Safety and tolerability of long-term treatment with darolutamide in patients with metastatic castration-resistant prostate cancer

BACKGROUND

In patients with metastatic castration-resistant prostate cancer, darolutamide was well tolerated for 25 months, but minimal long-term safety data are available.

METHODS

Treatment-emergent adverse events (TEAEs) for patients receiving darolutamide for a median of 38 months (n = 13) are described in this pooled analysis of individual patient data from phase 1/2 studies.

RESULTS

All patients reported TEAEs (mostly grade 1/2). The most common TEAEs were diarrhea, abdominal pain, and nausea. Serious TEAEs were reported in six patients (none related to darolutamide). All treatment-related TEAEs (n = 5) were grade 1.

CONCLUSIONS

Long-term darolutamide treatment was well tolerated; no new safety signals observed. In patients with mCRPC, long-term darolutamide treatment was well tolerated and no new safety signals were observed. These findings are consistent with previous reports, demonstrating a favorable safety and tolerability profile of darolutamide.

Cancer origin tracing and timing in two high-risk prostate cancers using multisample whole genome analysis: prospects for personalized medicine

BACKGROUND

Prostate cancer (PrCa) genomic heterogeneity causes resistance to therapies such as androgen deprivation. Such heterogeneity can be deciphered in the context of evolutionary principles, but current clinical trials do not include evolution as an essential feature. Whether or not analysis of genomic data in an evolutionary context in primary prostate cancer can provide unique added value in the research and clinical domains remains an open question.

METHODS

We used novel processing techniques to obtain whole genome data together with 3D anatomic and histomorphologic analysis in two men (GP5 and GP12) with high-risk PrCa undergoing radical prostatectomy. A total of 22 whole genome-sequenced sites (16 primary cancer foci and 6 lymph node metastatic) were analyzed using evolutionary reconstruction tools and spatio-evolutionary models. Probability models were used to trace spatial and chronological origins of the primary tumor and metastases, chart their genetic drivers, and distinguish metastatic and non-metastatic subclones.

RESULTS

In patient GP5, CDK12 inactivation was among the first mutations, leading to a PrCa tandem duplicator phenotype and initiating the cancer around age 50, followed by rapid cancer evolution after age 57, and metastasis around age 59, 5 years prior to prostatectomy. In patient GP12, accelerated cancer progression was detected after age 54, and metastasis occurred around age 56, 3 years prior to prostatectomy. Multiple metastasis-originating events were identified in each patient and tracked anatomically. Metastasis from prostate to lymph nodes occurred strictly ipsilaterally in all 12 detected events. In this pilot, metastatic subclone content analysis appears to substantially enhance the identification of key drivers. Evolutionary analysis' potential impact on therapy selection appears positive in these pilot cases.

CONCLUSIONS

PrCa evolutionary analysis allows tracking of anatomic site of origin, timing of cancer origin and spread, and distinction of metastatic-capable from non-metastatic subclones. This enables better identification of actionable targets for therapy. If extended to larger cohorts, it appears likely that similar analyses could add substantial biological insight and clinically relevant value.

Abstract 5644: Spatially resolved transcriptomics points to distinct malignant cell populations within primary and castration resistant prostate cancer

Background: Prostate cancer (PCa) is the second most common cancer in men. Despite its high prevalence, many patients carry an indolent form of the disease and are thus suspect to overtreatment. Conversely, some cases treated with androgen deprivation therapy can develop into castration resistant prostate cancer (CRPC), for which there is no curative treatment. Understanding why some tumors are more aggressive than others could lead to more accurate patient risk stratification. Here we characterize cancer and normal cell subpopulations within prostate tissue in their spatial context using a multimodal integrative approach.

Methods: We performed spatially resolved transcriptomics (ST) on a set of primary tumor PCa, CRPC and benign prostatic hyperplasia (BPH) patient samples. In addition to ST, we produced RNA-seq, DNA-seq and assay for transposase accessible chromatin using sequencing (ATAC-seq) data, allowing for multiomic integration within and across sample categories. We performed extensive analysis of ST data, employing unsupervised clustering, spot expression signal deconvolution, differential gene expression analysis and copy number variation (CNV) inference.

Main Results: The systematic analysis of spot expression profiles revealed a high degree of variation in nearby tissue regions, as we found up to three unique luminal cell populations inside a one millimeter radius in PCa. Similarly in locally recurrent CRPC, we identified cumulative CNVs in proximal luminal cell populations, with the inferred CNV profiles validated through DNA-seq. A set of marker genes was calculated for each unique cell population, with multiple PCa associated genes found to be differentially expressed. Although we observed significant variation in the luminal cell populations, the stromal gene expression was markedly similar across all samples.

Conclusions: We discovered shared, similar and unique cell populations both within and across different PCa and CRPC sections. We observed various luminal cell populations with distinct gene expression profiles in samples from both progression stages. The close spatial proximity of these cell clusters suggests that ST can be used to discover and examine finely detailed populations in their original spatial environment.

Citation Format: Antti Kiviaho, Heini M. Kallio, Sini K. Eerola, Elisa M. Vuorinen, Tomi Häkkinen, Sinja Taavitsainen, Ebrahim Afyounian, Teemu Tolonen, Juha Kesseli, Alfonso Urbanucci, Kirsi J. Rautajoki, Teuvo L. Tammela, Tapio Visakorpi, Matti Nykter. Spatially resolved transcriptomics points to distinct malignant cell populations within primary and castration resistant prostate cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5644.

Abstract 3904: Simvastatin intensifies anti-androgen efficacy against treatment-resistant prostate cancer cells

Androgen receptor (AR) signaling inhibitors (ARSIs) bicalutamide (Bic) and enzalutamide (Enza) are used in the treatment of castration resistant prostate cancer (CRPC). Prostate cancer (PCa) cells eventually develop treatment resistance against these drugs causing clinical challenges. The mechanisms behind treatment resistance are complex and only partially known. Androgen signaling is linked to lipid and cholesterol metabolism, and they likely play a role in the development of treatment resistance. Cholesterol producing mevalonate pathway can be inhibited by statins, but it is unknown whether statin treatment could enhance effects of ARSIs. We studied combined effects of simvastatin (Sim) with or without Bic or Enza in VCaP originated PCa cell lines resistant to these ARSIs. Unique treatment resistant cell lines were created with long-term cultures of VCaP cells. The cells were kept under anti-androgen influence until the cells were growing normally despite the ARSIs. We analyzed changes in cell growth, RNA expression, and relevant AR signaling and cholesterol metabolism protein expression. Prostate-specific antigen (PSA) secretion was measured as a marker of AR signaling activity. In Bic or Enza resistant cell lines, combination of 2.5 or 5 μM simvastatin + 10 μM Bic/Enza decreased cell growth more than Sim alone, i.e., ARSIs demonstrated efficacy in combination therapy against ARSI resistant cells. In Bic and Enza resistant cells, combination treatment increased the expression of 60 and 26 and decreased the expression of 33 and 48 genes, respectively, compared with simvastatin alone. Altogether, 16 genes expression changed similarly in both cell lines in response to combination therapy. In both cell lines, over 70% of all gene changes were seen on AR-regulated genes. In Bic resistant cells, Sim decreased PSA levels with or without Bic. On the contrary, in Enza resistant cells PSA levels were increased with combination of Sim and Enza. We showed that combined treatment with ARSI and Sim inhibited cell growth more than Sim alone in ARSI resistant cell lines. This suggests that inhibition of the mevalonate pathway could enhance androgen signaling inhibition and potentially circumvent ARSI resistance mechanisms. This phenomenon is supported by epidemiological studies as patients treated with anti-androgens responded better during simultaneous statin treatment. Gene expression differed in combination treatment compared to Sim alone. Future studies are needed on whether interventions on lipid and cholesterol metabolism could enhance treatment of CRPC. Knowledge about the precise mechanisms behind the treatment responses and resistance might lead to new therapeutic applications.

Citation Format: Aino Siltari, Olga Korhonen, Paavo Raittinen, Merja Bläuer, Heimo Syvälä, Teuvo L. Tammela, Teemu J. Murtola. Simvastatin intensifies anti-androgen efficacy against treatment-resistant prostate cancer cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3904.

Abstract 121: Differential resistance to hypoxia is linked to increased lipid accumulation in treatment resistant prostate cancer cells

Introduction: Solid tumors typically favor non-oxygen related pathways on utilizing energy for cell metabolism. This helps tumor cells to survive in hypoxic microenvironment which is common in solid tumors such as prostate cancer (PCa). PCa cells characteristically store lipids, especially cholesterol. Furthermore, hypoxia and lipid metabolism are both associated with decreased responses to immune system and resistance to cancer treatments. Aim of this study was to investigate the impact of hypoxia on cell proliferation and lipid metabolism in advanced PCa cells at various stages of treatment resistance.

