Updated interim efficacy analysis and long-term safety of abiraterone acetate in metastatic castration-resistant prostate cancer patients without prior chemotherapy (COU-AA-302)

Feasibility of Indirect Treatment Comparisons Between Niraparib Plus Abiraterone Acetate and Other First-Line Poly ADP-Ribose Polymerase Inhibitor Treatment Regimens for Patients with BRCA1/2 Mutation-Positive Metastatic Castration-Resistant Prostate Cancer

INTRODUCTION

Poly(ADP-ribose) polymerase inhibitors (PARPi) are a novel option to treat patients with metastatic castration-resistant prostate cancer (mCRPC). Niraparib plus abiraterone acetate and prednisone (AAP) is indicated for BRCA1/2 mutation-positive mCRPC. Niraparib plus AAP demonstrated safety and efficacy in the phase 3 MAGNITUDE trial (NCT03748641). In the absence of head-to-head studies comparing PARPi regimens, the feasibility of conducting indirect treatment comparisons (ITC) to inform decisions for patients with first-line BRCA1/2 mutation-positive mCRPC has been explored.

METHODS

A systematic literature review was conducted to identify evidence from randomized controlled trials on relevant comparators to inform the feasibility of conducting ITCs via network meta-analysis (NMA) or population-adjusted indirect comparisons (PAIC). Feasibility was assessed based on network connectivity, data availability in the BRCA1/2 mutation-positive population, and degree of within- and between-study heterogeneity or bias.

RESULTS

NMAs between niraparib plus AAP and other PARPi regimens (olaparib monotherapy, olaparib plus AAP, and talazoparib plus enzalutamide) were inappropriate due to the disconnected network, differences in trial populations related to effect modifiers, or imbalances within BRCA1/2 mutation-positive subgroups. The latter issue, coupled with the lack of a common comparator (except for olaparib plus AAP), also rendered anchored PAICs infeasible. Unanchored PAICs were either inappropriate due to lack of population overlap (vs. olaparib monotherapy) or were restricted by unmeasured confounders and small sample size (vs. olaparib plus AAP). PAIC versus talazoparib plus enzalutamide was not possible due to lack of published arm-level baseline characteristics and sufficient efficacy outcome data in the relevant population.

CONCLUSION

The current randomized controlled trial evidence network does not permit robust comparisons between niraparib plus AAP and other PARPi regimens for patients with 1L BRCA-positive mCRPC. Decision-makers should scrutinize any ITC results in light of their limitations. Real-world evidence combined with clinical experience should inform treatment recommendations in this indication.

Prostate cancer metastasis and health disparities: a systematic review

BACKGROUND

Prostate cancer (PCa), one of the most prevalent malignancies affecting men, significantly contributes to increased mortality rates worldwide. While the causative death is due to advanced metastatic disease, this occurrence disproportionately impacts men of African descent compared to men of European descent. In this review, we describe potential mechanisms underlying PCa metastases disparities and current treatments for metastatic disease among these populations, differences in treatment outcomes, and survival rates, in hopes of highlighting a need to address disparities in PCa metastases.

METHODS

We reviewed existing literature using databases such as PubMed, Google Scholar, and Science Direct using the following keywords: "prostate cancer metastases", "metastatic prostate cancer disparity", "metastatic prostate cancer diagnosis and treatment", "prostate cancer genetic differences and mechanisms", "genetic differences and prostate tumor microenvironment", and "men of African descent and access to clinical treatments". The inclusion criteria for literature usage were original research articles and review articles.

RESULTS

Studies indicate unique genetic signatures and molecular mechanisms such as Epithelial-Mesenchymal Transition (EMT), inflammation, and growth hormone signaling involved in metastatic PCa disparities. Clinical studies also demonstrate differences in treatment outcomes that are race-specific, for example, patients of African descent have a better response to enzalutamide and immunotherapy yet have less access to these drugs as compared to patients of European descent.

CONCLUSIONS

Growing evidence suggests a connection between a patient's genetic profile, the prostate tumor microenvironment, and social determinants of health that contribute to the aggressiveness of metastatic disease and treatment outcomes. With several potential pathways highlighted, the limitations in current diagnostic and therapeutic applications that target disparity in PCa metastases warrant rigorous research attention.

Treatment patterns and outcomes in metastatic castration-resistant prostate cancer patients with and without somatic or germline alterations in homologous recombination repair genes

BACKGROUND

Although germline BRCA mutations have been associated with adverse outcomes in prostate cancer (PC), understanding of the association between somatic/germline alterations in homologous recombination repair (HRR) genes and treatment outcomes in metastatic castration-resistant PC (mCRPC) is limited. The aim of this study was to investigate the prevalence and outcomes associated with somatic/germline HRR alterations, particularly BRCA1/2, in patients initiating first-line (1L) mCRPC treatment with androgen receptor signalling inhibitors (ARSi) or taxanes.

PATIENTS AND METHODS

Data from 729 mCRPC patients were pooled for CAPTURE from four multicentre observational studies. Eligibility required 1L treatment with ARSi or taxanes, adequate tumour samples and biomarker panel results. Patients underwent paired normal and tumour DNA analyses by next-generation sequencing using a custom gene panel including ATM, BRCA1, BRCA2, BRIP1, CDK12, CHEK2, FANCA, HDAC2, PALB2, RAD51B and RAD54L. Patients were divided into subgroups based on somatic/germline alteration(s): with BRCA1/2 mutations (BRCA); with HRR mutations except BRCA1/2 (HRR non-BRCA); and without HRR alterations (non-HRR). Patients without BRCA1/2 mutations were classified as non-BRCA. Radiographic progression-free survival (rPFS), progression-free survival 2 (PFS2) and overall survival (OS) were assessed.

RESULTS

Of 729 patients, 96 (13.2%), 127 (17.4%) and 506 (69.4%) were in the BRCA, HRR non-BRCA and non-HRR subgroups, respectively. BRCA patients performed significantly worse for all outcomes than non-HRR or non-BRCA patients (P < 0.05), while PFS2 and OS were significantly shorter for BRCA than HRR non-BRCA patients (P < 0.05). HRR non-BRCA patients also had significantly worse rPFS, PFS2 and OS than non-HRR patients. Exploratory analyses suggested that for BRCA patients, there were no significant differences in outcomes associated with 1L treatment choice (ARSi or taxanes) or with the somatic/germline origin of the alterations.

CONCLUSIONS

Worse outcomes were observed for mCRPC patients in the BRCA subgroup compared with non-BRCA subgroups, either HRR non-BRCA or non-HRR. Despite its heterogeneity, the HRR non-BRCA subgroup presented worse outcomes than the non-HRR subgroup. Screening early for HRR mutations, especially BRCA1/2, is crucial in improving mCRPC patient prognosis.

EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer. Part II-2024 Update: Treatment of Relapsing and Metastatic Prostate Cancer

BACKGROUND AND OBJECTIVE

The European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy and Oncology (ESTRO)-European Society of Urogenital Radiology (ESUR)-International Society of Urological Pathology (ISUP)-International Society of Geriatric Oncology (SIOG) guidelines on the treatment of relapsing, metastatic, and castration-resistant prostate cancer (PCa) have been updated. Here we provide a summary of the 2024 guidelines.

METHODS

The panel performed a literature review of new data, covering the time frame between 2020 and 2023. The guidelines were updated and a strength rating for each recommendation was added on the basis of a systematic review of the evidence.

KEY FINDINGS AND LIMITATIONS

Risk stratification for relapsing PCa after primary therapy may guide salvage therapy decisions. New treatment options, such as androgen receptor-targeted agents (ARTAs), ARTA + chemotherapy combinations, PARP inhibitors and their combinations, and prostate-specific membrane antigen-based therapy have become available for men with metastatic PCa.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Evidence for relapsing, metastatic, and castration-resistant PCa is evolving rapidly. These guidelines reflect the multidisciplinary nature of PCa management. The full version is available online (http://uroweb.org/guideline/ prostate-cancer/).

PATIENT SUMMARY

This article summarises the 2024 guidelines for the treatment of relapsing, metastatic, and castration-resistant prostate cancer. These guidelines are based on evidence and guide doctors in discussing treatment decisions with their patients. The guidelines are updated every year.

Real-world economic burden of metastatic castration-resistant prostate cancer before and after first-line therapy initiation

AIMS

To describe healthcare costs of patients with metastatic castration-resistant prostate cancer (mCRPC) initiating first-line (1 L) therapies from a US payer perspective.

METHODS

Patients initiating a Flatiron oncologist-defined 1 L mCRPC therapy (index date) on or after mCRPC diagnosis were identified from linked electronic medical records/claims data from the Flatiron Metastatic Prostate Cancer (PC) Core Registry and Komodo's Healthcare Map. Patients were excluded if they initiated a clinical trial drug in 1 L, had <12 months of insurance eligibility prior to index, or no claims in Komodo's Healthcare Map for the Flatiron oncologist-defined index therapy. All-cause and PC-related total costs per-patient-per-month (PPPM), including costs for services and procedures from medical claims (i.e. medical costs) and costs from pharmacy claims (i.e. pharmacy costs), were described in the 12-month baseline period before 1 L therapy initiation (including the baseline pre- and post- mCRPC progression periods) and during 1 L therapy (follow-up).

RESULTS

Among 459 patients with mCRPC (mean age 70 years, 57% White, 16% Black, 45% commercially-insured, 43% Medicare Advantage-insured, and 12% Medicaid-insured), average baseline all-cause total costs (PPPM) were $4,576 ($4,166 pre-mCRPC progression, $8,278 post-mCRPC progression). Average baseline PC-related total costs were $2,935 ($2,537 pre-mCRPC progression, $6,661 post-mCRPC progression). During an average 1 L duration of 8.5 months, mean total costs were $13,746 (all-cause) and $12,061 (PC-related) PPPM. The cost increase following 1 L therapy initiation was driven by higher PC-related outpatient and pharmacy costs. PC-related medical costs PPPM increased from $1,504 during baseline to $5,585 following 1 L mCRPC therapy initiation.

LIMITATIONS

All analyses were descriptive; statistical testing was not performed.

CONCLUSION

Incremental costs of progression to mCRPC are significant, with the majority of costs driven by higher PC-related costs. Using contemporary data, this study highlights the importance of utilizing effective therapies that slow progression and reduce healthcare resource demands despite the initial investment in treatment costs.

The prognostic value of Eastern Cooperative Oncology Group performance status on overall survival among patients with metastatic prostate cancer: a systematic review and meta-analysis

Background

There is heterogeneity in the literature regarding the strength of association between Eastern Cooperative Oncology Group performance status (ECOG PS) and mortality. We conducted a systematic review and meta-analysis of studies reporting the prognostic value of ECOG PS on overall survival (OS) in metastatic prostate cancer (mPC).

