Mortality in men with castration‐resistant prostate cancer—A long‐term follow‐up of a population‐based real‐world cohort

Patient characteristics, treatment patterns, and survival outcomes in patients with castration-resistant prostate cancer: results from the J-CaP registry

BACKGROUND

The optimal treatment sequence of approved therapies for castration-resistant prostate cancer (PC) is unclear. This study assessed real-world patient characteristics, treatment patterns, and effectiveness in patients with castration-resistant PC in Japan.

METHODS

Using data from the Japan Study Group of Prostate Cancer registry (2016-2018), this retrospective study included patients with ≥1 record of: primary androgen-deprivation therapy for hormone-sensitive PC and clinical progression to castration-resistant PC during primary androgen-deprivation therapy. The primary outcomes were patient characteristics, treatment patterns, and treatment duration. Other outcomes were overall survival (OS), cancer-specific survival (CSS), time to disease progression, and time to second disease progression.

RESULTS

A total of 600 patients were included. The mean age was 75.3 (SD: 7.9) years at PC diagnosis. The median prostate-specific antigen level was 135.5 (IQR: 37.3-542.2) ng/mL. The most common first-line castration-resistant PC treatments were enzalutamide (30%), docetaxel (20%), abiraterone (18%), flutamide (12%), and bicalutamide (8.7%). The most common second-line treatments were enzalutamide (28.5%), abiraterone (21.9%), and docetaxel (16.6%). The median treatment duration for enzalutamide, docetaxel, abiraterone, and flutamide was 254.0, 176.0, 197.0, and 111.5 days, respectively. Across all treatments, the median OS, CSS, time to disease progression, and second disease progression was 1028.0, 1239.0, 616.0, and 887.0 days, respectively.

CONCLUSION

Androgen receptor signaling inhibitors and docetaxel were the most common first- and second-line castration-resistant PC treatments. Enzalutamide was the preferred androgen receptor signaling inhibitor with the longest treatment duration.

Triplet therapy for metastatic castration-sensitive prostate cancer: Rationale and clinical evidence

Prostate cancer (PC) growth is hormone-dependent and it frequently develops distant metastases as disease progresses. Patients with metastatic castration-sensitive prostate cancer (mCSPC) initially respond to androgen deprivation therapy (ADT) but eventually become refractory and develop metastatic castration-resistant prostate cancer (mCRPC). Castration-resistance is associated with high lethality and metastases confer poor prognosis, therefore unmet needs in treatment for mCSPC remain high. So far, improvements in survival in mCSPC have been achieved by doublet combination therapy such as docetaxel or an androgen-receptor signaling inhibitor (ARSI) in addition to ADT. Further, recent phase 3 trials have shown that triplet therapy-a combination of ARSI, docetaxel, and ADT improves prognosis compared with docetaxel plus ADT in mCSPC. PC tumors manifest intra- and inter-tumoral heterogeneity at both the genetic and phenotypic level. As heterogeneity increases during sequential treatment and disease progression, it is reasonable to initiate combination therapy using drugs with different mechanisms of action early in the course of disease, such as mCSPC. Previous research about tumor heterogeneity and drug resistant mechanism support this rationale, as well as preclinical studies and real-world data provide the scientific evidence of benefit by combining ARSI and docetaxel. Here, we review the rationale and clinical evidence for triplet therapy in patients with mCSPC.

A Phase 2 Trial of Radium223 and Stereotactic Ablative Radiation Therapy in Hormone-Naïve Men with Oligometastatic Prostate Cancer to Bone: The RadSABR Study

PURPOSE

We hypothesized that treatment with Radium223 (Ra223) and Stereotactic ablative radiotherapy (SABR) in patients with bone-only metachronous oligometastastic hormone-sensitive prostate cancer (moHSPC) could safely delay the start of androgen deprivation therapy (ADT) and maintain quality of life (QoL).

METHODS AND MATERIALS

This prospective trial included 20 men with moHSPC and ≤5 bone-only metastases who previously had definitive treatment to the prostate and pelvic lymph nodes. Eligibility criteria were testosterone ≥ 100 ng/dL and metastases validated by conventional imaging. Exclusion criteria were postinitial treatment (LHRH) therapy or N1 disease at bone metastasis diagnosis. Treatment included 6 cycles of Ra223 and SABR (30 Gy in 5 fractions). Bone scans and Prostate Specific Antigen (PSA) levels were monitored regularly. The primary endpoint was freedom from ADT use at 15 months in ≥20% of patients. Patients were followed for 2 years, with clinically significant patient-reported outcome changes defined as >1/2 standard deviation from baseline. Statistical analyses used Wilcoxon rank sum, Pearson's χ2 tests, and univariate Cox regression, with significance set at P < .05 RESULTS: The median number of Ra223 cycles was 6. Freedom from ADT at 15 and 24 months was 50.0% and 40.0%, respectively (P < .001). Eleven (55%) and 5 (25%) patients had PSA declines exceeding 50% and 90%, respectively, with 2 patients achieving undetectable PSA levels (<0.01) at 2 years. No significant changes were observed in any patient-reported outcome QoL domains. Two patients had grade 3 skeletal-related events, and grade 2+ events attributed to Ra223 and SABR were observed in 4 and 2 patients, respectively.

