Indirect Comparison of Darolutamide versus Apalutamide and Enzalutamide for Nonmetastatic Castration-Resistant Prostate Cancer

Safety profile of darolutamide versus placebo: a systematic review and meta-analysis

BACKGROUND

Darolutamide is an androgen receptor pathway inhibitor (ARPI) used in patients with prostate cancer (PC). In pivotal trials, it has demonstrated a favorable toxicity profile. There are no head-to-head comparison studies between the different ARPIs, but the efficacy of these drugs seems to be similar making the toxicity profile a key element for treatment selection.

METHODS

We conducted a systematic review of all clinical trials assessing treatment with darolutamide for patients with PC using placebo as the control using the PubMed/Medline and Cochrane library databases. We also performed a meta-analysis to compare the safety of darolutamide versus placebo evaluating adverse events (AE) leading to treatment discontinuation and the rate of the AE reported as "AE of interest" in the ARAMIS trial. The comparison among darolutamide and the placebo group in terms of safety and tolerability was performed using odds ratio (OR) as meta-analytic outcome.

RESULTS

We identified three articles comprising 2902 patients for the systematic review and meta-analysis (1652 treated with darolutamide and 1250 with placebo). Darolutamide did not increase AE leading to treatment discontinuation compared to placebo (pooled OR: 1.176, 95% CI 0.918-1.507, p = 0.633). Regarding the "AE of interest" there was no difference between darolutamide and placebo in terms of asthenia, cardiac arrhythmia, cardiac disorder, coronary artery disorder, depression mood disorder, falls, fatigue, heart failure, hot flushes, hypertension, mental-impairment disorder, rash, seizure and weight loss. The only "AE of interest" with a statistically significant difference in favor of placebo was bone fractures (pooled OR: 1.523, 95% CI 1.081-2.146).

CONCLUSIONS

In our systematic review and meta-analysis, darolutamide showed a toxicity profile comparable to placebo with the exception of bone fractures. In the absence of head-to-head comparison studies between the different ARPIs, the results of our research suggest a preferred use of darolutamide in the approved settings.

Comparative analysis of novel hormonal agents in non-metastatic castration-resistant prostate cancer: A Taiwanese perspective

BACKGROUND

Non-metastatic castration-resistant prostate cancer (nmCRPC) is an asymptomatic condition with the potential to progress to metastasis. Novel hormonal agents (NHAs) are currently considered the gold standard treatment for nmCRPC, offering significant survival benefits. However, further evidence is needed to determine whether there are differences in the performance of these drugs among Asian populations.

METHODS

This retrospective analysis of nmCRPC patients aims to compare the efficacy and safety of three NHAs-apalutamide, darolutamide, and enzalutamide. Data were collected from two prominent prostate care centers in Taichung, Taiwan. Patient characteristics, treatment details, PSA responses, and adverse events were analyzed. Statistical comparisons were performed, and the study received Institutional Review Board approval.

RESULTS

Total of 64 patients were recruited in this study, including 29 darolutamide, 26 apalutamide, and 9 enzalutamide patients. Baseline characteristics varied between the three patient groups, but the treatment response still revealed similar results. The apalutamide group experienced more adverse events, notably skin rash. Discontinuation rates due to adverse events differed among the groups, and patients receiving darolutamide were less likely to discontinue treatment.

CONCLUSION

This real-world study provides insights into NHA utilization in nmCRPC within the Taiwanese population. Adverse event profiles varied, emphasizing the need for individualized treatment decisions. The study underscores the importance of regional considerations and contributes valuable data for optimizing treatment outcomes in nmCRPC.

Physician preferences for nonmetastatic castration-resistant prostate cancer treatment in China

Introduction

The treatment preferences of Chinese physicians who treat nonmetastatic castration-resistant prostate cancer (nmCRPC) and how they weigh the benefits and risks of nmCRPC treatment are still unknown. This study aimed to evaluate Chinese physicians' benefit-risk treatment preferences for nmCRPC and assist in setting nmCRPC treatment goals.

