Au/Doc/Quer@PDA/A10-3.2 Nanoparticles for targeted treatment of docetaxel-resistant prostate cancer

Docetaxel (Doc), as a first-line chemotherapy drug for prostate cancer (PC), often loses its therapeutic efficacy due to acquired resistance and lack of targeting specificity. Therefore, there is a need to develop a novel drug that can overcome Doc resistance and enhance its targeting ability to inhibit PC progression. In this study, we prepared Au/Doc/Quer@PDA/A10-3.2 nanoparticles (NPs) composite drug by encapsulating Doc and quercetin (Quer) within polydopamine (PDA)-coated Au NPs and further modifying them with RNA oligonucleotide aptamer A10-3.2. A10-3.2 was used for specific targeting of prostate-specific membrane antigen (PSMA)-positive PC cells (LNCaP). Quer was employed to reverse the resistance of Doc-resistant cell line (LNCaP/R) to Doc. Physical characterization using ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) confirmed the successful preparation of Au/Doc/Quer@PDA/A10-3.2 NPs. Fluorescence imaging and flow cytometry experiments demonstrated the targeting ability of Au/Doc/Quer@PDA/A10-3.2 NPs towards PSMA-positive LNCaP/R cells. Cell proliferation, apoptosis, invasion, and migration experiments revealed that Quer reversed the resistance of LNCaP/R cells to Doc. Immunoblotting experiments further confirmed the mechanism behind sensitization of chemotherapy by Quer. Finally, we evaluated the therapeutic efficacy of Au/Doc/Quer@PDA/A10-3.2 NPs in a mouse model of PC. In conclusion, this study synthesized and validated a novel nano-composite drug (Au/Doc/Quer@PDA/A10-3.2 NPs) for combating Doc-resistant PC, which could potentially be applied in clinical treatment of PC.

Impact of treatment on elder-relevant physical function and quality of life outcomes in older adults with metastatic castration-resistant prostate cancer

INTRODUCTION

Understanding physical function (PF) and quality of life (QoL) treatment effects are important in treatment decision-making for older adults with cancer. However, data are limited for older men with metastatic castration-resistant prostate cancer (mCRPC). We evaluated the effects of treatment on PF and QoL in older men with mCRPC.

MATERIALS AND METHODS

Men aged 65+ with mCRPC were enrolled in this multicenter prospective observational study. PF measures included instrumental activities of daily living, grip strength, chair stands, and gait speed. QoL measures included fatigue, pain, mood, and Functional Assessment of Cancer Therapy (FACT)-General total and sub-scale scores. Outcomes were collected at baseline, three, and six months. Linear mixed effects regression models were used to examine PF and QoL differences over time across various treatment cohorts.

RESULTS

We enrolled 198 men starting chemotherapy (n = 71), abiraterone (n = 37), enzalutamide (n = 67), or radium-223 (n = 23). At baseline, men starting chemotherapy had worse measures of PF, QoL, pain, and mood than the other groups. Over time, all PF measures remained stable, pain improved, but functional wellbeing (FWB) and mood worsened significantly for all cohorts. However, change over time in all outcomes was not appreciably different between treatment cohorts. Worst-case sensitivity analyses identified attrition (ranging from 22 to 42% by six months) as a major limitation of our study, particularly for the radium-223 cohort.

DISCUSSION

FWB and mood were most prone to deterioration over time, whereas pain improved with treatment. Although patients initiating chemotherapy had worse baseline PF and QoL, chemotherapy was not associated with significantly greater worsening over time compared to other common therapies for mCRPC. These findings may assist in treatment discussions with patients. However, given the modest sample size, attrition, and timeframe of follow-up, the impact of treatment on PF and QoL outcomes in this setting requires further study, particularly for radium-223.

The efficacy and safety of immune checkpoint inhibitors in metastatic castration-resistant prostate cancer: A systematic review and meta-analysis

BACKGROUND

We aim to assess the efficacy and safety profiles of immune checkpoint inhibitors in patients with metastatic castration-resistant prostate cancer using a meta-analysis.

METHODS

We extracted and examined data from phase I, II and III clinical trials from PubMed, Embase, Web of Science, and Cochrane Library, which included patients with metastatic castration-resistant prostate cancer who were treated with immune checkpoint inhibitors. We performed a meta-analysis to investigate several indexes of efficacy and safety, including the objective response rate, 1-year overall survival (OS) rate, prostate-specific antigen response rate, and adverse event rate of immune checkpoint inhibitors. The material data were calculated and pooled using The R Project for Statistical Computing and STATA 12.0 software.

RESULTS

We identified 12 clinical trials in our study. We assessed the pooled frequencies of all-grade AEs and grade ≥ 3 AEs first and showed 0.82 (95% CI: 0.74-0.91, I2 = 94%, P < .01) and 0.42 (95% CI: 0.33-0.54, I2 = 96%, P < .01), respectively. The objective response rate was 0.10 (95% CI: 0.04-0.19, I2 = 70%, P < .01), and the 1-year OS and prostate-specific antigen response rate were 0.55 (95% CI: 0.45-0.67, I2 = 93%, P < .01) and 0.18 (95% CI: 0.16-0.20, I2 = 43%, P = .03), respectively.

CONCLUSION

The immune checkpoint inhibitors therapy was well tolerated and showed potential to improve tumor responses in patients with metastatic castration-resistant prostate cancer.

Electronic patient-reported symptom monitoring in patients recovering from ambulatory minimally invasive gynecologic surgery: A prospective pilot study

OBJECTIVE

To evaluate the feasibility of an electronic symptom-tracking platform for patients recovering from ambulatory surgery.

METHOD

We assessed user response to an electronic system designed to self-report symptoms. Endpoints included compliance, postoperative symptoms, patient satisfaction. An 8-item symptom inventory (pain, nausea, vomiting, shortness of breath, fever, swelling, discharge, redness) was developed and made available on postoperative days (POD) 2-6. Responses exceeding defined thresholds of severity triggered alerts to healthcare providers. Symptoms, alerts, actions taken, urgent care center (UCC) visits, hospital admissions were tracked until POD 30. Patient satisfaction was evaluated on POD 7. A patient was defined as "responder" if at least 5/8 items on at least 3 PODs were completed. The assessment method was deemed successful if 64/100 patients responded.

RESULTS

97/102 patients were evaluable; 65 met "responder" criteria (67% responder rate; 95% CI 57-76%). 321 surveys were completed (median 4/patient), 248 (77%) in ≤2 min. Involving caregivers and allowing additional symptom-reporting improved the responder rate to 72% (95% CI 58-84%). Most commonly-reported moderate, severe, very severe symptoms were pain, nausea, swelling; 71% reported moderate to very severe pain on POD 2. Phone calls and adjustment of medications adequately addressed most symptoms. Two patients (2%) presented at UCC before, 6 (6%) after, POD 6; 1 (1%) was admitted. Most agreed or strongly agreed that electronic symptom-tracking was helpful, easy to use, and would recommend it to others.

CONCLUSION

Electronic symptom-tracking is feasible for patients undergoing ambulatory gynecologic cancer surgery. Symptom burden is high in the early postoperative period. Addressing patient-reported symptoms in a timely, automated manner may prevent severe downstream adverse events, reduce UCC visits and admission rates, and improve outcomes.

ASCO Resource-Stratified Guidelines: Methods and Opportunities

The objectives of this article are to describe the ASCO Resource-Stratified Guidelines and to provide background within the context of ASCO Guidelines and efforts to address the global cancer burden.