CONCLUSIONS

In this phase 2 trial, the initial use of Ra223 and SABR for moHSPC significantly delayed ADT use compared with historical controls. The therapy is well tolerated, preserves QoL, and can lead to undetectable PSA levels at 2 years.

Combined Blockade of Lipid Uptake and Synthesis by CD36 Inhibitor and SCD1 siRNA Is Beneficial for the Treatment of Refractory Prostate Cancer

Drug resistance is an important factor for prostate cancer (PCa) to progress into refractory PCa, and abnormal lipid metabolism usually occurs in refractory PCa, which presents great challenges for PCa therapy. Here, a cluster of differentiation 36 (CD36) inhibitor sulfosuccinimidyl oleate sodium (CD36i) and stearoyl-CoA desaturase 1 (SCD1) siRNA (siSCD1) are selected to inhibit lipid uptake and synthesis in PCa, respectively. To this end, a multiresponsive drug delivery nanosystem, HA@CD36i-TR@siSCD1 is designed. The hyaluronic acid (HA) gel "shell" of HA-TR nanosystem can release drugs in response to the acidic tumor microenvironment and hyaluronidase, and the tumor targeting (TR) cationic micellar "core" can release drugs in response to glutathione. This multiresponsive drug release is beneficial for the exogenous inhibition of lipid uptake by CD36i and the endogenous inhibition of lipid synthesis by siSCD1. The established HA-TR nanosystem has good tumor targeting ability and tumor penetration ability, and that HA@CD36i-TR@siSCD1 has good synergistic effects, which can significantly restrain the growth, invasion, and metastasis of PCa. Moreover, under high-fat conditions, the tumors are more sensitive to HA@CD36i-TR@siSCD1 treatment, almost no accumulation of lipid droplets is observed in HA@CD36i-TR@siSCD1-treated tumors, with enhanced antitumor immunity. Hence, this study provides a new treatment option for refractory PCa patients, especially those with a high-fat diet.

Association between DNA damage repair alterations and outcomes to 177Lu-PSMA-617 in advanced prostate cancer

BACKGROUND

177Lu-prostate-specific membrane antigen (PSMA)-617 (LuPSMA) is a radionuclide therapy approved for patients with PSMA-avid metastatic castrate-resistant prostate cancer (mCRPC). We evaluated whether alterations in the DNA damage repair (DDR) pathway were associated with outcomes to LuPSMA.

PATIENTS AND METHODS

We identified an institutional cohort of men (n = 134) treated with ≥2 cycles of LuPSMA who had panel-based germline and/or tumor genomic sequencing. Mutations or two-copy losses in any of BRCA1, BRCA2, ATM, CDK12, PALB2, RAD51, and MSH2 were considered DDR defects. The primary outcome was a ≥50% reduction in the prostate-specific antigen (PSA) level during LuPSMA therapy (PSA50); secondary outcomes were PSA progression-free survival (PSA-PFS) and overall survival (OS). Models were adjusted for age, number of prior systemic therapies, sites of metastasis, and log-transformed PSA at cycle 1.

RESULTS

Thirty-four patients (25%) harbored DDR alterations, most commonly in BRCA2 and ATM (both n = 13). The presence of a DDR defect was not associated with PSA50 [adjusted odds ratio 0.48 (0.20-1.09), P = 0.08], PSA-PFS [adjusted hazard ratio (HR) 1.29 (0.79-2.10), P = 0.30], or OS [adjusted HR 1.42 (0.74-2.72), P = 0.29], with a non-significant trend toward poorer outcomes among DDR-altered patients.

CONCLUSIONS

DDR alterations were not associated with outcomes following LuPSMA. This has implications for treatment sequencing in mCRPC, particularly in patients with DDR alterations.

