Overall survival and adverse events after treatment with darolutamide vs. apalutamide vs. enzalutamide for high-risk non-metastatic castration-resistant prostate cancer: a systematic review and network meta-analysis

Surgery with or Without Darolutamide in High-risk and/or Locally Advanced Prostate Cancer: The SUGAR (CCAFU-PR2) Phase 2 Trial Rationale and Protocol

BACKGROUND

High-risk prostate cancer (PCa) patients frequently experience recurrence and progression after radical prostatectomy (RP). Neoadjuvant androgen deprivation therapy (ADT) has not demonstrated a clear oncological benefit and is not currently recommended.

OBJECTIVE

The SUGAR trial is the first phase 2, randomised, controlled, multicentre, noncommercial, open-label study investigating single-agent perioperative darolutamide compared with the standard of care (ie, upfront RP, without neoadjuvant ADT).

DESIGN, SETTING, AND PARTICIPANTS

SUGAR aims to randomise 240 men affected by nonmetastatic PCa, with the major eligibility criteria being International Society of Urological Pathology grade group ≥4, seminal vesicle invasion at magnetic resonance imaging and/or clinically node-positive disease. Patients in the experimental arm will undergo neoadjuvant darolutamide monotherapy, RP, and adjuvant darolutamide, completing 9 mo of treatment.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint is noncurable recurrence-free survival, an innovative and clinically meaningful measure; the secondary endpoints encompass safety; recurrence-free, metastasis-free, and overall survival; pathological response; and quality of life. A predictive biomarker analysis will also be performed.

RESULTS AND LIMITATIONS

Initial data suggest that intensified neoadjuvant treatment with androgen receptor signalling inhibitors (ARSIs) is associated with a sustained pathological response and may improve outcomes, via tumour downstaging and micrometastasis eradication. ARSI monotherapy could further enhance tolerability.

CONCLUSIONS

SUGAR will provide efficacy and safety information on perioperative darolutamide monotherapy compared with upfront RP, in a contemporary high-risk PCa population undergoing surgery.

PATIENT SUMMARY

The on-going SUGAR clinical trial evaluates 9 mo of darolutamide treatment in addition to radical prostatectomy, in men affected by prostate cancer with specific high-risk characteristics. It investigates whether this hormonal treatment can lower the rates of noncurable recurrences, maintaining a favourable tolerability profile.

Impact of PSA nadir, PSA response and time to PSA nadir on overall survival in real-world setting of metastatic hormone-sensitive prostate cancer patients

BACKGROUND

To evaluate the impact of prostate-specific antigen (PSA) nadir, PSA response and time to PSA nadir (TTN) in metastatic hormone-sensitive prostate cancer (mHSPC) patients on overall survival (OS) in the era of combination therapies.

METHODS

Different PSA nadir cut-offs (including ultra-low PSA) were tested for OS analyses. Additionally, PSA response ≥99% was evaluated, as well as TTN categorized as <3 versus 3-6 versus 6-12 versus >12 months. Multivariable Cox regression models predicted the value of PSA nadir cut-offs, PSA response and TTN on OS. Sensitivity analyses were performed in de novo and high volume mHSPC patients.

RESULTS

Of 238 eligible patients, PSA cut-offs of <0.2 versus 0.2-4.0 versus >4.0 ng/mL differed significantly regarding median OS (96 vs. 56 vs. 44 months, p < 0.01), as well as in subgroup analyses of de novo mHSPC patients and multivariable Cox regression models. A more stringent PSA cut-off of <0.02 versus 0.02-0.2 versus >0.2 ng/mL also yielded significant median OS differences (not reached vs. 96 vs. 50 months, p < 0.01), even after additional multivariable adjustment. A PSA response ≥99% was also significantly associated with better OS than counterparty with <99% response, even after multivariable adjustment (both p < 0.02). When TTN groups were compared, patients with longer TTN harbored more extended OS than those with short TTN (<3 vs. 3-6 vs. 6-12 vs. >12 months: 34 vs. 50 vs. 67 vs. 96 months, p < 0.01). Virtually similar results were observed in sensitivity analyses for high volume mHSPC patients.

CONCLUSIONS

In times of combination therapies for mHSPC, a PSA nadir of respectively, <0.2 and <0.02 ng/mL are associated with best OS rates. Moreover, a relative PSA response ≥99% and a longer TTN are clinical important proxies for favorable OS estimates.