Material and Methods: PCa cells, VCaPs, were cultured for months to form several unique, treatment resistant advanced PCa cell lines as follows: first, cells were cultured with high (10 nM) testosterone level until they required testosterone for growth to form testosterone sensitive cell line (VCaP-T, demonstrating metastatic hormone sensitive PCa); second, VCaP-T cells were cultured further under low testosterone (0.1 nM) until they gained ability to grow at low androgen level, forming castration resistant cell line (VCaP-CT); third, VCaP-CT cells were further cultured with bicalutamide and/or enzalutamide, androgen signaling inhibitors, until they again gained ability to grow despite the treatment, forming cell lines resistant to these drugs (VCaP-CT-BR, VCap-CT-ER, and VCaP-CT-BR-ER, demonstrating bicalutamide-, enzalutamide-, or mutually resistant cell lines, respectively).All cell lines were exposed to hypoxia (3% O2) with or without simvastatin (1 and 2.5 μM) for 3 days and compared to the cells growing in normoxia. Changes in proliferation was measured using crystal violet staining and amount of intracellular lipids were evaluated using Oil Red O staining.

Results: Hypoxia decreased cell proliferation compared to normoxia by 20-25% in VCaP-T, VCaP-CT, and VCaP-CT-BR cells, but had no impact in enzalutamide-resistant cells VCaP-CT-ER or VCaP-CT-BR-ER. Simvastatin treatment decreased cell proliferation in all cell lines equally in hypoxia and normoxia.Compared to androgen-sensitive VCaP-T cells, all treatment resistant cell lines displayed greater intracellular lipid accumulation. Further analyses will address whether hypoxia and/or simvastatin treatment impacts amount of intracellular lipids and whether inhibition of lipid accumulation leads to less tolerance to hypoxia.

Conclusion: Enzalutamide resistant cell lines displayed greater hypoxia tolerance compared to androgen sensitive or treatment naïve castration resistant cells. This indicates these cells are adopted to hypoxic microenvironment. All treatment resistant cell lines had greater intracellular lipid accumulation compared to testosterone-sensitive cells, suggesting importance of lipid metabolism in treatment resistance and hypoxia tolerance.

Citation Format: Aino Siltari, Merja Bläuer, Heimo Syvälä, Teuvo L. Tammela, Teemu J. Murtola. Differential resistance to hypoxia is linked to increased lipid accumulation in treatment resistant prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 121.

Abstract 401: Single-cell transcriptome and chromatin sequencing uncover gene expression and gene regulatory patterns associated with enzalutamide resistance

Resistance to androgen receptor-targeted therapy due to tumor heterogeneity and clonal evolution is a key challenge for improving prostate cancer outcomes. Despite this, the transcriptomic and chromatin accessibility changes contributing to the emergence of resistance remain incompletely understood at the level of individual cells. Using single-cell assays for transposase-accessible chromatin (ATAC) and RNA sequencing in models of early treatment response and resistance to enzalutamide, we previously identified pre-existing and persistent cell subpopulations that possess regenerative potential when subjected to treatment. Here we analyze the chromatin and transcriptomes of these single cells to characterize their gene regulation and gene expression trajectories. We present evidence of a model of enzalutamide resistance emergence in which the pre-existing and treatment-persistent cells regenerate the bulk of resistant cells. This process is underpinned by chromatin reprogramming that increases the overall relaxation of chromatin upon resistance. We show that the reprogramming of the chromatin further differentially contributes to transcription factor-mediated transcriptional reprogramming via DNA motif exposure in different cell subpopulations. For example, in the treatment-persistent cells, we identify chromatin configurations characterized by the exposure of DNA motifs for GATA2, RELA (a NFkB subunit), CREB1, and E2F1. Pre-existing and treatment-persistent cells consistently display transcriptional features of high developmental potential and RNA velocity analysis identifies them as precursors of cell populations that arise from enzalutamide treatment. We also analyze the pre-existing and treatment-persistent cells in spatial transcriptomics of prostate cancer patient specimens based on their characteristic gene expression profiles. We find these cells to be enriched in cancerous regions of the tissue but also detect them within apparent benign regions, which has potential implications for treatment choice. In summary, we show patterns of gene expression regulation in preclinical models and patient samples that uncover mechanisms of resistance to androgen receptor-targeted therapy in prostate cancer.

Citation Format: Sinja Taavitsainen, Nikolai Engedal, Shaolong Cao, Florian Handle, Andrew Erickson, Stefan Prekovic, Daniel Wetterskog, Teemu Tolonen, Elisa M. Vuorinen, Antti Kiviaho, Reetta Nätkin, Tomi Häkkinen, Wout Devlies, Sallamari Henttinen, Roosa Kaarijärvi, Mari Lahnalampi, Heidi Kaljunen, Karolina Nowakowska, Heimo Syvälä, Merja Bläuer, Paolo Cremaschi, Frank Claessens, Tapio Visakorpi, Teuvo L. Tammela, Teemu Murtola, Kirsi J. Granberg, Alastair D. Lamb, Kirsi Ketola, Ian G. Mills, Gerhardt Attard, Wenyi Wang, Matti Nykter, Alfonso Urbanucci. Single-cell transcriptome and chromatin sequencing uncover gene expression and gene regulatory patterns associated with enzalutamide resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 401.

Darolutamide and health-related quality of life in patients with non-metastatic castration-resistant prostate cancer: An analysis of the phase III ARAMIS trial

BACKGROUND

In the ARAMIS trial, darolutamide plus androgen deprivation therapy (ADT) versus placebo plus ADT significantly improved metastasis-free survival (MFS), overall survival (OS) and time to pain progression in patients with non-metastatic castration-resistant prostate cancer (nmCRPC). Herein, we present analyses of patient-reported health-related quality of life (HRQoL) outcomes.

PATIENTS AND METHODS

This double-blind, placebo-controlled, phase III trial randomised patients with nmCRPC and prostate-specific antigen doubling time ≤10 months to darolutamide 600 mg (n = 955) twice daily or matched placebo (n = 554) while continuing ADT. The primary end-point was MFS; the secondary end-points included OS and time to pain progression. In this analysis, HRQoL was assessed by the time to deterioration using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) prostate cancer subscale (PCS) and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Prostate Cancer Module (EORTC QLQ-PR25) subscales.

RESULTS

Darolutamide significantly prolonged time to deterioration of FACT-P PCS versus placebo (hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.70-0.91; P = 0.0005) at the primary analysis (cut-off date: 3rd September 2018). Time to deterioration of EORTC QLQ-PR25 outcomes showed statistically significant delays with darolutamide versus placebo for urinary (HR 0.64, 95% CI 0.54-0.76; P < 0.0001) and bowel (HR 0.78, 95% CI 0.66-0.92; P = 0.0027) symptoms. Time to worsening of hormonal treatment-related symptoms was similar between the two groups.

CONCLUSION

In patients with nmCRPC who are generally asymptomatic, darolutamide maintained HRQoL by significantly delaying time to deterioration of prostate cancer-specific quality of life and disease-related symptoms versus placebo.

Liproca Depot: A New Antiandrogen Treatment for Active Surveillance Patients

BACKGROUND

There is increasing interest in nonmorbid treatments for low- and intermediate-risk prostate cancer with fewer side effects than surgery or radiotherapy.

OBJECTIVE

To investigate the tolerability, safety, and antitumor effects of the intraprostatic NanoZolid depot formulation Liproca Depot (LIDDS AB, Uppsala, Sweden) with antiandrogen 2-hydroxyflutamide (2-HOF) in men with low- or intermediate-risk localized prostate cancer managed with active surveillance.

DESIGN, SETTING, AND PARTICIPANTS

This clinical phase 2b trial, LPC-004, involved 61 patients. The 2-HOF-containing formulation Liproca Depot was injected transrectally into the prostate under ultrasound guidance. A single dose of 35% or 45% of the prostate volume (study part 1) and a fixed dose of 16 or 20 ml (study part 2) of the formulation were evaluated.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

The primary endpoints were tolerability and the reduction in serum prostate-specific antigen (PSA) 5 mo after injection. Antitumor effects were evaluated with magnetic resonance imaging (MRI) and prostate biopsies. Quality of life was assessed using a validated questionnaire (International Prostate Symptom Score).

RESULTS AND LIMITATIONS

All doses were safe and well tolerated, without hormonal side effects. In part 2 of the study, the PSA reduction was greatest for the group receiving 16 ml, with an average decrease of 14%, and 95% of patients had a PSA reduction. Some 78% of patients showed a prostate volume decrease compared to baseline. Prostate MRI and biopsies confirmed stable or reduced lesion size. However, post treatment biopsies were performed at the discretion of the investigator, and not routinely. Most patients were amenable to a second injection.

CONCLUSIONS

PSA and prostate volume decreased in most patients. Indications of efficacy were shown by post-treatment MRI and biopsies demonstrating stabilization or regression in the majority of cases.

PATIENT SUMMARY

Liproca Depot is a safe, minimally invasive treatment that offers the potential for cancer control in patients with intermediate-risk prostate cancer. Further clinical evaluation is warranted.