Effect of docetaxel on the regulation of proliferation and apoptosis of human prostate cancer cells

Prostate cancer is a common type of malignancy. Given the complexity of prostate cancer and the pressing challenge of chemoresistance, the current study was conducted to investigate the effect of docetaxel (Doc) on androgen receptor (AR)‑dependent and AR‑independent prostate cancers cells. Subsequent experiments were designed to explore the mechanism underlying the Doc‑induced apoptosis. Three different human prostate cancer cell lines, namely PC‑3, LNCaP and DU‑145, were exposed to various concentrations of Doc. The cytotoxic effects of Doc were evaluated by an MTT assay, while apoptosis and cell cycle distribution were determined by flow cytometric analysis of cells stained with Annexin V‑FITC and propidium iodide. Western blot assay was also used to measure the protein levels of B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated death promoter (Bad), total protein kinase B (Akt), phospho‑Akt and caspase‑3/9. Doc induced cytotoxicity in all three cell lines in a dose‑dependent manner. The half maximal inhibitory concentration values for the effect of Doc on PC‑3, DU‑145 and LNCaP cells were 3.72, 4.46 and 1.13 nM, respectively. Furthermore, the results indicated a significant difference in Doc sensitivity between AR‑dependent and AR‑independent prostate cancer cells. Evaluation of key gene expression at protein levels revealed a notable decrease in antiapoptotic Bcl‑2 and p‑Akt levels, along with a significant increase in pro‑apoptotic Bad, caspase‑3 and caspase‑9 levels. Therefore, Doc may induce cell apoptosis in prostate cancer via various pathways.

A Phase II Trial of AEZS-108 in Castration- and Taxane-Resistant Prostate Cancer

BACKGROUND

AEZS-108 (zoptarelin doxorubicin) is a cytotoxic hybrid molecule consisting of doxorubicin covalently coupled with a luteinizing hormone-releasing hormone (LHRH) analogue, which selectively targets doxorubicin to tumor cells expressing LHRH receptors. We report the clinical efficacy of AEZS-108 in a phase II trial in men with metastatic castrate-resistant prostate cancer who had disease progression after taxane-based chemotherapy.

PATIENTS AND METHODS

Patients received AEZS-108 210 mg/m² intravenously every 3 weeks. The primary end point was clinical benefit defined as nonprogression at 12 weeks with no dose-limiting toxicities (DLTs) or other toxicities requiring termination of treatment. Secondary end points included response rate, pain response, progression-free survival (PFS), and overall survival (OS). Circulating tumor cells (CTCs) were captured and tested for LHRH receptors, as well as for internalization of AEZS-108 using autofluorescence.

RESULTS

Twenty-five patients were enrolled; 20 patients had at least 1 measurable lesion at baseline. Patients received a median of 5 cycles (range, 1-9) and 44% of patients received at least 6 cycles with 2 patients who completed ≥ 8 cycles. Considering clinical benefits, 13 patients (52%) remained progression-free at 12 weeks with no DLT or other toxicities requiring termination of treatment. For clinical response according to Response Evaluation Criteria in Solid Tumors version 1.1 criteria, 1 patient (4%) experienced a confirmed partial response (PR) within 12 weeks, 14 patients (56%) had stable disease (SD), and 8 patients (32%) had disease progression. For maximal prostate-specific antigen (PSA) response, 1 patient (4%) experienced a confirmed PR within 12 weeks, 21 patients (84%) had SD, and 3 patients (12%) had disease progression as denoted by their best PSA response. Pain improved in 13 (59%) patients. The median PFS was 3.8 months (95% confidence interval [CI], 2.1-4.4), and median OS was 6.0 months (95% CI, 4.2-10.1) with a median follow-up of 16.1 months (range, 3.2-36.1). Baseline CTC enumeration was an independent predictor of OS but not PFS.

CONCLUSION

AEZS-108 showed activity in patients who were pretreated, a subset typically very difficult to treat, and maintained an acceptable safety profile.

Disease and Treatment Characteristics of Men Diagnosed With Metastatic Hormone-Sensitive Prostate Cancer in Real Life: Analysis From a Commercial Claims Database

BACKGROUND

Our understanding of the clinical characteristics and treatment patterns of men who present with newly diagnosed metastatic (M1) hormone-sensitive prostate cancer is based mainly on clinical trial data. We sought to characterize the M1 population seen in routine clinical practice using a commercial claims database.

PATIENTS AND METHODS

A US claims (2000-2013) database was used to identify patients with an index diagnosis of prostate cancer. M1 patients were identified by "International Classification of Diseases, 9th revision, Clinical Modification" diagnosis codes of metastasis to bone, viscera, distant lymph node, and unspecified sites within 90 days of the prostate cancer diagnosis. Progression to castration-resistant prostate cancer was identified by exposure to ≥ 1 drugs approved for castration-resistant prostate cancer, including docetaxel, abiraterone acetate, cabazitaxel, enzalutamide, sipuleucel-T, mitoxantrone, estramustine, and radium-223.

RESULTS

Among 326,907 patients with an index prostate cancer diagnosis, 9199 (2.8%) had M1 disease, including 6955 with specified metastatic disease involving the bone (77%), viscera (38%), or lymph nodes (21%). The initial treatment of M1 disease was castration in 51%, localized therapy in 16%, prostate cancer drug only in 18%, and no treatment in 15%. The median time to first castration was 33 days.

CONCLUSION

The proportion of men with prostate cancer who presented with M1 disease was consistent with other observations. Only 51% of the patients were treated according to national guidelines recommending medical or surgical castration. The proportion with visceral involvement at presentation was greater than expected from the clinical trials data in the same population. Just as seen in other medical conditions, clinical trial data are not representative of real-life patients seen in routine clinical practice.

Efficacy and toxicity of molecular targeted therapies in combination with docetaxel for metastatic castration-resistant prostate cancer: a meta-analysis of phase III randomized controlled trials

PURPOSE

For patients with metastatic castration-resistant prostate cancer (CRPC), the efficacy and safety of molecular targeted agents (MTAs) in combination with docetaxel are still unclear. We conducted this meta-analysis to assess the efficacy and toxicity of the addition of MTAs to docetaxel-based chemotherapy for the treatment of metastatic CRPC.

METHODS

Databases from PubMed, Web of Science, and abstracts presented at American Society of Clinical Oncology meeting up to 31 June 2014 were searched to identify relevant studies. Eligible studies included prospective phase III randomized controlled trials (RCTs) evaluating docetaxel with or without MTAs in patients with metastatic CRPC. The primary aim was to assess overall survival (OS). Secondary aims were to assess progression-free survival (PFS); overall response rates (ORRs), and grade 3-5 toxicities. Statistical analyses were conducted by using either random effects or fixed-effect models according to the heterogeneity of included studies.

RESULTS

A total of 5886 patients from five phase III RCTs were identified. No statistically significant difference in OS [hazard ratio (HR): 0·98, 95% confidence interval (CI): 0·91-1·04, P = 0·44], ORR [relative risk (RR): 1·32, 95% CI: 0·94-1·84, P = 0·11], and PSA response rate (RR: 1·22, 95% CI: 0·86-1·74, P = 0·27) was found between the two groups. The addition of MTAs to docetaxel significantly improved PFS (HR: 0·92, 95% CI: 0·86-0·98, P = 0·011). However, the benefits in PFS was accompanied by increasing the risk of developing grade 3-4 (RR: 1·19, 95% CI: 0·99-1·42, P = 0·062) and fatal (RR: 1·30, 95% CI: 1·01-1·66, P = 0·039) adverse events.

CONCLUSIONS

The findings of this study suggest that the palliation of CRPC with MTAs and docetaxel does not provide a significant survival benefit and is associated with increased severe toxicities.

Systemic therapy in men with metastatic castration-resistant prostate cancer:American Society of Clinical Oncology and Cancer Care Ontario clinical practice guideline

PURPOSE

To provide treatment recommendations for men with metastatic castration-resistant prostate cancer (CRPC).

METHODS

The American Society of Clinical Oncology and Cancer Care Ontario convened an expert panel to develop evidence-based recommendations informed by a systematic review of the literature.

