Role of novel hormonal therapies in the management of non-metastatic castration-resistant prostate cancer: a literature-based meta-analysis of randomized trials. Clin Transl Oncol. 2020;22:1033-1039. [PMID: 31617061 DOI: 10.1007/s12094-019-02228-2]

Darolutamide for non-metastatic castration-resistant prostate cancer: Efficacy, safety, and clinical perspectives of use

Darolutamide, a second-generation androgen receptor inhibitor (SGARI), has been shown to increase metastasis-free survival and overall survival among men with non-metastatic castration-resistant prostate cancer (nmCRPC). Its unique chemical structure potentially provides efficacy and safety advantages over the SGARIs apalutamide and enzalutamide, which are also indicated for nmCRPC. Despite a lack of direct comparisons, the SGARIs appear to have similar efficacy, safety, and quality of life (QoL) results. Indirect evidence suggests that darolutamide is preferred for its good adverse event profile, an attribute valued by physicians, patients, and their caregivers for maintaining QoL. Darolutamide and others in its class are costly; access may be a challenge for many patients and may lead to modifications to guideline-recommended regimens.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

HER2 Mediates PSMA/mGluR1-Driven Resistance to the DS-7423 Dual PI3K/mTOR Inhibitor in PTEN Wild-type Prostate Cancer Models

Prostate cancer remains a major cause of male mortality. Genetic alteration of the PI3K/AKT/mTOR pathway is one of the key events in tumor development and progression in prostate cancer, with inactivation of the PTEN tumor suppressor being very common in this cancer type. Extensive evaluation has been performed on the therapeutic potential of PI3K/AKT/mTOR inhibitors and the resistance mechanisms arising in patients with PTEN-mutant background. However, in patients with a PTEN wild-type phenotype, PI3K/AKT/mTOR inhibitors have not demonstrated efficacy, and this remains an area of clinical unmet need. In this study, we have investigated the response of PTEN wild-type prostate cancer cell lines to the dual PI3K/mTOR inhibitor DS-7423 alone or in combination with HER2 inhibitors or mGluR1 inhibitors. Upon treatment with the dual PI3K/mTOR inhibitor DS-7423, PTEN wild-type prostate cancer CWR22/22RV1 cells upregulate expression of the proteins PSMA, mGluR1, and the tyrosine kinase receptor HER2, while PTEN-mutant LNCaP cells upregulate androgen receptor and HER3. PSMA, mGluR1, and HER2 exert control over one another in a positive feedback loop that allows cells to overcome treatment with DS-7423. Concomitant targeting of PI3K/mTOR with either HER2 or mGluR1 inhibitors results in decreased cell survival and tumor growth in xenograft studies. Our results suggest a novel therapeutic possibility for patients with PTEN wild-type PI3K/AKT-mutant prostate cancer based in the combination of PI3K/mTOR blockade with HER2 or mGluR1 inhibitors.

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

BACKGROUND

The most recent overall survival (OS) and adverse event (AE) data have not been compared for the three guideline-recommended high-risk non-metastatic castration-resistant prostate cancer (nmCRPC) treatment alternatives.

METHODS

We performed a systematic review and network meta-analysis focusing on OS and AE according to the most recent apalutamide, enzalutamide, and darolutamide reports. We systematically examined and compared apalutamide vs. enzalutamide vs. darolutamide efficacy and toxicity, relative to ADT according to PRISMA. We relied on PubMed search for most recent reports addressing prospective randomized trials with proven predefined OS benefit, relative to ADT: SPARTAN, PROSPER, and ARAMIS. OS represented the primary outcome and AEs represented secondary outcomes.

RESULTS

Overall, data originated from 4117 observations made within the three trials that were analyzed. Regarding OS benefit relative to ADT, darolutamide ranked first, followed by enzalutamide and apalutamide, in that order. In the subgroup of PSA-doubling time (PSA-DT) ≤ 6 months patients, enzalutamide ranked first, followed by darolutamide and apalutamide in that order. Conversely, in the subgroup of PSA-DT 6-10 months patients, darolutamide ranked first, followed by apalutamide and enzalutamide, in that order. Regarding grade 3+ AEs, darolutamide was most favorable, followed by enzalutamide and apalutamide, in that order.

CONCLUSION

The current network meta-analysis suggests the highest OS efficacy and lowest grade 3+ toxicity for darolutamide. However, in the PSA-DT ≤ 6 months subgroup, the highest efficacy was recorded for enzalutamide. It is noteworthy that study design, study population, and follow-up duration represent some of the potentially critical differences that distinguish between the three studies and remained statistically unaccounted for using the network meta-analysis methodology. Those differences should be strongly considered in the interpretation of the current and any network meta-analyses.