Prevalence of autoimmune disorders among bladder pain syndrome patients' relatives

PURPOSE

Possible genetic background and autoimmune etiology of Bladder Pain Syndrome (BPS, formerly Interstitial Cystitis, IC) has been suggested. We studied whether familial clustering of BPS, other autoimmune diseases or fibromyalgia exist among BPS patients' genetically close relatives; possibly reflecting some common predisposing genetic background of these diseases.

MATERIALS AND METHODS

Altogether 420 first- or second-degree relatives of 94 BPS patients fulfilling the NIDDK criteria were asked to fill in a survey on the self-reported diagnosis of urinary tract diseases, fibromyalgia and 23 autoimmune diseases, together with filling the O'Leary-Sant symptom score. The ones with high symptom scores were interviewed and, if necessary, referred to a further clinical consultation. The prevalence of other diseases was compared to previously published prevalence percentages.

RESULTS

334 (80%) of 420 family members returned the questionnaire. Only one of the relatives fulfilled the NIDDK criteria, and one sibling pair among the original BPS patients was found. Asthma, ulcerative colitis, fibromyalgia, iritis and rheumatoid arthritis were more common in the study population than in the reference populations. The reported prevalence of atopic dermatitis and rhinoconjunctivitis causing allergies were lower. In addition, the results show that the O'Leary-Sant symptom score is not reliable in screening for new BPS cases.

CONCLUSIONS

Our study suggests that in BPS patients' families, fibromyalgia and autoimmune diseases including asthma, and especially the non-allergic form of asthma, may be over-represented.

Nonmetastatic, Castration-Resistant Prostate Cancer and Survival with Darolutamide

BACKGROUND

Darolutamide is a structurally distinct androgen-receptor inhibitor that is approved for the treatment of nonmetastatic, castration-resistant prostate cancer. In the planned primary analysis of a phase 3 trial, the median metastasis-free survival was significantly longer with darolutamide (40.4 months) than with placebo (18.4 months). The data for the analysis of overall survival were immature at the time of the primary analysis.

METHODS

In this double-blind, placebo-controlled trial, we randomly assigned 1509 men, in a 2:1 ratio, to receive darolutamide (955 patients) or placebo (554 patients) while they continued to receive androgen-deprivation therapy. After the results of the primary end-point analysis were found to be positive, unblinding of the treatment assignments occurred, and patients in the placebo group were permitted to cross over to receive open-label darolutamide treatment. At the time of this prespecified final analysis, which had been planned to be performed after approximately 240 deaths had occurred, overall survival and all other secondary end points were evaluated.

RESULTS

The median follow-up time was 29.0 months. At the time of unblinding of the data, all 170 patients who were still receiving placebo crossed over to receive darolutamide; 137 patients who had discontinued placebo before unblinding had occurred received at least one other life-prolonging therapy. Overall survival at 3 years was 83% (95% confidence interval [CI], 80 to 86) in the darolutamide group and 77% (95% CI, 72 to 81) in the placebo group. The risk of death was significantly lower, by 31%, in the darolutamide group than in the placebo group (hazard ratio for death, 0.69; 95% CI, 0.53 to 0.88; P = 0.003). Darolutamide was also associated with a significant benefit with respect to all other secondary end points, including the time to first symptomatic skeletal event and the time to first use of cytotoxic chemotherapy. The incidence of adverse events after the start of treatment was similar in the two groups; no new safety signals were observed.

CONCLUSIONS

Among men with nonmetastatic, castration-resistant prostate cancer, the percentage of patients who were alive at 3 years was significantly higher among those who received darolutamide than among those who received placebo. The incidence of adverse events was similar in the two groups. (Funded by Bayer HealthCare and Orion Pharma; ARAMIS ClinicalTrials.gov number, NCT02200614.).

Abstract 3513: Genome-wide scan for novel prostate cancer susceptibility loci with clinical consequence utilizing increased genetic drift of the Finnish population

Background: Prostate cancer (PC) is the second most common cancer in men worldwide with a rising prevalence. However, only limited number of clinically actionable variants are known. The objective of this study is to identify novel PC susceptibility loci with potential clinical relevance utilizing the increased genetic drift and reduced selective pressure of the recently bottlenecked powerful resource of the Finnish population.

Methods: We meta-analysed &gt;185.000 germline single nucleotide polymorphisms (SNPs) in 2738 PC cases and 2401 controls of Finnish origin in the Collaborative Oncological Gene-Environment Study (COGS) using Illumina iSelect custom SNP genotyping platform.

Results: Altogether 160 variants remain significant on GWAS level (p&lt;5 × 10−8) in 18 different gene regions. Out of the 160 identified PC susceptibility hits 78 (49%) are novel variants not reported earlier in association with PC. PC associated signals are in close proximity to one another forming genetic hot-spots on chromosomes 8, 7, 11, 17 and 19. The strength of association varies for 101 PC risk variants (OR 1.24-1.86) and 59 protective SNPs (OR 0.59-0.80). The strongest risk gene is CASC8 (OR=1.86; p=1.214 × 10−11). The most significant signals were found at the 8p21.2 chromosomal region (p&lt;7.6 × 10−16). Functional annotation identified a missense coding SNP at KLK3 gene to be a candidate causal variant. We showed evidence for association both with early-onset PC (OR 1.73; P=0.02), high serum PSA level at diagnosis (OR 1.36; P=0.024) and with aggressive PC (Gleason score ≥8; OR 1.44; P=0.02) at 17q21.

Conclusion: The results facilitate risk stratification for screening, clinical studies, treatment choices and functional research of PC

Citation Format: Csilla Sipeky, Teuvo L. Tammela, Anssi Auvinen, Johanna Schleutker. Genome-wide scan for novel prostate cancer susceptibility loci with clinical consequence utilizing increased genetic drift of the Finnish population [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3513.

Charlson Comorbidity Index Based On Hospital Episode Statistics Performs Adequately In Predicting Mortality, But Its Discriminative Ability Diminishes Over Time

Purpose

To evaluate the performance of Charlson Comorbidity Index (CCI) calculated using hospitalization and medication reimbursement databases in predicting mortality.

Patients and methods

Information on hospitalizations was obtained from the national Care Register for Health Care (HILMO) and on medication reimbursements and entitlements for special reimbursements for medications from the Social Insurance Institution for 77,440 men aged 56–71 years at baseline. The subjects were followed up for mortality via Statistics Finland with 20,562 deaths during a 13-year follow-up.

Results

Compared to a CCI score of 0, the age-adjusted hazard ratio for all-cause mortality associated with HILMO-based CCI scores of 1, 2 and 3 or more were 2.39 (95% CI 2.29–2.49), 2.96 (95% CI 2.81–3.13) and 6.42 (95% CI 5.95–6.93) at 13 years. The C-statistic was 0.72 at 1, 0.68 at 5 and 0.66 at 13 years, with only minor improvement over age alone (0.10, 0.06 and 0.04 accordingly). Addition of medication data did not improve predictive abilities and medication-based CCI performed poorly on its own.

Conclusion

The hospitalization-based CCI, as well as that based on both databases, predicts relative mortality adequately, but its discriminative ability diminishes over time. Conditions related to hospitalizations affect survival more than medications.

Evaluation of Clinically Relevant Drug-Drug Interactions and Population Pharmacokinetics of Darolutamide in Patients with Nonmetastatic Castration-Resistant Prostate Cancer: Results of Pre-Specified and Post Hoc Analyses of the Phase III ARAMIS Trial

BACKGROUND

Darolutamide, an androgen receptor antagonist with a distinct molecular structure, significantly prolonged metastasis-free survival versus placebo in the phase III ARAMIS study in men with nonmetastatic castration-resistant prostate cancer (nmCRPC). In this population, polypharmacy for age-related comorbidities is common and may increase drug-drug interaction (DDI) risks. Preclinical/phase I study data suggest darolutamide has a low DDI potential-other than breast cancer resistance protein/organic anion transporter protein substrates (e.g., statins), no clinically relevant effect on comedications is expected.

OBJECTIVE

Our objective was to evaluate the effect of commonly administered drugs on the pharmacokinetics of darolutamide and the effect of comedications potentially affected by darolutamide on safety in patients with nmCRPC.

PATIENTS AND METHODS

Comorbidities and comedication use in the 1509 ARAMIS participants treated with darolutamide 600 mg twice daily or placebo were assessed. A population pharmacokinetic analysis evaluated whether comedications affected the pharmacokinetics of darolutamide in a subset of 388 patients. A subgroup analysis of adverse events (AEs) in statin users versus nonusers was conducted.

RESULTS

Most participants (median age 74 years) had at least one comorbidity (98.4% in both arms) and used at least one comedication (98.7% with darolutamide vs. 98.0% with placebo); these were similar across study arms. Despite frequent use of comedications with DDI potential, no significant effects on darolutamide pharmacokinetics were identified. Comedications included lipid-modifying agents (34.5%), β-blockers (29.7%), antithrombotics (42.8%), and systemic antibiotics (26.9%). AE incidence was similar across study arms in statin users and nonusers. Study limitations include the small sample size for sub-analyses.

