Comparison of Oncologic Outcomes Between Two Alternative Sequences with Abiraterone Acetate and Enzalutamide in Patients with Metastatic Castration-Resistant Prostate Cancer: A Systematic Review and Meta-Analysis

Real-life data of abiraterone acetate and enzalutamide treatment in post-chemotherapy metastatic castration-resistant prostate cancer in Poland

Background

Abiraterone acetate (ABI) and Enzalutamide (ENZA) are second-generation hormone drugs that show breakthrough activity in post-chemotherapy, metastatic castration-resistant prostate cancer (mCRPC). The leading oncological and urological guidelines indicate both drugs with the same strong recommendation. There is a lack of randomized trials which compare the efficacy of ABI and ENZA. The current study aimed to compare the effectiveness of the drugs with an analysis of prognostic factors related to those drugs.

Patients and methods

The study included 420 patients with docetaxel (DXL) pretreated mCRPC from seven Polish cancer centers. Patients were treated according to inclusion and exclusion criteria in the Polish national drug program (1000 mg ABI and 10 mg prednisone, n=76.2%; ENZA, 160 mg; n=23.8%). The study retrospectively analyzed the overall survival (OS), time to treatment failure (TTF), PSA 50% decline rate (PSA 50%) and selected clinic-pathological data.

Results

In the study group, the median OS was 17 months (95% CI: 15.6-18.3). The median OS (26.1 vs. 15.7 mo.; p<0.001), TTF (14.2 vs. 7.6 mo.; p<0.001) and PSA 50% (87.5 vs. 56%; p<0.001) were higher in ENZA than in ABI treatment. Multivariate analysis shows that ENZA treatment and PSA nadir <17.35 ng/mL during or after DXL treatment were related to longer TTF. ENZA treatment, DXL dose ≥750 mg, PSA nadir <17.35 ng/mL during or after DXL treatment was related to longer OS.

Conclusions

ENZA treatment may be related to more favorable oncological outcomes than ABI treatment in the studied Polish population of patients. A 50% decline in PSA is an indicator of longer TTF and OS. Due to the non-randomized and retrospective nature of the analysis, the current results require prospective validation.

Quality of life for men with metastatic castrate-resistant prostate cancer participating in an aerobic and resistance exercise pilot intervention

BACKGROUND

Following a prostate cancer diagnosis, disease and treatment-related symptoms may result in diminished quality of life (QoL). Whether exercise improves QoL in men with metastatic castrate-resistant prostate cancer (mCRPC) is not fully understood.

METHODS

We conducted a 3-arm pilot randomized controlled trial to assess the feasibility, acceptability, safety, and efficacy of a 12-week remotely monitored exercise program among men with mCRPC. Here we report qualitative changes in QoL, consistent with the guidelines for pilot trials. Men were randomized to control, aerobic exercise, or resistance exercise. Exercise prescriptions were based on baseline cardiorespiratory and strength assessments. QoL outcomes were evaluated using self-reported questionnaires (e.g., QLQ-C30, PROMIS Fatigue, Pittsburgh Sleep Quality Index (PSQI), EPIC-26) collected at baseline and 12 weeks.

RESULTS

A total of 25 men were randomized (10 control, 8 aerobic, 7 resistance). Men were predominately white (76%) with a median age of 71 years (range: 51-84) and 10.5 years (range: 0.9-26.3) post prostate cancer diagnosis. The men reported poor sleep quality and high levels of fatigue at enrollment. Other baseline QoL metrics were relatively high. Compared to the controls at 12 weeks, the resistance arm reported some improvements in social function and urinary irritative/obstruction symptoms while the aerobic arm reported some improvements in social function and urinary incontinence, yet worsening nausea/vomiting. Compared to the resistance arm, the aerobic arm reported worse urinary irritative/obstruction symptoms and self-rated QoL, yet some improvements in emotional function, insomnia, and diarrhea.

CONCLUSIONS

The 3-month exercise intervention pilot appeared to have modest effects on QoL among mCRPC survivors on ADT. Given the feasibility, acceptability, and safety demonstrated in prior analyses, evaluation of the effect of the intervention on QoL in a larger sample and for extended duration may still be warranted.

Descriptive study on burden and communication of fatigue among castration-resistant prostate cancer patients in Japan

OBJECTIVE

Prostate cancer is a common malignancy and patients may progress to castration-resistant prostate cancer (CRPC). Among patients with CRPC, fatigue is a common symptom associated with current treatments. The aim of this real-world study was to describe patient-reported fatigue in Japanese patients treated with androgen receptor-axis-targeted therapies for CRPC.

METHODS

Data of this observational study were collected in a quantitative phase for the description of patient-reported fatigue, and a qualitative phase for elicitation of fatigue perception and barriers to reporting fatigue.