Metabolic reprogramming, malignant transformation and metastasis: Lessons from chronic lymphocytic leukaemia and prostate cancer

Metabolic reprogramming is a hallmark of cancer, crucial for malignant transformation and metastasis. Chronic lymphocytic leukaemia (CLL) and prostate cancer exhibit similar metabolic adaptations, particularly in glucose and lipid metabolism. Understanding this metabolic plasticity is crucial for identifying mechanisms contributing to metastasis. This review considers glucose and lipid metabolism in CLL and prostate cancer, exploring their roles in healthy and malignant states and during disease progression. In CLL, lipid metabolism supports cell survival and migration, with aggressive disease characterised by increased fatty acid oxidation and altered sphingolipids. Richter's transformation and aggressive lymphoma, however, exhibit a metabolic shift towards increased glycolysis. Similarly, prostate cell metabolism is unique, relying on citrate production in the healthy state and undergoing metabolic reprogramming during malignant transformation. Early-stage prostate cancer cells increase lipid synthesis and uptake, and decrease glycolysis, whereas metastatic cells re-adopt glucose metabolism, likely driven by interactions with the tumour microenvironment. Genetic drivers including TP53 and ATM mutations connect metabolic alterations to disease severity in these two malignancies. The bone microenvironment supports the metabolic demands of these malignancies, serving as an initiation niche for CLL and a homing site for prostate cancer metastases. By comparing these malignancies, this review underscores the importance of metabolic plasticity in cancer progression and highlights how CLL and prostate cancer may be models of circulating and solid tumours more broadly. The metabolic phenotypes throughout cancer cell transformation and metastasis, and the microenvironment in which these processes occur, present opportunities for interventions that could disrupt metastatic processes and improve patient outcomes.

Preclinical Characterization of ARX517, a Site-Specific Stable PSMA-Targeted Antibody-Drug Conjugate for the Treatment of Metastatic Castration-Resistant Prostate Cancer

Metastatic castration-resistant prostate cancer (mCRPC) is an advanced disease in which patients ultimately fail standard-of-care androgen deprivation therapies and exhibit poor survival rates. The prostate-specific membrane antigen (PSMA) has been validated as an mCRPC tumor antigen with overexpression in tumors and low expression in healthy tissues. Using our proprietary technology for incorporating synthetic amino acids into proteins at selected sites, we have developed ARX517, an antibody-drug conjugate composed of a humanized anti-PSMA antibody site-specifically conjugated to a tubulin inhibitor at a drug-to-antibody ratio of 2. After binding PSMA, ARX517 is internalized and catabolized, leading to cytotoxic payload delivery and apoptosis. To minimize premature payload release and maximize delivery to tumor cells, ARX517 employs a noncleavable polyethylene glycol linker and stable oxime conjugation enabled via synthetic amino acid protein incorporation to ensure its overall stability. In vitro studies demonstrate that ARX517 selectively induces cytotoxicity of PSMA-expressing tumor cell lines. ARX517 exhibited a long terminal half-life and high serum exposure in mice and dose-dependent antitumor activity in both enzalutamide-sensitive and -resistant cell line-derived xenograft and patient-derived xenograft models of prostate cancer. Repeat-dose toxicokinetic studies in nonhuman primates demonstrated that ARX517 was tolerated at exposures well above therapeutic exposures in mouse pharmacology studies, indicating a wide therapeutic index. In summary, ARX517 inhibited tumor growth in diverse mCRPC models, demonstrated a tolerable safety profile in monkeys, and had a wide therapeutic index based on preclinical exposure data. Based on the encouraging preclinical data, ARX517 is currently being evaluated in a phase I clinical trial (NCT04662580).

Engineering of layer-by-layer acetate-coated paclitaxel loaded poly(lactide-co-glycolide) acid nanoparticles for prostate cancer therapy- in vitro

It is hypothesized that layer-by-layer acetate-coated Paclitaxel-loaded PLGA nanoparticles (F2) can be engineered to potentiate the effectiveness of Paclitaxel (PTX) on LNCaP, a human prostate cancer cell line. The core of the layer-by-layer NPs is formed by nanoprecipitation, and the shell of the NPs is engineered using the sodium acetate's unique coating mechanism and surface-active properties. The resulting nanoformulation physicochemical properties are characterized by Fourier Transform Infra-Red (FTIR), Differential Scanning Calorimetry (DSC) Transmission Electron Microscopy (TEM), NanoSight NS300, spectrophotometry, Korsmeyer-Peppas model, respectively. The NP's cytotoxicity on LNCaP is assessed by MTS assay. The DSC and the FTIR confirm SA's coating of the NPs. The particle's mean diameters (PMD) are 89.4±2.3- to 114.4±7.6 nm. The TEM shows a unique multilayer and spherical nanoparticle. The encapsulation efficiency of commonly PTX-loaded PLGA NPs (F1) and F2 are 84.37±2.71% and 86.74±2.22, respectively. The drug transport mechanism of F1 and F2 is anomalous transport and case II, respectively. F2 follows a zero-order release mechanism. The cell viability is 45.08±2.18% and 60.17±4.72% when LNCaP is treated with 10 µg/mL of F2 and F1, respectively, after 48 hours of exposure. F2 and F1 cell growth inhibition are dose-dependent. This unique process of engineering the layer-by-layer NPs will provide new horizons for developing future innovative nanoparticles for targeted prostate cancer therapy.