CONCLUSIONS

These analyses suggest the pharmacokinetic profile of darolutamide is not affected by a number of commonly administered drugs in patients with nmCRPC. Although pharmacokinetic data have indicated that darolutamide has the potential to interact with rosuvastatin, used to assess DDI in these studies, this finding did not seem to translate into increased AEs due to statin use in the ARAMIS trial. Clinicaltrials.gov identifier: NCT02200614.

Bias-corrected estimates of effects of PSA screening decisions on the risk of prostate cancer diagnosis and death: Analysis of the Finnish randomized study of screening for prostate cancer

More information is needed about effects of prostate-specific antigen (PSA) screening for informed decision making. The objective of our study is to evaluate the effects of an implemented screening decision on the risk of prostate cancer (PC) diagnosis and PC death. In a randomized trial, 31,867 Finnish men aged 55-67 years were allocated to the screening arm and 48,282 to the control arm during 1996-1999. Two to three screening rounds were offered to the screening arm with a PSA cut-off of 4.0 ng/ml. A counterfactual exclusion method was used to adjust for the effects of screening noncompliance and PSA contamination on risk of PC death and PC incidence by prognostic group at 15 years of follow up. After correcting for noncompliance and contamination, PSA screening led to 32.4 (95% CI 26.4, 38.6) more PC diagnoses per 1,000 men after 15 years and 1.4 (95% CI 0.0, 2.8) fewer PC deaths compared to the control arm. The corresponding results of an intention-to-screen analysis were 16.5 (95% CI 12.3, 20.7) and 0.8 (95% CI 0.5, 2.0), respectively. These results can be used for patient counseling in informed decision making about PC screening. A limitation of the study was the lack of comprehensive data on contamination.

Darolutamide in Nonmetastatic, Castration-Resistant Prostate Cancer

BACKGROUND

Darolutamide is a structurally unique androgen-receptor antagonist that is under development for the treatment of prostate cancer. We evaluated the efficacy of darolutamide for delaying metastasis and death in men with nonmetastatic, castration-resistant prostate cancer.

METHODS

We conducted a randomized, double-blind, placebo-controlled, phase 3 trial involving men with nonmetastatic, castration-resistant prostate cancer and a prostate-specific antigen doubling time of 10 months or less. Patients were randomly assigned in a 2:1 ratio to receive darolutamide (600 mg [two 300-mg tablets] twice daily) or placebo while continuing androgen-deprivation therapy. The primary end point was metastasis-free survival, with the presence of metastasis determined by independent central review of radiographic imaging every 16 weeks.

RESULTS

In total, 1509 patients underwent randomization (955 to the darolutamide group and 554 to the placebo group). In the planned primary analysis, which was performed after 437 primary end-point events had occurred, the median metastasis-free survival was 40.4 months with darolutamide, as compared with 18.4 months with placebo (hazard ratio for metastasis or death in the darolutamide group, 0.41; 95% confidence interval, 0.34 to 0.50; P<0.001). Darolutamide was also associated with benefits with regard to all secondary end points, including overall survival, time to pain progression, time to cytotoxic chemotherapy, and time to a symptomatic skeletal event. The incidence of adverse events that occurred or worsened during the treatment period and had a frequency of 5% or more or were of grade 3 or higher was similar in the two groups; all such events except fatigue occurred in less than 10% of patients in either group. The percentage of patients who discontinued the assigned regimen because of adverse events was 8.9% in the darolutamide group and 8.7% in the placebo group. Darolutamide was not associated with a higher incidence of seizures, falls, fractures, cognitive disorder, or hypertension than placebo.

CONCLUSIONS

Among men with nonmetastatic, castration-resistant prostate cancer, metastasis-free survival was significantly longer with darolutamide than with placebo. The incidence of adverse events was similar for darolutamide and placebo. (Funded by Bayer HealthCare and Orion Pharma; ARAMIS ClinicalTrials.gov number, NCT02200614.).

Constitutively active androgen receptor splice variants AR-V3, AR-V7 and AR-V9 are co-expressed in castration-resistant prostate cancer metastases

BACKGROUND

A significant subset of prostate cancer (PC) patients with a castration-resistant form of the disease (CRPC) show primary resistance to androgen receptor (AR)-targeting drugs developed against CRPC. As one explanation could be the expression of constitutively active androgen receptor splice variants (AR-Vs), our current objectives were to study AR-Vs and other AR aberrations to better understand the emergence of CRPC.

METHODS

We analysed specimens from different stages of prostate cancer by next-generation sequencing and immunohistochemistry.

RESULTS

AR mutations and copy number variations were detected only in CRPC specimens. Genomic structural rearrangements of AR were observed in 5/30 metastatic CRPC patients, but they were not associated with expression of previously known AR-Vs. The predominant AR-Vs detected were AR-V3, AR-V7 and AR-V9, with the expression levels being significantly higher in CRPC cases compared to prostatectomy samples. Out of 25 CRPC metastases that expressed any AR variant, 17 cases harboured expression of all three of these AR-Vs. AR-V7 protein expression was highly heterogeneous and higher in CRPC compared to hormone-naïve tumours.

CONCLUSIONS

AR-V3, AR-V7 and AR-V9 are co-expressed in CRPC metastases highlighting the fact that inhibiting AR function via regions common to all AR-Vs is likely to provide additional benefit to patients with CRPC.

Abstract 4226: Association between NSAID, statins, and bisphosphonates and prostate cancer survival during androgen deprivation therapy

We study the association between non-steroidal anti-inflammatory drugs (NSAIDs), Statins, and Bisphosphonates (BPs), and prostate cancer (PCa) survival during androgen deprivation therapy (ADT). STAMPEDE trial has demonstrated better PCa-specific survival in men using combination of celecoxib (CEL) and zoledronic acid (ZA) during ADT compared to ADT alone. The mechanism is unclear. ZA inhibits mevalonate pathway (MevP) previously linked with cancer growth. We evaluated PCa survival among men on ADT and simultaneously using BPs including ZA or statins, another drug group inhibiting MevP, and NSAIDs including CEL. We hypothesized that combined use of a MevP inhibitor and NSAID would be associated with improved PCa survival.

Our study cohort includes 4,428 men from the Finnish Randomized Study of PCa Screening (FinRSPC) initiating ADT in 1995-2015. Cox proportional hazards model with adjustment for age, FinRSPC study arm, tumor clinical characteristics and co-morbidities (obtained from national registries) was used to calculate HRs and 95% CI for PCa death. Medication use was analyzed as time-dependent variable.

Compared to non-users, the risk of PCa death was increased in users of NSAIDs or acetaminophen, and lowered in statin users. Use of BPs or coxibs alone were not associated with the risk. Coxibs and statins together were associated with lowered risk to a similar degree as statins alone. No statistically significant risk differences were observed for other combinations.

Statin users with high-risk prostate cancer undergoing ADT have lowered risk of PCa death. NSAID users have increased risk of PCa death, which becomes statistically insignificant when used with statins. Statin and BP use together shows no statistically significant evidence of negating the effects of statin. No clear additive benefit was observed for statins and coxibs together over statins alone. Our findings do not support additive benefits of MevP inhibitor and NSAIDs.

Statistical significance codes: *** : p = 0.001, ** : p = 0.01, * : p = 0.1DrugHR95 % CISignificanceStatin0.780.680.90***Acetylsalisylic acid0.900.761.07Coxib1.070.941.22NSAID1.171.041.31**Acetaminophen1.661.511.82***Bisphosphonate0.790.381.64Bisphosphonate and NSAID0.890.551.42Statin and NSAID1.070.901.27Statin and Bisphosphonate1.140.861.50Coxib and Bisphosphonate0.850.421.74Coxib and Statin0.800.621.02*EAU tumor Risk Group2.662.353.00***

Citation Format: Paavo V. Raittinen, Kirsi Talala, Kimmo Taari, Teuvo L. Tammela, Pauliina Ilmonen, Anssi Auvinen, Teemu J. Murtola. Association between NSAID, statins, and bisphosphonates and prostate cancer survival during androgen deprivation therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4226.