RESULTS

When added to androgen deprivation, therapies demonstrating improved survival, improved quality of life (QOL), and favorable benefit-harm balance include abiraterone acetate/prednisone, enzalutamide, and radium-223 ((223)Ra; for men with predominantly bone metastases). Improved survival and QOL with moderate toxicity risk are associated with docetaxel/prednisone. For asymptomatic/minimally symptomatic men, improved survival with unclear QOL impact and low toxicity are associated with sipuleucel-T. For men who previously received docetaxel, improved survival, unclear QOL impact, and moderate to high toxicity risk are associated with cabazitaxel/prednisone. Modest QOL benefit (without survival benefit) and high toxicity risk are associated with mitoxantrone/prednisone after docetaxel. No benefit and excess toxicity are observed with bevacizumab, estramustine, and sunitinib.

RECOMMENDATIONS

Continue androgen deprivation (pharmaceutical or surgical) indefinitely. Abiraterone acetate/prednisone, enzalutamide, or (223)Ra should be offered; docetaxel/prednisone should also be offered, accompanied by discussion of toxicity risk. Sipuleucel-T may be offered to asymptomatic/minimally symptomatic men. For men who have experienced progression with docetaxel, cabazitaxel may be offered, accompanied by discussion of toxicity risk. Mitoxantrone may be offered, accompanied by discussion of limited clinical benefit and toxicity risk. Ketoconazole or antiandrogens (eg, bicalutamide, flutamide, nilutamide) may be offered, accompanied by discussion of limited known clinical benefit. Bevacizumab, estramustine, and sunitinib should not be offered. There is insufficient evidence to evaluate optimal sequences or combinations of therapies. Palliative care should be offered to all patients.

Clinical practice guidelines and consensus statements in oncology--an assessment of their methodological quality

BACKGROUND

Consensus statements and clinical practice guidelines are widely available for enhancing the care of cancer patients. Despite subtle differences in their definition and purpose, these terms are often used interchangeably. We systematically assessed the methodological quality of consensus statements and clinical practice guidelines published in three commonly read, geographically diverse, cancer-specific journals. Methods Consensus statements and clinical practice guidelines published between January 2005 and September 2013 in Current Oncology, European Journal of Cancer and Journal of Clinical Oncology were evaluated. Each publication was assessed using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) rigour of development and editorial independence domains. For assessment of transparency of document development, 7 additional items were taken from the Institute of Medicine's standards for practice guidelines and the Journal of Clinical Oncology guidelines for authors of guidance documents.

METHODS

Consensus statements and clinical practice guidelines published between January 2005 and September 2013 in Current Oncology, European Journal of Cancer and Journal of Clinical Oncology were evaluated. Each publication was assessed using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) rigour of development and editorial independence domains. For assessment of transparency of document development, 7 additional items were taken from the Institute of Medicine's standards for practice guidelines and the Journal of Clinical Oncology guidelines for authors of guidance documents.

FINDINGS

Thirty-four consensus statements and 67 clinical practice guidelines were evaluated. The rigour of development score for consensus statements over the three journals was 32% lower than that of clinical practice guidelines. The editorial independence score was 15% lower for consensus statements than clinical practice guidelines. One journal scored consistently lower than the others over both domains. No journals adhered to all the items related to the transparency of document development. One journal's consensus statements endorsed a product made by the sponsoring pharmaceutical company in 64% of cases.

CONCLUSION

Guidance documents are an essential part of oncology care and should be subjected to a rigorous and validated development process. Consensus statements had lower methodological quality than clinical practice guidelines using AGREE II. At a minimum, journals should ensure that that all consensus statements and clinical practice guidelines adhere to AGREE II criteria. Journals should consider explicitly requiring guidelines to declare pharmaceutical company sponsorship and to identify the sponsor's product to enhance transparency.

Economic evaluation of sipuleucel-T immunotherapy in castration-resistant prostate cancer

The objective is to examine the cost-utility of sipuleucel-T immunotherapy in asymptomatic or minimally symptomatic castration-resistant prostate cancer patients. The addition of sipuleucel-T immunotherapy to standard treatment led to a gain of 0.37 quality-adjusted life-year (QALY) at an additional cost of US$104,536. The incremental cost-utility ratio was US$283,000 per QALY saved. Threshold sensitivity analyses indicated that a price reduction of at least 53%, or application in a group of patients resulting in the relative reduction in the mortality rate of at least 39%, ought to augment the economic value of this regimen. Sipuleucel-T immunotherapy treatment at the current price with 96.5% certainty is not cost-effective. The specific group of patients who will benefit more from the treatment should be revealed and treated, or the cost of the vaccine should be lowered significantly to increase its economic value. Accounting for crossover treatment in control patients improves sipuleucel-T's value (US$132,000 per QALY saved) although further investigation is necessary.

Novel combination of docetaxel and thymoquinone induces synergistic cytotoxicity and apoptosis in DU-145 human prostate cancer cells by modulating PI3K-AKT pathway

BACKGROUND

The treatment of castrate-resistant prostate cancer (CRPC) still remains as an important challenge of daily oncology practice. Docetaxel significantly prolongs overall survival in men with CRPC. Thymoquinone (TQ), one of the flavonoid compounds isolated from Nigealla sativa, has been shown to possess cytotoxic activity against a variety of cancer cell lines.

MATERIALS AND METHODS

The aim of the study was to investigate the possible synergistic cytotoxic/apoptotic effects of a novel combination, docetaxel and TQ in DU-145 hormone- and drug-refractory prostate cancer cells and their effects on PI3K and ERK signaling pathways.

RESULTS

We observed that the combination of docetaxel and TQ resulted in a significant synergistic cytotoxicy and apoptosis as compared to any single agent alone, in a dose-dependent manner. It was found that viability of the combination treated cells was not significantly changed in the presence of LY294002 as compared to inhibitor treated cells. However, in the presence of FR180204, viability of combination treated cells was significantly decreased as compared to inhibitor treated cells. In conclusion, cytotoxic effect of the docetaxel and TQ combination is correlated with the block of the PI3K/Akt signaling pathway in DU-145 cells.

CONCLUSION

Therefore, this combination strategy may be an alternative approach for the challenging era of daily oncologic practice. Also, the combination of docetaxel and TQ might allow a reduction in docetaxel doses and diminish adverse effects of docetaxel while maintaining the therapeutic effect in patients with CRPC.

Comparison of the efficacy and safety of denosumab versus bisphosphonates in breast cancer and bone metastases treatment: A meta-analysis of randomized controlled trials

Breast cancer is the most common type of cancer in females worldwide. Patients with breast cancer and bone metastases may experience increased osteoclast activity, resulting in local bone destruction and skeletal complications, including pain, hypercalcemia and skeletal-related events. Intravenous bisphosphonates (BPs) are the standard treatment administered to patients with breast cancer and bone metastases to prevent skeletal-related events. However, in certain patients, BPs may cause renal toxicity, acute-phase reactions and osteonecrosis of the jaw. More effective, safer and more tolerable therapies, which prevent bone destruction and skeletal complications, are required in order to improve patient quality of life. Denosumab is a fully human monoclonal antibody that binds to and neutralizes receptor activator of nuclear factor-κB ligand, which is a key mediator in the pathogenesis of a broad range of skeletal diseases, thereby inhibiting osteoclast function and bone resorption. Therefore, we conducted a meta-analysis to compare both the safety and efficacy of denosumab and BPs in the treatment of breast cancer and bone metastases. Five databases, two clinical trial registry platforms and reference lists of relevant papers were analyzed. The meta-analysis concluded that denosumab was more effective at preventing pain and skeletal-related events than BPs, in patients with breast cancer and bone metastases. Patients receiving denosumab demonstrated a higher level of clinical improvement in terms of health-related quality of life than patients receiving BPs. Compared with BPs, denosumab reduced the incidence of certain indicators of adverse events, including pyrexia, bone pain, edema and renal failure.

