected individual HRQoL as a secondary endpoint by using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire. In four studies, the time to HRQoL change was analyzed, but its definitions varied. In two studies, the mean changes in HRQoL between the baseline and the 12- or 16-week follow-up were analyzed. None of the six studies reported in a single endpoint both the quantity and the quality of life.

Conclusions

Our mini-review, which only focused on recent publications in journals with high-impact, suggests moving PC clinical research towards patient-centered outcomes-based studies. This may help physicians to propose the most appropriate treatment on behalf of patients. We recommend the use of indicators such as Quality-Adjusted Life-Years (QALYs) as principal endpoint in future clinical trials.

Electronic supplementary material

The online version of this article (10.1186/s12955-018-0870-6) contains supplementary material, which is available to authorized users.

Taxane-based Combination Therapies for Metastatic Prostate Cancer

CONTEXT

Multiple single-agent therapies improving survival are approved for the treatment of metastatic castration-resistant prostate cancer (mCRPC), including two chemotherapies, two androgen-signaling axis-targeting agents, an immunotherapeutic vaccine, and a radiopharmaceutical. Combination therapy can target multiple oncogenic pathways simultaneously, while potentially curbing the development of treatment resistance.

OBJECTIVE

To provide a succinct overview of taxane-based combination therapies currently being evaluated for the treatment of metastatic prostate cancer.

EVIDENCE ACQUISITION

We searched MEDLINE/PubMed^® and relevant congress databases for literature focused on taxane-based combination therapies being evaluated for the treatment of metastatic prostate cancer. In addition, a systematic search of www.clinicaltrials.gov was performed to gather information regarding ongoing taxane-based combination trials in prostate cancer. This search included phase II or III trials starting after January 1, 2010, which included the terms "docetaxel" or "cabazitaxel" and "prostate", and was then manually filtered for combination studies.

EVIDENCE SYNTHESIS

Single-agent therapy yields modest increments in survival. The success of combining docetaxel with androgen deprivation to improve overall survival (OS) for metastatic hormone-sensitive disease suggests the potential of similar approaches in mCRPC. Several classes of biological drugs have previously been combined with docetaxel for mCRPC in clinical trials without improvement in OS. However, combining docetaxel or cabazitaxel with newer agents with established single-agent benefit, such as radium-223, second-generation androgen pathway-targeted agents, or other chemotherapies, has the potential to benefit patients when compared with taxane chemotherapy alone. Our search revealed that the majority of trials currently assessing taxanes are focused on combination therapies: a combination approach is being evaluated in 37 of 47 trials assessing docetaxel and in 18 of 34 trials assessing cabazitaxel.

CONCLUSIONS

Despite prior failures, novel taxane-based combination therapies have the potential to improve outcomes in mCRPC. Challenges include the absence of validated predictive biomarkers for the selection of suitable patients and the potential for enhanced toxicity.

PATIENT SUMMARY

Patients with metastatic prostate cancer have access to multiple therapies improving survival. Many advanced epithelial cancers are treated with combinations of drugs; however, prostate cancer has remained an exception. A number of clinical studies have shown that combining chemotherapy with other classes of therapy may improve patient outcomes in prostate cancer. Here, we summarize the various combinations that are tested in the clinic and review the results.

Additive naftopidil treatment synergizes docetaxel-induced apoptosis in human prostate cancer cells

PURPOSE

Docetaxel (DTX) is a standard chemotherapeutic drug for castration-resistant prostate cancer (CRPC), although adverse events are common. To overcome this problem, researchers have evaluated the efficacy of DTX treatment in combination with other drugs. Naftopidil is a tubulin-binding drug with fewer adverse events, implying the usefulness of this drug in clinical applications when combined with DTX. Here, we investigated the efficacy of additive naftopidil treatment in combination with DTX on prostate cancer (PCa) cells.

METHODS

The effects of combination treatment with DTX plus naftopidil were analyzed using two animal models of LNCaP cells plus PrSC xenografts (sub-renal capsule grafting) and PC-3 xenografts (intratibial injection).

RESULTS

Combination treatment with DTX plus naftopidil significantly inhibited cell growth in LNCaP cells compared with DTX alone. Analysis of the cooperativity index (CI) showed that combination treatment exhibited additive effects on DTX-induced growth inhibition in LNCaP cells. In contrast, combination treatment showed more than an additive (synergistic) effect on DTX-induced apoptosis in LNCaP and PC-3 cells. In LNCaP cells plus PrSC xenografts, combination treatment showed synergistic effects on DTX-induced apoptosis. The synergistic effects of naftopidil on DTX-induced apoptosis were also observed in PC-3 xenografts.

CONCLUSIONS

Our results demonstrated that additive naftopidil treatment in combination with DTX increased the efficacy of DTX for the treatment of LNCaP and PC-3 tumors in vivo. Thus, additive naftopidil treatment showed a synergistic effect on DTX-induced apoptosis in PCa cells in vitro and in vivo, suggesting that this treatment approach may yield improved clinical benefits compared with DTX alone.