Methods

A paper-based discrete choice experiment (DCE) survey was administered to 80 nmCRPC-treating physicians. DCE responses were analyzed to produce the preference weight and the relative importance score for each attribute level. The marginal rate of substitution (MRS) was used to quantify the amount of overall survival (OS) physicians were willing to trade for a reduction in treatment-related adverse events (AEs). We further conducted the exploratory analysis, stratifying physicians from 5 perspectives into different subgroups and examining the treatment preferences and OS trade-off in each subgroup.

Results

In terms of efficacy attributes, physicians placed greater emphasis on OS than time to pain progression. With regard to safety attributes, serious fracture was perceived as the most important AE by physicians, followed by serious fall, cognitive problems, skin rash, and fatigue. In the exploratory analysis, we found generally that physicians with less clinical practice experience and those from more economically developed regions placed more emphasis on AEs and were willing to give up more of their patients' OS to reduce the risk of AEs.

Conclusion

Physicians from mainland China value the importance of minimizing treatment-related AEs when considering different treatment options for patients with nmCRPC, and they are willing to trade a substantial amount of OS to avoid AEs.

A multidisciplinary approach to address unmet needs in the management of patients with non-metastatic castration-resistant prostate cancer

BACKGROUND

With the availability of second-generation androgen receptor inhibitors (SGARIs), the treatment landscape has changed dramatically for patients with nonmetastatic castration-resistant prostate cancer (nmCRPC). In clinical trials, the SGARIs (apalutamide, enzalutamide, darolutamide) increased metastasis-free survival (MFS), overall survival (OS), and patient quality of life compared to placebo. These drugs were subsequently integrated into nmCRPC clinical practice guidelines. With advances in radiographic imaging, disease assessment, and patient monitoring, nmCRPC strategies are evolving to address limitations related to tracking disease progression using prostate-specific antigen (PSA) kinetics.

METHODS

A panel of 10 multidisciplinary experts in prostate cancer conducted reviews and discussions of unmet needs in the management and monitoring of patients with nmCRPC in order to develop consensus recommendations.

RESULTS

Across the SGARI literature, patient MFS and OS are generally comparable for all treatments, but important distinctions exist regarding short- and long-term drug safety profiles and drug-drug interactions. With respect to disease monitoring, a substantial proportion of patients using SGARIs may experience disease progression without rising PSA levels, suggesting a need for enhanced radiographic imaging in addition to PSA monitoring. Recent data also indicate that novel prostate-specific membrane antigen positron emission tomography radiotracers provide enhanced accuracy for disease detection, as compared to conventional imaging.

CONCLUSIONS

Clinical decision-making in nmCRPC has become more complex, with new opportunities to apply precision medicine to patient care. Multidisciplinary teams can ensure that patients with nmCRPC receive optimal and individualized disease management.

Risk of Fractures and Falls in Men with Advanced or Metastatic Prostate Cancer Receiving Androgen Deprivation Therapy and Treated with Novel Androgen Receptor Signalling Inhibitors: A Systematic Review and Meta-analysis of Randomised Controlled Trials

CONTEXT

The addition of androgen receptor signalling inhibitors (ARSIs) to standard androgen deprivation therapy (ADT) has improved survival outcomes in patients with advanced prostate cancer (PCa). Advanced PCa patients have a higher incidence of osteoporosis, compounded by rapid bone density loss upon commencement of ADT resulting in an increased fracture risk. The effect of treatment intensification with ARSIs on fall and fracture risk is unclear.

OBJECTIVE

To assess the risk of falls and fractures in men with PCa treated with ARSIs.

EVIDENCE ACQUISITION

A systematic review of EMBASE, MEDLINE, The Cochrane Library, and The Health Technology Assessment Database for randomised control trials between 1990 and June 2023 was conducted in accordance with Preferred Reporting Items for Systematic Review and Meta-analyses guidance. Risk ratios were estimated for the incidence of fracture and fall events. Subgroup analyses by grade of event and disease state were conducted.

