A phase II randomised trial of abiraterone acetate plus prednisone in combination with docetaxel or docetaxel plus prednisone after disease progression to abiraterone acetate plus prednisone in patients with metastatic castration-resistant prostate cancer: The ABIDO-SOGUG trial

Current androgen receptor antagonists under investigation for resistant prostate cancer: progress and challenges

INTRODUCTION

Prostate cancer represents a significant oncological challenge, with its natural history predominantly driven by androgen receptor (AR) signaling. The pivotal role of this pathway underscores the rationale for targeting AR activity in therapeutic strategies. However, the development of resistance mechanisms has highlighted the need for advanced therapies to address the complexity of the castration-resistant status.

AREAS COVERED

We analyzed the evolving role of second-generation androgen receptor signaling inhibitors (ARSIs) in the management of non-metastatic and metastatic castration-resistant prostate cancer, we critically examine emerging combination strategies involving ARSIs, novel agents targeting resistance pathways, and the mechanisms underlying treatment resistance. The review also provides insights into future directions for enhancing outcomes. PubMed literature research using keywords related to castration-resistant prostate cancer and its treatments was performed, including the most relevant trials and reviews.

EXPERT OPINION

ARSIs have revolutionized the management of prostate cancer, providing substantial clinical benefits and representing the cornerstone of current treatment paradigms. However, key challenges remain, including determining optimal treatment sequencing, overcoming resistance mechanisms, and tailoring therapies to specific molecular subtypes. Biomarker-driven approaches are critical for refining patient selection and improving therapeutic outcomes. Ongoing trials investigating novel hormonal-axis-directed agents and innovative combination therapies aim to expand the arsenal of effective treatment.

Systemic treatment options for metastatic castration resistant prostate cancer: A living systematic review

Background

Optimal treatment selection for metastatic castration resistant prostate cancer (mCRPC) remains challenging due to evolving standards of care in castration sensitive setting.

Purpose

To synthesize and appraise evidence on systemic therapy for mCRPC patients stratified by prior therapy and HRR alterations informing a clinical practice guideline.

Data Sources

MEDLINE and EMBASE (inception to 5 March 2025) using living search.

Study Selection

Randomized clinical trials assessing systemic therapy in mCRPC.

Data Extraction

Primary outcomes assessed were progression free survival (PFS) and overall survival (OS).

Data Synthesis

This report of the living systematic review (LSR) includes 143 trials with 17,523 patients (59 phase III/IV trials, 8,941 patients; 84 phase II, 8,582 patients). In the setting of prior androgen deprivation therapy (ADT) alone or ADT+docetaxel, treatment benefit was observed with poly (ADP-ribose) polymerase inhibitors (PARPi) in combination with androgen receptor pathway inhibitors (ARPI) for BRCA+ subgroup. In the setting of prior ADT+ARPI or ADT+ARPI+docetaxel, treatment benefit was observed with PARPi monotherapy for BRCA+ subgroup. Treatment benefit with PARPi may be observed for select non-BRCA homologous recombination repair (HRR) alterations (CDK12, PALB2). Treatment benefit was observed with abiraterone, enzalutamide, cabazitaxel, docetaxel (if no prior docetaxel), and Lu177 (if PSMA+) for patients without HRR alterations.

Limitations

Study-level data and indirectness in evidence.

Conclusion

Findings from the current LSR suggest that optimal treatment for mCRPC should be individualized based on prior therapy and HRR alterations. Current evidence favors PARPi alone (ARPI exposed) or in combination with ARPI (ARPI naïve) for patients with BRCA alterations, while ARPI alone, chemotherapy, and Lu177 remain potential options for patients without HRR alterations.

Comparative therapeutic efficacy and safety of first-line and second-line therapies for metastatic castration-resistant prostate cancer: a systematic review and network meta-analysis

Background

There is no cross-sectional comparison on therapeutic and adverse effects for treatments of metastatic castration-resistant prostate cancer (mCRPCa). We aimed to horizontally compare them for all common first-line and second-line therapies.

Methods

We conducted a network meta-analysis with a systematic review in four databases (Pubmed, Web of Science, Embase, and Cochrane Library) up to January 5th, 2025. All randomized controlled trials (RCT) related to mCRPCa treatments with a clear description in study design were included. Endpoints included the radiographic progression-free survival (rPFS), overall survival (OS), time to PSA progression (TTPP), PSA progression rate (PSARR), and adverse events. All data was extracted by two researchers and analyzed with Gemtc package in R and Stata15. This NMA protocol was registered online (ID: CRD42025633178).