Advancements in platinum chemotherapy for metastatic castration-resistant prostate cancer: Insights and perspectives

Despite improvements in survival, metastatic castration-resistant prostate cancer (mCRPC) remains a significant clinical challenge. While taxanes, new hormonal agents, radiopharmaceuticals, and PARP inhibitors offer valuable treatment options, this review explores the potential of platinum chemotherapies (carboplatin, cisplatin, and oxaliplatin) as alternative choices. Existing research demonstrates promising preliminary results for platinum-based therapies in mCRPC showing PSA response rates (7.7-95 %) and improved overall survival (8-26.6 months). However, chemotherapy-related cytopenias are a frequent side effect. Further research is underway to evaluate the efficacy of platinum regimens against specific mCRPC histopathological variants, particularly aggressive subtypes where the carboplatin and cabazitaxel combination is already recommended. The unique DNA-targeting action of platinum therapy holds promise for patients with deficient DNA repair (dDDR), especially those with BRCA mutations. This potential is supported by both preclinical and ongoing clinical research. Given the limited success of immunotherapy in mCRPC, researchers are exploring the potential for platinum therapies to enhance its efficacy. Additionally, trials are investigating the synergy of combining platinum therapy with both immunotherapy and PARP inhibitors. Further exploration into the effectiveness of platinum therapies in specific mCRPC subpopulations, particularly those with dDDR, is crucial for optimizing their future use. In conclusion, this review highlights the promising potential of platinum-based chemotherapy as a valuable treatment option for mCRPC. While current evidence is encouraging, ongoing research is essential to further optimize its efficacy, identify optimal combinations with other therapies, and better understand its impact on specific mCRPC subpopulations.

Integrating PARP Inhibitors in mCRPC Therapy: Current Strategies and Emerging Trends

Metastatic castrate-resistant prostate cancer (mCRPC) is associated with poor prognosis. DNA damage response (DDR) genes are commonly altered in mCRPC rendering them as promising therapeutic targets. Poly (ADP ribose) polymerase inhibitors (PARPi) demonstrated antitumor activity in mCRPC patients with DDR gene mutations through synthetic lethality. Multiple clinical trials with PARPi monotherapy exhibited encouraging clinical outcomes in selected patients with mCRPC. More recently, three Phase III randomized clinical trials (RCTs) combining PARPi with androgen receptor signaling inhibitors (ARSIs) demonstrated improved antitumor activity compared to ARSI monotherapy in mCRPC patients as the first-line therapy. Clinical benefit was more pronounced in patients harboring DDR alterations, specifically BRCA1/2. Interestingly, antitumor activity was also observed irrespective of DDR gene mutations, highlighting BRCAness phenotype with androgen receptor blockade resulting in synergistic activity between ARSIs and PARPi. In this review, we discuss the clinical efficacy and safety data of the combination of PARPi plus ARSI in all Phase 3 randomized controlled trials (RCTs), emphasizing strategies for patient selection and highlighting emerging trends based on clinical trial data.

Combination of PARP Inhibitors and Androgen Receptor Pathway Inhibitors in Metastatic Castration-Resistant Prostate Cancer

Despite recent advances in the treatment of metastatic prostate cancer, progression to a castration-resistant state remains inevitable for most and prognosis is limited. Genetic testing for homologous recombination repair pathway alterations is recommended for all patients with advanced prostate cancer given that a mutation is present in up to 25% of cases. Poly(ADP-ribose) polymerase (PARPis) are now approved for use in patients with metastatic castration-resistant prostate cancer who have progressed on an androgen receptor pathway inhibitor (ARPI) and harbour a germline or somatic homologous recombination repair mutation. Preclinical data support a synergistic effect with an ARPI and PARPi, and various ARPI-PARPi combinations have therefore been explored in phase III clinical trials. Despite heterogeneous findings, a clear hierarchy of benefit is evident, with patients harbouring a BRCA mutation deriving the greatest magnitude of benefit, followed by any homologous recombination repair mutation. The benefit in homologous recombination repair-proficient cohort is less clear, and questions remain about whether ARPI-PARPi combination therapy should be offered to patients without a homologous recombination repair mutation. With ARPIs now considered standard-of-care for metastatic hormone-sensitive prostate cancer, ARPI-PARPi combination therapy is currently being explored earlier in the treatment paradigm. The purpose of this review is to discuss the rationale behind ARPI-PARPi combination therapy, summarise the results of key clinical trials, and discuss clinical considerations and future perspectives.