Taxanes in the management of metastatic castration-resistant prostate cancer: efficacy and management of toxicity

Androgen deprivation is the therapy of choice in the majority of patients with metastatic prostate cancer. However, a state of castration resistance ultimately occurs after hormone therapy, thus defining metastatic castration-resistant prostate cancer (mCRPC). mCRPC has historically been considered a relatively chemoresistant tumor. However, due to its ability to improve survival and the quality of life in comparison with mitoxantrone, docetaxel has been established as the standard chemotherapeutic agent for first-line therapy since 2004. Moreover, recent results have shown that the novel taxane cabazitaxel is able to prolong the overall survival of patients with mCRPC previously treated with docetaxel. Even though these taxanes display a favorable toxicity profile, their routine use in clinical practice requires knowledge about the most frequent and distinct adverse events that may result from their administration.

Stromal insulin-like growth factor binding protein 3 (IGFBP3) is elevated in the diseased human prostate and promotes ex vivo fibroblast-to-myofibroblast differentiation

Dysregulation of the IGF axis is implicated in the development of benign prostatic hyperplasia (BPH) and prostate cancer (PCa), 2 of the most common diseases affecting elderly males. PCa is the second leading cause of male-related cancer death in Western societies. Although distinct pathologies, BPH and PCa are both characterized by extensive stromal remodeling, in particular fibroblast-to-myofibroblast differentiation, thought to be induced by elevated local production of TGFβ1. We previously showed that TGFβ1-mediated fibroblast-to-myofibroblast differentiation of primary human prostatic stromal cells resulted in the dsyregulation of several components of the IGF axis, including the induction of IGF binding protein 3 (IGFBP3). Using isoform-specific lentiviral-mediated knockdown, we demonstrate herein that IGFBP3 is essential for TGFβ1-mediated differentiation. Although recombinant human IGFBP3 alone was not sufficient to induce differentiation, IGFBP3 synergistically potentiated TGFβ1-mediated stromal remodeling predominantly via an IGF-independent mechanism. Consistent with these in vitro findings, IGFBP3 immunohistochemistry revealed elevated levels of IGFBP3 in the hyperplastic fibromuscular stroma of BPH specimens and in the tumor-adjacent stroma of high-grade PCa. Collectively these data indicate that the dysregulation of the stromal IGF axis, in particular elevated IGFBP3, plays a crucial role in fibroblast-to-myofibroblast differentiation in the diseased prostatic stroma and indicate the therapeutic potential of inhibiting stromal remodeling and the resulting dysregulation of the stromal IGF axis as a novel strategy for the treatment of advanced PCa and BPH.

Pleuropulmonary and lymph node progression after docetaxel - benefits from treatment with cabazitaxel in metastatic prostate cancer

INTRODUCTION

To date, there are no guidelines for a rational and more favourable sequence of treatment after docetaxel. Two drugs (cabazitaxel and abiraterone) have recently been approved as second-line treatment after docetaxel failure in metastatic castration-resistant prostate cancer (mCRPC), but there are no studies comparing abiraterone versus cabazitaxel. The most suitable drug is chosen based on the physician's opinion and the patient's characteristics. In patients with a good performance status who are able to receive either treatment, it would be convenient to begin with cabazitaxel and to reserve abiraterone in case there is a worsening of the general status, in consideration of abiraterone's more favourable toxicity profile.

CASE REPORT

We describe the case of a 74-year-old male with mCRPC who presented with an interesting and uncommon tumour dissemination (pleuropulmonary) occurring after the first standard treatment with docetaxel. Intravenous treatment with cabazitaxel 25 mg/m(2) and oral prednisone 10 mg continuously was initiated. The patient received a total of 8 cycles of chemotherapy. A reduction of mediastinal adenopathies and infrarenal para-aortic stable bone involvement and an absence of pleural effusion were observed. No relevant toxicity was noted. Since February 2012, a progressive PSA increase without clinical deterioration has been noted.

CONCLUSIONS

The selection criteria for second- and third-line systemic treatment and the excellent response obtained with cabazitaxel in an unusual disease setting are described. The results confirm the long duration and quality of response of cabazitaxel treatment. Further therapeutic options in this group of patients are suggested.

Systemic therapy in men with metastatic castration-resistant prostate cancer: a systematic review

AIMS

Since 2004, docetaxel-based chemotherapy has been the standard of care for men with metastatic castration-resistant prostate cancer (mCRPC), but recently randomised controlled trials (RCTs) of novel agents have shown promise in extending overall survival. These trials have evaluated agents delivered before chemotherapy, to replace or supplement docetaxel, or addressed treatment options for men who have progressed on docetaxel therapy. This review was undertaken to determine which systemic therapies improve cancer- or patient-related outcomes in men with mCRPC.

MATERIALS AND METHODS

Searches were carried out in MEDLINE, EMBASE, the Cochrane Library and relevant conference proceedings. Eligible articles included RCTs comparing systemic therapy or combination (excluding primary or secondary androgen deprivation therapy, bone protective agents or radionuclides) with placebo or other agents in men with mCRPC.

RESULTS

Twenty-five RCTs met the selection criteria. In chemotherapy-naive patients, targeted therapy with tasquinimod conferred a benefit in progression-free survival. Immunotherapy with sipuleucel-T extended overall survival and was well tolerated, but had no effect on the time to disease progression. Hypercastration with abiraterone extended progression-free survival, whereas overall survival was improved but not statistically proven. In the chemotherapy setting, updated and new trials of docetaxel alone confirmed the survival benefit seen in previous studies. A survival benefit with the addition of estramustine to docetaxel shown in a previous study did not lead to an improvement in pain palliation or quality of life. Trials of combining targeted therapies with docetaxel generally did not extend survival. The addition of bevacizumab improved progression-free survival, but not overall survival. The addition of GVAX immunotherapy or calcitriol was harmful. In the post-chemotherapy setting, progression-free and overall survival benefits were detected with cabazitaxel, abiraterone and enzalutamide. Cabazitaxel was associated with greater toxicity, whereas abiraterone and enzalutamide had less severe adverse effects. Satraplatin and sunitinib both extended progression-free survival, but did not improve overall survival.

CONCLUSION

Docetaxel-based chemotherapy remains the standard of care in men with mCRPC who are candidates for palliative systemic therapy. Promising results are emerging with sipuleucel-T and abiraterone in the pre-docetaxel setting and cabazitaxel, abiraterone and enzalutamide in patients who progress on or after docetaxel. Further research to determine the optimal choice, sequence or even the combination of these agents is necessary.

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

PURPOSE As part of the ENTHUSE (Endothelin A Use) program, the efficacy and safety of zibotentan (ZD4054), an oral specific endothelin A receptor antagonist, has been investigated in combination with docetaxel in patients with metastatic castration-resistant prostate cancer (CRPC). PATIENTS AND METHODS In this randomized, double-blind, placebo-controlled, phase III study, patients received intravenous docetaxel 75 mg/m(2) on day 1 of 21-day cycles plus oral zibotentan 10 mg or placebo once daily. The primary end point was overall survival (OS). Secondary end points included time to pain and prostate-specific antigen (PSA) progression, pain and PSA response, progression-free survival, health-related quality of life, and safety. Results A total of 1,052 patients received study treatment (docetaxel-zibotentan, n = 524; docetaxel-placebo, n = 528). At the time of data cutoff, there had been 277 and 280 deaths, respectively. There was no difference in OS for patients receiving docetaxel-zibotentan compared with those receiving docetaxel-placebo (hazard ratio, 1.00; 95% CI, 0.84 to 1.18; P = .963). No significant differences were observed on secondary end points, including time to pain progression (median 9.3 v 10.0 months, respectively) or pain response (odds ratio, 0.84; 95% CI, 0.61 to 1.16; P = .283). The median time to death was 20.0 and 19.2 months for the zibotentan and placebo groups, respectively. The most commonly reported adverse events in zibotentan-treated patients were peripheral edema (52.7%), diarrhea (35.4%), alopecia (33.9%), and nausea (33.3%). CONCLUSION Docetaxel plus zibotentan 10 mg/d did not result in a significant improvement in OS compared with docetaxel plus placebo in patients with metastatic CRPC.