Abstract 1802: Constitutively active androgen receptor splice variants AR-V3, AR-V7 and AR-V9 are co-expressed in castration-resistant prostate cancer metastases

Prostate cancer (PC) is the most commonly diagnosed male cancer both in the United States and in Europe. Approximately 20-25% of cases will develop metastatic disease, which eventually progresses to lethal castration-resistant form of the disease (CRPC). Even though the exact mechanism by which CRPC develops remains to be fully understood, several mechanisms of castration resistance have been identified. Importantly, androgen signaling remains active even in the CRPC stage. This has led to the clinical development of second-generation AR-targeting drugs enzalutamide and abiraterone that target the ligand-binding domain of AR directly and indirectly, respectively. Unfortunately, a significant subset of patients show primary resistance to these agents. One potential explanation for this is the presence of AR splice variants (AR-Vs). AR-Vs are alternatively spliced isoforms of the AR mRNA usually resulting in truncated AR protein product. Even though AR-Vs lack variable portions of the AR COOH-terminal domain including the ligand-binding domain (LBD), they are constitutively active as transcription factors. The aim of this work was to study AR-Vs and also AR rearrangements, mutations and copy number variations (CNVs) to better understand the emergence of CRPC. This was done by analyzing specimens from different stages of prostate cancer by next-generation sequencing methods. Our sample cohorts included hormone-naïve PCs and lymph node metastases as well as locally recurrent and metastatic CRPCs. AR mutations and CNVs were detected only in CRPC specimens. Genomic structural rearrangements of AR (AR-GSRs) were observed in 5/30 metastatic CRPC patients but they were not associated with the expression of previously known AR-Vs, and their variant allele fractions were low. The main AR-Vs detected were AR-V3, AR-V7 and AR-V9, whose expression levels were higher in CRPC cases in comparison to prostatectomy samples. The differences were statistically significant for either variant alone or when their expression fractions were combined (p=0.0006). In addition, metastatic CRPC cases expressed significantly more AR-V3, AR-V7 and AR-V9 when compared to non-androgen deprived pelvic lymph node metastases (p=0.0282). The expression of these AR-Vs was strongly associated with the levels of full-length AR. Out of 25 CRPC metastases that expressed any AR variant, 17 cases harbored expression of all three of these AR-Vs. In conclusion, AR-V3, AR-V7 and AR-V9 tend to be co-expressed in metastatic CRPC highlighting the fact that targeting of the AR ligand-binding domain might not be sufficient to achieve a treatment response in certain patients. Consequently, targeting of AR via regions common to all AR-Vs is likely to provide additional benefit to patients suffering from CRPC.

Citation Format: Heini M. Kallio, Reija Hieta, Anniina Brofeldt, Matti Annala, Kati Kivinummi, Teuvo L. Tammela, Matti Nykter, William B. Isaacs, Hans G. Lilja, G Steven Bova, Tapio Visakorpi. Constitutively active androgen receptor splice variants AR-V3, AR-V7 and AR-V9 are co-expressed in castration-resistant prostate cancer metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1802.

Impacts of a population-based prostate cancer screening programme on excess total mortality rates in men with prostate cancer: a randomized controlled trial

Objectives To assess the effect of screening in terms of excess mortality in the European Randomized Study of Screening for Prostate Cancer (ERSPC). Methods A total of 141,578 men aged 55-69 were randomized to systematic screening or usual care in ERSPC sections in Finland, Italy, the Netherlands and Sweden. The excess number of deaths was defined as the difference between the observed number of deaths in the prostate cancer (PC) patients and the expected number of deaths up to 31 December 2006. The expected number was derived from mortality of all study participants before a diagnosis with PC adjusted for study centre, study arm and study attendance. The excess mortality rates were compared between the two study arms. Results The PC incidence was 9.25 per 1000 person-years in the intervention arm and 5.49 per 1000 person-years in the control arm, relative risk (RR) 1.69 (95% confidence interval [CI] 1.62-1.76). The excess mortality among men with PC was 0.29 per 1000 person-years in the intervention arm and 0.37 per 1000 person-years in the control arm; the RR for excess mortality was 0.77 (95% CI 0.55-1.08). The absolute risk reduction in the excess mortality was 0.08 per 1000 person-years. The overall mortality was not significantly different between the intervention and the control arms of the study: RR 0.99 (95% CI 0.96-1.01). Conclusions Although the reduction in excess mortality was not statistically significant, the between-arm reduction in excess mortality rate was in line with the previously reported 20% reduction in the disease-specific mortality. This finding indicates that the reduction in PC mortality in the ERSPC trial cannot be due to a bias in cause of death adjudication.

A Four-kallikrein Panel and β-Microseminoprotein in Predicting High-grade Prostate Cancer on Biopsy: An Independent Replication from the Finnish Section of the European Randomized Study of Screening for Prostate Cancer

BACKGROUND

A panel of four kallikrein markers (total, free, and intact prostate-specific antigen [PSA] and human kallikrein-related peptidase 2 [hK2]) improves predictive accuracy for Gleason score ≥7 (high-grade) prostate cancer among men biopsied for elevated PSA. A four-kallikrein panel model was originally developed and validated by the Dutch center of the European Randomized Study of Screening for Prostate Cancer (ERSPC). The kallikrein panel is now commercially available as 4Kscore™.

OBJECTIVE

To assess whether these findings could be replicated among participants in the Finnish section of ERSPC (FinRSPC) and whether β-microseminoprotein (MSP), a candidate prostate cancer biomarker, adds predictive value.

DESIGN, SETTING, AND PARTICIPANTS

Among 4861 biopsied screening-positive participants in the first three screening rounds of FinRSPC, a case-control subset was selected that included 1632 biopsy-positive cases matched by age at biopsy to biopsy-negative controls.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The predictive accuracy of prespecified prediction models was compared with biopsy outcomes.

RESULTS AND LIMITATIONS

Among men with PSA of 4.0-25ng/ml, 1111 had prostate cancer, 318 of whom had high-grade disease. Total PSA and age predicted high-grade cancer with an area under the curve of 0.648 (95% confidence interval [CI] 0.614-0.681) and the four-kallikrein panel increased discrimination to 0.746 (95% CI 0.717-0.774). Adding MSP to the four-kallikrein panel led to a significant (Wald test; p=0.015) but small increase (0.003) in discrimination. Limitations include a risk of verification bias among men with PSA of 3.0-3.99ng/ml and the absence of digital rectal examination results.

CONCLUSIONS

These findings provide additional evidence that kallikrein markers can be used to inform biopsy decision-making. Further studies are needed to define the role of MSP.

PATIENT SUMMARY

Four kallikrein markers and β-microseminoprotein in blood improve discrimination of high-grade prostate cancer at biopsy in men with elevated prostate-specific antigen.

Impact of Prostatic-specific Antigen Threshold and Screening Interval in Prostate Cancer Screening Outcomes: Comparing the Swedish and Finnish European Randomised Study of Screening for Prostate Cancer Centres

BACKGROUND

The European Randomised Study of Screening for Prostate Cancer trial has shown a 21% reduction in prostate cancer (PC) mortality with prostate-specific antigen (PSA)-based screening. Sweden used a 2-yr screening interval and showed a larger mortality reduction than Finland with a 4-yr interval and higher PSA cut-off.

OBJECTIVE

To evaluate the impact of screening interval and PSA cut-off on PC detection and mortality.

DESIGN, SETTING, AND PARTICIPANTS

We analysed the core age groups (55-69 yr at entry) of the Finnish (N=31 866) and Swedish (N=5901) screening arms at 13 yr and 16 yr of follow-up. Sweden used a screening interval of 2 yr and a PSA cut-off of 3.0ng/ml, while in Finland the screening interval was 4 yr and the PSA cut-off 4.0ng/ml (or PSA 3.0-3.9ng/ml with free PSA<16%).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We compared PC detection rate and PC mortality between the Finnish and Swedish centres and estimated the impact of different screening protocols.

RESULTS AND LIMITATIONS

If the Swedish screening protocol had been followed in Finland, 122 additional PC cases would have been diagnosed at screening, 84% of which would have been low-risk cancers, and four leading to PC death. In contrast, if a lower PSA threshold had been applied in Finland, at least 127 additional PC would have been found, with 19 PC deaths.

CONCLUSIONS

The small number of deaths among cases that would have been potentially detectable in Finland with the Swedish protocol (or those that would have been missed in Sweden with the Finnish approach) is unlikely to explain the differences in mortality in this long of a follow-up.

PATIENT SUMMARY

A prostate-specific antigen threshold of 3ng/ml versus 4ng/ml or a screening interval of 2 yr instead of 4 yr is unlikely to explain the larger mortality reduction achieved in Sweden compared with Finland.

Safety and Antitumour Activity of ODM-201 (BAY-1841788) in Castration-resistant, CYP17 Inhibitor-naïve Prostate Cancer: Results from Extended Follow-up of the ARADES Trial

BACKGROUND

Patients with castration-resistant prostate cancer (CRPC) had extended responses to the androgen receptor antagonist ODM-201, in phase 1/2 studies.

OBJECTIVE

To evaluate the safety and antitumour activity of prolonged ODM-201 treatment in patients with CRPC.

DESIGN, SETTING, AND PARTICIPANTS

The ARADES trial was a multicentre phase 1 (dose escalation) and phase 2 (dose expansion) trial; 134 patients with CRPC were stratified by previous chemotherapy to receive ODM-201. This paper reports extended follow-up in CYP17 inhibitor (CYP17i)-naïve patients.

INTERVENTION

Patients (n=77) received oral ODM-201 twice daily at daily doses of 200-1800mg.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Safety, measured as the occurrence of adverse events (AEs), prostate-specific antigen (PSA), and radiographic progression.