Methods

PubMed was searched from inception to March 21, 2022. A meta-analysis pooling the effect of ECOG PS categories (≥2 vs. <2, 2 vs. <2, and ≥1 vs. <1) on OS was performed separately for studies including patients with metastatic castration-resistant prostate cancer (mCRPC) and metastatic castration-sensitive prostate cancer (mCSPC) using a random-effects model. Analyses were stratified by prior chemotherapy and study type.

Results

Overall, 75 studies, comprising 32,298 patients, were included. Most studies (72/75) included patients with mCRPC. Higher ECOG PS was associated with a significant increase in mortality risk, with the highest estimate observed among patients with mCRPC with an ECOG PS of ≥2 versus <2 (hazard ratio [HR]: 2.10, 95% confidence interval [CI]: 1.87-2.37). When stratifying by study type, there was a higher risk estimate of mortality among patients with mCRPC with an ECOG PS of ≥1 versus <1 in real-world data studies (HR: 1.98, 95% CI: 1.72-2.26) compared with clinical trials (HR: 1.32, 95% CI: 1.13-1.54; p < 0.001). There were no significant differences in the HR of OS stratified by previous chemotherapy.

Conclusion

ECOG PS was a significant predictor of OS regardless of category, previous chemotherapy, and mPC population. Additional studies are needed to better characterize the effect of ECOG PS on OS in mCSPC.

Unleashing novel horizons in advanced prostate cancer treatment: investigating the potential of prostate specific membrane antigen-targeted nanomedicine-based combination therapy

Prostate cancer (PCa) is a prevalent malignancy with increasing incidence in middle-aged and older men. Despite various treatment options, advanced metastatic PCa remains challenging with poor prognosis and limited effective therapies. Nanomedicine, with its targeted drug delivery capabilities, has emerged as a promising approach to enhance treatment efficacy and reduce adverse effects. Prostate-specific membrane antigen (PSMA) stands as one of the most distinctive and highly selective biomarkers for PCa, exhibiting robust expression in PCa cells. In this review, we explore the applications of PSMA-targeted nanomedicines in advanced PCa management. Our primary objective is to bridge the gap between cutting-edge nanomedicine research and clinical practice, making it accessible to the medical community. We discuss mainstream treatment strategies for advanced PCa, including chemotherapy, radiotherapy, and immunotherapy, in the context of PSMA-targeted nanomedicines. Additionally, we elucidate novel treatment concepts such as photodynamic and photothermal therapies, along with nano-theragnostics. We present the content in a clear and accessible manner, appealing to general physicians, including those with limited backgrounds in biochemistry and bioengineering. The review emphasizes the potential benefits of PSMA-targeted nanomedicines in enhancing treatment efficiency and improving patient outcomes. While the use of PSMA-targeted nano-drug delivery has demonstrated promising results, further investigation is required to comprehend the precise mechanisms of action, pharmacotoxicity, and long-term outcomes. By meticulous optimization of the combination of nanomedicines and PSMA ligands, a novel horizon of PSMA-targeted nanomedicine-based combination therapy could bring renewed hope for patients with advanced PCa.

Expression and Therapeutic Targeting of TROP-2 in Treatment-Resistant Prostate Cancer

PURPOSE

Men with metastatic castration-resistant prostate cancer (mCRPC) frequently develop resistance to androgen receptor signaling inhibitor (ARSI) treatment; therefore, new therapies are needed. Trophoblastic cell-surface antigen (TROP-2) is a transmembrane protein identified in prostate cancer and overexpressed in multiple malignancies. TROP-2 is a therapeutic target for antibody-drug conjugates (ADC).

EXPERIMENTAL DESIGN

TROP-2 gene (TACSTD2) expression and markers of treatment resistance from prostate biopsies were analyzed using data from four previously curated cohorts of mCRPC (n = 634) and the PROMOTE study (dbGaP accession phs001141.v1.p1, n = 88). EPCAM or TROP-2-positive circulating tumor cells (CTC) were captured from peripheral blood for comparison of protein (n = 15) and gene expression signatures of treatment resistance (n = 40). We assessed the efficacy of TROP-2-targeting agents in a mouse xenograft model generated from prostate cancer cell lines.

RESULTS

We demonstrated that TACSTD2 is expressed in mCRPC from luminal and basal tumors but at lower levels in patients with neuroendocrine prostate cancer. Patients previously treated with ARSI showed no significant difference in TACSTD2 expression, whereas patients with detectable AR-V7 expression showed increased expression. We observed that TROP-2 can serve as a cell surface target for isolating CTCs, which may serve as a predictive biomarker for ADCs. We also demonstrated that prostate cancer cell line xenografts can be targeted specifically by labeled anti-TROP-2 agents in vivo.

CONCLUSIONS

These results support further studies on TROP-2 as a therapeutic and diagnostic target for mCRPC.

Health-related quality of life and pain outcomes with [177Lu]Lu-PSMA-617 plus standard of care versus standard of care in patients with metastatic castration-resistant prostate cancer (VISION): a multicentre, open-label, randomised, phase 3 trial

BACKGROUND

In VISION, the prostate-specific membrane antigen (PSMA)-targeted radioligand therapy lutetium-177 [177Lu]Lu-PSMA-617 (vipivotide tetraxetan) improved radiographic progression-free survival and overall survival when added to protocol-permitted standard of care in patients with metastatic castration-resistant prostate cancer. Here, we report additional health-related quality of life (HRQOL), pain, and symptomatic skeletal event results.

METHODS

This multicentre, open-label, randomised, phase 3 trial was conducted at 84 cancer centres in nine countries in North America and Europe. Eligible patients were aged 18 years or older; had progressive PSMA-positive metastatic castration-resistant prostate cancer; an Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2; and had previously received of at least one androgen receptor pathway inhibitor and one or two taxane-containing regimens. Patients were randomly assigned (2:1) to receive either [177Lu]Lu-PSMA-617 plus protocol-permitted standard of care ([177Lu]Lu-PSMA-617 group) or standard of care alone (control group) using permuted blocks. Randomisation was stratified by baseline lactate dehydrogenase concentration, liver metastases, ECOG performance status, and androgen receptor pathway inhibitor inclusion in standard of care. Patients in the [177Lu]Lu-PSMA-617 group received intravenous infusions of 7·4 gigabecquerel (GBq; 200 millicurie [mCi]) [177Lu]Lu-PSMA-617 every 6 weeks for four cycles plus two optional additional cycles. Standard of care included approved hormonal treatments, bisphosphonates, and radiotherapy. The alternate primary endpoints were radiographic progression-free survival and overall survival, which have been reported. Here we report the key secondary endpoint of time to first symptomatic skeletal event, and other secondary endpoints of HRQOL assessed with the Functional Assessment of Cancer Therapy-Prostate (FACT-P) and EQ-5D-5L, and pain assessed with the Brief Pain Inventory-Short Form (BPI-SF). Patient-reported outcomes and symptomatic skeletal events were analysed in all patients who were randomly assigned after implementation of measures designed to reduce the dropout rate in the control group (on or after March 5, 2019), and safety was analysed according to treatment received in all patients who received at least one dose of treatment. This trial is registered with ClinicalTrials.gov, NCT03511664, and is active but not recruiting.

FINDINGS

Between June 4, 2018, and Oct 23, 2019, 831 patients were enrolled, of whom 581 were randomly assigned to the [177Lu]Lu-PSMA-617 group (n=385) or control group (n=196) on or after March 5, 2019, and were included in analyses of HRQOL, pain, and time to first symptomatic skeletal event. The median age of patients was 71 years (IQR 65-75) in the [177Lu]Lu-PSMA-617 group and 72·0 years (66-76) in the control group. Median time to first symptomatic skeletal event or death was 11·5 months (95% CI 10·3-13·2) in the [177Lu]Lu-PSMA-617 group and 6·8 months (5·2-8·5) in the control group (hazard ratio [HR] 0·50, 95% CI 0·40-0·62). Time to worsening was delayed in the [177Lu]Lu-PSMA-617 group versus the control group for FACT-P score (HR 0·54, 0·45-0·66) and subdomains, BPI-SF pain intensity score (0·52, 0·42-0·63), and EQ-5D-5L utility score (0·65, 0·54-0·78). Grade 3 or 4 haematological adverse events included decreased haemoglobin (80 [15%] of 529 assessable patients who received [177Lu]Lu-PSMA-617 plus standard of care vs 13 [6%] of 205 who received standard of care only), lymphocyte concentrations (269 [51%] vs 39 [19%]), and platelet counts (49 [9%] vs five [2%]). Treatment-related adverse events leading to death occurred in five (1%) patients who received [177Lu]Lu-PSMA-617 plus standard of care (pancytopenia [n=2], bone marrow failure [n=1], subdural haematoma [n=1], and intracranial haemorrhage [n=1]) and no patients who received standard of care only.

INTERPRETATION

[177Lu]Lu-PSMA-617 plus standard of care delayed time to worsening in HRQOL and time to skeletal events compared with standard of care alone. These findings support the use of [177Lu]Lu-PSMA-617 in patients with metastatic castration-resistant prostate cancer who received previous androgen receptor pathway inhibitor and taxane treatment.

FUNDING

Advanced Accelerator Applications (Novartis).

Integrated analysis reveals FOXA1 and Ku70/Ku80 as targets of ivermectin in prostate cancer

Ivermectin is a widely used antiparasitic drug and shows promising anticancer activity in various cancer types. Although multiple signaling pathways modulated by ivermectin have been identified in tumor cells, few studies have focused on the exact target of ivermectin. Herein, we report the pharmacological effects and targets of ivermectin in prostate cancer. Ivermectin caused G0/G1 cell cycle arrest, induced cell apoptosis and DNA damage, and decreased androgen receptor (AR) signaling in prostate cancer cells. Further in vivo analysis showed ivermectin could suppress 22RV1 xenograft progression. Using integrated omics profiling, including RNA-seq and thermal proteome profiling, the forkhead box protein A1 (FOXA1) and non-homologous end joining (NHEJ) repair executer Ku70/Ku80 were strongly suggested as direct targets of ivermectin in prostate cancer. The interaction of ivermectin and FOXA1 reduced the chromatin accessibility of AR signaling and the G0/G1 cell cycle regulator E2F1, leading to cell proliferation inhibition. The interaction of ivermectin and Ku70/Ku80 impaired the NHEJ repair ability. Cooperating with the downregulation of homologous recombination repair ability after AR signaling inhibition, ivermectin increased intracellular DNA double-strand breaks and finally triggered cell death. Our findings demonstrate the anticancer effect of ivermectin in prostate cancer, indicating that its use may be a new therapeutic approach for prostate cancer.