Immunotherapy and endothelin receptor antagonists for treatment of castration-resistant prostate cancer

Recently, novel therapies of prostate cancer, such as immunotherapy, endothelin receptor antagonists, novel androgen receptor antagonist and novel taxanes, and others have been introduced into clinical practice. This study was performed to summarize these results of immunotherapy and endothelin receptor antagonists in the treatment of castration-resistant prostate cancer (CRPC) and derive a more precise estimation of their effect on future treatment. The PubMed database, references of published trials, and review articles were searched. Two reviewers independently extracted data of these trials. We used hazard ratios (HRs) to assess the effects on overall survival (OS), progression-free survival (PFS), or time to disease progression (TTP), and relative risk (RR) for the different types of toxicity. In addition, 95% confidence intervals (CIs) give a sense of the precision of the estimate. Nine randomized controlled trials were ultimately identified. The pooled HR showed that immunotherapy could prolong OS significantly in patients with CRPC compared to placebo (HR = 0.70, 95% CI: 0.58-0.83, p < 0.001). Endothelin receptor antagonists also had modest benefits (HR = 0.90, 95% CI: 0.82-1.00, p = 0.046). Nevertheless, there were no significant benefits from both therapies on PFS or TTP. In addition, immunotherapy led to more fatigue, pyrexia, chills, and endothelin receptor antagonists led to more peripheral edema, anemia, and dyspnea. Our article suggested that the very acceptable toxicity and improving OS in patients with CRPC made immunotherapy an attractive option for such patients. However, future studies with thoughtful clinical trial designs are warranted.

New Agents for the Management of Castration-Resistant Prostate Cancer

OBJECTIVE:

To review the activity of 3 new agents approved for the management of advanced castration-resistant prostate cancer (CRPC): sipuleucel-T, cabazitaxel, and abiraterone acetate.

DATA SOURCES:

Literature was accessed through MEDLINE (1977-June 2012) and abstracts from the American Society of Clinical Oncology (2000–2012) using the terms castration-resistant and hormone-refractory prostate cancer, sipuleucel-T, cabazitaxel, abiraterone, Provenge, Jevtana, and Zytiga. Reference citations from publications identified were also reviewed.

STUDY SELECTION AND DATA EXTRACTION:

Articles identified from the data sources in English on human subjects were evaluated.

DATA SYNTHESIS:

Options for patients with CRPC have been limited, with little to offer those who failed or could not tolerate docetaxel-based therapy. Three new drugs, with very different mechanisms of action, have changed that and will undoubtedly change the treatment paradigm for these patients. Each agent has demonstrated an impact on patient survival. Sipuleucel-T, the first immunotherapy approved for treatment of CRPC, improved median overall survival by 4.1 months and reduced the risk of death by 22% in a placebo-controlled trial of asymptomatic patients. Sipuleucel-T can be administered prior to docetaxel-based therapy. Cabazitaxel, a taxane chemotherapy agent, improved median overall survival by 2.4 months and reduced the risk of death by 30% in a Phase 3 trial of patients whose cancer progressed during or after docetaxel-based therapy. Abiraterone acetate, a hormonal therapy, improved median overall survival by 3.9 months and reduced the risk of death by 35% in patients with relapse during or after docetaxel-based therapy.

CONCLUSIONS:

The advent of new agents for the management of advanced CRPC has increased the choices for patients whose options were limited. Additional experience will determine the optimal sequencing of these agents, their roles in combination therapy, and their activity in patients with earlier disease.

Finding the place of histone deacetylase inhibitors in prostate cancer therapy

Histone deacetylase inhibitors (HDACIs) are showing promise as therapeutic agents for hematological malignancies and solid tumors. In the case of prostate cancer, HDACIs are effective at inhibiting proliferation and inducing apoptosis in a range of in vitro and in vivo experimental models. Recent studies have revealed that the actions of HDACIs in prostate cancer cells extend beyond regulation of histone acetylation and affect proteins involved in maintaining cellular homeostasis and tumor progression, including the androgen receptor, p21(WAF1) and VEGF. The broad spectrum of HDACI targets has allowed rational design of combinations with other therapeutic agents to target multiple pathways involved in prostate cancer progression, including angiogenesis and androgen signaling. In particular, synergistic inhibition of prostate cancer cell growth has been demonstrated using HDACIs in combination with radio- and chemo-therapy, Apo2L/TRAIL, angiogenesis inhibitors, heat-shock protein 90 inhibitors and androgen receptor antagonists. This review examines the current understanding of the actions of HDACIs in prostate cancer cells, both in a laboratory and a clinical context and discusses the potential utility of combination strategies for the treatment of prostate cancer.

Managing side effects of the novel taxane cabazitaxel in castrate-resistant prostate cancer

Cabazitaxel, a novel taxane, was approved in June 2010 by the U.S. Food and Drug Administration for treatment of metastatic castrate-resistant prostate cancer (mCRPC) in men previously treated with docetaxel. In TROPIC (N = 755), an open-label, randomized, phase III trial, cabazitaxel (plus prednisone) was associated with improvement in median overall survival compared with mitoxantrone plus prednisone (15.1 versus 12.7 months, p < 0.0001) in patients with mCRPC who had progressed following docetaxel-based regimens. That corresponds to a 30% relative reduction in risk of death compared with the mitoxantrone regimen. In addition, significant benefit existed in median progression-free survival with cabazitaxel versus the mitoxantrone regimen (2.8 versus 1.4 months, p < 0.0001). Most common adverse events (AEs) associated with cabazitaxel were hematologic; the rates (all grade) of neutropenia, leukopenia, and anemia were greater than 90%. Diarrhea, fatigue, asthenia, and back pain were the most common grade 3 or higher nonhematologic AEs. Because expected AEs from cabazitaxel therapy can delay or even interrupt treatment, oncology nurses need to be aware of those risks and their management. This article reviews the vital role of nurses in identifying patients at high risk for AEs associated with cabazitaxel therapy and reviews strategies for prevention and management of symptoms.

Ocular Toxicity of Targeted Therapies

Molecularly targeted agents are commonly used in oncology practice, and many new targeted agents are currently being tested in clinical trials. Although these agents are thought to be more specific and less toxic then traditional cytotoxic chemotherapy, they are associated with a variety of toxicities, including ocular toxicity. Many of the molecules targeted by anticancer agents are also expressed in ocular tissues. We reviewed the literature for described ocular toxicities associated with both approved and investigational molecularly targeted agents. Ocular toxicity has been described with numerous approved targeted agents and also seems to be associated with several classes of agents currently being tested in early-phase clinical trials. We discuss the proposed pathogenesis, monitoring guidelines, and management recommendations. It is important for oncologists to be aware of the potential for ocular toxicity, with prompt recognition of symptoms that require referral to an ophthalmologist. Ongoing collaboration between oncologists and ocular disease specialists is critical as the use of molecularly targeted agents continues to expand and novel targeted drug combinations are developed.

Denosumab in patients with cancer and skeletal metastases: a systematic review and meta-analysis

BACKGROUND

We conducted a systematic review of the literature to determine the efficacy and safety of denosumab in reducing skeletal-related events (SRE) in patients with bone metastases.

METHODS

A literature search using MEDLINE, EMBASE, Web of Science and The Cochrane Collaboration Library identified relevant controlled clinical trials up-to-March 14, 2012. Two independent reviewers assessed studies for inclusion, according to predetermined criteria, and extracted relevant data. The primary outcomes of interest were SRE, time to first on-study SRE, and overall survival. Secondary outcomes included pain, quality of life, bone turnover markers (BTM), and adverse events.

RESULTS

Six controlled trials including 6142 patients were analyzed. Compared to zoledronic acid, denosumab had lower incidence of SRE with a risk ratio (RR) of 0.84 (95% confidence intervals (CI) 0.80-0.88), delayed the onset of first on-study SRE (RR 0.83; 95% CI 0.75-0.90) and time to worsening of pain (RR 0.84; 95% CI 0.77-0.91). No difference was observed in overall survival with pooled hazard ratio of 0.98 (95% CI 0.90-1.0). For total adverse events, denosumab was similar to zoledronic acid (RR 0.97; 95% CI 0.89-1.0). No significant differences were observed in the frequency of osteonecrosis of the jaw (RR 1.4; 95% CI 0.92-2.1). Patients on denosumab had a greater risk of developing hypocalcemia (RR 1.9; 95% CI 1.6-2.3).