Treatment Landscape of Nonmetastatic Castration-Resistant Prostate Cancer: A Window of Opportunity

The treatment for nonmetastatic castration-resistant prostate cancer (nmCRPC) is a highly unmet medical need. The classic treatment approach for these patients-androgen deprivation therapy (ADT) alone-until metastatic progression is now considered suboptimal. Several randomized phase III clinical trials have demonstrated significant clinical benefits-including significantly better overall survival (OS)-for treatments that combine ADT with apalutamide, enzalutamide, and darolutamide. As a result, these approaches are now included in treatment guidelines and are considered a standard of care. In the present article, we discuss the changing landscape of the management of patients with nmCRPC.

Management of Patients with Nonmetastatic Castration-Resistant Prostate Cancer: Recommendations of a Multidisciplinary Panel of Experts from South America

Most prostate cancer patients who undergo androgen-deprivation therapy or orchiectomy will eventually develop castration-resistant prostate cancer (CRPC), often preceded by a nonmetastatic CRPC state known as M0CRPC. The recent development of second-generation antiandrogens provides clinicians with efficacious and safe treatments for M0CRPC. However, the complexity of these patients, who typically have to deal with underlying comorbidities and polypharmacy, often challenges therapeutic decisions in this setting. The recent development of novel imaging techniques also provides clinicians with tools for detecting metastases with high sensitivity and specificity. However, the lack of evidence on the early detection of metastases and the corresponding impact on therapeutic decisions makes these techniques a double-edged sword that must be managed appropriately. Here, we present the expert view of the rapidly evolving concept of M0CRPC and provide recommendations for the identification of these patients, the appropriate use of the emerging imaging modalities, and patients’ management, particularly considering their clinical complexity and the recent development of next-generation antiandrogens.

A Systematic Review and Meta-Analysis of Randomized Controlled Trials With Novel Hormonal Therapies for Non-Metastatic Castration-Resistant Prostate Cancer: An Update From Mature Overall Survival Data

Introduction

To get better insight into the management of non-metastatic castration-resistant prostate cancer (M0 CRPC), in this meta-analysis and review we aimed to present an updated evaluation of the efficacy and safety of novel hormonal therapies (nHT) for M0 CRPC according to final analyses with mature overall survival (OS) and safety data.

Methods

We analyzed metastasis-free survival (MFS), OS, time to prostate-specific antigen (PSA) progression, second-line therapies data, adverse events (AEs), including all AEs, serious AEs (SAEs), AEs leading to discontinuation of trial regimen, AEs leading to death, fatigue, dizziness, cardiovascular events, and fractures; moreover, we evaluated the impact of PSA doubling time (PSA-DT), Eastern Cooperative Oncology Group (ECOG) score, use of bone-targeted therapy, lymph lodes (LN) status, and prior HT on final OS data. A comparison among the placebo arms of the included trials in terms of survival and safety profiles was assessed.

Results

According to the pooled analysis with updated and mature OS data, OS was significantly improved with nHT compared to placebo (hazard ratio (HR)= 0.74, 95% confidence interval (CI)= 0.66–0.84). nHT significantly improved OS over placebo across all pre-specified subgroups. Subgroup analysis revealed a greater OS benefit in patients with PSA-DT >6 months than ≤6 months (HR= 0.69 versus HR= 0.75), ECOG 0 than 1 (HR= 0.70 versus HR= 0.80), N1 disease than N0 (HR= 0.61 versus HR= 0.78), and in those receiving bone-targeted therapy (HR= 0.65 versus HR= 0.74), and a comparable OS by number of prior HT (HR= 0.75 versus HR= 0.76, for HT= 1 and ≥2); yet, differences between pre-specified subgroups were not significant (all p> 0.05). Overall, the nHT arm was significantly associated with higher rates of AEs, when compared with the placebo arm. The long-term analysis showed a worse safety profile with nHT than the interim analysis.

Conclusions

According to final analyses, nHT have shown to improve OS over placebo in the setting of high-risk M0 CRPC. The long-term analysis showed a worse safety profile with nHT than the interim analysis, whit distinct profiles among different nHT. The lack of survival data regarding second-line therapies remains a major issue.