[First clinical and oncological experiences with triplet therapy for high-volume metastatic hormone-sensitive prostate cancer]

BACKGROUND

Treatment with androgen deprivation therapy (ADT) plus extended hormone therapy (ARTA) is the standard of care for metastatic hormone-sensitive prostate cancer (mHSPC). Recent data of triplet combination therapies of ADT + ARTA (abiraterone/darolutamide) + docetaxel chemotherapy showed a survival advantage for specific mHSPC patient subgroups.

PURPOSE

What treatment response is observed in real-world mHSPC setting using triplet combination therapy and what are the expected side effects?

RESULTS

All patients receiving triplet combination therapy of ADT + ARTA (abiraterone/darolutamide) + docetaxel were included in the current study. A total of 14 patients with a median age of 62 years and 10/14 abiraterone or 4/14 darolutamide therapy could be included. The median PSA before initiation of therapy was 77 ng/ml (IQR 44-150). Overall, 86% of patients had a PSA response > 90% and the median PSA nadir was 0.3 ng/ml. Severe adverse events (grade III) during triplet therapy occurred in two patients (35,7%) with respectively febrile neutropenia 7.1% (1/14) and diarrhea with infection 7.1%. Other low grade adverse events (grade I/II) consisted of polyneuropathy (1/14), mucositis (1/14), xerostomia (1/14), weight loss (1/14) and fatigue (3/14) were detected. Chemotherapy was interrupted in one patient due to adverse events. After a median follow-up of ten months (IQR: 7-17), two patients (14.2%) showed progression to castration resistance.

CONCLUSION

Triplet therapy shows a very good PSA response in clinical practice. Adverse events during therapy are mainly triggered by classical chemotherapy-known side effects.

Adverse events related to darolutamide treatment: analysis of "real life" data from EudraVigilance and the Food and Drug Administration database entries

BACKGROUND

Aim of our study was to analyze adverse events (AEs) associated with darolutamide using real life data from Eudra-Vigilance (EV) and the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) databases.

METHODS

EV database in European Economic Area (EEA) and the FDA FAERS database were queried to identify darolutamide AEs occurred from 30th July 2019 to May 2022. AEs were recorded in according to category and severity. Real-life data was compared to Aramis registry study.

RESULTS

The total number of AEs including data from both databases was 409 reported by FDA-FAERS and 253 reported by EV databases. On registry study, 794 AEs were reported, with serious AEs occurring in 24.8% of patients in the darolutamide group and with 1 death related to trial regimen. The most frequently reported AEs from both database were general disorders (33% and 26%), investigations (19% and 22%), gastrointestinal (15% and 11%), renal and urinary (9%), gastrointestinal (6%) and musculoskeletal disorder (5%).

CONCLUSIONS

According to our results darolutamide is safe in a real-life scenario and the most frequent side effect is fatigue. Although up to now there are few reports in both real-life databases, these data are encouraging for clinicians using darolutamide in every day clinical practice.

Real-world evidence of outcomes of oligometastatic hormone-sensitive prostate cancer patients treated with metastasis-directed therapy

OBJECTIVE

To investigate characteristics and outcomes of oligometastatic hormone-sensitive prostate cancer (mHSPC) patients undergoing metastases-directed therapy (MDT) with external beam radiation therapy (EBRT).

MATERIALS AND METHODS

We relied on an institutional tertiary-care database to identify mHSPC patients who underwent EBRT as MDT between 12/2019 and 12/2022. Main outcomes consisted of progression to metastatic castration-resistant prostate cancer (mCRPC) and overall mortality (OM). Oligometastatic was defined as ≤3 metastases and bone and/or lymph node deposits were treated with conventional doses up to 54 Gy or with hypofractionated stereotactic regimes of median 24 Gy (20-27 Gy).

RESULTS

Overall, 37 patients treated with EBRT as MDT were identified. The median follow-up was 13 months. Median age at MDT was 71 years and 84% exhibited ECOG performance status 0. The median baseline PSA at diagnosis was 10 ng/mL. Overall, primary local therapy consisted of radical prostatectomy (65%), followed by external beam radiation therapy to the prostate (11%), focal therapy (8%), and palliative transurethral resection of the prostate (5%). Overall, 32% exhibited de novo oligometastatic mHSPC. Bone metastases were present in 78% versus 19% lymph node metastases versus 3% both. The distribution of targeted oligo-metastases was 62% versus 38% for respectively one metastasis versus more than one metastasis. Androgen deprivation therapy (ADT) was combined with MDT in 84%. Moreover, 19% received combination therapy with apalutamide/enzalutamide and 12% with abiraterone or docetaxel. The median time to mCRPC was 50 months. In incidence analyses, 13% developed mCRPC after 24 months. OM after 24 months was 15% in mHSPC patients receiving MDT. Significant OM differences were observed after stratification into targeted metastatic burden (<0.05). No high-grade adverse events were recorded during MDT.