Osteoblast Secretome Modulated by Abiraterone Treatment Affects Castration Resistant Prostate Cancer Cell Proliferation

Abiraterone is a selective inhibitor of androgen biosynthesis approved for the treatment of metastatic patients affected by castration-resistant or castration-sensitive prostate cancer. Intriguingly, clinical data revealed that abiraterone also delayed disease progression in bone improving bone-related endpoints. Our group has previously demonstrated in vitro a direct effect of abiraterone on osteoclast and osteoblast function suggesting its ability to modulate bone microenvironment. Here, we performed an extensive proteomic analysis to investigate how abiraterone influences osteoblast cell secretome and, consequently, osteoblast/prostate cancer cells interaction. A panel of 507 soluble molecules were analyzed in osteoblast conditioned media (OCM) obtained from osteoblast treated or not with abiraterone. Subsequently, OCM was added to prostate cancer cells to investigate its potential effect on prostate cancer cell proliferation and androgen receptor (AR) activation status. Out of 507 screened molecules, 39 of them were differentially expressed in OCM from osteoblasts treated with abiraterone (OCM ABI) compared to OCM obtained from untreated OBs (OCM CTRL). Pathway enrichment analysis revealed that abiraterone down-modulated the release of specific osteoblast soluble factors, positively associated with cell proliferation pathways (false discovery rate adjusted p-value = 0.0019). In vitro validation data showed that OCM ABI treatment significantly reduced cancer proliferation in C4-2B cells (p = 0.022), but not in AR- negative PC-3 cells. Moreover, we also found a reduction in AR activation in C4-2B cells (p = 0.017) confirming the “indirect” anti-tumor AR-dependent effect of abiraterone mediated by osteoblasts. This study provides the first evidence of an additional antitumor effect of abiraterone through the modulation of multiple osteoblast proliferative signals.

Factors influencing survival in metastatic castration resistant prostate cancer therapy

INTRODUCTION

The number of patients with metastatic castration resistant prostate cancer (mCRPC) is expecting to increase due to the long-life expectancy of those with advanced disease who are also more commonly diagnosed today because of stage migration. Several compounds are available for treating these patients.

AREAS COVERED

We reviewed currently available treatments for mCRPC, their mechanism of action and resistance and we explored possible predictors of treatment success useful to predict survival in mCRPC patients.

EXPERT OPINION

A combination of molecular, clinical, pathological, and imaging features is necessary to correctly estimate patients' risk of death. The combination of these biomarkers may allow clinicians to tailor treatments based on cancer history and patients' features. The search of predictive biomarkers remains an unmet medical need for most patients with mCRPC.

Outcome of 177 Lu-PSMA Radionuclide Treatment in Advanced Prostate Cancer and Its Association With Clinical Parameters : A Single-Center Experience

PURPOSE

This study was set out to analyze the efficacy and safety of 177 Lu-PSMA-617 (LuPSMA) treatment in metastatic castration-resistant prostate cancer (mCRPC) patients.

PATIENTS AND METHODS

Progressive mCRPC patients who received at least 1 cycle of LuPSMA therapy were evaluated retrospectively. Demographic, clinic, and histopathological data were documented. Treatment efficacy was determined based on biochemical response criteria (Prostate Cancer Clinical Trial Working Group 3), and toxicity rates were defined based on CTCAE v4.03. The prognostic significance of laboratory/clinical data and 68 Ga-PSMA PET/CT quantitative results were analyzed using SPSS Version 24.0.

RESULTS

One hundred patients (median prostate-specific antigen [PSA] level, 75.7 ng/mL) who met the eligibility criteria were identified. The median number of cycles received per patient was 3 (range, 1-9). After the first cycles of LuPSMA, biochemical partial response, biochemical stable disease, and biochemical progressive disease were observed in 31%, 36%, and 33% of patients, respectively. Any PSA decline was determined in 60% of patients. After the fourth cycle of treatment, biochemical partial response, biochemical stable disease, and biochemical progressive disease were defined in 48%, 26%, and 26% of patients, respectively. The median overall survival (OS) from the first cycle of LuPSMA was 14 months. Patients who had any PSA response after the first cycle had significantly longer OS than nonresponders (median OS: 17 vs 9 months; P ≤ 0.001). Total PSMA-derived tumor volume ( P = 0.004), total PSMA activity per lesion ( P = 0.01), PSA ( P = 0.007), alkaline phosphatase ( P = 0.002), lactate dehydrogenase ( P < 0.001), and hemoglobin ( P < 0.001) were significant prognostic factors for OS in univariate Cox regression analysis.

CONCLUSIONS

LuPSMA therapy is a favorable treatment for mCRPC with remarkable therapeutic efficacy and low toxicity rates, even in progressive disease under standard therapies. Baseline PSMA-based tumor burden, PSA, alkaline phosphatase, lactate dehydrogenase, and hemoglobin were significant predictors of OS and can be useful for selection of the best candidate for LuPSMA therapy.

Itraconazole Reverts ABCB1-Mediated Docetaxel Resistance in Prostate Cancer

Docetaxel (DTX) was the first chemotherapeutic agent to demonstrate significant efficacy in the treatment of men with metastatic castration-resistant prostate cancer. However, response to DTX is generally short-lived, and relapse eventually occurs due to emergence of drug-resistance. We previously established two DTX-resistant prostate cancer cell lines, LNCaP^R and C4-2B^R, derived from the androgen‐dependent LNCaP cell line, and from the LNCaP lineage-derived androgen-independent C4-2B sub-line, respectively. Using an unbiased drug screen, we identify itraconazole (ITZ), an oral antifungal drug, as a compound that can efficiently re-sensitize drug-resistant LNCaP^R and C4-2B^R prostate cancer cells to DTX treatment. ITZ can re-sensitize multiple DTX-resistant cell models, not only in prostate cancer derived cells, such as PC-3 and DU145, but also in docetaxel-resistant breast cancer cells. This effect is dependent on expression of ATP-binding cassette (ABC) transporter protein ABCB1, also known as P-glycoprotein (P-gp). Molecular modeling of ITZ bound to ABCB1, indicates that ITZ binds tightly to the inward-facing form of ABCB1 thereby inhibiting the transport of DTX. Our results suggest that ITZ may provide a feasible approach to re-sensitization of DTX resistant cells, which would add to the life-prolonging effects of DTX in men with metastatic castration-resistant prostate cancer.

Review of second-generation androgen receptor inhibitor therapies and their role in prostate cancer management

PURPOSE OF REVIEW

We review the published literature on the indications of second-generation androgen receptor inhibitors, Poly(ADP-Ribose) Polymerase (PARP) inhibitors, combination therapies, and their evolution throughout the advanced prostate cancer continuum.

RECENT FINDINGS

Enzalutamide trials have published data supporting its use in metastatic hormone-sensitive prostate cancer (mHSPC), nonmetastatic castration-resistant prostate cancer (nmCRPC), and metastatic castration-resistant prostate cancer (mCRPC). Apalutamide trials have supported its indication for mHSPC and nmCRPC. Darolutamide trials currently support its use for nmCRPC. Abiraterone trials have supported its use in mCRPC and mHSPC. Olaparib and rucaparib have shown clinical benefit in heavily pretreated patients with mCRPC and DNA repair mutation genes.

SUMMARY

Phase 3 trials and peer-reviewed literature demonstrate that enzalutamide, apalutamide, and darolutamide prolong overall survival (OS) in men with nmCRPC. Abiraterone, enzalutamide, and apalutamide improve OS in men with mHSPC. Abiraterone and enzalutamide have data supporting improvement in OS in men with mCRPC.

First-line treatment of metastatic castration-resistant prostate cancer: the real-world Italian cohort of the Prostate Cancer Registry

BACKGROUND

With the availability of multiple treatment options for metastatic castration-resistant prostate cancer (mCRPC), new real-world data on disease management and drugs' performance are needed.

METHODS

We described characteristics, management and clinical outcomes of patients receiving first-line mCRPC treatment within the Italian cohort of the real-world, prospective, international Prostate Cancer Registry. Patients were enrolled consecutively (2013-2016) in 32 Italian sites and followed for 3 years.

RESULTS

238 patients were included: 157 received first-line abiraterone acetate plus prednisone ("abiraterone" thereafter) and 70 first-line docetaxel; 11 patients receiving other treatments were not considered. Compared with docetaxel-treated patients, those receiving abiraterone were significantly older (age ⩾75: 63.7% vs 38.6%), less frequently had a Gleason score >8 (48.2% vs 67.6%, p<0.005) at initial diagnosis, and more frequently an ECOG score ⩾1 (52.7% vs 36.2%, p<0.05) and comorbidities (76.4% vs 57.1%, p<0.05) at baseline; they reported a lower analgesic use (15.3% vs 30%, p<0.005). In the abiraterone group (median follow-up 22.1 months), median time to progression (TTP) and progression-free survival (PFS) were, respectively, 14.4 months (95% confidence interval, CI, 10.6-18.0) and 13.0 months (95% CI, 9.1-16.8); median overall survival (OS) was not reached, and 3-year OS was 59.1%. In the docetaxel treatment group (median follow-up 25.3 months), median TTP, PFS and OS were, respectively, 8.2 months (95% CI, 6.1-10.3), 8.2 months (95% CI, 5.8-10.3) and 33.2 months (95% CI, 19.2-not estimable).

CONCLUSION

This investigation provided valuable information on the overall mCRPC treatment pattern and the effectiveness of first-line abiraterone and docetaxel in a population representative of everyday practice.

Real-world experience of abiraterone acetate plus prednisone in chemotherapy-naive patients with metastatic castration-resistant prostate cancer: long-term results of the prospective ABItude study

Background

Limited real-world data exist on the effectiveness and safety of abiraterone acetate plus prednisone (abiraterone hereafter) in the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) naive to chemotherapy. Most of the few available studies had a retrospective design and included a small number of patients. In the interim analysis of the ABItude study, abiraterone showed good clinical effectiveness and safety profile in the chemotherapy-naive setting over a median follow-up of 18 months.

Patients and methods

We evaluated clinical and patient-reported outcomes (PROs) of chemotherapy-naive mCRPC patients treated with abiraterone as for clinical practice in the Italian, observational, prospective, multicentric ABItude study. mCRPC patients were enrolled at abiraterone start (February 2016-June 2017) and followed up for 3 years; clinical endpoints and PROs, including quality of life (QoL) and pain, were prospectively collected. Kaplan–Meier curves were estimated.