Computational drug discovery pipelines identify NAMPT as a therapeutic target in neuroendocrine prostate cancer

Neuroendocrine prostate cancer (NEPC) is an aggressive advanced subtype of prostate cancer that exhibits poor prognosis and broad resistance to therapies. Currently, few treatment options are available, highlighting a need for new therapeutics to help curb the high mortality rates of this disease. We designed a comprehensive drug discovery pipeline that quickly generates drug candidates ready to be tested. Our method estimated patient response to various therapeutics in three independent prostate cancer patient cohorts and selected robust candidate drugs showing high predicted potency in NEPC tumors. Using this pipeline, we nominated NAMPT as a molecular target to effectively treat NEPC tumors. Our in vitro experiments validated the efficacy of NAMPT inhibitors in NEPC cells. Compared with adenocarcinoma LNCaP cells, NAMPT inhibitors induced significantly higher growth inhibition in the NEPC cell line model NCI-H660. Moreover, to further assist clinical development, we implemented a causal feature selection method to detect biomarkers indicative of sensitivity to NAMPT inhibitors. Gene expression modifications of selected biomarkers resulted in changes in sensitivity to NAMPT inhibitors consistent with expectations in NEPC cells. Validation of these markers in an independent prostate cancer patient dataset supported their use to inform clinical efficacy. Our findings pave the way for new treatments to combat pervasive drug resistance and reduce mortality. Furthermore, this research highlights the use of drug sensitivity-related biomarkers to understand mechanisms and potentially indicate clinical efficacy.

Combination of Blood Adiponectin and Leptin Levels Is a Predictor of Biochemical Recurrence in Prostate Cancer Invading the Surrounding Adipose Tissue

Biochemical recurrence is a process that progresses to castration-resistant prostate cancer (CRPC) and prediction of biochemical recurrence is useful in determining early therapeutic intervention and disease treatment. Prostate cancer is surrounded by adipose tissue, which secretes adipokines, affecting cancer progression. This study aimed to investigate the correlation between blood adipokines and CRPC biochemical recurrence. We retrospectively analyzed the clinical data, including preoperative serum adipokine levels, of 99 patients with pT3a pN0 prostate cancer who underwent proctectomy between 2011 and 2019. The primary outcome was biochemical recurrence (prostate-specific antigen: PSA > 0.2). We identified 65 non-recurrences and 34 biochemical recurrences (one progressed to CRPC). The initial PSA level was significantly higher (p = 0.006), but serum adiponectin (p = 0.328) and leptin (p = 0.647) levels and their ratio (p = 0.323) were not significantly different in the biochemical recurrence group compared with the non-recurrence group. In contrast, significantly more biochemical recurrences were observed in the group with adiponectin < 6 μg/mL and Leptin < 4 ng/mL (p = 0.046), initial PSA > 15 ng/mL, clinical Gleason pattern ≥ 4, and positive resection margin. A significant difference was also observed in the multivariate analysis (hazard ratio: 4.04, 95% confidence interval: 1.21-13.5, p = 0.0232). Thus, low preoperative serum adiponectin and high leptin levels were significantly associated with biochemical recurrence in adipose tissue-invasive prostate cancer, suggesting that they may be useful predictors of biochemical recurrence. Further studies with larger cases are needed to increase the validity of this study.

Computer-aided drug discovery strategies for novel therapeutics for prostate cancer leveraging next-generating sequencing data

INTRODUCTION

Prostate cancer (PC) is the most common malignancy and accounts for a significant proportion of cancer deaths among men. Although initial therapy success can often be observed in patients diagnosed with localized PC, many patients eventually develop disease recurrence and metastasis. Without effective treatments, patients with aggressive PC display very poor survival. To curb the current high mortality rate, many investigations have been carried out to identify efficacious therapeutics. Compared to de novo drug designs, computational methods have been widely employed to offer actionable drug predictions in a fast and cost-efficient way. Particularly, powered by an increasing availability of next-generation sequencing molecular profiles from PC patients, computer-aided approaches can be tailored to screen for candidate drugs.

AREAS COVERED

Herein, the authors review the recent advances in computational methods for drug discovery utilizing molecular profiles from PC patients. Given the uniqueness in PC therapeutic needs, they discuss in detail the drug discovery goals of these studies, highlighting their translational values for clinically impactful drug nomination.

EXPERT OPINION

Evolving molecular profiling techniques may enable new perspectives for computer-aided approaches to offer drug candidates for different tumor microenvironments. With ongoing efforts to incorporate new compounds into large-scale high-throughput screens, the authors envision continued expansion of drug candidate pools.