RESULTS AND LIMITATIONS

The safety profile of extended ODM-201 treatment (median treatment duration 8.2 mo, 95% confidence interval [CI] 5.6-11.0) was consistent with that reported at the time of the original data cutoff in the main ARADES trial, with no unexpected safety concerns over time. The majority of AEs (61.1%) were mild (grade 1); the most common AE was fatigue/asthenia (35.1% of patients), with no clear relationship to ODM-201. Median time to PSA progression was 25.2 mo (95% CI 11.3-25.2) for chemotherapy-naïve men and not reached (NR; 95% CI 5.5-NR) for chemotherapy-pretreated patients; a trend for improved antitumour response was observed for chemotherapy-naïve patients. The median time to radiographic progression was longer for chemotherapy-naïve (14.0 mo, 95% CI 8.1-33.3) than for chemotherapy-pretreated (7.2 mo, 95% CI 2.7-11.0) patients.

CONCLUSIONS

Prolonged exposure to ODM-201 was well tolerated, with no additional safety concerns; disease suppression was sustained, especially in chemotherapy-naïve patients. These data support further development of ODM-201 in men with CYP17i-naïve CRPC.

PATIENT SUMMARY

Extended ODM-201 therapy was well tolerated, with beneficial antitumour activity in men with advanced prostate cancer, indicating that ODM-201 may represent a new active treatment for men with CRPC. This extension trial is registered at ClinicalTrials.gov (www.clinicaltrials.gov) under identification number NCT01429064.

What explains the differences between centres in the European screening trial? A simulation study

BACKGROUND

The European Randomised study of Screening for Prostate Cancer (ERSPC) is a multicentre, randomised screening trial on men aged 55-69 years at baseline without known prostate cancer (PrCa) at randomisation to an intervention arm invited to screening or to a control arm. The ERSPC has shown a significant 21% reduction in PrCa mortality at 13 years of follow-up. The effect of screening appears to vary across centres, for which several explanations are possible. We set to assess if the apparent differences in PrCa mortality reduction between the centres can be explained by differences in screening protocols.

METHODS

We examined the centre differences by developing a simulation model and estimated how alternative screening protocols would have affected PrCa mortality.

RESULTS

Our results showed outcomes similar to those observed, when the results by centres were reproduced by simulating the screening regimens with PSA threshold of 3 versus 4ng/ml, or screening interval of two versus four years. The findings suggest that the differences are only marginally attributable to the different screening protocols.

CONCLUSION

The small screening impact in Finland was not explained by the differences in the screening protocols. A possible reason for it was the contamination of and the unexpectedly low PrCa mortality in the Finnish control arm.

Enzalutamide in Men with Chemotherapy-naïve Metastatic Castration-resistant Prostate Cancer: Extended Analysis of the Phase 3 PREVAIL Study

Enzalutamide significantly improved radiographic progression-free survival (rPFS) and overall survival (OS) among men with chemotherapy-naïve metastatic castration-resistant prostate cancer at the prespecified interim analysis of PREVAIL, a phase 3, double-blind, randomized study. We evaluated the longer-term efficacy and safety of enzalutamide up to the prespecified number of deaths in the final analysis, which included an additional 20 mo of follow-up for investigator-assessed rPFS, 9 mo of follow-up for OS, and 4 mo of follow-up for safety. Enzalutamide reduced the risk of radiographic progression or death by 68% (hazard ratio [HR] 0.32, 95% confidence interval [CI] 0.28-0.37; p<0.0001) and the risk of death by 23% (HR 0.77, 95% CI 0.67-0.88; p=0.0002). Median investigator-assessed rPFS was 20.0 mo (95% CI 18.9-22.1) in the enzalutamide arm and 5.4 mo (95% CI 4.1-5.6) in the placebo arm. Median OS was 35.3 mo (95% CI 32.2-not yet reached) in the enzalutamide arm and 31.3 mo (95% CI 28.8-34.2) in the placebo arm. At the time of the OS analysis, 167 patients in the placebo arm had crossed over to receive enzalutamide. The most common adverse events in the enzalutamide arm were fatigue, back pain, constipation, and arthralgia. This final analysis of PREVAIL provides more complete assessment of the clinical benefit of enzalutamide. PREVAIL is registered on ClinicalTrials.gov as NCT01212991.

PATIENT SUMMARY

According to data from longer follow-up, enzalutamide continued to provide benefit over placebo in patients with metastatic castration-resistant prostate cancer.

Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same region.

Rapid and accurate detection of urinary pathogens by mobile IMS-based electronic nose: a proof-of-principle study

Urinary tract infection (UTI) is a common disease with significant morbidity and economic burden, accounting for a significant part of the workload in clinical microbiology laboratories. Current clinical chemisty point-of-care diagnostics rely on imperfect dipstick analysis which only provides indirect and insensitive evidence of urinary bacterial pathogens. An electronic nose (eNose) is a handheld device mimicking mammalian olfaction that potentially offers affordable and rapid analysis of samples without preparation at athmospheric pressure. In this study we demonstrate the applicability of ion mobility spectrometry (IMS) –based eNose to discriminate the most common UTI pathogens from gaseous headspace of culture plates rapidly and without sample preparation. We gathered a total of 101 culture samples containing four most common UTI bacteries: E. coli, S. saprophyticus, E. faecalis, Klebsiella spp and sterile culture plates. The samples were analyzed using ChemPro 100i device, consisting of IMS cell and six semiconductor sensors. Data analysis was conducted by linear discriminant analysis (LDA) and logistic regression (LR). The results were validated by leave-one-out and 5-fold cross validation analysis. In discrimination of sterile and bacterial samples sensitivity of 95% and specificity of 97% were achieved. The bacterial species were identified with sensitivity of 95% and specificity of 96% using eNose as compared to urine bacterial cultures. In conclusion: These findings strongly demonstrate the ability of our eNose to discriminate bacterial cultures and provides a proof of principle to use this method in urinanalysis of UTI.

Pharmacokinetics of an injectable modified-release 2-hydroxyflutamide formulation in the human prostate gland using a semiphysiologically based biopharmaceutical model

The local distribution of 2-hydroxyflutamide (2-HOF) in prostate tissue after a single intraprostatic injection of a novel parenteral modified-release (MR) formulation in patients with localized prostate cancer was estimated using a semiphysiologically based biopharmaceutical model. Plasma concentration-time profiles for 2-HOF were acquired from a phase II study in 24 patients and the dissolution of the MR formulation was investigated in vitro. Human physiological values and the specific physicochemical properties of 2-HOF were obtained from the literature or calculated via established algorithms. A compartmental modeling approach was adopted for tissue and blood in the prostate gland, where the compartments were modeled as a series of concentric spherical shells contouring the centrally positioned depot formulation. Discrete fluid connections between the blood compartments were described by the representative flow of blood, whereas the mass transport of drug from tissue to tissue and tissue to blood was described by a one-dimensional diffusion approximation. An empirical dissolution approach was adopted for the release of 2-HOF from the formulation. The model adequately described the plasma concentration-time profiles of 2-HOF. Predictive simulations indicated that the local tissue concentration of 2-HOF within a distance of 5 mm from the depot formulation was approximately 40 times higher than that of unbound 2-HOF in plasma. The simulations also indicated that spreading the formulation throughout the prostate gland would expose more of the gland and increase the overall release rate of 2-HOF from the given dose. The increased release rate would initially increase the tissue and plasma concentrations but would also reduce the terminal half-life of 2-HOF in plasma. Finally, an in vitro-in vivo correlation of the release of 2-HOF from the parenteral MR formulation was established. This study shows that intraprostatic 2-HOF concentrations are significantly higher than systemic plasma concentrations and that increased distribution of 2-HOF throughout the gland, using strategic imaging-guided administration, is possible. This novel parenteral MR formulation, thus, facilitates good pharmacological effect while minimizing the risk of side effects.

Impacts of a population-based prostate cancer screening programme on excess total mortality rates in men with prostate cancer: a randomized controlled trial

OBJECTIVES

To assess the effect of screening in terms of excess mortality in the European Randomized Study of Screening for Prostate Cancer (ERSPC).

METHODS

A total of 141,578 men aged 55–69 were randomized to systematic screening or usual care in ERSPC sections in Finland, Italy, the Netherlands and Sweden. The excess number of deaths was defined as the difference between the observed number of deaths in the prostate cancer (PC)patients and the expected number of deaths up to 31 December 2006. The expected number was derived from mortality of all study participants before a diagnosis with PC adjusted for study centre,study arm and study attendance. The excess mortality rates were compared between the two study arms.

RESULTS

The PC incidence was 9.25 per 1000 person-years in the intervention arm and 5.49 per 1000 person-years in the control arm, relative risk (RR) 1.69 (95% confidence interval [CI]1.62–1.76). The excess mortality among men with PC was 0.29 per 1000 person-years in the intervention arm and 0.37 per 1000 person-years in the control arm; the RR for excess mortality was 0.77 (95% CI 0.55–1.08). The absolute risk reduction in the excess mortality was 0.08 per 1000 person-years. The overall mortality was not significantly different between the intervention and the control arms of the study: RR 0.99 (95% CI 0.96–1.01).