EVIDENCE SYNTHESIS

Twenty-three studies were eligible for inclusion. Fracture outcomes were reported in 17 studies (N = 18 811) and fall outcomes in 16 studies (N = 16 537). A pooled analysis demonstrated that ARSIs increased the risk of fractures (relative risk [RR] 2.32, 95% confidence interval [CI] 2.00-2.71; p < 0.01) and falls (RR 2.22, 95% CI 1.81-2.72; p < 0.01) compared with control. A subgroup analysis demonstrated an increased risk of both fractures (RR 2.13, 95% CI 1.70-2.67; p < 0.01) and falls (RR 2.19, 95% CI 1.53-3.12; p < 0.0001) in metastatic hormone-sensitive PCa patients, and an increased risk of fractures in the nonmetastatic (RR 2.27, 95% CI 1.60-3.20; p < 0.00001) and metastatic castrate-resistant (RR 2.85, 95% CI 2.16-3.76; p < 0.00001) settings. The key limitations include an inability to distinguish fragility from pathological fractures and potential for a competing risk bias.

CONCLUSIONS

Addition of an ARSI to standard ADT significantly increases the risk of fractures and falls in men with prostate cancer.

PATIENT SUMMARY

We found a significantly increased risk of both fractures and falls with a combination of novel androgen signalling inhibitors and traditional forms of hormone therapy.

Enzalutamide versus Abiraterone Plus Prednisolone for Nonmetastatic Castration-Resistant Prostate Cancer: A Sub-Analysis from the ENABLE Study for PCa

Enzalutamide (ENZ) and abiraterone plus prednisolone (ABI) can improve the survival of patients with castration-resistant prostate cancer (CRPC). However, the agent that is more effective against nonmetastatic CRPC remains unclear. To evaluate the agent that can be used as the first-line treatment for CRPC, an investigator-initiated, multicenter, randomized controlled trial (ENABLE Study for PCa) including both metastatic and nonmetastatic CRPC was conducted in Japan. The prostate-specific antigen (PSA) response rate, overall survival, some essential survival endpoints, and safety of patients with nonmetastatic CRPC were also analyzed. In this subanalysis, 15 and 26 patients in the ENZ and ABI arms, respectively, presented with nonmetastatic CRPC. There was no significant difference in terms of the PSA response rate between the ENZ and ABI arms (80% and 64%, respectively; p = 0.3048). The overall survival did not significantly differ between the two arms (HR: 0.68; 95% CI: 0.22-2.14, p = 0.5260). No significant differences were observed in terms of radiographic progression-free survival and cancer-specific survival between the ENZ and ABI arms (HR: 0.81; 95% CI: 0.35-1.84; p = 0.6056 and HR: 0.72; 95% CI: 0.19-2.73; p = 0.6443, respectively). Only four and six patients in the ENZ and ABI arms, respectively, had ≥grade 3 adverse events. ABI and ENZ had similar efficacy and safety profiles in patients with nonmetastatic CRPC.

Adverse events and costs among non-metastatic castration-resistant prostate cancer patients

BACKGROUND

Limited real-world evidence exists on the economic burden of adverse events (AEs) to the healthcare system among patients with non-metastatic castration-resistant prostate cancer (nmCRPC) treated with second-generation androgen receptor antagonists (ARAs). Current data is needed to understand real-world clinical event rates among ARAs and the cost of these events.

OBJECTIVES

Describe the incidence of non-central nervous system (CNS)-related AEs and CNS-related AEs among nmCRPC patients treated in the United States with second-generation ARAs (apalutamide and enzalutamide) and evaluate healthcare resource utilization (HCRU) and costs for these patients.