CONCLUSIONS

Denosumab was more effective than zoledronic acid in reducing the incidence of SRE, and delayed the time to SRE. No differences were found between denosumab and zoledronic acid in reducing overall mortality, or in the frequency of overall adverse events.

PAGE4 positivity is associated with attenuated AR signaling and predicts patient survival in hormone-naive prostate cancer

Aberrant activation of the androgen receptor (AR) plays a key role during prostate cancer (PCa) development and progression to castration-resistant prostate cancer (CR-PCa) after androgen deprivation therapy, the mainstay systemic treatment for PCa. New strategies to abrogate AR activity and biomarkers that predict aggressive tumor behavior are essential for improved therapeutic intervention. PCa tissue microarrays herein reveal that prostate-associated gene 4 (PAGE4), an X-linked cancer/testis antigen, is highly up-regulated in the epithelium of preneoplastic lesions compared with benign epithelium, but subsequently decreases with tumor progression. We show that AR signaling is attenuated in PAGE4-expressing cells both in vitro and in vivo, most likely via impaired androgen-induced AR nuclear translocation and subsequently reduced AR protein stabilization and phosphorylation at serines 81 and 213. Consistently, epithelial PAGE4 protein levels inversely correlated with AR activation status in hormone-naive and CR-PCa clinical specimens. Moreover, PAGE4 impaired the development of CR-PCa xenografts, and strong PAGE4 immunoreactivity independently predicted favorable patient survival in hormone-naive PCa. Collectively, these data suggest that dysregulation of epithelial PAGE4 modulates AR signaling, thereby promoting progression to advanced lethal PCa and highlight the potential value of PAGE4 as a prognostic and therapeutic target.

Phase 3, randomized, placebo-controlled study of zibotentan (ZD4054) in patients with castration-resistant prostate cancer metastatic to bone

BACKGROUND

Endothelin-1 and the endothelin A (ET(A) ) receptor have been implicated in prostate cancer progression in bone. This study aimed to determine whether the specific ET(A) receptor antagonist, zibotentan, prolonged overall survival (OS) in patients with castration-resistant prostate cancer and bone metastases who were pain-free or mildly symptomatic for pain.

METHODS

Patients were randomized 1:1 to zibotentan 10 mg/day or placebo, plus standard prostate cancer treatment. The primary endpoint was OS. Secondary endpoints included times to pain progression, chemotherapy use, new bone metastases, and safety. Efficacy endpoints were analyzed using a log-rank test.

RESULTS

A total of 594 patients were randomized (zibotentan, n = 299; placebo, n = 295). Median OS was 24.5 months in zibotentan-treated patients versus 22.5 months for placebo, but the difference did not reach statistical significance (hazard ratio, 0.87; 95.2% confidence interval, 0.69-1.10; P = .240). No statistically significant differences were observed for any secondary efficacy endpoints. Peripheral edema (44%) and headache (31%) were the most commonly reported adverse events in the zibotentan group. Cardiac failure events were higher in the zibotentan group than placebo (any grade, 5.7% and 1.7%; Common Terminology Criteria for Adverse Events grade ≥3, 3.0% and 1.0%, respectively); these were manageable and reversible.

CONCLUSIONS

In this large, randomized, placebo-controlled phase 3 trial, treatment with zibotentan 10 mg/day did not lead to a statistically significant improvement in OS in this patient population. Zibotentan had an acceptable safety profile.

Combination effects of docetaxel and Doxorubicin in hormone-refractory prostate cancer cells

Combination effects of docetaxel (DOC) and doxorubicin (DOX) were investigated in prostate cancer cells (PC3 and DU145). Combination indices (CIs) were determined using the unified theory in various concentrations and mixing ratios (synergy: CI < 0.9, additivity: 0.9 < CI < 1.1, and antagonism: CI > 1.1). DOC showed a biphasic cytotoxicity pattern with the half maximal inhibitory concentration (IC50) at the picomolar range for PC3 (0.598 nM) and DU145 (0.469 nM), following 72 h drug exposure. The IC50s of DOX were 908 nM and 343 nM for PC3 and DU145, respectively. Strong synergy was seen when PC3 was treated with DOC at concentrations lower than its IC50 values (0.125~0.5 nM) plus DOX (2~8 times IC50). Equipotent drug combination treatments (7 × 7) revealed that the DOC/DOX combination leads to high synergy and effective cell death only in a narrow concentration range in DU145. This study provides a convenient method to predict multiple drug combination effects by the estimated CI values as well as cell viability data. The proposed DOC/DOX mixing ratios can be used to design combination drug cocktails or delivery systems to improve chemotherapy for cancer patients.

Castration-resistant prostate cancer: systemic therapy in 2012

Prostate cancer is the most common non-cutaneous neoplasm in the male population worldwide. It is typically diagnosed in its early stages, and the disease exhibits a relatively indolent course in most patients. Despite the curability of localized disease with prostatectomy and radiation therapy, some patients develop metastatic disease and die. Although androgen deprivation is present in the majority of patients with metastatic prostate cancer, a state of androgen resistance eventually develops. Castration-resistant prostate cancer, defined when there is progression of disease despite low levels of testosterone, requires specialized care, and improved communication between medical and urologic oncologists has been identified as a key component in delivering effective therapy. Despite being considered a chemoresistant tumor in the past, the use of a prostate-specific antigen has paved the way for a new generation of trials for castration-resistant prostate cancer. Docetaxel is a life-prolonging chemotherapy that has been established as the standard first-line agent in two phase III clinical trials. Cabazitaxel, a novel taxane with activity in cancer models resistant to paclitaxel and docetaxel, is the only agent that has been compared to a chemotherapy control in a phase III clinical trial as a second-line therapy; it was found to prolong the overall survival of patients with castration-resistant prostate cancer previously treated with docetaxel when compared to mitoxantrone. Other agents used in this setting include abiraterone and sipuleucel-T, and novel therapies are continually being investigated in an attempt to improve the outcome for patients with castration-resistant prostate cancer.

Ten years of docetaxel-based therapies in prostate adenocarcinoma: a systematic review and meta-analysis of 2244 patients in 12 randomized clinical trials

BACKGROUND

Chemotherapy can reduce serum prostate-specific antigen (PSA) levels and relieve pain in some patients with castration-resistant prostate cancer (CRPC). To improve therapeutic efficacy numerous randomized trials have investigated docetaxel-based combination regimens. The present analysis tries to overcome the statistical limitations of the individual trials and investigates the treatment effects in total and in various combination groups.

METHODS

The Medline, Embase, Cancerlit, and American Society of Clinical Oncology Abstract databases were searched for published randomized placebo-controlled trials evaluating the use of docetaxel-based regimens in patients with CRPC. The outcomes assessed were overall survival, overall response rate, PSA response rate, and adverse effects.

RESULTS

Twelve articles (2244 participants) were included in the meta-analysis. The analysis demonstrates a higher PSA response rate from docetaxel-based combinations when compared with docetaxel alone (relative risk [RR] = 1.16; P = .010). The estimated median survival in docetaxel-based combinations was statistically significantly longer than in the docetaxel-alone group (22.0 vs. 18.4 months; P = .037). Grade 3 or 4 neutropenia as well as grade 3 or 4 thromboembolic events were similar in both arms (overall RR, 0.87 [confidence interval (CI) 0.71-1.07]; P = .20 and overall RR 1.52 [0.79 - 2.90]; P = .21, respectively).

CONCLUSION

The analysis of 12 randomized trials provides evidence in favor of docetaxel-based combination chemotherapy for patients with CRPC and good performance status.