Early PSA decline after starting second-generation hormone therapy in the post-docetaxel setting predicts cancer-specific survival in metastatic castrate-resistant prostate cancer

BACKGROUND

The objective of this study was to evaluate the prognostic value of early PSA decline following initiation of second-generation hormone therapy (2nd HT), namely abiraterone acetate or enzalutamide, in patients with taxane-refractory metastatic castrate-resistant prostate cancer (mCRPC) and evaluate utility of this metric in informing intensified surveillance/imaging protocols.

METHODS

We retrospectively identified 75 mCRPC patients treated with 2nd HT following docetaxel failure (defined as PSA rise and radiographic progression). Patients were categorized patients into two cohorts based on the first PSA within 3 months after initiation of therapy: PSA reduction ≥50% (Group A) and PSA reduction <50% (Group B). The primary endpoint was cancer-specific mortality (CSM). The secondary endpoint was radiographic disease progression (rDP) on 2nd HT. In univariate and multivariate analyses, we investigated factors associated with rPD and CSM.

RESULTS

We included 75 patients (52 in Group A, 23 in Group B) in the analytic cohort. Baseline clinico-demographic characteristics, including median age, primary Gleason score risk group, median pre-treatment PSA, disease burden, site of metastases, and pre-treatment ECOG score were not statistically different between the two groups. Median follow up time was 30 months and the median time to radiographic disease progression was 28.1 and 12.5 months (p = 0.002) in cohorts A and B, respectively. On univariate and multivariate analyses, both PSA reduction ≥50% and volume of metastatic disease were significantly associated with a decreased risk of radiographic disease progression (HR 0.41, 95% CI 0.21-0.80, p = 0.0113) as well as a decreased risk of cancer-specific mortality (HR 0.29, 95% CI 0.09-0.87, p = 0.0325).

CONCLUSION

PSA reduction ≥50% within 3 months of starting 2nd HT was associated with significantly improved radiographic disease progression-free survival and 3-year cancer-specific mortality. This suggests using PSA 50%-decline metric in surveillance patients with on 2nd HT and identifies patients who require further evaluation with imaging.

Marital Status, Living Arrangement, and Survival among Individuals with Advanced Prostate Cancer in the International Registry for Men with Advanced Prostate Cancer

BACKGROUND

Studies have shown improved survival among individuals with cancer with higher levels of social support. Few studies have investigated social support and overall survival (OS) in individuals with advanced prostate cancer in an international cohort. We investigated the associations of marital status and living arrangements with OS among individuals with advanced prostate cancer in the International Registry for Men with Advanced Prostate Cancer (IRONMAN).

METHODS

IRONMAN is enrolling participants diagnosed with advanced prostate cancer (metastatic hormone-sensitive prostate cancer, mHSPC; castration-resistant prostate cancer, CRPC) from 16 countries. Participants in this analysis were recruited between July 2017 and January 2023. Adjusting for demographics and tumor characteristics, the associations were estimated using Cox regression and stratified by disease state (mHSPC, CRPC), age (<70, ≥70 years), and continent of enrollment (North America, Europe, Other).

RESULTS

We included 2,119 participants with advanced prostate cancer, of whom 427 died during up to 5 years of follow-up (median 6 months). Two-thirds had mHSPC. Most were married/in a civil partnership (79%) and 6% were widowed. Very few married participants were living alone (1%), while most unmarried participants were living alone (70%). Married participants had better OS than unmarried participants [adjusted HR: 1.44; 95% confidence interval (CI): 1.02-2.02]. Widowed participants had the worst survival compared with married individuals (adjusted HR: 1.89; 95% CI: 1.22-2.94).

CONCLUSIONS

Among those with advanced prostate cancer, unmarried and widowed participants had worse OS compared with married participants.

IMPACT

This research highlighted the importance of social support in OS within this vulnerable population.

Cost-effectiveness and budget impact analysis of enzalutamide in comparison to abiraterone in treatment of metastatic prostate cancer resistant to castration in Iran

INTRODUCTION

In recent years, enzalutamide and abiraterone have been widely used as treatments for metastatic castration-resistant prostate cancer (mCRPC). However, the cost-effectiveness of these drugs in Iran is unknown. This study evaluated the cost-effectiveness of enzalutamide for the treatment of metastatic prostate cancer resistant to castration in Iran.

METHODS

A 3-state Markov model was developed to evaluate the cost-effectiveness of enzalutamide and abiraterone from a social perspective over 10 years. The clinical inputs were obtained from the meta-analysis studies. The direct medical costs were obtained from the tariffs of the healthcare system, while the direct non-medical and indirect costs were collected from the patients. The data of utilities were derived from the literature. In addition, sensitivity analyses were conducted to assess the uncertainties.