RESULTS

In the quantitative phase (N = 22), fatigue was investigated in two formats: symptoms report and Brief Fatigue Inventory (BFI). In the report of the symptoms, 12 patients reported tiredness, and four moderate-to-severe tiredness during treatment. In the BFI, all patients reported fatigue; eight reported moderate-to-severe fatigue. The most affected BFI domain was mood: five patients reporting moderate-to-severe impact. In interviews (qualitative phase; N = 8), diverse patient experience on fatigue was observed, including apathetic feelings, affected speed and distance during the walk, negative impact on profession, housework, or driving, reduced outgoing activity, and difficulty in enjoying time with grandchildren or travel. Five out of eight patients communicated fatigue to their physicians but received diverse reactions.

CONCLUSION

Patient interviews highlighted the impact of fatigue on patients' lives and difficulties in communicating fatigue to physicians. Fatigue frequency after medication may need to be monitored and its burden is considered to provide treatment that meets the needs, wishes, and circumstances of each patient. Further research is needed to elucidate how fatigue affects patients' lives, and underscore patient-physician communication difficulties.

Abiraterone, Orteronel, Enzalutamide and Docetaxel: Sequential or Combined Therapy?

Objective: To summarize the current therapeutic status using chemotherapeutic agent docetaxel and endocrine therapeutic agents (ARAT, abiraterone, orteronel or enzalutamide) for the treatment of metastatic castration-resistant prostate cancer (mCRPC), including sequential therapy and combined therapy, to promote the consensus on the optimal regimen for achieving superior treatment efficacy.

Methods: Through literature search in PubMed, articles with the following relevant keywords were collected and anlyzed: CRPC, abiraterone, orteronel and enzalutamide, median survival, overall survival, prostate specific antigen (PSA), PSA response rate and median radiologic progression-free survival.

Results: Fifty-eight articles were obtained and analyzed in this review. These articles included androgen axis-targeting agents after docetaxel, docetaxel after androgen axis-targeting agents, Triple sequential and combination therapy, covering four current drugs for mCRPC treatment: docetaxel, abiraterone, orteronel, and enzalutamide. It was found that there may be some cross-resistance between androgen axis-targeting agents, which will reduce the efficacy of subsequent drug treatment. Although neither of the studies of using combination therapy showed serious drug toxicity, the efficacy of sequential therapy was not as good as expected. Most adverse reactions after treatment were reported to be level 1–2.

Conclusion: Based on the results of the current studies, abiraterone followed by enzalutamide treatment is the best sequential treatment for most docetaxel-naïve patients. This treatment achieves not only good OS, but also PFS and PSA response rates. In addition, for patients who have previously failed docetaxel treatment, enzalutamide is the best choice as the subsequent treatment.

Efficacy and safety of bipolar androgen therapy in mCRPC after progression on abiraterone or enzalutamide: A systematic review

PURPOSE

To further determine the efficacy and safety of bipolar androgen therapy (BAT) on patients with metastatic castration-resistant prostate cancer (mCRPC) after progression on abiraterone (ABI) or enzalutamide (ENZA).

MATERIALS AND METHODS

We systematically searched the Pubmed, Web of Science and ClinicalTrials.gov up to June 2021. Literature review, study selection, and data extraction were conducted by 2 reviewers. Risk of bias was assessed according to the methodology of the European Association of Urology (EAU). A systematic review and pooled analysis were performed. The primary outcomes were PSA50 after BAT and AR-targeted therapy rechallenge, objective response rate (ORR) after BAT, and AEs after BAT. The definition of PSA50 was that participants achieving a PSA decline ≥50% according to Prostate Cancer Working Group (PCWG2) criteria. The ORR determined by determined by Response Evaluation Criteria in Solid Tumors (RECIST) included patients experienced partial response (PR) or complete response (CR).

RESULTS

In a total of 74 unique records, 5 studies were eligible for inclusion. Participants who underwent BAT achieved PSA50 of 0.26 (95% CI [0.20, 0.32]) and objective response rate (ORR) of 0.32 (95% CI [0.21, 0.44]). Patients completed BAT proceeded to AR-target therapy (ABI or ENZA) achieved moderate response (PSA50 0.54, 95% CI [0.30, 0.76]). Based on our multiple subgroup analysis, type of post-BAT AR-target therapy had a strong impact on PSA50 of AR-target therapy rechallenge. Most of adverse events (AEs) were low grade.

CONCLUSIONS

The present study indicated that BAT could induce clinical responses in mCRPC patients after progression on ABI or ENZA, with an acceptable side effects profile. BAT could also be able to restore sensitivity to ABI and ENZA rechallenge in a subset of patients.

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.