CONCLUSIONS

Although the reduction in excess mortality was not statistically significant, the between arm reduction in excess mortality rate was in line with the previously reported 20% reduction in the disease-specific mortality. This finding indicates that the reduction in PC mortality in the ERSPC trial cannot be due to a bias in cause of death adjudication.

Detection of prostate cancer by an electronic nose: a proof of principle study

PURPOSE

We evaluate the ability of an electronic nose to discriminate prostate cancer from benign prostatic hyperplasia using urine headspace, potentially offering a clinically applicable noninvasive and rapid diagnostic method.

MATERIALS AND METHODS

The ChemPro® 100-eNose was used to discriminate prostate cancer from benign prostatic hyperplasia using urine sample headspace. Its performance was tested with 50 patients with confirmed prostate cancer and 24 samples from 15 patients with benign prostatic hyperplasia (15 patients provided urine preoperatively and 9 patients provided samples 3 months postoperatively) scheduled to undergo robotic assisted laparoscopic radical prostatectomy or transurethral resection of prostate, respectively. The patients provided urine sample preoperatively and those with benign prostatic hyperplasia also provided samples 3 months postoperatively to be used as a pooled control sample population. A discrimination classifier was identified for eNose and subsequently, sensitivity and specificity values were determined. Leave-one-out cross-validation was performed.

RESULTS

Using leave-one-out cross-validation the eNose reached a sensitivity of 78%, a specificity of 67% and AUC 0.77.

CONCLUSIONS

The electronic nose is capable of rapidly and noninvasively discriminating prostate cancer and benign prostatic hyperplasia using urine headspace in patients undergoing surgery.

Excess all-cause mortality in the evaluation of a screening trial to account for selective participation

OBJECTIVE

In addition to disease-specific mortality, a randomized controlled cancer screening trial may be evaluated in terms of excess mortality, in which case no patient-specific information on causes of death is needed. We studied the effect of not accounting for attendance on the calculated excess mortality in a prostate cancer screening trial.

METHODS

The numerator of the excess mortality rate related to prostate cancer diagnoses in each study arm equals the excess number of deaths observed in the cancer patients. The estimation of the expected number of deaths in the absence of the prostate cancer diagnoses has to account for the self-selection of those participating in the trial, particularly if the proportion of non-participants is substantial.

SETTING

The European prostate cancer screening trial (ERSPC).

RESULTS

In the screening arm, non-attendees had roughly twice the mortality rate of attendees. Approximately twice as many cancers were detected in the screening arm compared with the control arm, primarily in attendees. Unless attendance is properly accounted for, the expected mortality of prostate cancer patients in the screening arm is overestimated by 0.9-3.6 deaths per 1000 person-years.

CONCLUSIONS

Attendees have a lower all-cause mortality rate (are healthier) and a higher probability of a prostate cancer diagnosis than non-attendees and the men randomized to the control arm. If attendance is not accounted for, the excess mortality and the between-arm excess mortality rate ratio are underestimated and screening is considered more effective than it actually is. These effects may be sizeable, notably if non-attendance is common. Correcting for attendance status is important in the calculation of the excess mortality rate in prostate cancer patients that can be used in conjunction with a disease-specific mortality analysis in a randomized controlled cancer screening trial.

Detection of smell print differences between nonmalignant and malignant prostate cells with an electronic nose

AIM

To determine whether an electronic nose can differentiate cultured nonmalignant and malignant prostatic cells from each other and whether the smell print is secreted to the surrounding medium.

MATERIALS & METHODS

Prostatic nonmalignant (EP-156T and controls) and malignant (LNCaP) cell lines, as well as conditioned and unconditioned media, were collected. The smell prints of the samples were analyzed by a ChemPro(®) 100 electronic nose device. The data were normalized and dimension reduction was conducted. The samples were classified and misclassification rates were calculated.

RESULTS

The electronic nose differentiated the nonmalignant and malignant cell lines from each other, achieving misclassification rates of 2.9-3.6%. Cells did not differ from the conditioned medium but differed from the unconditioned medium (misclassification rates: 0.0-25.6%).

CONCLUSION

Malignant and nonmalignant prostatic cell lines have distinct smell prints. Prostatic cancer cells seem to modify the smell print of their medium.

Dutasteride treatment over 2 years delays prostate-specific antigen progression in patients with biochemical failure after radical therapy for prostate cancer: results from the randomised, placebo-controlled Avodart After Radical Therapy for Prostate Cancer Study (ARTS)

BACKGROUND

Rising prostate-specific antigen (PSA) levels after radical therapy are indicative of recurrent or residual prostate cancer (PCa). This biochemical recurrence typically predates clinically detectable metastatic disease by several years. Management of patients with biochemical recurrence is controversial.

OBJECTIVE

To assess the effect of dutasteride on progression of PCa in patients with biochemical failure after radical therapy.

DESIGN, SETTING, AND PARTICIPANTS

Randomised, double-blind, placebo-controlled trial in 294 men from 64 centres across 9 European countries.

INTERVENTION

The 5α-reductase inhibitor, dutasteride.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary end point was time to PSA doubling from start of randomised treatment, analysed by log-rank test stratified by previous therapy and investigative-site cluster. Secondary end points included time to disease progression and the proportion of subjects with disease progression.

RESULTS AND LIMITATIONS

Of the 294 subjects randomised (147 in each treatment group), 187 (64%) completed 24 mo of treatment and 107 discontinued treatment prematurely (71 [48%] of the placebo group, 36 [24%] of the dutasteride group). Dutasteride significantly delayed the time to PSA doubling compared with placebo after 24 mo of treatment (p<0.001); the relative risk (RR) reduction was 66.1% (95% confidence interval [CI], 50.35-76.90) for the overall study period. Dutasteride also significantly delayed disease progression (which included PSA- and non-PSA-related outcomes) compared with placebo (p<0.001); the overall RR reduction in favour of dutasteride was 59% (95% CI, 32.53-75.09). The incidence of adverse events (AEs), serious AEs, and AEs leading to study withdrawal were similar between the treatment groups. A limitation was that investigators were not blinded to PSA levels during the study.

CONCLUSIONS

Dutasteride delayed the biochemical progression of PCa in patients with biochemical failure after radical therapy for clinically localised disease. The safety and tolerability of dutasteride were generally consistent with previous experience.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov, NCT00558363.

Denosumab and bone-metastasis-free survival in men with castration-resistant prostate cancer: results of a phase 3, randomised, placebo-controlled trial

BACKGROUND

Bone metastases are a major cause of morbidity and mortality in men with prostate cancer. Preclinical studies suggest that osteoclast inhibition might prevent bone metastases. We assessed denosumab, a fully human anti-RANKL monoclonal antibody, for prevention of bone metastasis or death in non-metastatic castration-resistant prostate cancer.

METHODS

In this phase 3, double-blind, randomised, placebo-controlled study, men with non-metastatic castration-resistant prostate cancer at high risk of bone metastasis (prostate-specific antigen [PSA] ≥8·0 μg/L or PSA doubling time ≤10·0 months, or both) were enrolled at 319 centres from 30 countries. Patients were randomly assigned (1:1) via an interactive voice response system to receive subcutaneous denosumab 120 mg or subcutaneous placebo every 4 weeks. Randomisation was stratified by PSA eligibility criteria and previous or ongoing chemotherapy for prostate cancer. Patients, investigators, and all people involved in study conduct were masked to treatment allocation. The primary endpoint was bone-metastasis-free survival, a composite endpoint determined by time to first occurrence of bone metastasis (symptomatic or asymptomatic) or death from any cause. Efficacy analysis was by intention to treat. The masked treatment phase of the trial has been completed. This trial was registered at ClinicalTrials.gov, number NCT00286091.

FINDINGS

1432 patients were randomly assigned to treatment groups (716 denosumab, 716 placebo). Denosumab significantly increased bone-metastasis-free survival by a median of 4·2 months compared with placebo (median 29·5 [95% CI 25·4-33·3] vs 25·2 [22·2-29·5] months; hazard ratio [HR] 0·85, 95% CI 0·73-0·98, p=0·028). Denosumab also significantly delayed time to first bone metastasis (33·2 [95% CI 29·5-38·0] vs 29·5 [22·4-33·1] months; HR 0·84, 95% CI 0·71-0·98, p=0·032). Overall survival did not differ between groups (denosumab, 43·9 [95% CI 40·1-not estimable] months vs placebo, 44·8 [40·1-not estimable] months; HR 1·01, 95% CI 0·85-1·20, p=0·91). Rates of adverse events and serious adverse events were similar in both groups, except for osteonecrosis of the jaw and hypocalcaemia. 33 (5%) patients on denosumab developed osteonecrosis of the jaw versus none on placebo. Hypocalcaemia occurred in 12 (2%) patients on denosumab and two (<1%) on placebo.

INTERPRETATION

This large randomised study shows that targeting of the bone microenvironment can delay bone metastasis in men with prostate cancer.