METHODS AND STUDY DESIGN

This was a retrospective observational cohort study using claims data from Optum Clinformatics Data Mart to identify adult males with prostate cancer, castration, no metastases, and >1 claim for apalutamide or enzalutamide. The study was conducted from January 2017 to March 2020, with a patient index identification period from January 2018 to December 2019. AEs were classified as CNS-related or non-CNS-related.

RESULTS

Of 605 patients (156 apalutamide and 449 enzalutamide), most were ≥65 years (94%) and had ≥1 non-CNS-related AE (55%). Many had ≥1 CNS-related AE (32%). Pain (12%) and arthralgia (11%) were the most frequently reported non-CNS-related AEs. Fatigue/asthenia (14%) and dizziness (7%) were the most frequently reported CNS-related AEs. Among patients with versus without non-CNS-related AEs, 34% versus 8% had emergency room (ER) events, and 25% versus 2% had inpatient events. Among patients with versus without CNS-related AEs, 41% versus 14% had ER events, and 38% versus 4% had inpatient events. Adjusted per-patient per-year cost (in 2020 USD) differences were significant between patients with and without non-CNS-related AEs ($30,765, p = 0.0018) and between patients with and without CNS-related AEs ($40,689, p = 0.0017).

CONCLUSION

There is significant HCRU and cost burden among nmCRPC patients treated with ARAs developing AEs, highlighting the need for treatments with improved tolerability. Additional studies are warranted to include recently approved agents.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[Novel hormone treatment for advanced prostate cancer]

The systemic treatment of advanced prostate cancer (PCa) has undergone an absolute revolution in the past decade. Numerous new substances have been approved for all stages of advanced disease and treatment has been increasingly intensified. The focus continues to be on substances with an effect on the androgen receptor axis. In this review, approved treatment options for metastatic hormone-sensitive PCa (mHSPC), non-metastatic castration-refractory PCa (nmCRPC) and metastatic castration-refractory PCa (mCRPC) are summarized. A special focus is on novel hormone therapeutic agents. Based on recent trial data, potential triple combinations for mHSPC as well as treatment sequence options and novel targeted agents for mCRPC are also highlighted.

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.

Impact of darolutamide on local symptoms: pre-planned and post hoc analyses of the ARAMIS trial

OBJECTIVE

To assess, the effect of darolutamide (a structurally distinct androgen receptor inhibitor) on urinary and bowel symptoms, using data from the phase III ARAMIS trial (NCT02200614) that showed darolutamide significantly reduced the risk of metastasis and death versus placebo.

PATIENTS AND METHODS

Patients with non-metastatic castration-resistant prostate cancer (nmCRPC) were randomised 2:1 to darolutamide (n = 955) or placebo (n = 554). Local symptom control was assessed by first prostate cancer-related invasive procedures and post hoc analyses of time to deterioration in quality of life (QoL) using total urinary and bowel symptoms, and individual questions for these symptoms from the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Prostate Cancer Module subscales and Functional Assessment of Cancer Therapy-Prostate prostate cancer subscale. Prostate-specific antigen (PSA) responses were correlated with urinary and bowel adverse events (AEs).

RESULTS

Fewer patients receiving darolutamide (4.7%) versus placebo (9.6%) underwent invasive procedures, and time to first procedure was prolonged with darolutamide (hazard ratio 0.42, 95% confidence interval 0.28-0.62). Darolutamide significantly (P < 0.01) delayed worsening of QoL for total urinary and bowel symptoms versus placebo, mostly attributed by individual symptoms of urinary frequency, associated pain, and interference with daily activities. AEs of urinary retention and dysuria were less frequent with darolutamide, and greater PSA response (≥90%, ≥50% and <90%, <50%) among darolutamide-treated patients was associated with lower incidences of urinary retention (2.2%, 4.2%, 5.1%) and dysuria (0.5%, 3.2%, 5.1%), respectively.

CONCLUSIONS

Darolutamide demonstrated a positive impact on local disease recurrence and symptom control in patients with nmCRPC, delayed time to deterioration in QoL related to urinary and bowel symptoms, and a favourable safety profile showing similar incidence of urinary- and bowel-related AEs compared with placebo.