CONCLUSION

Our real-world data suggest that MDT represents a safe treatment option for well-selected oligometastatic mHSPC patients.

Based on ARASENS trial: efficacy and safety of darolutamide as an emerging option of endocrinotherapy for metastatic hormone-sensitive prostate cancer-an updated systematic review and network meta-analysis

PURPOSE

The newly published ARASENS trial has demonstrated the clinical efficacy of darolutamide for metastatic hormone-sensitive prostate cancer (mHSPC). However, the use of darolutamide as the latest first-line androgen receptor pathway inhibitor for mHSPC has not been compared with other androgen receptor targeted agents (ARTAs). Given the lack of head-to-head randomized trials, we performed this updated meta-analysis to conduct indirect comparison for the efficacy and safety of darolutamide with other new-generation ARTAs.

METHODS

By searching the databases of PubMed, Scopus, Cochrane Library, and Embase, 9 large randomized controlled trials evaluating ARTAs for mHSPC patients were eventually screened according to PRISMA. We extracted data from overall survival, castration-resistant progression, and adverse events for network meta-analysis using the Bayesian and standard frequentist models.

RESULTS

Darolutamide combination emerged with superiority (HR = 0.68, 95%CrI = 0.57-0.81) among four androgen receptor inhibitors for patients with high Gleason score (HR = 0.71, 95%CrI = 0.59-0.86). Darolutamide was best tolerated in several androgen suppression-related adverse events (AEs).

CONCLUSION

Darolutamide appears to be an optional androgen receptor inhibitor for mHSPC patients, especially for patients with Gleason score ≥ 8. Its well-tolerated characteristic may provide a preferred drug option for patients with poor cardiovascular function and bone health.

Adverse Events and Androgen Receptor Signaling Inhibitors in the Treatment of Prostate Cancer: A Systematic Review and Multivariate Network Meta-analysis

CONTEXT

Androgen receptor signaling inhibitor (ARSi) agents are emerging as standard treatments for prostate cancer across the disease spectrum, but much remains unknown regarding how their side-effect profiles compare.

OBJECTIVE

To systematically evaluate the literature regarding adverse events (AEs) between the ARSi drugs abiraterone, apalutamide, darolutamide, and enzalutamide in the treatment of metastatic castration-resistant prostate cancer (mCRPC), nonmetastatic CRPC (nmCRPC), and metastatic castration-sensitive prostate cancer (mCSPC).

EVIDENCE ACQUISITION

PubMed, Web of Science, and Embase were queried for double-blind, randomized controlled trials (RCTs) of ARSi therapy up to September 2022 according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. Two teams reviewed titles and abstracts, and 14 RCTs were included for analysis.

EVIDENCE SYNTHESIS

Forest plots were used to summarize risk ratios for the most common AEs. According to surface under the cumulative ranking curve (SUCRA) values, enzalutamide was ranked as the most toxic treatment regarding hypertension outcomes (SUCRA 0%, most likely to be the bottom-ranked treatment) in both mCRPC and nmCRPC (SUCRA 0%). Enzalutamide was also ranked as the most toxic regarding headache across all prostate cancer entities (SUCRA 0%, for mCRPC, 1% for nmCRPC, and 3% for mCSPC).

CONCLUSIONS

Our findings suggest that the ARSi side-effect profiles do not significantly differ, except that enzalutamide was ranked the most toxic regarding hypertension in mCRPC and nmCRPC, and the most toxic regarding headache across all prostate cancer settings. These results highlight the importance of close blood-pressure monitoring for enzalutamide, and future research should explore possible connections between cardiovascular and neurological risk with ARSi therapy. In addition, these comparisons rely on the validity of cross-trial comparisons.

PATIENT SUMMARY

We reviewed the side-effect profiles of second-generation antiandrogen drugs for the treatment of prostate cancer. Side effects were similar, apart from higher risk of high blood pressure and headache risk with enzalutamide.