Treatment-Emergent Co-Morbidities and Survival in Patients With Metastatic Castration-Resistant Prostate Cancer Receiving Abiraterone or Enzalutamide

Secondary hormone therapy, abiraterone and enzalutamide, has improved outcomes for metastatic castration-resistant prostate cancer (mCRPC) and prolonged patients' lives significantly. Various studies have compared the cancer-related outcomes, adverse effects, and drug-induced comorbidities in patients with mCRPC who are treated with abiraterone or enzalutamide. However, few studies have explored associations between survival and comorbidities or comprehensive analyzed newly developed comorbidities during and after secondary hormone therapy. We attempted to clarify whether the Charlson comorbidity index (CCI) overall or itemized is predictive for overall survival, and we compared newly developed comorbidities between abiraterone and enzalutamide groups. We extracted data about expenses and comorbidities for patients who have mCRPC, received abiraterone and enzalutamide and met pre-examination operation criteria between September 2016 and December 2017 from the Taiwan National Health Insurance database. A total of 1153 patients with mCRPC who received abiraterone (n = 782) or enzalutamide (n = 371) with or without previous chemotherapy were included. We used the propensity score to match confounding factors, including age, pre-existing comorbidities, and precipitating factors for comorbidity (e.g., hypertension, hyperlipidemia), to eliminate selection bias in the comparison of newly developed comorbidities. Cox regression analysis was used for overall survival. We found that enzalutamide is superior to abiraterone with regard to overall survival. Our study revealed that there is no statistically significant difference in development of new comorbidities between abiraterone and enzalutamide group. Moreover, the CCI score, rather than any single item of the CCI, was a statistically significant predictor for overall survival.

Optimal treatment sequencing of abiraterone acetate plus prednisone and enzalutamide in patients with castration-resistant metastatic prostate cancer: A systematic review and meta-analysis

PURPOSE

To evaluate the impact of the hormonal treatment sequencing including abiraterone acetate plus prednisone (AAP) and enzalutamide (ENZ) in mCRPC, and determine which sequence provides more benefits for patients.

METHODS

Studies published in English between 1 January 2013 and 30 September 2017 were identified in PubMed and EMBASE electronic databases. Studies assessing the efficacy of treatment sequences, based on AAP and ENZ, in mCRPC patients, were eligible for analysis.

RESULTS

Seventeen studies met the inclusion criteria. Two assessed both treatment sequences AAP → ENZ and ENZ → AAP; it was found that sequence of AAP → ENZ showed a statistically significantly longer PSA-PFS than the observed in ENZ → AAP (pooled HR: 0,54; 95% CI; 0,36-0,82; p < 0,05). The nine studies analysing Doc → AAP → ENZ sequence, revealed favourable results in terms of PFS. The 5 studies which analysed AAP → ENZ sequence, show a decrease in PSA levels ≥ 50% in 11-41% of patients treated with enzalutamide after previous treatment with AAP. In the two studies that analysed the Doc → ENZ → AAP sequence, PSA response rates were much lower than those reported with Doc → AAP → ENZ, with decreases in PSA ≥ 30 of 3-18% and PSA ≥ 50 of 8-11%.

CONCLUSION

Significant clinical efficacy of AAP administered as the first-line treatment in mCRPC patients followed by enzalutamide, delaying disease progression, compared with the ENZ → AAP sequence. However, more studies and randomized trials are needed, to validate the best treatment sequencing.

Novel therapies for advanced urologic cancers

PURPOSE OF REVIEW

Systemic treatment of advanced urogenital malignancies has changed significantly in recent years and it will continue to change rapidly in upcoming years. It is the scope of this review article to providing the reader with the most recently approved treatment strategies to be used in daily routine for the individualized and most optimal treatment of our patients.

RECENT FINDINGS

Immunooncological therapy (IOT) has emerged as the treatment of choice in metastatic renal cell carcinoma and we describe the most relevant clinical trials and we will give some differential therapeutic recommendation who might be best treated with which combination therapy considering both oncological efficacy and treatment-related toxicity. New neoadjuvant treatment options for muscle-invasive bladder cancer are reported. With regard to metastatic prostate cancer, the landscape of medical therapy is continuously evolving and the new, and most relevant therapeutic strategies for metastatic hormone-naive and castration-resistant PCA are described. Last, but not least, we highlight latest developments in the management of advanced testis cancer.

SUMMARY

The novel treatment options reported in this article are ready for use in daily routine and already represent or will shortly represent new guideline-recommended therapies.

Anti prostate cancer therapy: Aptamer-functionalized, curcumin and cabazitaxel co-delivered, tumor targeted lipid-polymer hybrid nanoparticles

Prostate cancer (PC) is the most common type of newly diagnosed malignancy in men. Combined chemotherapy has been shown to be an effective strategy for the treatment of PC therapy. Lipid-polymer hybrid nanoparticles (LPNs) are core-shell nanoparticles composed of a polymer core and a lipid shell, which are reported to provide significant advantages for combined PC therapy. This study synthesized an aptamer conjugated ligand and designed an aptamer-functionalized, curcumin (CUR) and cabazitaxel (CTX) co-delivered LPNs (APT-CUR/CTX-LPNs). APT-CUR/CTX-LPNs had a mean size of 121.3 ± 4.2 nm and a positive surface charge (23.5 ± 2.6 mV). Both CUR and CTX were sustained released from LPNs. Aptamer-functionalized APT-CUR/CTX-LPNs exhibited good cell inhibition ability, high tumor accumulation, and remarkable tumor inhibition efficiency at the drug ratio of 2:5 (CUR:CTX). The novel LPNs offers great promise for the double drugs delivery to the prostate cancer cells and tumor xenograft in vivo, showing the potential of synergistic combination therapy for prostate cancer.