Safety differences across androgen receptor inhibitors in nonmetastatic castration-resistant prostate cancer

Approval of apalutamide, enzalutamide and darolutamide has transformed the treatment landscape and guideline recommendations for patients with nonmetastatic castration-resistant prostate cancer but now raises the issue of decision-making regarding treatment selection. In this commentary, we discuss the efficacy and safety of these second-generation androgen receptor inhibitors and propose that for patients with nonmetastatic castration-resistant prostate cancer, safety considerations for these treatments are especially important. We examine these considerations in the context of patient and caregiver preferences as well as patient clinical characteristics. We further posit that consideration of treatments' safety profiles should include not only the initial direct impacts from potential treatment-emergent adverse events and drug-drug interaction events, but also the full cascade of potentially avoidable healthcare complications.

Darolutamide Maintenance in Patients With Metastatic Castration-Resistant Prostate Cancer With Nonprogressive Disease After Taxane Treatment (SAKK 08/16)

PURPOSE

To assess the efficacy and safety of darolutamide maintenance after successful taxane chemotherapy in patients with metastatic castration-resistant prostate cancer (mCRPC).

PATIENTS AND METHODS

Swiss Group for Clinical Cancer Research (SAKK) 08/16 is a randomized phase II study. Patients with mCRPC who received prior androgen-receptor pathway inhibitors (ARPIs) and subsequently had nonprogressive disease on a taxane were randomly assigned to darolutamide 600 mg twice a day or placebo twice a day. The primary end point was radiographic progression-free survival (rPFS) at 12 weeks. Secondary end points were rPFS, event-free survival, overall survival (OS), prostate-specific antigen (PSA) 50% response rate, and adverse events.

RESULTS

Overall, 92 patients were recruited by 26 centers. Prior taxane was docetaxel in 93% and cabazitaxel in 7%. Prior ARPI was abiraterone in 60%, enzalutamide in 31%, and both in 9%. rPFS at 12 weeks was significantly improved with darolutamide (64.7% v 52.2%; P = .127). Median rPFS on darolutamide was 5.5 versus 4.5 months on placebo (hazard ratio [HR], 0.54; 95% CI, 0.32 to 0.91; P = .017), and median event-free survival was 5.4 versus 2.9 months (HR, 0.46; 95% CI, 0.29 to 0.73; P = .001). PSA 50% response rate was improved (22% v 4%; P = .014). Median OS for darolutamide was 24 versus 21.3 months for placebo (HR, 0.62; 95% CI, 0.3 to 1.26; P = .181). Treatment-related adverse events were similar in both arms.

CONCLUSION

SAKK 08/16 met its primary end point, showing that switch maintenance with darolutamide after prior taxane chemotherapy and at least one ARPI resulted in a statistically significant but clinically modest rPFS prolongation with good tolerability. The median OS with darolutamide maintenance appears promising. Should these findings be confirmed in a larger trial, maintenance treatment could be a novel strategy in managing patients with mCRPC, especially those who responded well to prior ARPI.

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.

Functional impact of androgen-targeted therapy on patients with castration-resistant prostate cancer

Context

Second-generation androgen receptor inhibitors (ARIs) extend metastasis-free survival, prolong overall survival, and delay symptoms when added to androgen deprivation therapy for the treatment of castration-sensitive or castration-resistant prostate cancer (CRPC). However, ARIs may adversely impact physical and cognitive function, thereby decreasing quality of life and prognosis.

Objective

To evaluate the evidence regarding the potential effects of ARIs on physical and cognitive function and to contextualize how drug-related adverse effects may influence treatment decisions in CRPC.

Evidence acquisition

We performed a literature search using MEDLINE from January 1998 to June 2020 using terms relating to prostate cancer, androgen deprivation, and physical and cognitive function. We selected 61 publications for analysis.