Results

Of the 481 patients enrolled, 454 were assessable for final study analyses. At abiraterone start, the median age was 77 years, with 58.6% elderly patients and 69% having at least one comorbidity (57.5% cardiovascular diseases). Visceral metastases were present in 8.4% of patients. Over a median follow-up of 24.8 months, median progression-free survival (any progression reported by the investigators), time to abiraterone discontinuation, and overall survival were, respectively, 17.3 months [95% confidence interval (CI) 14.1-19.4 months], 16.0 months (95% CI 13.1-18.2 months), and 37.3 months (95% CI 36.5 months-not estimable); 64.2% of patients achieved ≥50% reduction in prostate-specific antigen. QoL assessed by Functional Assessment of Cancer Therapy—Prostate, the European Quality of Life 5 Dimensions 3 Level, and European Quality of Life Visual Analog Scale remained stable during treatment. Median time to pain progression according to Brief Pain Inventory data was 31.1 months (95% CI 24.8 months-not estimable). Sixty-two patients (13.1%) had at least one adverse drug reaction (ADR) and 8 (1.7%) one serious ADR.

Conclusion

With longer follow-up, abiraterone therapy remains safe, well tolerated, and active in a large unselected population.

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A prospective real-life study of abiraterone acetate in mCRPC patients.

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In 481 chemotherapy-naive mCRPC patients (median follow-up: 25 months), abiraterone plus prednisone was effective and safe.

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QoL, measured with various tools, remained stable during treatment with abiraterone plus prednisone.

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The median time to pain progression was 31.1 months.

Abiraterone switches castration-resistant prostate cancer dependency from adrenal androgens towards androgen receptor variants and glucocorticoid receptor signalling

INTRODUCTION

Castration-resistant prostate cancer (CRPC) remains dependent on androgen receptor (AR) signalling, which is largely driven by conversion of adrenal androgen precursors lasting after castration. Abiraterone, an inhibitor of the steroidogenic enzyme CYP17A1, has been demonstrated to reduce adrenal androgen synthesis and prolong CRPC patient survival. To study mechanisms of resistance to castration and abiraterone, we created coculture models using human prostate and adrenal tumours.

MATERIALS AND METHODS

Castration-naïve and CRPC clones of VCaP were incubated with steroid substrates or cocultured with human adrenal cells (H295R) and treated with abiraterone or the antiandrogen enzalutamide. Male mice bearing VCaP xenografts with and without concurrent H295R xenografts were castrated and treated with placebo or abiraterone. Response was assessed by tumour growth and PSA release. Plasma and tumour steroid levels were assessed by LC/MS-MS. Quantitative polymerase chain reaction determined steroidogenic enzyme, nuclear receptor and AR target gene expression.

RESULTS

In vitro, adrenal androgens induced castration-naïve and CRPC cell growth, while precursors steroids for de novo synthesis did not. In a coculture system, abiraterone blocked H295R-induced growth of VCaP cells. In vivo, H295R promoted castration-resistant VCaP growth. Abiraterone only inhibited VCaP growth or PSA production in the presence of H295R. Plasma steroid levels demonstrated CYP17A1 inhibition by abiraterone, whilst CRPC tumour tissue steroid levels showed no evidence of de novo intratumoural androgen production. Castration-resistant and abiraterone-resistant VCaP tumours had increased levels of AR, AR variants and glucocorticoid receptor (GR) resulting in equal AR target gene expression levels compared to noncastrate tumours.

CONCLUSIONS

In our model, ligand-dependent AR-regulated regrowth of CRPC was predominantly supported via adrenal androgen precursor production while there was no evidence for intratumoural androgen synthesis. Abiraterone-resistant tumours relied on AR overexpression, expression of ligand-independent AR variants and GR signalling.

Pain and health-related quality of life with olaparib versus physician's choice of next-generation hormonal drug in patients with metastatic castration-resistant prostate cancer with homologous recombination repair gene alterations (PROfound): an open-label, randomised, phase 3 trial

BACKGROUND

The PROfound study showed significantly improved radiographical progression-free survival and overall survival in men with metastatic castration-resistant prostate cancer with alterations in homologous recombination repair genes and disease progression on a previous next-generation hormonal drug who received olaparib then those who received control. We aimed to assess pain and patient-centric health-related quality of life (HRQOL) measures in patients in the trial.

METHODS

In this open-label, randomised, phase 3 study, patients (aged ≥18 years) with metastatic castration-resistant prostate cancer and gene alterations to one of 15 genes (BRCA1, BRCA2, or ATM [cohort A] and BRIP1, BARD1, CDK12, CHEK1, CHEK2, FANCL, PALB2, PPP2R2A, RAD51B, RAD51C, RAD51D, and RAD54L [cohort B]) and disease progression after a previous next-generation hormonal drug were randomly assigned (2:1) to receive olaparib tablets (300 mg orally twice daily) or a control drug (enzalutamide tablets [160 mg orally once daily] or abiraterone tablets [1000 mg orally once daily] plus prednisone tablets [5 mg orally twice daily]), stratified by previous taxane use and measurable disease. The primary endpoint (radiographical progression-free survival in cohort A) has been previously reported. The prespecified secondary endpoints reported here are on pain, HRQOL, symptomatic skeletal-related events, and time to first opiate use for cancer-related pain in cohort A. Pain was assessed with the Brief Pain Inventory-Short Form, and HRQOL was assessed with the Functional Assessment of Cancer Therapy-Prostate (FACT-P). All endpoints were analysed in patients in cohort A by modified intention-to-treat. The study is registered with ClinicalTrials.gov, NCT02987543.

FINDINGS

Between Feb 6, 2017, and June 4, 2019, 245 patients were enrolled in cohort A and received study treatment (162 [66%] in the olaparib group and 83 [34%] in the control group). Median duration of follow-up at data cutoff in all patients was 6·2 months (IQR 2·2-10·4) for the olaparib group and 3·5 months (1·7-4·9) for the control group. In cohort A, median time to pain progression was significantly longer with olaparib than with control (median not reached [95% CI not reached-not reached] with olaparib vs 9·92 months [5·39-not reached] with control; HR 0·44 [95% CI 0·22-0·91]; p=0·019). Pain interference scores were also better in the olaparib group (difference in overall adjusted mean change from baseline score -0·85 [95% CI -1·31 to -0·39]; pnominal=0·0004). Median time to progression of pain severity was not reached in either group (95% CI not reached-not reached for both groups; HR 0·56 [95% CI 0·25-1·34]; pnominal=0·17). In patients who had not used opiates at baseline (113 in the olaparib group, 58 in the control group), median time to first opiate use for cancer-related pain was 18·0 months (95% CI 12·8-not reached) in the olaparib group versus 7·5 months (3·2-not reached) in the control group (HR 0·61; 95% CI 0·38-0·99; pnominal=0·044). The proportion of patients with clinically meaningful improvement in FACT-P total score during treatment was higher for the olaparib group than the control group: 15 (10%) of 152 evaluable patients had a response in the olaparib group compared with one (1%) of evaluable 77 patients in the control group (odds ratio 8·32 [95% CI 1·64-151·84]; pnominal=0·0065). Median time to first symptomatic skeletal-related event was not reached for either treatment group (olaparib group 95% CI not reached-not reached; control group 7·8-not reached; HR 0·37 [95% CI 0·20-0·70]; pnominal=0·0013).

INTERPRETATION

Olaparib was associated with reduced pain burden and better-preserved HRQOL compared with the two control drugs in men with metastatic castration-resistant prostate cancer and homologous recombination repair gene alterations who had disease progression after a previous next-generation hormonal drug. Our findings support the clinical benefit of improved radiographical progression-free survival and overall survival identified in PROfound.

FUNDING

AstraZeneca and Merck Sharp & Dohme.

Assessment and Management of Cognitive Function in Patients with Prostate Cancer Treated with Second-Generation Androgen Receptor Pathway Inhibitors

Preservation of cognitive function is an important outcome in oncology. Optimal patient management requires an understanding of cognitive effects of the disease and its treatment and an efficacious approach to assessment and management of cognitive dysfunction, including selection of treatments to minimize the risk of cognitive impairment. Awareness is increasing of the potentially detrimental effects of cancer-related cognitive dysfunction on functional independence and quality of life. Prostate cancer occurs most often in older men, who are more likely to develop cognitive dysfunction than younger individuals; this population may be particularly vulnerable to treatment-related cognitive disorders. Prompt identification of treatment-induced cognitive dysfunction is a crucial aspect of effective cancer management. We review the potential etiologies of cognitive decline in patients with prostate cancer, including the potential role of androgen receptor pathway inhibitors; commonly used tools for assessing cognitive function validated in metastatic castration-resistant prostate cancer and adopted in non-metastatic castration-resistant prostate cancer trials; and strategies for management of cognitive symptoms. Many methods are currently used to assess cognitive function. The prevalence and severity of cognitive dysfunction vary according to the instruments and criteria applied. Consensus on the definition of cognitive dysfunction and on the most appropriate approaches to quantify its extent and progression in patients treated for prostate cancer is lacking. Evidence-based guidance on the appropriate tools and time to assess cognitive function in patients with prostate cancer is required.

Androgen Receptor Targeted Therapy + Radiotherapy in Metastatic Castration Resistant Prostate Cancer

Objectives

To investigate whether radiotherapy as metastasis-directed therapy (MDT) on oligo-progressive sites in metastatic castration-resistant prostate cancer (mCRPC) patients during treatment with androgen receptor-targeted therapy (ARTT) may lead to control resistant lesions, prolonging ARTT. We analysed progression free survival, overall survival and prognostic parameters that can identify patients that best suit to this approach.

Patients and Methods

Retrospective analysis of a total of 67 lesions in 42 mCRPC patients treated with ablative or palliative RT to oligoprogressive lesions during ARTT. Twenty-eight patients (67%) underwent ARTT with Abiraterone acetate and 14 patients (33%) underwent ARTT with Enzalutamide. Median time between the start of ADT and ARTT beginning was 50.14 months (range 3.37-219 months). We treated 58 lesions (87%) with 3D conformal radiotherapy (3DCRT) and nine lesions (13%) with stereotactic body radiotherapy (SBRT). The Kaplan Meier method was used to assess the median overall survival (OS) and the progression-free survival (PFS).

Results

Median follow-up was 28 months (range 3-82 months). Median OS was 32.5 months (95% CI 25.77-39.16), 1 and 2-year OS were 71.6% and 64.1%, respectively. Median PFS was 19,8 months (95% CI 11.34–28.31), 1 and 2-year PFS were 67.2% and 47.4%, respectively. Median OS for patients that underwent radiotherapy before 6 months from the start of ARTT was 23.4 months (95% CI 2.04-44.89) and 45.5 months (95% CI 31.19-59.8) for patients that underwent radiotherapy after 6 months (p = 0.009).