RESULTS

Compared with Abiraterone, enzalutamide was associated with a high incremental cost-effectiveness ratio (ICER) of $6,260 per QALY gained. According to the one-way sensitivity analysis, ICER was most heavily influenced by the prices of enzalutamide and Abiraterone, non-medical costs, and indirect costs. Regardless of the variation, enzalutamide remained cost-effective. The budget impact analysis of enzalutamide in the health system during 5 years was estimated at $6,362,127.

CONCLUSIONS

At current prices, adding enzalutamide to pharmaceutical lists represents the cost-effective use of the healthcare resources in Iran for the treatment of metastatic castration-resistant prostate cancer.

Personalizing approaches to the management of metastatic hormone sensitive prostate cancer: role of advanced imaging, genetics and therapeutics

PURPOSE

To summarize contemporary and emerging strategies for the diagnosis and management of metastatic hormone sensitive prostate cancer (mHSPC), focusing on diagnostic testing and therapeutics.

METHODS

Literature review using PUBMED-Medline databases as well as clinicaltrials.gov to include reported or ongoing clinical trials on treatment for mHSPC. We prioritized the findings from phase III randomized clinical trials, systematic reviews, meta-analyses and clinical practice guidelines.

RESULTS

There have been significant changes to the diagnosis and staging evaluation of mHSPC with the integration of increasingly accurate positron emission tomography (PET) imaging tracers that exceed the performance of conventional computerized tomography (CT) and bone scan. Germline multigene testing is recommended for the evaluation of patients newly diagnosed with mHSPC given the prevalence of actionable alterations that may create candidacy for specific therapies. Although androgen deprivation therapy (ADT) remains the backbone of treatment for mHSPC, approaches to first-line treatment include the integration of multiple agents including androgen receptor synthesis inhibitors (ARSI; abiraterone) Androgen Receptor antagonists (enzalutamide, darolutamide, apalautamide), and docetaxel chemotherapy. The combination of ADT, ARSI, and docetaxel chemotherapy has recently been evaluated in a randomized trial and was associated with significantly improved overall survival including in patients with a high burden of disease. The role of local treatment to the prostate with radiation has been evaluated in randomized trials with additional studies underway evaluating the role of cytoreductive radical prostatectomy.

CONCLUSION

The staging and initial management of patients with mHSPC has undergone significant advances in the last decade with advancements in the diagnosis, treatment and sequencing of therapies.

Computational drug discovery for castration-resistant prostate cancers through in vitro drug response modeling

Prostate cancer (PC) is the most frequently diagnosed malignancy and a leading cause of cancer deaths in US men. Many PC cases metastasize and develop resistance to systemic hormonal therapy, a stage known as castration-resistant prostate cancer (CRPC). Therefore, there is an urgent need to develop effective therapeutic strategies for CRPC. Traditional drug discovery pipelines require significant time and capital input, which highlights a need for novel methods to evaluate the repositioning potential of existing drugs. Here, we present a computational framework to predict drug sensitivities of clinical CRPC tumors to various existing compounds and identify treatment options with high potential for clinical impact. We applied this method to a CRPC patient cohort and nominated drugs to combat resistance to hormonal therapies including abiraterone and enzalutamide. The utility of this method was demonstrated by nomination of multiple drugs that are currently undergoing clinical trials for CRPC. Additionally, this method identified the tetracycline derivative COL-3, for which we validated higher efficacy in an isogenic cell line model of enzalutamide-resistant vs. enzalutamide-sensitive CRPC. In enzalutamide-resistant CRPC cells, COL-3 displayed higher activity for inhibiting cell growth and migration, and for inducing G1-phase cell cycle arrest and apoptosis. Collectively, these findings demonstrate the utility of a computational framework for independent validation of drugs being tested in CRPC clinical trials, and for nominating drugs with enhanced biological activity in models of enzalutamide-resistant CRPC. The efficiency of this method relative to traditional drug development approaches indicates a high potential for accelerating drug development for CRPC.