Cost-Utility Analysis of Darolutamide Combined with Androgen Deprivation Therapy for Patients with High-Risk Non-Metastatic Castration-Resistant Prostate Cancer in China

INTRODUCTION

The increasing incidence of prostate cancer (PC) in China leads to a significant disease burden. Although three novel androgen inhibitors (darolutamide, apalutamide, and enzalutamide) have been approved for patients with high-risk non-metastatic castration-resistant prostate cancer (nmCRPC), the economic evaluation of these novel treatments in China remains unknown. In this study, we aimed to evaluate the cost-utility of darolutamide combined with androgen deprivation therapy (ADT), comparing with apalutamide + ADT and enzalutamide + ADT, in patients with high-risk nmCRPC from a healthcare system perspective in China.

METHODS

A partitioned survival model was developed to capture time spent by patients in three health states: nmCRPC, metastatic CRPC (mCRPC), and death. Clinical outcomes from the ARAMIS, PROSPER, and SPARTAN studies were obtained. In the absence of head-to-head studies, indirect treatment comparisons were conducted to capture the comparative effectiveness between darolutamide + ADT, apalutamide + ADT, and enzalutamide + ADT. The prices of apalutamide and enzalutamide were assumed to be the same as the initial launch price of darolutamide, since post-negotiation prices after national reimbursement drug list (NRDL) inclusion remain confidential. Other health resources costs, baseline characteristics, treatment patterns, and utility were collected through literature or clinical expert interviews. Selected sensitivity analyses were also performed.

RESULTS

For a 20-year time horizon, darolutamide + ADT was associated with lower cost per quality-adjusted life years (QALYs) than apalutamide + ADT and enzalutamide + ADT (202,897 Chinese yuan (CNY)/QALY vs. 228,998 CNY/QALY and 221,409 CNY/QALY, respectively) (exchange rate, 1 USD = 6.7871 CNY). Darolutamide + ADT had better health outcomes and lower total costs compared to both apalutamide + ADT (+ 0.22 QALYs and - 72,818 CNY) and enzalutamide + ADT (+ 0.09 QALYs and - 67,451 CNY). Across the modelled sensitivity analyses (including hazard ratios and drug costs), darolutamide + ADT remained dominant or cost-effective.

CONCLUSIONS

This economic evaluation suggested that, in comparison with apalutamide + ADT and enzalutamide + ADT, darolutamide + ADT was a dominant or cost-effective treatment option for patients with high-risk nmCRPC in China.

nmCRPC, a look in the continuous care of prostate cancer patients: state of art and future perspectives

Non-metastatic castration resistant prostate cancer (nmCRPC) is a clinical setting defined as confirmed rising levels of PSA in patients treated with ADT but without detectable metastases on conventional imaging with computerized tomography (CT) and technetium-99 m scintigraphy. Men with nmCRPC and a PSA doubling time (PSADT) ≤ 10 months are considered at high risk of rapidly developing metastases with a consequent possible impact on survival. Three recent phase III trials have demonstrated, in this setting, the efficacy of adding a next-generation androgen receptor targeted agent (ARTA) to ADT in respect to ADT only, in delaying the development of metastases (metastasis-free survival, MFS) and prolong overall survival. The magnitude of clinical benefit of these agents was even more meaningful if considering the low incidence of drug related adverse events. Our review described the latest advances in the management of nmCRPC, deriving from the pivotal clinical trials, SPARTAN, PROSPER and ARAMIS, in order to support clinicians to optimally manage these patients. Of note, the emergence of novel, more accurate, next-generation imaging techniques (including Ga PSMA-PET/CT), as well as eventual future tumor biomarkers, is modifying the entity and definition of the nmCRPC setting, with a consequent impact on patient's diagnosis and management.

[Androgen deprivation therapy plus chemotherapy ± androgen receptor-targeting agents for metastatic hormone-sensitive prostate cancer]

BACKGROUND

Although androgen deprivation therapy (ADT) alone has been the standard of care (SOC) in the treatment of metastatic hormone-sensitive prostate cancer (mHSPC) for decades, combination therapies of novel hormone therapy (androgen receptor-targeting agents [ARTA]) or docetaxel chemotherapy have more recently replaced single ADT treatment. In addition, data for triplet therapies with ADT plus ARTA (abiraterone/darolutamide) and docetaxel chemotherapy are now available.

OBJECTIVES

The present review addresses the question which therapy is suitable for which mHSPC patient. Who benefits from doublet therapy and which patient from triplet therapy? Which side effects can be expected?