Evidence synthesis

Treatment-induced deterioration in physical and cognitive function may impair the independence and well-being of patients with CRPC. Patient-reported outcomes from clinical trials of ARIs provide quantitative evidence of their impact on these domains, which appears to vary between ARIs, reflecting the different adverse event profiles of these agents. Thus, the risk of physical or cognitive dysfunction may be managed or mitigated by appropriate selection of treatment options. Studies in patients with CRPC have assessed the cognitive effects of ARIs with validated instruments, whereas quantitative analysis of the impact on physical function has been limited.

Conclusion

Several validated instruments utilized for the assessment of physical and cognitive function in clinical studies have been adapted for clinical practice; however, consensus on the standardization of these assessments is required. Future clinical studies employing validated tools may generate data on the impact of ARIs and guide treatment decisions for patients with CRPC.

Patient summary

We review the hormonal therapies used to treat men with prostate cancer and the effects they have on physical and cognitive function. We discuss how to measure these effects and how this may assist when choosing treatment.

The Overall Survival and Safety of Men with Metastatic Hormone-Sensitive Prostate Cancer Treated with Combination Therapy of Novel Androgen Receptor Antagonists and Androgen-Deprivation Therapy: A Systematic Review and Meta-Analysis

Background

Several novel androgen receptor antagonists have been introduced into the treatment of metastatic hormone-sensitive prostate cancer (mHSPC). We conducted a meta-analysis to evaluate the survival and safety of the combination therapy of novel androgen receptor antagonist and androgen-deprivation therapy (ADT) in patients with mHSPC.

Methods

Electronic databases were searched for randomized controlled trials (RCTs) of ADT combined with novel androgen receptor antagonists compared with ADT alone in men with mHSPC. Revman 5.4 and STATA 14.0 were used to performed the meta-analysis, and hazard ratio (HR) and odds ratio (OR) with 95% confidence intervals (CIs) were used as the measurement indicators of outcome variables.

Results

Six RCTs were eventually identified for meta-analysis. Compared with ADT alone, the combination therapy of novel androgen receptor antagonists and ADT can significantly improve the overall survival (OS) and progression-free survival (PFS), as the pooled HR were 0.66, 95%CI (0.60, 0.72), P < 0.00001 and 0.43, 95%CI (0.34, 0.54), P < 0.00001, respectively, despite increasing the risk of any serious adverse events (OR: 1.18, 95%CI (1.04, 1.33), P=0.008). Discussion. This study showed that compared with ADT alone, the combination therapy of novel androgen receptor antagonists and ADT can significantly improve the survival status of mHSPC patients, while it increases the risk of serious adverse events.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Real-world burden of adverse events for apalutamide- or enzalutamide-treated non-metastatic castration-resistant prostate cancer patients in the United States

Background

Second-generation androgen receptor inhibitors (ARIs) have been associated with adverse events (AEs) such as fatigue, falls, fractures, and rash in non-metastatic castration-resistant prostate cancer (nmCRPC) patients as identified in clinical trials. The objectives of this study were to describe the incidence and management of AEs in patients receiving apalutamide and enzalutamide.

Methods

This retrospective chart review study was conducted in nmCRPC-treating sites in the United States. Patients starting apalutamide or enzalutamide between February 1, 2018 and December 31, 2018 were included and any AEs they experienced were recorded. AEs, including those considered to be of special interest as defined in the pivotal clinical trials of the second-generation ARIs, were analyzed and grouped retrospectively in this study. Detailed chart data (patient demographics, clinical characteristics, treatment history, type of AE, outcomes, and resource utilization) were then collected for a randomly selected subset among patients with ≥1 AE to characterize AEs and their management. Descriptive results were summarized.