Androgens as therapy for androgen receptor-positive castration-resistant prostate cancer

Prostate cancer is the most frequently diagnosed non-cutaneous tumor of men in Western countries. While surgery is often successful for organ-confined prostate cancer, androgen ablation therapy is the primary treatment for metastatic prostate cancer. However, this therapy is associated with several undesired side-effects, including increased risk of cardiovascular diseases. Shortening the period of androgen ablation therapy may benefit prostate cancer patients. Intermittent Androgen Deprivation therapy improves quality of life, reduces toxicity and medical costs, and delays disease progression in some patients. Cell culture and xenograft studies using androgen receptor (AR)-positive castration-resistant human prostate cancers cells (LNCaP, ARCaP, and PC-3 cells over-expressing AR) suggest that androgens may suppress the growth of AR-rich prostate cancer cells. Androgens cause growth inhibition and G1 cell cycle arrest in these cells by regulating c-Myc, Skp2, and p27Kip via AR. Higher dosages of testosterone cause greater growth inhibition of relapsed tumors. Manipulating androgen/AR signaling may therefore be a potential therapy for AR-positive advanced prostate cancer.

Optimising the use of bone-targeted agents in patients with metastatic cancers: a practical guide for medical oncologists

Bone metastases can be associated with a significant worsening of patient morbidity and mortality. Bisphosphonates have been extensively researched and shown to delay the onset and reduce the incidence of complications from bone metastases. The most commonly used bisphosphonates are intravenous pamidronate, intravenous ibandronate, intravenous zoledronic acid and oral/intravenous clodronate. Several bone-targeted agents with innovative mechanisms of action are currently being developed. These include receptor activator of nuclear factor-kB ligand (RANKL) inhibitors, CCR1 inhibitors, Src inhibitors, DKK1-neutralising antibodies, activin antagonists and endothelin-1 inhibitors. In an era of individualised medicine, oncologists are being faced with an increasing number of questions when dealing with bone-targeted agents. These questions not only include the choice of which drug to use (i.e. bisphosphonates or RANKL inhibitor) but also the best treatment strategy to use. This review will provide medical oncologists with a practical guide to the use of bone-targeted agents.

Docetaxel/Prednisone (D + P): Metastatic Hormone-Refractory Prostate Cancer

This Hospital Pharmacy feature is extracted from Off-Label Drug Facts, a quarterly publication available from Wolters Kluwer Health. Off-Label Drug Facts is a practitioner-oriented resource for information about specific drug uses that are unapproved by the US Food and Drug Administration. This new guide to the literature enables the health care professional or clinician to quickly identify published studies on off-label uses and determine if a specific use is rational in a patient care scenario. References direct the reader to the full literature for more comprehensive information before patient care decisions are made. Direct questions or comments regarding Off-Label Drug Uses to jgeneral@kumc.edu .

Role of androgen deprivation treatment in patients with castration-resistant prostate cancer, receiving docetaxel-based chemotherapy

OBJECTIVES

To assess the impact of continued androgen deprivation therapy (ADT) in patients with castration-resistant prostate cancer (CRPC) receiving first-line docetaxel-based chemotherapy.

METHODS

A retrospective review was performed on 78 patients fulfilling the criteria for CRPC who were treated with docetaxel-based chemotherapy over 5 years.

RESULTS

Thirty-nine patients received concurrent ADT (ADT group), whereas 39 patients discontinued ADT (No-ADT group). PSA response rates were 66.7% for ADT patients and 48.7% for No-ADT patients (P = 0.27). The median progression-free survival and overall survival were 5.0 months and 24.8 months for ADT patients and 4.9 months and 22.1 months for No-ADT patients, respectively (P = 0.57, P = 0.94). Follow-up testosterone levels were available in 13 patients of the No-ADT group and none of them recovered a normal serum testosterone level over a median follow-up duration of 8.3 months from ADT discontinuation. ADT was recommenced in 21 of 39 patients in the No-ADT group and, of these, 6 (29%) achieved a PSA response.

CONCLUSION

Clinical outcomes were not significantly different when patients with CRPC received concurrent ADT, or were not so treated, when receiving first-line docetaxel-based chemotherapy. Despite ADT withdrawal, serum testosterone level did not recover to the noncastrated level during the period of chemotherapy, and reinduction of hormone sensitivity occurred in about one-quarter of patients.

Current and emerging treatment modalities for metastatic castration-resistant prostate cancer

Docetaxel-based therapy is established as the standard first-line chemotherapy in patients with metastatic castration-resistant prostate cancer (mCRPC), based on results from two landmark Phase III studies. However, prognosis remains poor, with a median survival of less than 2 years. There is no standard of care for patients who progress during or after docetaxel treatment, which represents a real unmet medical need. Several small retrospective studies suggest that patients with mCRPC who responded to first-line docetaxel-based therapy are sensitive to re-treatment, but a survival benefit in prospective randomized trials has not been demonstrated. Epithelial-stromal interactions in the tumour microenvironment appear to play a central role in prostate cancer progression and response to therapy. Recent insights into the molecular mechanisms that underpin prostate cancer progression have allowed the identification of potential therapeutic targets. New agents, including angiogenesis inhibitors, hormone therapies, chemotherapies, bone targeting agents, vaccines and immunotherapies are currently undergoing clinical development in advanced prostate cancer using docetaxel as a backbone. Several Phase III studies have now been completed. Sipuleucel-T prolonged survival compared with placebo in asymptomatic or minimally symptomatic patients with mCRPC. Cabazitaxel plus prednisone prolonged survival in patients with mCRPC who progressed during or after docetaxel-based therapy compared with the active agent mitoxantrone, plus prednisone. Multidisciplinary management and optimization of the role and timing of new agents in this evolving treatment continuum will be critical to maximizing patient outcomes. Identification of predictive markers and better gene expression profiling will be critical to tailoring therapies to individual patients and disease states, whereas validated surrogate markers of overall survival will help accelerate drug approval.

The long and winding road for the development of tasquinimod as an oral second-generation quinoline-3-carboxamide antiangiogenic drug for the treatment of prostate cancer

IMPORTANCE OF THE FIELD

Prostate cancer is the mostly commonly diagnosed non-skin cancer in males. The culmination of the last 70 years of clinical drug development has documented that androgen ablation plus taxane-based systemic chemotherapy enhances survival, but is not curative, in metastatic prostate cancer. To effect curative therapy, additional drugs must be developed that enhance the response when combined with androgen ablation/taxane therapy.

AREAS COVERED IN THIS REVIEW

The history of the discovery and development of tasquinimod as a second-generation oral quinoline-3-carboxamide analogue for prostate cancer will be presented.

WHAT THE READER WILL GAIN

The mechanism for such anticancer efficacy is via tasquinimod's ability to inhibit the 'angiogenic switch' within cancer sites required for their continuous lethal growth.

TAKE HOME MESSAGE

Tasquinimod is a novel inhibitor of tumor angiogenesis that enhances the therapeutic anticancer response when combined with other standard-of-care modalities (radiation, androgen ablation, and/or taxane-based chemotherapies) in experimental animal models, but does not inhibit normal wound healing. It has successfully completed clinical Phase II testing in humans and will shortly enter registration Phase III evaluation for the treatment of metastatic prostate cancer.

Evolving role of bone biomarkers in castration-resistant prostate cancer

The preferential metastasis of prostate cancer cells to bone disrupts the process of bone remodeling and results in lesions that cause significant pain and patient morbidity. Although prostate-specific antigen (PSA) is an established biomarker in prostate cancer, it provides only limited information relating to bone metastases and the treatment of metastatic bone disease with bisphosphonates or novel noncytotoxic targeted or biological agents that may provide clinical benefits without affecting PSA levels. As bone metastases develop, factors derived from bone metabolism are released into blood and urine, including N- and C-terminal peptide fragments of type 1 collagen and bone-specific alkaline phosphatase, which represent potentially useful biomarkers for monitoring metastatic bone disease. A number of clinical trials have investigated these bone biomarkers with respect to their diagnostic, prognostic, and predictive values. Results suggest that higher levels of bone biomarkers are associated with an increased risk of skeletal-related events and/or death. As a result of these findings, bone biomarkers are now being increasingly used as study end points, particularly in studies investigating novel agents with putative bone effects. Data from prospective clinical trials are needed to validate the use of bone biomarkers and to confirm that marker levels provide additional information beyond traditional methods of response evaluation for patients with metastatic prostate cancer.