RESULTS

Triplet therapy consisting of ADT + docetaxel + abiraterone/darolutamide resulted in a significantly longer overall survival compared to therapy consisting of ADT + docetaxel of all mHSPC (ARASENS) and primary metastatic high-volume (PEACE-1) mHSPC patients. In the setting of high-volume mHSPC, prolonged overall survival is seen for the specific triplet combination of ADT + docetaxel + abiraterone. In the low-volume mHSPC setting, only an extended progression-free survival but not overall survival was observed. Data regarding the classification of high- vs. low-volume mHSPC for the triplet therapy consisting of darolutamide are currently not available. Side effects with triplet therapies are almost comparable with those of doublet therapies and relate to typical chemotherapy-associated (neutropenia) and ARTA-specific side effects (abiraterone).

CONCLUSION

ADT alone or ADT + docetaxel should no longer play a role in first-line therapy for mHSPC. Accordingly, therapy consisting of ADT + ARTA or ADT + ARTA + docetaxel represents the current primary treatment option pending further data and regarding patient-specific characteristics (age, ECOG status, metastatic burden, primary/secondary metastatic disease).

Androgen receptor pathway inhibitors, prostate cancer, and older adults: a global Young International Society of Geriatric Oncology drug review

Prostate cancer is a disease of older adults that has undergone a significant therapeutic paradigm shift in the last decade with the emergence of novel androgen receptor pathway inhibitors (ARPis). One of the more commonly used ARPis is enzalutamide. This drug, along with darolutamide and apalutamide, initially received approvals in the metastatic castrate-resistant prostate cancer setting but is now utilized frequently in the metastatic castrate-sensitive and non-metastatic castration-resistant settings. Landmark phase III data illustrating ARPi efficacy in older adults are limited to those with excellent performance status. However, its role in unfit older prostate cancer patients remains to be explored in the context of a narrative review. This first-of-its-kind drug review aims to shed light on the most up-to-date evidence behind the unique toxicity profile of ARPis in the context of geriatric vulnerabilities such as cognitive and functional impairment, along with potential solutions and supporting evidence that exists to circumvent these issues in the vulnerable older adult.

AR and PI3K/AKT in Prostate Cancer: A Tale of Two Interconnected Pathways

Prostate cancer (PCa) is the most common cancer in men. The androgen receptor (AR) has a pivotal role in the pathogenesis and progression of PCa. Many therapies targeting AR signaling have been developed over the years. AR signaling inhibitors (ARSIs), including androgen synthesis inhibitors and AR antagonists, have proven to be effective in castration-sensitive PCa (CSPC) and improve survival, but men with castration-resistant PCa (CRPC) continue to have a poor prognosis. Despite a good initial response, drug resistance develops in almost all patients with metastatic CRPC, and ARSIs are no longer effective. Several mechanisms confer resistance to ARSI and include AR mutations but also hyperactivation of other pathways, such as PI3K/AKT/mTOR. This pathway controls key cellular processes, including proliferation and tumor progression, and it is the most frequently deregulated pathway in human cancers. A significant interaction between AR and the PI3K/AKT/mTOR signaling pathway has been shown in PCa. This review centers on the current scene of different AR and PI3K signaling pathway inhibitors, either as monotherapy or in combination treatments in PCa, and the treatment outcomes involved in both preclinical and clinical trials. A PubMed-based literature search was conducted up to November 2022. The most relevant and recent articles were selected to provide essential information and current evidence on the crosstalk between AR and the PI3K signaling pathways. The ClinicalTrials.gov registry was used to report information about clinical studies and their results using the Advanced research tool, filtering for disease and target.

The efficacy and adverse events of conventional and second-generation androgen receptor inhibitors for castration-resistant prostate cancer: A network meta-analysis

BACKGROUND

Second-generation androgen receptor inhibitors (ARIs) have been developed and approved for treating castration-resistant prostate cancer (CRPC). There is a lack of direct comparison of the therapeutic effects and adverse events between the conventional ARI (bicalutamide) and three second-generation ARIs (enzalutamide, apalutamide and darolutamide).

METHODS

Our network meta-analysis evaluated therapeutic effects and adverse events of the conventional ARI (bicalutamide) and the second-generation ARIs in treating CRPC. We systematically searched the Pubmed, Cochrane library and Embase databases for studies published until October 2022 and only randomized clinical trials (RCTs) were included. The progression-free survival, prostate-specific antigen (PSA) progression-free survival, overall survival (PFS/PSA-PFS/OS), PSA response rate and relative adverse events (AEs) of CRPC patients were collected and synthesized. We then performed subgroup analysis. The non-metastatic and metastatic CRPC (nm/mCRPC) observations were analyzed separately. Data analyses were performed using R software (4.2.1) based on Bayesian framework.