FUNDING

Amgen Inc.

Comparison of dutasteride and finasteride for treating benign prostatic hyperplasia: the Enlarged Prostate International Comparator Study (EPICS)

OBJECTIVE

• To assess the efficacy and safety of dutasteride compared with finasteride in treating men with symptomatic benign prostatic hyperplasia (BPH) for 12 months.

PATIENTS AND METHODS

• The Enlarged Prostate International Comparator Study was a multicentre, randomized, double-blind, 12-month, parallel-group study. • Men aged ≥ 50 years with a clinical diagnosis of BPH received once-daily treatment with dutasteride 0.5 mg (n= 813) or finasteride 5 mg (n= 817). After a 4-week placebo run-in period, patients were randomized to receive dutasteride or finasteride for 48 weeks, followed by an optional 24-month, open-label phase, during which patients received dutasteride 0.5 mg once daily. • The primary endpoint was change in prostate volume, and the secondary endpoints included improvement in American Urological Association Symptom Index (AUA-SI) scores, improvement in maximum urinary flow rate (Q(max)) and long-term safety in the 24-month open-label phase.

RESULTS

• Both dutasteride and finasteride were effective at reducing prostate volume with no significant difference between the two treatments during the study. • Similar reductions in mean AUA-SI scores and Q(max) were also observed for men in both treatment groups. • A similar percentage of adverse events was experienced by patients of both treatment groups, and no new adverse events were reported in the open-label phase.

CONCLUSION

• Dutasteride and finasteride, when administered for 12 months, were similarly effective in reducing prostate volume and improving Q(max) and urinary symptoms associated with BPH in men with an enlarged prostate.

Abstract A35: LDL induces prostate cancer cell growth and inhibits growth-reducing effects of simvastatin

Background: Several epidemiological studies have reported decreased risk of advanced prostate cancer among men using statins, a widely used group of cholesterol-lowering drugs. The association is possibly linked to serum LDL reduction during statin therapy. We studied in vitro the importance of LDL on growth of normal and cancerous prostate epithelial cells and evaluated its association with growth reducing effect of simvastatin.

Methods: Four normal prostatic epithelial cell lines (P96E, P97E, PWR-1E, RWPE-1) and two cancer cell lines (LNCaP and VCaP) were grown in cholesterol-free conditions. Cells were treated with 1 µg/ml, 15 µg/ml or 50 µg/ml LDL, 100 nM or 10 µM simvastatin and/or 100 µM mevalonate for seven days. Cellular growth rate was measured with crystal violet staining.

Results: In normal epithelial cells, 1 µg/ml and 15 µg/ml LDL did not have marked effect on cell growth, while 50 µg/ml LDL had a growth reducing effect. Conversely, in cancer cells cellular growth was stimulated in direct correlation with LDL concentration. Simvastatin at 100 nM concentration caused clear growth reduction in normal epithelial cells, and 10 µM simvastatin had a cytotoxic effect. Growth reduction by 100 nM simvastatin was attenuated by increasing LDL concentrations, the effect being completely reversed by 15 µg/ml LDL. However, the cytotoxic effect of 10 µM simvastatin could not be reversed by LDL alone, but required combination of 100 µM mevalonate and 15 µg/ml LDL.

Conclusions: Our results demonstrate the importance of LDL for prostate cancer cell growth. The growth reducing effect of simvastatin depends on the level of extracellular LDL. Our study supports the epidemiological studies suggesting that statins’ prostate cancer risk reducing effects depend on LDL reduction. Hypercholesterolemia could be a prostate cancer risk factor.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A35.

Abstract 4093: miR-193b is an epigenetically regulated putative tumor suppressor in prostate cancer

miRNAs have proven to be key regulators of gene expression and are differentially expressed in various diseases, including cancer. Our aim was to identify epigenetically dysregulated genes in prostate cancer. We performed miRNA expression profiling after relieving epigenetic modifications in six prostate cancer cell lines and non-malignant prostate epithelial cells. 38 miRNAs showed increased expression in any prostate cancer cell line after 5-aza-2′-deoxycytidine (5azadC) and trichostatin A (TSA) treatments. Six of these also had decreased expression in clinical prostate cancer samples compared to benign prostatic hyperplasia. Among these, miR-193b was methylated in 22Rv1 cell line at a CpG island ∼1kb upstream of the miRNA locus. Expressing miR-193b in 22Rv1 cells using pre-miR-193b oligonucleotides caused a significant growth reduction (p&lt;0.001) resulting from a decrease of cells in S-phase of the cell cycle (p&lt;0.01). In addition, the anchorage independent growth was partially inhibited in transiently miR-193b -expressing 22Rv1 cells (p&lt;0.01). Altogether, our data suggest that miR-193b is an epigenetically silenced putative tumor suppressor in prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4093.

Effect of dutasteride on the risk of prostate cancer

BACKGROUND

We conducted a study to determine whether dutasteride reduces the risk of incident prostate cancer, as detected on biopsy, among men who are at increased risk for the disease.

METHODS

In this 4-year, multicenter, randomized, double-blind, placebo-controlled, parallel-group study, we compared dutasteride, at a dose of 0.5 mg daily, with placebo. Men were eligible for inclusion in the study if they were 50 to 75 years of age, had a prostate-specific antigen (PSA) level of 2.5 to 10.0 ng per milliliter, and had had one negative prostate biopsy (6 to 12 cores) within 6 months before enrollment. Subjects underwent a 10-core transrectal ultrasound-guided biopsy at 2 and 4 years.

RESULTS

Among 6729 men who underwent a biopsy or prostate surgery, cancer was detected in 659 of the 3305 men in the dutasteride group, as compared with 858 of the 3424 men in the placebo group, representing a relative risk reduction with dutasteride of 22.8% (95% confidence interval, 15.2 to 29.8) over the 4-year study period (P<0.001). Overall, in years 1 through 4, among the 6706 men who underwent a needle biopsy, there were 220 tumors with a Gleason score of 7 to 10 among 3299 men in the dutasteride group and 233 among 3407 men in the placebo group (P=0.81). During years 3 and 4, there were 12 tumors with a Gleason score of 8 to 10 in the dutasteride group, as compared with only 1 in the placebo group (P=0.003). Dutasteride therapy, as compared with placebo, resulted in a reduction in the rate of acute urinary retention (1.6% vs. 6.7%, a 77.3% relative reduction). The incidence of adverse events was similar to that in studies of dutasteride therapy for benign prostatic hyperplasia, except that in our study, as compared with previous studies, the relative incidence of the composite category of cardiac failure was higher in the dutasteride group than in the placebo group (0.7% [30 men] vs. 0.4% [16 men], P=0.03).

CONCLUSIONS

Over the course of the 4-year study period, dutasteride reduced the risk of incident prostate cancer detected on biopsy and improved the outcomes related to benign prostatic hyperplasia. (ClinicalTrials.gov number, NCT00056407.)

Identification of seven new prostate cancer susceptibility loci through a genome-wide association study

Prostate cancer (PrCa) is the most frequently diagnosed cancer in males in developed countries. To identify common PrCa susceptibility alleles, we previously conducted a genome-wide association study in which 541,129 SNPs were genotyped in 1,854 PrCa cases with clinically detected disease and in 1,894 controls. We have now extended the study to evaluate promising associations in a second stage in which we genotyped 43,671 SNPs in 3,650 PrCa cases and 3,940 controls and in a third stage involving an additional 16,229 cases and 14,821 controls from 21 studies. In addition to replicating previous associations, we identified seven new prostate cancer susceptibility loci on chromosomes 2, 4, 8, 11 and 22 (with P = 1.6 x 10(-8) to P = 2.7 x 10(-33)).

TCEB1 promotes invasion of prostate cancer cells

Amplification of the long arm of chromosome 8 is one of the most recurrent findings in prostate cancer and it is associated with poor prognosis. Several minimal regions of amplification suggest multiple target genes which are yet to be identified. We have previously shown that TCEB1, EIF3S3, KIAA0196 and RAD21 are amplified and overexpressed in prostate cancer and they are located in the 8q area. In this study, we examined the functional effects of these genes to prostate cancer cell phenotype. We overexpressed and inhibited the genes by lentivirus mediated overexpression and RNA interference, respectively. shRNA mediated TCEB1 silencing decreased significantly cellular invasion of PC-3 and DU145 cells through Matrigel. TCEB1 silencing reduced the anchorage-independent growth of PC-3 cells. Similar effects were not seen with any other genes. When overexpressed in NIH 3T3 cells, TCEB1 and EIF3S3 increased the growth rate of the cells. Transcriptional profiling of TCEB1 silenced PC-3 cells revealed decrease of genes involved in invasion and metastasis. Finally, we also confirmed here the overexpression of TCEB1 in hormone-refractory prostate tumors. This study indicates that TCEB1 promotes invasion of prostate cancer cells, is involved in development of hormone-refractory prostate cancer and is thereby a strong candidate to be one of the target genes for the 8q gain.