Conclusion

Local ablative radiation therapy directed to progressive metastasis is a non-invasive, well tolerated treatment with efficacy on prolonging clinical benefit of systemic therapies with ARTT. Patients who underwent RT >6 months from the start of ARTT presented a statistically better OS and PFS compared with patients who underwent radiotherapy <6 months from the start of ARTT.

Predicting patient-specific response to adaptive therapy in metastatic castration-resistant prostate cancer using prostate-specific antigen dynamics

Abiraterone acetate (AA) has been proven effective for metastatic castration-resistant prostate cancer (mCRPC), and it has been proposed that adaptive AA may reduce toxicity and prolong time to progression, when compared to continuous AA. We developed a simple quantitative model of prostate-specific antigen (PSA) dynamics to evaluate prostate cancer (PCa) stem cell enrichment as a plausible driver of AA treatment resistance. The model incorporated PCa stem cells, non-stem PCa cells and PSA dynamics during adaptive therapy. A leave-one-out analysis was used to calibrate and validate the model against longitudinal PSA data from 16 mCRPC patients receiving adaptive AA in a pilot clinical study. Early PSA treatment response dynamics were used to predict patient response to subsequent treatment. We extended the model to incorporate metastatic burden and also investigated the survival benefit of adding concurrent chemotherapy for patients predicted to become resistant. Model simulations demonstrated PCa stem cell self-renewal as a plausible driver of resistance to adaptive therapy. Evolutionary dynamics from individual treatment cycles combined with metastatic burden measurements predicted patient response with 81% accuracy (specificity=92%, sensitivity=50%). In those patients predicted to progress, simulations of the addition of concurrent chemotherapy suggest a benefit between 1% and 11% reduction in probability of progression when compared to adaptive AA alone. This study developed the first mCRPC patient-specific mathematical model to use early PSA treatment response dynamics to predict subsequent responses to adaptive AA, demonstrating the putative value of integrating mathematical modeling into clinical decision making.

Bone health management in the continuum of prostate cancer disease: a review of the evidence with an expert panel opinion

Bone health impairment is a frequent detrimental consequence of the high bone tropism of prostate cancer (PCa) cells. It is further worsened by administration of androgen-deprivation therapy (ADT), the current standard of care in the management of advanced PCa, through a rapid and dramatic increase in bone turnover and body mass changes. As a result, patients may experience substantial pain and poor quality of life (QoL) and have an increased risk of death. Notwithstanding the importance of this issue, however, bone health preservation is not yet a widespread clinical goal in daily practice.

To address this urgent unmet need, following a thorough discussion of available data and sharing of their clinical practice experience, a panel of Italian experts in the field of bone health and metabolism formulated a number of practical advices for optimising the monitoring and treatment of bone health in men undergoing ADT during all phases of the disease. The rationale behind the venture was to raise awareness on the importance of bone preservation in this complex setting, while providing an instrument to support physicians and facilitate the management of bone health.

Current evidence regarding the effects on bone health of ADT, of novel hormone therapies (which improve progression delay, pain control and QoL while consistently carrying the risk of non-pathological fractures in both non-metastatic and metastatic PCa) and of bone turnover inhibitors (whose use is frequently suboptimal) is reviewed. Finally, the expert opinion to optimise bone health preservation is given.

Recent Development and Future Prospects of Molecular Targeted Therapy in Prostate Cancer

Prostate cancer (PC) is a rapidly increasing ailment worldwide. The previous decade has observed a rapid advancement in PC therapies that was evident from the number of FDA approvals during this phase. Androgen deprivation therapies (ADT) have traditionally remained a mainstay for the management of PCs, but the past decade has experienced the emergence of newer classes of drugs that can be used with or without the administration of ADT. FDA approved poly (ADP-ribose) polymerase inhibitors (PARPi), such as olaparib and rucaparib, after successful clinical trials against gene-mutated metastatic castration-resistant prostate cancer. Furthermore, drugs like apalutamide, darolutamide, and enzalutamide with an androgen-targeted mechanism of action have manifested superior results in non-metastatic castration-resistant prostate cancer (nmCRPC), metastatic castration-sensitive prostate cancer (mCSPC), and metastatic castration-resistant prostate cancer (mCRPC), respectively, with or without previously administered docetaxel. Relugolix, an oral gonadotropin-releasing hormone antagonist, and a combination of abiraterone acetate plus prednisone were also approved by FDA after a successful trial in advanced PC and mCRPC, respectively. This review aims to analyze the FDA-approved agents in PC during the last decade and provide a summary of their clinical trials. It also presents an overview of the ongoing progress of prospective molecules still under trial.

Cost-effectiveness analysis of enzalutamide for patients with chemotherapy-naïve metastatic castration-resistant prostate cancer in Japan

Background

We aimed to evaluate cost-effectiveness of enzalutamide in chemotherapy-naïve metastatic castration-resistant prostate cancer patients in Japan.

Methods

A Markov model was developed to capture time spent by patients in various health states: stable, progression and death. Abiraterone acetate and docetaxel were set as active comparators. Clinical outcomes were obtained from the PREVAIL, COU-AA-302 and TAX327 trials. Treatment sequence, concomitant drugs and therapies for adverse events were estimated from responses to a survey by 14 Japanese prostate cancer experts. The analytic perspective was public healthcare payer, with a 10-year time horizon. The incremental cost-effectiveness ratio was estimated from quality-adjusted life-years and Japanese public healthcare costs. Probabilistic sensitivity analysis was performed to assess the robustness of the findings.

Results

According to the survey, the most common treatment sequences were (i) enzalutamide → docetaxel → cabazitaxel (enzalutamide-first sequencing), (ii) abiraterone → enzalutamide → docetaxel (abiraterone-first sequencing) and (iii) docetaxel→ enzalutamide → cabazitaxel (docetaxel-first sequencing). In the base-case analysis, enzalutamide-first sequencing saved 1.74 million Japanese Yen versus abiraterone-first sequencing, with a 0.129 quality-adjusted life-year gain (dominant). Enzalutamide-first sequencing had a cost increase of 4.44 million Japanese Yen over docetaxel-first sequencing, with a 0.371 quality-adjusted life-years gain. The incremental cost-effectiveness ratio of enzalutamide-first sequencing versus docetaxel-first sequencing was estimated as 11.94 million Japanese Yen/quality-adjusted life-years. Probabilistic sensitivity analyses demonstrated that, compared with abiraterone-first sequencing, enzalutamide-first sequencing had an 87.4% probability of being dominant.

Conclusions

Results modeled herein suggest that the enzalutamide-first sequencing is more cost-effective than the abiraterone-first sequencing, but less cost-effective than docetaxel-first sequencing for chemotherapy-naïve patients with metastatic castration-resistant prostate cancer.

Serum testosterone levels and testosterone 'bounce' phenomenon predict response to novel anti-androgen therapies in castration-resistant prostate cancer

BACKGROUND

The relevance of continuous testosterone (TT) monitoring in castration-resistant prostate cancer (CRPC) remains in question.

OBJECTIVE

To determine if TT levels before and during novel anti-androgen therapies (NAAT), and the TT 'bounce' phenomenon may predict treatment response in CRPC.

MATERIALS AND METHODS

From 2014 through 2018, we identified 92 CRPC patients treated with either Abiraterone or Enzalutamide from a prospectively maintained cancer registry. The TT levels measured before and during NAAT were correlated with the oncological outcomes, determined by PSA response (% change), PSA progression-free survival (PFS) and overall survival (OS).

RESULTS AND LIMITATIONS

At CRPC, 58 (63.0%) and 34 (37.0%) patients opted for Abiraterone and Enzalutamide respectively. Median TT levels at CRPC status before and during NAAT were 10.37 ng/dl and 20.46 ng/dl respectively. PSA response was superior in patients with a higher TT before NAAT (P:0.048, median difference: 18.22%, 95% CI 0.70 - 40.37) and longer time to CRPC (P: 0.041, median difference: 15.31%, 95% CI 1.84 -34.84), with a trend towards lower TT during NAAT (P: 0.062). Over a follow up of 33.0 months, 65 patients (70.7%) developed PSA progression. PSA PFS was longer in patients with higher TT before NAAT (16.3 vs. 10.8 months; P: 0.023), lower TT during NAAT (17.0 vs. 9.1 months; P: 0.001), and longer time to CRPC (13.4 vs. 8.0 months; P: 0.032). Importantly, better OS was observed in lower TT during NAAT (45.0 vs. 33.0 months; P:0.029) and longer time to CRPC (43.0 vs. 31.0 months; P: 0.025). The TT 'bounce' phenomenon was observed in 28 patients (33.3%), and was associated with a poorer PSA response (P: 0.029, median difference: 18.90%, 95% CI 3.83 - 41.45), shorter PSA PFS (8.6 vs 15.2 months, P: 0.002) and shorter OS (29.0 vs. 45.0 months, P: 0.012).

CONCLUSION

In CRPC patients, TT behaviors before and during NAAT, and the 'bounce' phenomenon continue to predict treatment response and could guide clinical decisions.

Quality of life in men with metastatic castration-resistant prostate cancer treated with enzalutamide or abiraterone: a systematic review and meta-analysis

BACKGROUND

Enzalutamide and abiraterone acetate plus prednisone (AAP) have similar efficacy in metastatic castration-resistant prostate cancer (mCRPC), but different mechanisms of action. The aim was to compare patient-reported health-related quality of life (HRQoL) in men treated with enzalutamide vs AAP for mCRPC.

METHODS

We systematically reviewed the literature in June 2020 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Patient-reported outcomes (PROs) until the last follow-up were summarised in a narrative synthesis. Short-term changes (12 weeks) in HRQoL, measured by the Functional Assessment of Cancer Therapy-Prostate total score (FACT-P), were compared between treatment groups and were analysed for enzalutamide and AAP in separate meta-analyses. Higher FACT-P scores indicate better HRQoL.

RESULTS

Eight studies were included in the systematic review, four of which were randomised clinical trials (RCTs) eligible for the meta-analyses. The meta-analyses showed mean within-subject FACT-P changes from baseline to week 12 of -1.3 points (95% confidence interval [CI] -2.7; 0.1) for enzalutamide and 4.7 points (95% CI -0.1; 9.6) for AAP. One RCT and three non-randomised studies directly compared enzalutamide with AAP. The RCT showed better short-term HRQoL for AAP (6.8 FACT-P-points, 95% CI 1.7; 11.8) and better long-term HRQoL for AAP in men ≥75 years (7.35 FACT-P-points, 95% CI 2.59; 12.11). The non-randomised studies showed no difference in long-term HRQoL but had all a serious risk of bias. Limitations of the included studies include that the PRO in the included trials were inconsistently reported and that only one study defined the HRQoL measures in their published protocol.