RESULTS

6,993 subjects from seven eligible RCTs were analyzed. Enzalutamide, apalutamide and darolutamide were more effective than bicalutamide in treating CRPC, and the performance of darolutamide was slightly worse than the other two second-generation ARIs. Similar adverse events rate were observed among the second-generation ARIs and bicalutamide. Apalutamide showed a slightly higher rate of Grade 3+ AEs, percentages of AE-related drug withdrawals and AE-related mortality. Patients receiving enzalutamide had significantly higher rate of hypertension and fatigue. In subgroup analysis, enzalutamide showed better therapeutic effects compared with bicalutamide in both nmCRPC and mCRPC groups. In nmCRPC group, enzalutamide and apalutamide had more benefits on PFS and PSA-PFS compared with darolutamide. We displayed the probability ranking map of PFS, PSA-PFS, OS, time to cytotoxic chemotherapy, PSA response rate and relative AE outcomes.

CONCLUSION

The current network meta-analysis indicated that the second-generation ARIs were superior to the conventional ARI, bicalutamide. The three second-generation ARIs showed incomplete equivalence on CRPC treatment. The darolutamide was slightly less effective compared with enzalutamide and apalutamide. The adverse events of apalutamide were worse than the others, but no statistical significance was observed among these vital AEs. All ARIs were generally well-tolerated. These results may provide reference to clinical decision and further direct comparison trials.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42022370842.

Efficacy of cabazitaxel in fourth or later line of therapy in metastatic castration-resistant prostate cancer: Multi-institutional real-world experience in Germany

OBJECTIVE

Since multiple oncological treatment options in metastatic castration-resistant prostate cancer (mCRPC) are available, optimal sequencing of therapies are under investigation. However, the efficacy of Cabazitaxel (CAB) in fourth and later lines of therapy is rarely investigated.

MATERIAL AND METHODS

Fifty three patients with mCRPC treated with CAB in fourth line or later were included in our retrospective study, which involved eight uro-oncology centers in Germany. Clinical and tumor characteristics, as well as PSA-response rates were analyzed. Kaplan-Meier plots addressed overall survival (OS) and progression-free survival (PFS). Logistic regression models predicted risk factors of overall mortality (OM).

RESULTS

Of 53 patients, 79% (n=42), 19% (n=10) and 2% (n=1) received CAB in fourth, fifth and sixth line. A median of 4 cycles of CAB were administered. Median PSA at start of CAB was 199ng/ml (interquartile range (IQR) 70-869). In total, 89% had bone and 40% visceral metastases prior to the start of CAB. Moreover, 30% of patients received Docetaxel in first line therapy for mCRPC. Most frequent sequence of therapy was abiraterone followed by docetaxel and followed by enzalutamide. Overall, median PSA-response rate was -20% (IQR -80 to +10%). Patients with docetaxel in first line had a significantly better median PSA-response on CAB (-80 vs. 20%, P=0.03). Median OS, radiographic PFS and overall PFS were 14.8 (Confidence interval (CI): 11.0-20.8), 3.0 (CI: 2.9-4.0) and 2.9 (CI: 2.0-3.3) months, respectively. In multivariable analyses, visceral metastases, PSA >100ng/ml, ISUP4+5 and later administration of Docetaxel were predictors of OM.

CONCLUSION

Real-world experiences indicate that favorable oncologic outcomes can be achieved with CAB especially regarding PSA-response and OS even in the fourth line or later in patients with mCRPC.

Treatment Landscape for Patients with Castration-Resistant Prostate Cancer: Patient Selection and Unmet Clinical Needs

Metastatic castration resistant prostate cancer (CRPC) is an inevitably fatal disease. However, in recent years, several treatments have been shown to improve the outcome of CRPC patients both in the non-metastatic (nmCRPC) as well as the metastatic setting (mCRPC). In nmCRPC patients with a PSA doubling time <10 months, the addition of enzalutamide, apalutamide and darolutamide to androgen deprivation therapy (ADT) compared to ADT alone resulted in improved metastases free (MFS) and overall survival (OS). For mCRPC patients, several treatment options have been shown to be effective: two taxane based chemotherapies (docetaxel and cabazitaxel), two androgen-receptor pathway inhibitors (ARPI) (abiraterone and enzalutamide), two radiopharmaceutical agents (radium 223 and 177Lutetium-PSMA-617), one immunotherapy treatment (sipuleucel-T) and two poly ADP-ribose polymerase (PARP) inhibitors (olaparib and rucaparib). Pembrolizumab is US Food and Drug Administration (FDA) approved in all MSI high solid tumors, although a very small proportion of prostate cancer patients harboring this characteristic will benefit. Despite having a broad variety of treatments available, there are still several unmet clinical needs for CRPC. The objective of this review was to describe the therapeutic landscape in CRPC patients, to identify criteria for selecting patients for specific treatments currently available, and to address the current challenges in this setting.