Burden of metastatic bone disease from genitourinary malignancies

Bone metastases are common among patients with stage IV genitourinary cancers. Most patients with bone metastases develop at least one debilitating and potentially life-limiting skeletal-related event. These events are associated with increased medical expenses and decreased quality of life. Current guidelines recommend screening for bone metastases in men with high-risk prostate cancer, but guidance for screening and treatment of bone metastases from genitourinary cancers varies by country and setting. Several bisphosphonates have been evaluated in the advanced genitourinary cancer setting. Zoledronic acid has demonstrated efficacy in significantly reducing the risk of skeletal-related events in patients with bone metastases from a broad range of solid tumors including prostate, renal and bladder cancers, and is recommended for preserving bone health.

Src kinase inhibitors: an emerging therapeutic treatment option for prostate cancer

IMPORTANCE OF THE FIELD

Once prostate cancer becomes castration-resistant, bone metastases are a significant problem and treatment options are limited. As a result, there is a need for more effective therapies that have antitumor and anti-bone metastatic effects. Because Src and Src-family kinases (SFKs) are involved in multiple signaling pathways central to prostate cancer development, progression, and metastasis, in addition to normal and pathologic osteoclast activities, Src inhibition represents a valid therapeutic strategy for investigation.

AREAS COVERED IN THIS REVIEW

Here, current treatment options for advanced prostate cancer, the preclinical rationale behind using Src inhibitors, emerging data from clinical trials of Src inhibitors in prostate cancer, and future therapeutic directions are described. Data published in peer-reviewed journals within the last 20 years or presented at recent European or American Society of Clinical Oncology conferences have been reviewed.

WHAT THE READER WILL GAIN

Readers will gain an insight into the development of therapeutic Src inhibitors, including dasatinib and saracatinib; an understanding of their effects on prostate cancer cells and the bone microenvironment; and emerging clinical data.

TAKE HOME MESSAGE

Src is implicated in prostate cancer progression and metastasis, therefore treatment with Src inhibitors warrants further investigation.

American Society of Clinical Oncology provisional clinical opinion: chronic hepatitis B virus infection screening in patients receiving cytotoxic chemotherapy for treatment of malignant diseases

PURPOSE An American Society of Clinical Oncology (ASCO) provisional clinical opinion (PCO) offers timely clinical direction to ASCO's membership following publication or presentation of potentially practice-changing information. This PCO addresses recommendations for chronic hepatitis B virus (HBV) infection screening in patients receiving cytotoxic or immunosuppressive chemotherapy for treatment of malignant diseases.

CLINICAL CONTEXT

The Centers for Disease Control and Prevention (CDC) issued Recommendations for Identification and Public Health Management of Persons with Chronic Hepatitis B Virus Infection, recommending screening for hepatitis B infection (hepatitis B surface antigen [HBsAg], antihepatitis B core antigen [anti-HBc], and antibodies to HBsAg [anti-HBs]) for "persons receiving cytotoxic or immunosuppressive therapy (eg, chemotherapy for malignant diseases...)."

PROVISIONAL CLINICAL OPINION

The evidence is insufficient to determine the net benefits and harms of routine screening for chronic HBV infection in individuals with cancer who are about to receive cytotoxic or immunosuppressive therapy or who are already receiving therapy. Individuals with cancer who undergo certain cytotoxic or immunosuppressive therapies and have HBV infection or prior exposure to HBV may be at elevated risk of liver failure from HBV reactivation. As such, HBV screening requires clinical judgment. Physicians may consider screening patients belonging to groups at heightened risk for chronic HBV infection or if highly immunosuppressive therapy is planned. Highly immunosuppressive treatments include, but are not limited to, hematopoietic cell transplantation and regimens including rituximab. Screening based on a high risk of prior HBV exposure or risk of reactivation due to planned therapeutic regimens should include testing for HBsAg as a serologic marker for HBV infection. In some populations, testing for anti-HBc should also be considered. There is no evidence to support serologic testing for anti-HBs in this context. When evidence for chronic HBV infection is found, antiviral therapy before and throughout the course of chemotherapy may be considered to reduce the risk of HBV reactivation, although evidence from controlled trials of this approach is limited. Screening and/or treating HBV infection should not delay the initiation of chemotherapy.

NOTE

ASCO's provisional clinical opinions (PCOs) reflect expert consensus based on clinical evidence and literature available at the time they are written, and are intended to assist physicians in clinical decision-making and identify questions and settings for further research. Due to the rapid flow of scientific information in oncology, new evidence may have emerged since the time a PCO was submitted for publication. PCOs are not continually updated and may not reflect the most recent evidence. PCOs address only the topics specifically identified in the PCO and are not applicable to interventions, diseases or stages of disease not specifically identified. PCOs cannot account for individual variation among patients, and cannot be considered inclusive of all proper methods of care or exclusive of other treatments. It is the responsibility of the treating physician or other health care provider, relying on independent experience and knowledge of the patient, to determine the best course of treatment for the patient. Accordingly, adherence to any PCO is voluntary, with the ultimate determination regarding its application to be made by the physician in light of each patient's individual circumstances. ASCO PCOs describe the use of procedures and therapies in clinical practice and cannot be assumed to apply to the use of these interventions in the context of clinical trials. ASCO assumes no responsibility for any injury or damage to persons or property arising out of or related to any use of ASCO's PCOs, or for any errors or omissions.

Antitumour activity of MDV3100 in castration-resistant prostate cancer: a phase 1-2 study

BACKGROUND

MDV3100 is an androgen-receptor antagonist that blocks androgens from binding to the androgen receptor and prevents nuclear translocation and co-activator recruitment of the ligand-receptor complex. It also induces tumour cell apoptosis, and has no agonist activity. Because growth of castration-resistant prostate cancer is dependent on continued androgen-receptor signalling, we assessed the antitumour activity and safety of MDV3100 in men with this disease.

METHODS

This phase 1-2 study was undertaken in five US centres in 140 patients. Patients with progressive, metastatic, castration-resistant prostate cancer were enrolled in dose-escalation cohorts of three to six patients and given an oral daily starting dose of MDV3100 30 mg. The final daily doses studied were 30 mg (n=3), 60 mg (27), 150 mg (28), 240 mg (29), 360 mg (28), 480 mg (22), and 600 mg (3). The primary objective was to identify the safety and tolerability profile of MDV3100 and to establish the maximum tolerated dose. The trial is registered with ClinicalTrials.gov, number NCT00510718.

FINDINGS

We noted antitumour effects at all doses, including decreases in serum prostate-specific antigen of 50% or more in 78 (56%) patients, responses in soft tissue in 13 (22%) of 59 patients, stabilised bone disease in 61 (56%) of 109 patients, and conversion from unfavourable to favourable circulating tumour cell counts in 25 (49%) of the 51 patients. PET imaging of 22 patients to assess androgen-receptor blockade showed decreased (18)F-fluoro-5alpha-dihydrotestosterone binding at doses from 60 mg to 480 mg per day (range 20-100%). The median time to progression was 47 weeks (95% CI 34-not reached) for radiological progression. The maximum tolerated dose for sustained treatment (>28 days) was 240 mg. The most common grade 3-4 adverse event was dose-dependent fatigue (16 [11%] patients), which generally resolved after dose reduction.

INTERPRETATION

We recorded encouraging antitumour activity with MDV3100 in patients with castration-resistant prostate cancer. The results of this phase 1-2 trial validate in man preclinical studies implicating sustained androgen-receptor signalling as a driver in this disease.

FUNDING

Medivation, the Prostate Cancer Foundation, National Cancer Institute, the Howard Hughes Medical Institute, Doris Duke Charitable Foundation, and Department of Defense Prostate Cancer Clinical Trials Consortium.