Darolutamide in hormone-sensitive and castration-resistant prostate cancer

Introduction: Important changes in the treatment of prostate cancer have taken place in recent years. Non-metastatic castration-resistant prostate cancer (nmCRPC) has been clinically delineated. In this setting, three drugs have been approved in high-risk disease: apalutamide, enzalutamide and darolutamide.Areas covered:This manuscript aims to profile darolutamide, its clinical development, pharmacologic properties, efficacy and safety. We presented the results of published clinical studies, but we also investigated ongoing ones.Expert opinion: An indirect comparison with the other two aforementioned drugs emerged. While the clinical efficacy is comparable, the toxicity profile is different for darolutamide, resulting in greater tolerance. We must wait for the results of the trials that study darolutamide in hormone-sensitive disease, both in the metastatic phase and in the localized phase. Clinical experience will also be important to determine ever more personalized treatments for patients.

Seizures and Neuropsychiatric Toxicity in Patients with Non-Metastatic CRPC Treated with New Antiandrogens: Systematic Review and Meta-Analysis

INTRODUCTION

Recently, enzalutamide, apalutamide, and darolutamide have shown benefits in metastasis-free survival in non-metastatic castration-resistant prostate cancer (nmCRPC) patients compared to placebo. Previous evidence about the safety profile of these new androgens is limited. This meta-analysis studies seizure and neuropsychiatric effects of new anti-androgens compared to placebo in nmCRPC patients.

METHODS

PubMed and Cochrane databases were systematically reviewed until 1 March 2020 by 2 independent researchers using a pre-specified search strategy. Placebo-compared randomized controlled trials (RCTs) of nmCRPC patients treated with new anti-androgens providing data on neuropsychiatric events and seizures were included. Variables were seizure, headache, mental impairment, and dizziness. Pooled risk ratios (RR) were calculated using the Mantel-Hansel random effects model and Review Manager v5.3 software.

RESULTS

After systematic review, 3 eligible RCTs were selected that included 4,104 patients; 2,687 comprised the treatment group and 1,417 the control group. No significant increase in RR for seizures was registered with the new anti-androgens compared to placebo (RR 1.96; 95% confidence interval [CI] 0.40-9.61). However, 2 trials excluded patients with risk factors or a history of seizures. There was also no significant increase RR for grade ≥3 seizures (RR 2.50; 95% CI 0.12-52.02). RR for suffering dizziness (any grade) was 1.57 (95% CI 1.07-2.32) with the new anti-androgens, but no significant differences were found in the other study regarding neuropsychiatric events or grade ≥3 events.

CONCLUSIONS

New anti-androgens (i.e., enzalutamide, apalutamide, and darolutamide) are acceptably safe in terms of seizures and neuropsychiatric toxicity compared to placebo in patients with nmCRPC.

Nonmetastatic castration-resistant prostate cancer: Novel agents to treat a lethal disease

Nonmetastatic castration-resistant prostate cancer (nmCRPC) - defined as prostate-specific antigen (PSA) > 2 ng/mL, testosterone castration levels < 1.7 nm/L, and the absence of metastatic lesions on conventional imaging (computed tomography or bone scan) - has been defined as a lethal disease by the Prostate Cancer Work Group. One-third of patients with prostate cancer who receive androgen deprivation therapy for biochemical recurrence after local treatment will develop CRPC, with death occurring an average of 2.5 years after diagnosis of castration resistance. Most patients diagnosed with nmCRPC are asymptomatic or minimally symptomatic at diagnosis due to local treatment. In patients with short PSA doubling times (< 10 mo) and high baseline PSA levels, there is a high risk of bone metastases followed by prostate cancer-related mortality. These patients also present significant morbidity that negatively impacts quality of life (QoL). Recently, the results of three randomized trials (PROSPER, SPARTAN, and ARAMIS) were published. Those trials evaluated the efficacy of three different androgen receptor inhibitors - enzalutamide, apalutamide, and darolutamide - in patients with nmCRPC. In all three trials, the study drugs improved both metastasis-free survival and overall survival compared to placebo, plus on-going androgen deprivation therapy without a negative impact on QoL. In patients with nmCRPC, the most important clinical objective is early detection and treatment to maintain a low tumor burden and to prolong the symptom-free interval. For patients with nmCRPC, these novel drugs offer new hope for better QoL and survival outcomes.