Sequential therapy with darolutamide in patients with non-metastatic castration-resistant prostate cancer resistant to enzalutamide or apalutamide

Enzalutamide, apalutamide, and darolutamide are currently recommended for patients with non-metastatic castration-resistant prostate cancer (nmCRPC), but cross-resistance of androgen receptor-axis-targeted therapies (ARAT) occurs. Because darolutamide has a distinct chemical structure to other non-steroidal antiandrogens, it may be effective for nmCRPC patients resistant to enzalutamide or apalutamide. We retrospectively evaluated the efficacy of switching to darolutamide in patients with nmCRPC. We included nine nmCRPC patients who experienced biochemical progression on enzalutamide or apalutamide and were switched over to darolutamide. Five patients (55.5%) had a PSA response >50% decline after starting darolutamide, with an average of 73% PSA decline. Median progression-free survival was 6 months. In conclusion, an ARAT switch from enzalutamide or apalutamide to darolutamide might be effective for nmCRPC. Although the validation in a large-scale cohort is necessary, the switch to darolutamide could be a promising therapeutic option after the progression of 1st line ARAT in nmCRPC patients.

Decisions and dilemmas in non-metastatic castration-resistant prostate cancer management

Non-metastatic castration-resistant prostate cancer (nmCRPC) indicates a condition characterized by the progression of the prostate-specific antigen without radiographic evidence of distant metastasis on conventional imaging during androgen deprivation therapy (ADT). Recently, 3 phase III trials have shown that the addition of next-generation androgen-receptor inhibitors (ARIs) apalutamide, darolutamide, and enzalutamide to ADT allows patients with high-risk nmCRPC to delay the appearance of metastasis and to obtain long-term clinical benefits. However, the lack of head-to head comparison makes it difficult to choose one among these agents. We reviewed the literature and explained the rationale of the possible therapeutic choices. In any case, the availability of novel ARIs means that patients with nmCRPC have now a new effective treatment option that provides them a renewed hope.

The Hospitalization-Related Costs of Adverse Events for Novel Androgen Receptor Inhibitors in Non-Metastatic Castration-Resistant Prostate Cancer: An Indirect Comparison

INTRODUCTION

Three novel androgen receptor inhibitors are approved in the USA for the treatment of non-metastatic castration-resistant prostate cancer (nmCRPC): apalutamide, enzalutamide, and darolutamide. All three therapies have demonstrated prolonged metastasis-free survival in their respective phase III trials, with differing safety profiles. The objective of this study was to compare the mean per-patient costs of all-cause adverse events (AEs) requiring hospitalization between darolutamide versus apalutamide and enzalutamide for nmCRPC in the USA.

METHODS

All-cause grade ≥ 3 AEs with corresponding any-grade AEs reported among at least 10% of patients in any arm of the ARAMIS (darolutamide), SPARTAN (apalutamide), and PROSPER (enzalutamide) trials were selected for inclusion in the primary analyses. After matching-adjusted indirect comparison, AE costs were calculated by multiplying the AE rates from the trials by their respective unit costs of hospitalization taken from the US Healthcare Cost and Utilization Project (HCUP) database. Sensitivity analyses which further included any-grade AEs reported among at least 5% of patients were also performed.

RESULTS

After reweighting and adjusting for the trials' placebo arms, the mean per-patient AE costs were $1021 and $387 lower for darolutamide than for apalutamide and enzalutamide, respectively, over the trials' duration (SPARTAN and PROSPER, 43 months; ARAMIS, 48 months). For darolutamide vs. apalutamide, the largest drivers of the per-patient cost differences were fracture (adjusted difference $416), hypertension ($143), and rash ($219); for darolutamide vs. enzalutamide, they were fatigue not including asthenia ($290) and hypertension including increased blood pressure (i.e., any AE of hypertension or with elevated blood pressure not yet classified as hypertension) ($60). The results of the sensitivity analyses were consistent with the primary results.

CONCLUSIONS

Patients with nmCRPC treated with darolutamide in ARAMIS incurred lower AE-related costs (USD), as determined using HCUP costing data, compared with patients treated with either apalutamide (in SPARTAN) or enzalutamide (in PROSPER).