CONCLUSIONS

AAP seems to be associated with better short-term HRQoL than enzalutamide. This difference was not apparent at longer follow-up, but the long-term studies had serious risks of bias.

Pulmonary metastasectomy in germ cell tumors and prostate cancer

Pulmonary oligo-metastases and oligo-recurrences are terms used to define a set of clinical conditions consisting of limited metastatic malignant disease characterized by an intermediate aggressive behavior compared to diffuse metastatic conditions. If the primary tumor has been controlled and extra-thoracic lesions are excluded, there is a suggestion in the medical literature that removal of such lesions could potentially prolong survival. The lungs are a common metastatic spreading site, especially from epithelial malignancies and sarcomas; pulmonary surgical or interventional metastasectomy have been proposed with curative intent in case of limited tumor load (usually less than 5 lesions). There are many series reporting data about colorectal, renal or breast lung metastasectomy, but the absence of multi centric prospective trials determines a lack of definitive evidence, especially for less common tumors such as metastatic germ cell and prostate cancer. They rarely present in the oligo-metastatic form and their management is often based on personal experience. The aim of our article is to review the latest evidence in the treatment of pulmonary metastatic germ cell and prostate tumors. We cover the full range of treatments: from surgery to ablative radiotherapy and combination of local and systemic therapy. Despite the absence of evidence based guidelines, it emerges that pulmonary metastasectomy should always be considered when general criteria for resection have been met. In germ cell tumors surgery should be mainly reserved for residual disease after chemotherapy, whereas in prostate cancer, pulmonary metastasectomy should be preferred to avoid or delay hormonal deprivation therapy and its side effects.

Survival outcomes in patients with chemotherapy-naive metastatic castration-resistant prostate cancer treated with enzalutamide or abiraterone acetate

Objective

Evaluation of the comparative effectiveness of enzalutamide and abiraterone in patients with metastatic castration-resistant prostate cancer (mCRPC) is limited to meta-analyses of randomized trials that exclude patients with significant comorbidities. We evaluated overall survival (OS) in patients with chemotherapy-naive mCRPC treated with enzalutamide or abiraterone acetate (abiraterone) in a real-world single payer setting.

Methods

A retrospective analysis (4/1/2014–3/31/2018) of the Veterans Health Administration (VHA) database was conducted. Patients with mCRPC had ≥1 pharmacy claim for enzalutamide or abiraterone (first claim date = index date) following disease progression on surgical/medical castration, without chemotherapy <12 months prior to index date. Patients had continuous VHA enrollment for ≥12 months pre-index date and were followed until death, disenrollment, or end of study. Kaplan–Meier analysis and multivariable Cox proportional hazards regression models examined the OS treatment effect.

Results

Patients with chemotherapy-naive mCRPC (N = 3174; enzalutamide, n = 1229; abiraterone, n = 1945) had mean ages of 74 and 73 years, respectively. Median follow-up was 18.27 and 19.07 months with enzalutamide and abiraterone, respectively. Enzalutamide-treated patients had longer median treatment duration than abiraterone-treated patients (9.93 vs 8.47 months, respectively, p = 0.0008). After baseline comorbidity adjustment, enzalutamide-treated patients had a 16% reduced risk of death (hazard ratio [HR] = 0.84; 95% CI, 0.76–0.94; p = 0.0012). For patients who remained on first line-therapy only, enzalutamide-treated patients had improved OS versus abiraterone-treated patients (HR = 0.71; 95% CI, 0.62–0.82). Enzalutamide-treated patients who crossed over to abiraterone had a comparable risk of death versus abiraterone-treated patients who crossed over to enzalutamide (HR = 1.10; 95% CI, 0.89–1.35). These results were confirmed by sensitivity analysis, which considered prognostic variables.

Conclusions

Retrospective analysis of the VHA database indicated that chemotherapy-naive patients with mCRPC initiating therapy with enzalutamide had improved survival versus abiraterone.

A Phase 2 Trial of Abiraterone Followed by Randomization to Addition of Dasatinib or Sunitinib in Men With Metastatic Castration-Resistant Prostate Cancer

BACKGROUND

Resistance to novel androgen signaling inhibition and metastatic castration-resistant prostate cancer (mCRPC) progression is likely dependent on tumor microenvironment interactions. The Src pathway and neoangiogenesis have been implicated in prostate cancer progression. We studied the effect of adding the targeted agents dasatinib and sunitinib to abiraterone acetate (AA) in men with mCRPC.

PATIENTS AND METHODS

In this open-label randomized phase 2 study, mCRPC patients received AA. At resistance to AA, they were randomized 1:1 to combination with dasatinib or sunitinib. At second progression, patients crossed over. The primary end point was time to treatment failure (TTF), defined as time to progression or death. Secondary end points included overall survival and safety.

RESULTS

From March 2011 to February 2015, a total of 179 patients were enrolled and 132 subsequently randomized. Median TTF was 5.7 months in the dasatinib group and 5.5 months in the sunitinib group. There was no difference between the two groups in terms of TTF (hazard ratio, 0.85; 95% confidence interval, 0.59-1.22). Median overall survival from study entry was 26.3 months in the dasatinib group and 27.7 months in the sunitinib group (hazard ratio, 1.02; 95% confidence interval, 0.71-1.47). Grade 3 or higher adverse events related to study medication were more frequent with sunitinib (n = 44, 46%) compared to dasatinib (n = 26, 24%). At data cutoff, 7 patients were experiencing a continuous response to AA, with a median duration of treatment of 5.7 years.

CONCLUSION

There is no difference in overall survival and TTF between dasatinib and sunitinib combined with abiraterone in the treatment of patients with bone mCRPC.

Overall Survival Among Chemotherapy-Naive Patients With Castration-Resistant Prostate Cancer Under Abiraterone Versus Enzalutamide: A Direct Comparison Based on a 2014-2018 French Population Study (the SPEAR Cohort)

Abiraterone acetate (ABI) and enzalutamide (ENZ) are considered to be clinically relevant comparators among chemotherapy-naive patients with castration-resistant prostate cancer. No clinical trials comparing overall survival with ABI versus ENZ in a head-to-head approach have been published so far. A few observational studies with low power suggested a potential benefit of ENZ. We used the French National Health Data System to compare overall survival of new users of ABI and ENZ among chemotherapy-naive patients with castration-resistant prostate cancer in 2014-2017, followed through 2018 (the SPEAR cohort, a 2014-2018 cohort study). With an intent-to-treat approach, a survival analysis was performed, estimating hazard ratios for overall survival with the inverse probability weighted Cox model method. Among 10,308 new users, 64% were treated with ABI and 36% with ENZ. The crude mortality rate was 25.2 per 100 person-years (95% confidence interval (CI): 24.4, 26.0) for ABI and 23.7 per 100 person-years (95% CI: 22.6, 24.9) for ENZ. In the weighted analysis, ENZ was associated with better overall survival compared with ABI (hazard ratio = 0.90 (95% CI: 0.85, 0.96) with a median overall survival of 31.7 months for ABI and 34.2 months for ENZ). When restricting to 2015-2017 new users, the effect estimate shifted up to a hazard ratio of 0.93 (95% CI: 0.86, 1.01).

Can local treatment prolong the sensitivity of metastatic prostate cancer to androgen deprivation or even prevent castration resistance?

Purpose

A number of observational clinical studies suggest that prior primary tumor treatment favorably influences the course of metastatic prostate cancer (PCa), but its mechanisms of action are still speculative. Here, we describe the long-lasting sensitivity to various forms of androgen deprivation in patients after radical prostatectomy (RP) for locally advanced PCa as one potential mechanism.

Methods

A consecutive series of 115 radical prostatectomies after inductive therapy for T4 prostate cancer was re-analyzed, and long-term survival, as well as recurrence patterns and responses to different forms of hormonal manipulation, were assessed.

Results

The estimated biochemical response-free, PCa-specific, and overall survival rates after 200 months were 20%, 65%, and 47% with a median overall survival of 156 months. The majority of patients, although not cured of locally advanced PCa (84/115), showed long-term survival after RP. PCa-specific and overall survival rates of these 84 patients with biochemical recurrence were 61% and 44% at 150 months. Long-term sensitivity to ADT was found to be the main reason for the favorable tumor-specific survival in spite of biochemical recurrence.

Conclusions

Sensitivity to primary or secondary hormonal manipulation was the main reason for the long-term survival of patients who had not been cured by surgery only. The results suggest that treatment of the primary tumor-bearing prostate delays castration-resistant PCa and enhances the effect of hormonal therapies in a previously unknown manner. The underlying cellular and molecular mechanisms need to be explored in more detailed analyses, which could profoundly impact treatment concepts of locally advanced and metastatic PCa.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-020-03568-3.

Sequential Docetaxel in ≥7 Cycles Followed by Cabazitaxel Improves Oncological Outcomes in Patients with Metastatic Castration-Resistant Prostate Cancer

Background. Docetaxel (DOC) was the first regimen that increased the survival and became the standard-of-care in patients with metastatic castration-resistant prostate cancer (mCRPC). However, it is unclear whether switching to second-line chemotherapy or optimal sequencing of cabazitaxel (CBZ) ensures better clinical outcomes. We aimed to evaluate the efficacy of sequential therapy with DOC and CBZ and the effect of the number of prior DOC cycles on oncological outcomes in patients with mCRPC. Methods. We retrospectively included 46 mCRPC patients who received DOC followed by CBZ at quaternary hospitals in Japan between February 2015 and March 2019. Participants received intravenous DOC (40–75 mg/m2) every 3–4 weeks; CBZ (15–25 mg/m2) was administered every 3–4 weeks. Androgen-deprivation therapy and prednisolone 5 mg (twice daily) were administered throughout both regimens. The primary endpoints were overall (OS) and progression-free survival (PFS). The secondary endpoints were the rates of ≥30% and ≥50% reduction in prostate-specific antigen (PSA) levels at chemotherapy initiation. Results. Participants were divided into two groups according to DOC cycles (Groups A and B: ≤6 and ≥7 DOC cycles, respectively). The rates of ≥30% and ≥50% reduction in PSA levels were higher in Group B than in Group A, but there were no significant differences in both groups. Median OS in Groups A and B was 12.7 and 71.0 months, respectively $\left(P<0.001\right)$ ; median PFS in Groups A and B was 3 and 12 months, respectively $\left(P<0.001\right)$ . Conclusions. Administration of ≥7 cycles of DOC followed by CBZ may improve oncological outcomes in patients with mCRPC.

Effects of abiraterone acetate plus prednisone on bone turnover markers in chemotherapy-naïve mCRPC patients after ADT failure: A prospective analysis of the italian real-world study ABITUDE

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Bone remodeling is disrupted in metastatic disease, affecting > 70% of mCRPC men.