Potential role for protein kinase D inhibitors in prostate cancer

Protein kinase D (PrKD), a novel serine-threonine kinase, belongs to a family of calcium calmodulin kinases that consists of three isoforms: PrKD1, PrKD2, and PrKD3. The PrKD isoforms play a major role in pathologic processes such as cardiac hypertrophy and cancer progression. The charter member of the family, PrKD1, is the most extensively studied isoform. PrKD play a dual role as both a proto-oncogene and a tumor suppressor depending on the cellular context. The duplicity of PrKD can be highlighted in advanced prostate cancer (PCa) where expression of PrKD1 is suppressed whereas the expressions of PrKD2 and PrKD3 are upregulated to aid in cancer progression. As understanding of the PrKD signaling pathways has been better elucidated, interest has been garnered in the development of PrKD inhibitors. The broad-spectrum kinase inhibitor staurosporine acts as a potent PrKD inhibitor and is the most well-known; however, several other novel and more specific PrKD inhibitors have been developed over the last two decades. While there is tremendous potential for PrKD inhibitors to be used in a clinical setting, none has progressed beyond preclinical trials due to a variety of challenges. In this review, we focus on PrKD signaling in PCa and the potential role of PrKD inhibitors therein, and explore the possible clinical outcomes based on known function and expression of PrKD isoforms at different stages of PCa.

Development of castration resistance in prostate cancer patients treated with luteinizing hormone-releasing hormone analogues (LHRHa): results of the ANARESISTANCE study

PURPOSE

Evaluate the percentage of patients with prostate cancer treated with luteinizing hormone-releasing hormone analogues (LHRHa) that develop castration resistance after a follow-up period of 3 years. The secondary objective is to evaluate the variables potentially related to the progression to castration resistant prostate cancer (CRPC).

METHODS

A post-authorization, nation-wide, multicenter, prospective, observational, and longitudinal study that included 416 patients treated with LHRHa between 2012 and 2017 is presented. Patients were followed for 3 years or until development of CRPC, thus completing a per-protocol population of 350 patients. A Cox regression analysis was carried out to evaluate factors involved in progression to CRPC.

RESULTS

After 3 years of treatment with LHRHa 18.2% of patients developed CRPC. In contrast, in the subgroup analysis, 39.6% of the metastatic patients developed CRPC, compared with 8.8% of the non-metastatic patients. The patients with the highest risk of developing CRPC were those with a nadir prostate-specific antigen (PSA) > 2 ng/ml (HR 21.6; 95% CI 11.7-39.8; p < 0.001) and those receiving concomitant medication, most commonly bicalutamide (HR 1.8; 95% CI 1-3.1, p = 0.0431).

CONCLUSIONS

The proportion of metastatic patients developing CRPC after 3 years of treatment with LHRHa is consistent with what has been previously described in the literature. In addition, this study provides new findings on CRPC in non-metastatic patients. Concomitant medication and nadir PSA are statistically significant predictive factors for the time to diagnosis of CRPC, the nadir PSA being the strongest predictor.

Modeling Disease Trajectories for Castration-resistant Prostate Cancer Using Nationwide Population-based Data

Background

Little is known about disease trajectories for men with castration-resistant prostate cancer (CRPC).

Objective

To create a state transition model that estimates time spent in the CRPC state and its outcomes.

Design, setting, and participants

The model was generated using population-based prostate-specific antigen data from 40% of the Swedish male population, which were linked to nationwide population-based databases. We compared the observed and predicted cumulative incidence of transitions to and from the CRPC state.

Outcome measurements and statistical analysis

We measured time spent in the CRPC state and the proportion of men who died of prostate cancer during follow-up by CRPC risk category.

Results and limitations

Time spent in the CRPC state varied from 1.1 yr for the highest risk category to 3.9 yr for the lowest risk category. The proportion of men who died from prostate cancer within 10 yr ranged from 93% for the highest risk category to 54% for the lowest. There was good agreement between the model estimates and observed data.

Conclusions

There is large variation in the time spent in the CRPC state, varying from 1 yr to 4 yr according to risk category.

Patient summary

It is possible to accurately estimate the disease trajectory and duration for men with castration-resistant prostate cancer.

Emerging hormonal agents for the treatment of prostate cancer

INTRODUCTION

Prostate cancer is the most common solid organ malignancy in men in the United States. Until recently, treatment options for men with metastatic disease were limited and patients faced poor outcomes with minimal alternatives. The landscape of prostate cancer treatment has transformed and taken shape over the last 20 years with novel hormonal and non-hormonal therapeutics that have demonstrated significant improvement in survival. However, patients with advanced disease still face imminent progression on hormone blockade therapy.

AREAS COVERED

There is a significant market opportunity to devise novel, more potent agents for patients with hormone-resistant disease. Here we review the existing treatment options in men with advanced prostate cancer, the market opportunity within this field, goals of current research, and the novel agents under investigation, including androgen receptor degraders, testosterone synthesis pathway inhibitors, DNA-binding domain and N-terminal domain antagonists, and the combination of hormonal and non-hormonal agents.

EXPERT OPINION

Combination therapy regimens and novel agents targeting alternative binding domains of the androgen receptor are of great interest, as they may overcome resistance mechanisms and hold promise as the future of advanced prostate cancer treatment.