Mipsagargin: The Beginning-Not the End-of Thapsigargin Prodrug-Based Cancer Therapeutics

Søren Brøgger Christensen isolated and characterized the cell-penetrant sesquiterpene lactone Thapsigargin (TG) from the fruit Thapsia garganica. In the late 1980s/early 1990s, TG was supplied to multiple independent and collaborative groups. Using this TG, studies documented with a large variety of mammalian cell types that TG rapidly (i.e., within seconds to a minute) penetrates cells, resulting in an essentially irreversible binding and inhibiting (IC₅₀~10 nM) of SERCA 2b calcium uptake pumps. If exposure to 50–100 nM TG is sustained for >24–48 h, prostate cancer cells undergo apoptotic death. TG-induced death requires changes in the cytoplasmic Ca²⁺, initiating a calmodulin/calcineurin/calpain-dependent signaling cascade that involves BAD-dependent opening of the mitochondrial permeability transition pore (MPTP); this releases cytochrome C into the cytoplasm, activating caspases and nucleases. Chemically unmodified TG has no therapeutic index and is poorly water soluble. A TG analog, in which the 8-acyl groups is replaced with the 12-aminododecanoyl group, afforded 12-ADT, retaining an EC₅₀ for killing of <100 nM. Conjugation of 12-ADT to a series of 5–8 amino acid peptides was engineered so that they are efficiently hydrolyzed by only one of a series of proteases [e.g., KLK3 (also known as Prostate Specific Antigen); KLK2 (also known as hK2); Fibroblast Activation Protein Protease (FAP); or Folh1 (also known as Prostate Specific Membrane Antigen)]. The obtained conjugates have increased water solubility for systemic delivery in the blood and prevent cell penetrance and, thus, killing until the TG-prodrug is hydrolyzed by the targeting protease in the vicinity of the cancer cells. We summarize the preclinical validation of each of these TG-prodrugs with special attention to the PSMA TG-prodrug, Mipsagargin, which is in phase II clinical testing.

Evolving Castration Resistance and Prostate Specific Membrane Antigen Expression: Implications for Patient Management

Metastatic castration-resistant prostate cancer (mCRPC) remains an incurable disease, despite multiple novel treatment options. The role of prostate-specific membrane antigen (PSMA) in the process of mCRPC development has long been underestimated. During the last years, a new understanding of the underlying molecular mechanisms of rising PSMA expression and its association with disease progression has emerged. Accurate understanding of these complex interactions is indispensable for a precise diagnostic process and ultimately successful treatment of advanced prostate cancer. The combination of different novel therapeutics such as androgen deprivation agents, 177LU-PSMA radioligand therapy and PARP inhibitors promises a new kind of efficacy. In this review, we summarize the current knowledge about the most relevant molecular mechanisms around PSMA in mCRPC development and how they can be implemented in mCRPC management.

Treatment and trials in non-metastatic castration-resistant prostate cancer

Metastatic prostate cancer is associated with considerable morbidity and mortality. Standard treatment for non-metastatic prostate cancer, to prevent metastatic progression, is androgen deprivation therapy (ADT); however, many patients will eventually develop castration-resistant prostate cancer (CRPC), which can prove challenging to treat. Between the stages of non-metastatic androgen-sensitive disease and metastatic CRPC is an intermediate disease state that has been termed non-metastatic CRPC (nmCRPC), which is a heterogeneous, man-made disease stage that occurs after a patient who has no radiological evidence of metastasis shows evidence of cancer progression even after ADT. Awareness of nmCRPC has risen owing to an increased use of ADT and its eventual failure. Men with nmCRPC are at a high risk of progression to mCRPC, with historically few options to halt this process. However, in the past two decades, multiple therapies have been investigated for the treatment of nmCRPC, including endothelin receptor antagonists and bone-targeted therapies, but none has changed the standard of care. In the past decade, the efficacy of androgen receptor pathway-targeting modalities has been investigated. Three novel nonsteroidal antiandrogen agents for treating high-risk nmCRPC have been investigated; the PROSPER, SPARTAN and ARAMIS trials were phase III, randomized, placebo-controlled clinical trials that investigated the efficacy and safety of enzalutamide, apalutamide and darolutamide, respectively. All three therapeutics showed statistically significant improvements in metastasis-free survival, progression to antineoplastic therapy was lengthened and at final analysis, overall survival was significantly improved. The comparative efficacy and safety of all three agents has not yet been investigated in a comprehensive clinical trial, but approval of these medications by the FDA and other regulatory agencies means that providers now have three effective therapeutic options to augment ADT for patients with nmCRPC.