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In metastatic disease, abnormal levels of specific BTMs are released.

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We prospectively measured four BTMs markers in chemotherapy-naïve mCRPC men on AAP therapy.

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AAP seems to act on the microenvironment of metastatic but not of normal bone.

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This action likely contributes to the antitumoral activity of AAP.

Background

Bone remodeling is disrupted in metastatic disease, which affects > 70% of metastatic castration-resistant prostate cancer (mCRPC) patients. As a result, abnormal levels of specific bone turnover biomarkers (BTMs) are released. In this prospective ancillary analysis of the Italian real-world study ABITUDE, four markers were measured during abiraterone acetate plus prednisone (AAP) treatment in chemotherapy-naïve mCRPC men failing androgen-deprivation therapy.

Methods

Patients were enrolled if a blood sample was obtained before the first administration of abiraterone (baseline); ad-hoc blood samples were withdrawn during routine tests after 3, 6, and 12 months. A centralized lab measured bone alkaline phosphatase (BALP, osteoblast activity marker), type-I collagen-C-telopeptide (CTX-1, bone resorption marker), parathyroid hormone (PTH) and vitamin D (vitD). At each time point, intra-patient variations vs baseline were compared by the signed-rank test (statistical significance: P-value < 0.05).

Results

Of 481 patients enrolled in ABITUDE, 186 (median age: 76 [range: 53–93] years) met the substudy criteria: 74.7% had bone metastases, 11.8% were on bone-targeted therapies (BTT) and 14.0% on vitD supplementation. BALP decreased significantly at month 6 (P = 0.0010) and 12 (P < 0.0001) and CTX-1 at month 6 (P = 0.0028); PTH increased at month 3 (P < 0.0001); no significant difference in vitD levels was observed. Similar findings were observed in BTT-untreated patients. The reduction in BALP and CTX-1 levels was more pronounced in patients with than without bone metastases; in the latter group, no significant variation in BALP and CTX-1 levels was observed.

Conclusions

AAP seems to exert an effect on the microenvironment of metastatic but not of normal bone, which likely contributes to its antitumoral activity.

Effectiveness of abiraterone acetate plus prednisone in chemotherapy-naïve patients with metastatic castration-resistant prostate cancer in a large prospective real-world cohort: the ABItude study

Background:

Real-world data on chemotherapy-naïve patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone plus prednisone are limited, largely deriving from small retrospective studies.

Methods:

ABitude is an Italian, observational, prospective, multicenter study of mCRPC patients receiving abiraterone plus prednisone in clinical practice. Chemotherapy-naïve mCRPC patients were consecutively enrolled at abiraterone start (February 2016 to June 2017) and are being followed for 3 years, with evaluation approximately every 6 months. Several clinical and patients reported outcomes were examined.

Results:

In this second interim analysis, among 481 enrolled patients, 453 were evaluable for analyses. At baseline, the median age was 77 years and ~69% of patients had comorbidities (mainly cardiovascular diseases). Metastases were located mainly at bones and lymph nodes; 8.4% of patients had visceral metastases. During a median follow-up of 18 months, 1- and 2-year probability of radiographic progression-free survival were 73.9% and 56.2%, respectively; the corresponding rates for overall survival were 87.3% and 70.4%. In multivariable analyses, the number of bone metastases significantly affected radiographic progression-free survival and overall survival. During abiraterone plus prednisone treatment, 65% of patients had a ⩾50% prostate-specific antigen decline, and quality of life remained appreciably high. Among symptomatic patients according to the Brief Pain Inventory) (32%), scores significantly declined after 6 months of treatment. Overall, eight patients (1.7%) had serious adverse reactions to abiraterone.

Conclusions:

Abiraterone plus prednisone is effective and safe for chemotherapy-naïve mCRPC patients in clinical practice.

EAU-EANM-ESTRO-ESUR-SIOG Guidelines on Prostate Cancer. Part II-2020 Update: Treatment of Relapsing and Metastatic Prostate Cancer

OBJECTIVE

To present a summary of the 2020 version of the European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy & Oncology (ESTRO)-European Society of Urogenital Radiology (ESUR)-International Society of Geriatric Oncology (SIOG) guidelines on the treatment of relapsing, metastatic, and castration-resistant prostate cancer (CRPC).

EVIDENCE ACQUISITION

The working panel performed a literature review of the new data (2016-2019). The guidelines were updated, and the levels of evidence and/or grades of recommendation were added based on a systematic review of the literature.

EVIDENCE SYNTHESIS

Prostate-specific membrane antigen positron emission tomography computed tomography scanning has developed an increasingly important role in men with biochemical recurrence after local therapy. Early salvage radiotherapy after radical prostatectomy appears as effective as adjuvant radiotherapy and, in a subset of patients, should be combined with androgen deprivation. New treatments have become available for men with metastatic hormone-sensitive prostate cancer (PCa), nonmetastatic CRPC, and metastatic CRPC, along with a role for local radiotherapy in men with low-volume metastatic hormone-sensitive PCa. Also included is information on quality of life outcomes in men with PCa.

CONCLUSIONS

The knowledge in the field of advanced and metastatic PCa and CRPC is changing rapidly. The 2020 EAU-EANM-ESTRO-ESUR-SIOG guidelines on PCa summarise the most recent findings and advice for use in clinical practice. These PCa guidelines are first endorsed by the EANM and reflect the multidisciplinary nature of PCa management. A full version is available from the EAU office or online (http://uroweb.org/guideline/prostate-cancer/).

PATIENT SUMMARY

This article summarises the guidelines for the treatment of relapsing, metastatic, and castration-resistant prostate cancer. These guidelines are evidence based and guide the clinician in the discussion with the patient on the treatment decisions to be taken. These guidelines are updated every year; this summary spans the 2017-2020 period of new evidence.

Efficacy of cabazitaxel and the influence of clinical factors on the overall survival of patients with castration-resistant prostate cancer: A local experience of a multicenter retrospective study

AIM

To date, the optimal sequencing of life-prolonging therapies for patients with metastatic castration-resistant prostate cancer (mCRPC) remains unclear owing to a lack of prospective trials. This study aimed to evaluate the efficacy and safety of cabazitaxel (CBZ) treatment and examine the prognostic factors for oncological outcomes in patients with mCRPC who received CBZ after docetaxel (DOC).

METHODS

This multi-institutional retrospective study included 44 patients with mCRPC who received CBZ. All enrolled patients had histologically confirmed prostate cancer (PCa) with distant metastases and had received DOC before CBZ administration. The primary endpoint was the oncological outcomes, including the overall (OS) and progression-free survival (PFS). The secondary endpoints were adverse events due to CBZ and rates of ≥30% reduction in prostate-specific antigen (PSA) levels.

RESULTS

The median follow-up period was 9.2 months (range, 0.2-34 months). During this time, 34 patients (77%) died of PCa. The median OS and PFS were 12.2 (range, 0.2-34 months) and 1.4 months (range, 0.4-17 months), respectively. According to the PSA decline rate, patients who achieved a ≥30% reduction in PSA levels had significantly longer OS than those who showed a <30% reduction in PSA levels (P = 0.002). Regarding the number of cycles of CBZ, patients who received ≥4 cycles of CBZ showed significantly longer OS than those who received <4 cycles of CBZ (P < 0.001). Patients who had visceral metastasis showed significantly shorter OS than those without visceral metastasis (P = 0.012).

CONCLUSION

This study demonstrated that CBZ was effective and safe in Japanese local patients in a real-world setting. Patients with mCRPC who received ≥4 cycles of CBZ showed a ≥30% reduction in the serum PSA levels, and did not have visceral metastasis might achieve longer OS.

Apalutamide and Overall Survival in Prostate Cancer

BACKGROUND

The phase 3 SPARTAN study evaluated apalutamide versus placebo in patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) and prostate-specific antigen doubling time of ≤10 mo. At primary analysis, apalutamide improved median metastasis-free survival (MFS) by 2 yr and overall survival (OS) data were immature.

OBJECTIVE

We report the prespecified event-driven final analysis for OS.

DESIGN, SETTING, AND PARTICIPANTS

A total of 1207 patients with nmCRPC (diagnosed by conventional imaging) were randomised 2:1 to apalutamide (240mg/d) or placebo, plus on-going androgen deprivation therapy. After MFS was met and the study was unblinded, 76 (19%) patients still receiving placebo crossed over to apalutamide.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

OS and time to cytotoxic chemotherapy (TTChemo) were analysed by group-sequential testing with O'Brien-Fleming-type alpha spending function.

RESULTS AND LIMITATIONS

At median 52-mo follow-up, 428 deaths had occurred. The median treatment duration was 32.9 mo for apalutamide group and 11.5 mo for placebo group. Median OS was markedly longer with apalutamide versus placebo, reaching prespecified statistical significance (73.9 vs 59.9 mo, hazard ratio [HR]: 0.78 [95% confidence interval {CI}, 0.64-0.96]; p=0.016). Apalutamide also lengthened TTChemo versus placebo (HR: 0.63 [95% CI, 0.49-0.81]; p=0.0002). Discontinuation rates in apalutamide and placebo groups due to progressive disease were 43% and 74%, and due to adverse events 15% and 8.4%, respectively. Subsequent life-prolonging therapy was received by 371 (46%) patients in the apalutamide arm and by 338 (84%) patients in the placebo arm including 59 patients who received apalutamide after crossover. Safety was consistent with previous reports; when adverse events were adjusted for treatment exposure, rash had the greatest difference of incidence between the apalutamide and placebo groups.

CONCLUSIONS

Extension of OS with apalutamide compared with placebo conferred impactful benefit in patients with nmCRPC. There was a 22% reduction in the hazard of death in the apalutamide group despite 19% crossover (placebo to apalutamide) and higher rates of subsequent therapy in the placebo group.

PATIENT SUMMARY

With data presented herein, all primary and secondary study end points of SPARTAN were met; findings demonstrate the value of apalutamide as a treatment option for nonmetastatic castration-resistant prostate cancer.

Efficacy and safety of abiraterone acetate plus prednisone in Japanese patients with newly diagnosed, metastatic hormone-naive prostate cancer: final subgroup analysis of LATITUDE, a randomized, double-blind, placebo-controlled, phase 3 study

Background

LATITUDE was a randomized, double-blind, international and phase 3 study of abiraterone acetate plus prednisone in patients with high-risk metastatic hormone-naïve prostate cancer. In the first interim analysis of LATITUDE (clinical cutoff date: 31 October 2016), significant prolongation in overall survival and radiographic progression-free survival (co-primary endpoints) was observed when compared with placebo. The results of the Japanese subgroup analysis of LATITUDE first interim analysis were consistent with those of the overall population. In this study, overall survival and safety results from the final analysis of the Japanese subgroup of the LATITUDE study are presented (clinical cutoff date: 15 August 2018).