Results

Forty-three sites participated in the study. A total of 699 patients were included, of whom 525 (75.1%) experienced ≥1 AE. The most common AEs were fatigue/asthenia (34.3%), hot flush (13.9%), and arthralgia (13.6%). In the subset of 250 patients randomly selected from those who experienced ≥1 AE, patients were primarily White (72.0%), the mean age was 71 years, 86.0% had an Eastern Cooperative Oncology Group score of 0–1 at nmCRPC diagnosis, and the average prostate specific antigen (PSA) value at diagnosis was 23.2 ng/mL. PSA-doubling time < 10 months was chosen as reason to initiate treatment in 40% of patients. The median duration of follow-up was 1.1 years, with 14.4% of patients progressing to metastasis by end of study period. Grade 3–4 and Grade 5 AEs occurred in 14.4 and 0.4% of patients, respectively. Actions taken to manage AEs included AE-directed treatment (38.0%), ARI discontinuation (10.4%), dose reduction (7.6%), and AE-related hospitalization (4.8%).

Conclusions

This study highlights the burden of AEs among nmCRPC patients treated with apalutamide or enzalutamide, providing a relevant real-world benchmark as clinical trial evidence and the treatment landcape for nmCRPC continues to evolve.

An oral first-in-class small molecule RSK inhibitor suppresses AR variants and tumor growth in prostate cancer

Ribosomal S6 kinase has been shown to play a key role in cellular resistance to endocrine therapy in prostate cancer through its regulation of YB‐1/androgen receptor (AR) signaling. PMD‐026, an oral first‐in‐class small molecule kinase inhibitor, is the first identified ribosomal S6 kinase inhibitor. This study investigated the effect of PMD‐026 on YB‐1/AR signaling and its antitumor effect in prostate cancer in vitro and in vivo. Castration‐resistant prostate cancer 22Rv1 cells that express high‐level AR variants were used in this study. The effect of PMD‐026 on YB‐1/AR signaling was investigated by quantitative real‐time PCR and western blot analysis. The effects of PMD‐026 on prostate cancer cells were investigated by cytotoxicity analysis, apoptosis assay, and cell cycle assay in vitro and a mouse castration model in vivo. PMD‐026 decreased YB‐1 phosphorylation as well as AR V7 mRNA and AR variant expressions in 22Rv1 cells. PMD‐026 suppressed cell proliferation alone and in combination with the second‐generation antiandrogens enzalutamide and darolutamide by inducing cellular apoptosis and G2/M arrest. In a mouse xenograft model, PMD‐026 suppressed tumor growth, and the combination of PMD‐026 and enzalutamide inhibited tumor growth more prominently than single treatments. Our results demonstrate an excellent antitumor effect of the novel ribosomal S6 kinase inhibitor PMD‐026 and the combination effect with the antiandrogen enzalutamide in castration‐resistant prostate cancer. These findings warrant a clinical trial of PMD‐026 in prostate cancer patients.

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).

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.

Novel Treatment Strategy Using Second-Generation Androgen Receptor Inhibitors for Non-Metastatic Castration-Resistant Prostate Cancer

Non-metastatic castration-resistant prostate cancer (nmCRPC) is defined by a progressively rising prostate-specific antigen level, despite a castrate level of testosterone, in the absence of obvious radiologic evidence of metastatic disease on conventional imaging modalities. As a significant proportion of patients with nmCRPC develop metastatic diseases, the therapeutic goals of physicians for these patients are to delay metastasis development, preserve quality of life, and increase overall survival (OS). Since 2018, the treatment of nmCRPC has changed dramatically with the introduction of second-generation androgen receptor inhibitors, such as enzalutamide (ENZA), apalutamide (APA), and darolutamide (DARO). These drugs demonstrated substantial improvements in metastasis-free survival (MFS) and OS in phase III randomized clinical trials. In addition, these drugs have an excellent safety profile, preserve quality of life, and can delay disease-related symptoms. A recently published indirect meta-analysis reported that APA and ENZA showed better findings in MFS and that DARO had relatively fewer adverse effects. However, in the absence of a direct comparison, careful interpretation is required. Thus, APA, ENZA, and DARO should be considered the new standard drugs for treating nmCRPC.