Darolutamide: An Evidenced-Based Review of Its Efficacy and Safety in the Treatment of Prostate Cancer

Men treated with androgen deprivation therapy for rising PSA after failed local therapy will often develop castrate resistance, and the appearance of metastases predicts a poor prognosis. Thus, researchers have long sought to prolong the onset of metastasis in patients with nonmetastatic castration-resistant prostate cancer (CRPC). Until 2018, patients in this group had no FDA-approved treatment options. They were typically managed with androgen-deprivation therapy (ADT) to maintain castrate systemic testosterone levels and given approved therapies for metastatic CRPC once metastases appeared. However, third-generation androgen receptor inhibitors (ARIs) have dramatically changed the treatment paradigm, having shown the ability to extend metastasis-free survival (MFS) significantly over ADT alone in Phase 3 trials. The newest of these, darolutamide, prolonged MFS 22 months over placebo while also improving a host of secondary and exploratory endpoints such as overall survival (OS), prostate-specific antigen (PSA) progression and time to pain progression, chemotherapy initiation, and symptomatic skeletal events. Among third-generation ARIs, darolutamide is unique in that it incorporates two pharmacologically active diastereomers and has demonstrated resistance to all known androgen receptor (AR) mutations. Additionally, patients taking darolutamide appear to experience comparatively few central nervous system-related adverse events (AEs) such as fatigue and falls, and no increases in seizures have been reported in the drug's clinical or preclinical development. Various authors attribute the low incidence of CNS-related AEs to darolutamide's minimal penetration of the blood-brain barrier (BBB). Other side effects ranging from hot flashes to hypothyroidism also occurred at rates similar to those of the placebo arm in Phase 3. As ADT in itself raises cardiovascular risk, the cardiovascular safety of third-generation antiandrogens as a category warrants continued scrutiny. In total, however, published data suggest that darolutamide provides a reasonable option for patients with nonmetastatic CRPC. Ongoing research will determine darolutamide's potential role in additional disease states such as localized and castration-sensitive PCa.

Castration-resistant prostate cancer without metastasis at presentation may achieve cancer-specific survival in patients who underwent prior radical prostatectomy

PURPOSE

Radical prostatectomy (RP) is relatively better oncological outcomes in patients with prostate cancer (PCa). However, the incidence of castration-resistant PCa (CRPC) and PCa-specific mortality in patients with biochemical recurrence (BCR) after RP remains unclear. The aim of this study was to evaluate the cancer-specific survival (CSS) in patients with CRPC after RP, in particular those who had metastases or not.

METHODS

We retrospectively reviewed the data of 1582 consecutive patients who underwent RP between July 1996 and January 2019. The enrolled patients had histologically confirmed stage T1a-T3b PCa without lymph node involvement or distant metastasis. The endpoints were oncological outcomes, including CSS and BCR, in patients with PCa with or without metastases at the time of diagnosis with CRPC.

RESULTS

A total of 1474 patients were enrolled in this study. By the end of the follow-up period, 352 patients (24.6%) in the enrolled patients had BCR after RP. A total of 42 patients (2.9%) developed CRPC and 18 (1.3%) had died of PCa. With regard to metastasis in patients who diagnosed CRPC, the 5-year CSS rate was 100% for nonmetastatic CRPC (nmCRPC) patients and 53.8% for metastatic CRPC (mCRPC) patients after RP. The 5-year CSS rate was 100% for nmCRPC patients and 27.1% for mCRPC patients after the diagnosis with CRPC.

CONCLUSIONS

CRPC is one of the lethal causes with PCa death. However, nmCRPC may achieve relatively good prognosis in patients with PCa after RP.

Serum N-glycan profiling is a potential biomarker for castration-resistant prostate cancer

We investigated the diagnostic and prognostic potential of serum N-glycan profiling for castration-resistant prostate cancer (CRPC). We retrospectively investigated serum N-glycan structural analysis by glycoblotting for 287 patients with benign prostatic hyperplasia (BPH), 289 patients with newly diagnosed prostate cancer (PC), 57 patients with PC treated with androgen-deprivation therapy without disease progression (PC-ADT), and 60 patients with CRPC. N-Glycan profiling was compared between the non-CRPC (BPH, newly diagnosed PC and PC-ADT) and CRPC patients. We obtained the quantitative score for CRPC (CRPC N-glycan score) by discriminant analysis based on the combination of 9 N-glycans that were significantly associated with CRPC. The median CRPC N-glycan score was found to be significantly greater in CRPC patients than in non-CRPC patients. The CRPC N-glycan score could classify CRPC patients with sensitivity, specificity, and area under the curve of 87%, 69%, and 0.88, respectively. The CRPC N-glycan score >1.7 points was significantly associated with poor prognosis in patients with CRPC. The glycoprotein analysis showed that not immunoglobulins but α-1-acid glycoprotein (AGP) were a potential candidate for the carrier protein of N-glycans. The overexpression of specific N-glycans may be associated with their castration-resistant status and be a potential biomarker for CRPC.