Methods

Abiraterone acetate (1000 mg/day) and prednisone (5 mg/day) were administered orally in the abiraterone acetate plus prednisone group, and matching placebos in the placebo group.

Results

Of the 1199 patients included in LATITUDE, 70 constituted the Japanese subgroup (abiraterone acetate plus prednisone: n = 35, placebo: n = 35). Following a median (range) follow-up of 56.6 (2.5, 64.2) months, the median overall survival was not reached in both the treatment arms of the Japanese subgroup (hazard ratio: 0.61; 95% confidence interval: 0.27–1.42; nominal P = 0.2502). A total of 23 deaths (abiraterone acetate plus prednisone: 9 [25.7%], placebo group: 14 [40.0%]) were reported in Japanese subgroup. Grade 3/4 adverse events were reported in 24 (68.6%) and 9 (25.7%) patients in the abiraterone acetate plus prednisone and placebo groups, respectively.

Conclusions

In this Japanese subgroup analysis, addition of abiraterone acetate plus prednisone to androgen-deprivation therapy demonstrated favorable efficacy and safety outcomes in patients with newly diagnosed, high-risk metastatic hormone-naïve prostate cancer. Survival benefits observed in the Japanese subgroup first interim analysis were sustained long-term and were consistent with the overall population.

Pharmacokinetics, Safety, and Antitumor Effect of Apalutamide with Abiraterone Acetate plus Prednisone in Metastatic Castration-Resistant Prostate Cancer: Phase Ib Study

PURPOSE

Apalutamide is a next-generation androgen receptor (AR) inhibitor approved for patients with nonmetastatic castration-resistant prostate cancer (CRPC) and metastatic castration-sensitive prostate cancer. We evaluated the pharmacokinetics, safety, and antitumor activity of apalutamide combined with abiraterone acetate plus prednisone (AA-P) in patients with metastatic CRPC (mCRPC).

PATIENTS AND METHODS

Multicenter, open-label, phase Ib drug-drug interaction study conducted in 57 patients with mCRPC treated with 1,000 mg abiraterone acetate plus 10 mg prednisone daily beginning on cycle 1 day 1 (C1D1) and 240 mg apalutamide daily starting on C1D8 in 28-day cycles. Serial blood samples for pharmacokinetic analysis were collected on C1D7 and C2D8.

RESULTS

Systemic exposure to abiraterone, prednisone, and prednisolone decreased 14%, 61%, and 42%, respectively, when apalutamide was coadministered with AA-P. No increase in mineralocorticoid excess-related adverse events was observed. Patients without prior exposure to AR signaling inhibitors had longer median treatment duration and greater mean decrease in prostate-specific antigen (PSA) from baseline compared with those who had received prior therapy. Confirmed PSA reductions of ≥50% from baseline at any time were observed in 80% (12/15) of AR signaling inhibitor-naïve patients and 14% (6/42) of AR signaling inhibitor-treated patients.

CONCLUSIONS

Treatment with apalutamide plus AA-P was well tolerated and showed evidence of antitumor activity in patients with mCRPC, including those with disease progression on AR signaling inhibitors. No clinically significant pharmacokinetic interaction was observed between abiraterone and apalutamide; however, apalutamide decreased exposure to prednisone. These data support development of 1,000 mg abiraterone acetate plus 10 mg prednisone daily with 240 mg apalutamide daily in patients with mCRPC.

Abiraterone acetate in combination with prednisone in the treatment of prostate cancer: safety and efficacy

INTRODUCTION

Metastatic prostate cancer is a life-threatening disease and an important public health concern with prevalence rates varying drastically between high- and low-income countries. Androgen-deprivation therapy alone has been the first-line treatment option for decades, temporarily controlling disease until invariable tumor regression. At the castration-resistant stage, metastatic disease becomes lethal. In recent years several new treatments, including second-generation hormone therapies, have proven to be life-prolonging in metastatic castration-resistant prostate cancer, and at an earlier hormone-sensitive stage. Abiraterone acetate in combination with prednisone was the first approved hormone therapy demonstrating survival benefit, and represents, to date, an alternative, or a second-line treatment after taxane-based chemotherapy, in addition to androgen-deprivation therapy, in hormone sensitive, and metastatic castration-resistant prostate cancer.

AREA COVERED

We performed a literature review of papers from 2012 to 2020 using PubMed, Web of Science, and Embase searching for the safety and efficacy of abiraterone acetate in prostate cancer management. Search results were limited to phase III-IV trials and post hoc analysis of Phase III trials evaluated Abiraterone acetate in the English language.

EXPERT OPINION

This literature review confirms the role of abiraterone acetate in the therapeutic landscape with well-proven safety and efficacy, demonstrated in trials and post-approval studies.

Hormonal prostate cancer therapies and cardiovascular disease: a systematic review

Therapeutic intervention for prostate cancer mostly relies on eliminating circulating androgen or antagonizing its effect at the cellular level. As the use of endocrine therapies grows, an under-reported incidence of cardiovascular toxicities occurs in prostate cancer patients. In this review, we summarize data of clinical studies, investigating the cardiovascular and metabolic alterations associated with the use of old and new endocrine drugs (gonadotropin-releasing hormone [GnRH] agonists and antagonists, androgen receptor inhibitors, 17α-hydroxylase/c-17,20-lyase [CYP17] inhibitor) in prostate cancer. To date, studies looking for links between cardiovascular complications and hormone-mediated therapies in prostate cancer have reached conflicting results. Several confounding factors, such as age of patients and related cardiovascular liability, other comorbidities, and use of concomitant drugs, have to be carefully evaluated in future clinical trials. Further research is needed given the continuous advancements being made in prostate cancer treatment.

Metastasis-directed therapy in castration-refractory prostate cancer (MEDCARE): a non-randomized phase 2 trial

Background

Patients diagnosed with metastatic castration-refractory prostate cancer (mCRPC) rely on a limited number of therapeutic agents resulting in a median survival of 2–3 years. A subgroup of those patients with mCRPC presents with oligoprogressive disease, with a limited number of progressive lesions while other metastases are still controlled by ongoing systemic treatment.

Methods

In this single arm prospective phase II trial, we aim to include 18 patients with oligoprogressive mCRPC (1–3 metastases and/or local recurrence) who will be treated with metastasis-directed therapy to all visible progressive lesions. Progression is based on conventional imaging, as the use of PSMA PET-CT is considered investigational. However all patients will undergo PSMA PET-CT and the images will be blinded until progression. Primary endpoint is the postponement of the start of next-line systemic treatment (NEST) and the additional clinical value of PSMA PET-CT. Recruitment of patients for this trial started in January 2020 and will be completed approximately by December 2020.

Discussion

In this phase 2 trial on oligoprogressive mCRPC, we will investigate the benefit of progression-directed therapy while continuing ongoing systemic treatment. We hypothesize that progression-directed therapy (PDT) with surgery or stereotactic body radiation therapy for these oligoprogressive lesions will postpone the start of next-line systemic treatment and therefore serve as a new or add-on therapy in the spectrum of treatments available for mCRPC. The results of this trial will serve as guidance for a later randomized phase 3 trial. All participants are given an information sheet and are required to give written informed consent. Results will be published in a peer-reviewed journal.

Trial registration

This study is registered at ClinicalTrials.gov: NCT04222634 (December 18th 2019).

Rhabdomyolysis and acute kidney injury induced by the association of rosuvastatin and abiraterone: A case report and review of the literature

Introduction

Abiraterone acetate is an inhibitor of androgens biosynthesis, approved as first-line treatment in castration-resistant prostate cancer and metastatic castration-sensitive prostate cancer. Abiraterone has been rarely associated with severe rhabdomyolysis, but the mechanism of muscle toxicity is unknown.

Case report

We hereby present a case of severe rhabdomyolysis resulting in acute on chronic kidney injury following abiraterone initiation in a patient previously under rosuvastatin.

Management and outcome

Rhabdomyolysis was resolutive after rosuvastatin and abiraterone discontinuation, and kidney function recovered. There was no recurrence of muscle toxicity after re-initiation of abiraterone alone.

Discussion

Abiraterone selectively inhibits CYP17 as well as the hepatic transporter OATP1B1. OATP1B1 is an efflux transporter, whose function is to extract several drugs from the portal blood, allowing them to undergo hepatic metabolism. We hypothesize that abiraterone-induced inhibition of plasmatic uptake of rosuvastatin by OATP1B1 increased plasmatic concentration of rosuvastatin, leading to toxicity on muscle cells. We therefore suggest that the association between rosuvastatin and abiraterone should be avoided.

Abiraterone acetate plus Prednisone/Prednisolone compared with Enzalutamide in metastatic castration resistant prostate cancer before or after chemotherapy: A retrospective study of real‐world data (ACES)

Background

Abiraterone acetate combined with Prednisone/Prednisolone (AA+P) and Enzalutamide (ENZ) have proven survival benefit in men with metastatic castration‐resistant prostate cancer (mCRPC) in chemotherapy‐naïve and prior chemotherapy patients. There have been no studies directly comparing the effectiveness of ENZ to AA+P in mCRPC patients.

Methods

A retrospective, survival analysis study of 143 real‐world mCRPC patients (90 in AA+P and 53 in ENZ group) was conducted. Patients who started their treatment between February 2012 and May 2016 were included. The primary end point was biochemical progression‐free survival (bPFS). Secondary end points were radiological progression‐free survival (rPFS) and overall survival (OS). Toxicity data were also collected. Data were analyzed using Cox proportional hazards (PH) models, adjusting for covariates: prior radical treatment; Gleason score; prostate‐specific antigen; age; and chemotherapy naïve or not.

Results

After median follow‐up of 15 months (interquartile range 7 to 23), 112 events of biochemical progression were observed (71 in AA+P and 41 in ENZ). About 41% in AA+P group and 30% patients in ENZ group received prior chemotherapy. The chance of biochemical progression was significantly lower among ENZ patients than AA+P patients, when adjusting for all covariates in the Cox PH model (hazard ratio [HR] 0.54, 95% confidence interval [CI] 0.35 to 0.82, P = .004). There was a trend implying the chance of rPFS could be higher among ENZ patients than AA+P patients (HR 1.24, 95% CI 0.76 to 2.02, P = .4). There is no difference in OS between ENZ and AA+P patients, when adjusting for all covariates in the Cox PH model (HR 0.91, 95% CI 0.59 to 1.41, P = .7). About 38% of ENZ patients reported fatigue compared to 16% of AA+P patients, while hypertension was reported slightly more in AA+P patients.

Conclusions

This study showed a statistically significant difference in bPFS, favoring ENZ, but no significant difference in rPFS or OS.