Findings

After screening among 33,694 articles, 24 RCTs involving 13,059 cases were included. For first-line treatments, combination therapies with second-generation androgen receptor inhibitors (ARIs) showed superior efficacies in OS [HR of poly(ADP-ribose) polymerase inhibitors (PARPi) + ARI: 0.63 (0.32,1.25)], TTPP [HR of Lu177 + ARI: 0.07 (0.01,0.87)] and PSARR [RR of Lu177 + ARI: 33.02 (15.56,71.62)] with the highest SUCRA (Surface under the Cumulative Ranking Curve) (72%, 91% and 97% respectively). PARPi + ARI also performed best for rPFS (SUCRA: 85%, with an insignificant HR [0.12 (0.02,2.35)]. For post-docetaxel second-line treatments, ARI also emerged as the preferred option. Efficacies of post-ARI second-line treatments were not evaluated due to the lack of related RCTs. No obvious heterogeneity and publication bias was detected during the therapeutic comparison.

Interpretation

This study provided comparative evidence for first-line and post-chemotherapy second-line mCRPCa treatment options. Second-generation ARIs exhibited good efficacy, particularly when combined with other treatments. However, the safety analysis necessitated balance between benefits and adverse events, especially for combination therapies. Stronger evidence is needed through direct comparisons in future clinical trials.

Funding

The study was supported by The National Natural Science Foundation of China (No. 82172568).

Assessment of the therapeutic efficacy of [177Lu]Lu-PSMA-X compared to taxane chemotherapy in taxane-chemo-naïve patients with metastatic castration-resistant prostate cancer: A systematic review and meta-analysis

INTRODUCTION AND AIM

Radioligand therapy (RLT) with 177Lu-labelled prostate specific membrane antigen ([177Lu]Lu-PSMA-X, referring with "PSMA-X" to a generic PSMA chemical compound) inhibitors has emerged as a viable treatment option in metastatic castration resistant prostate cancer patients having previously progressed on taxane and androgen receptor inhibitors. The aim of this study was to perform a systematic review and meta-analysis to assess the therapeutic efficacy of [177Lu]Lu-PSMA-X compared to taxane chemotherapy in taxane-chemo-naïve patients with metastatic castration-resistant prostate cancer.

MATERIALS AND METHODS

Searches in several bibliographic databases were made using relevant key words, and articles published up to March 2024 were included. The endpoints included prostate specific antigen (PSA) response rate (RR), progression-free survival, and overall survival. Individual patient data were pooled when feasible. PSA50 was defined as the median proportion of patients achieving at least a 50% decline in serum PSA from baseline. A meta-analysis of the PSA50 response rate (proportion meta-analysis) was performed, generating pooled estimates and 95% confidence intervals (95% CI).

RESULTS

From the initially selected 8,414 studies published between 2019 and 2023, 24 were included in the [177Lu]Lu-PSMA-X treated group and 17 in the taxane treated group. Our findings show that [177Lu]Lu-PSMA-X RLT yielded comparable PSA50 responses in taxane-naïve patients versus those receiving taxane chemotherapy, despite considerable study heterogeneity. Notably, the taxane-naïve group had more extensive pretreatment.

CONCLUSIONS

This meta-analysis combines the largest cohorts of taxane-naïve mCRPC patients treated with [177Lu]Lu-PSMA-X RLT and taxane-treated mCRPC. It underscores similar PSA50 response rates in both groups, suggesting a potential role for [177Lu]Lu-PSMA-X RLT in taxane-naïve patients who cannot or choose not to undergo chemotherapy.

Intensification Approaches and Treatment Sequencing in Metastatic Castration-resistant Prostate Cancer: A Systematic Review

BACKGROUND AND OBJECTIVE

Recently, research on treatment intensification has gathered momentum, and three novel therapy combinations were approved for metastatic castration-resistant prostate cancer (mCRPC). This systematic review summarizes the current and emerging evidence around intensified strategies for mCRPC and provides guidance for an ideal therapeutic sequencing.

METHODS

Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) guidelines were followed to perform this review. PubMed, EMBASE, Web of Science, Cochrane Library, ClinicalTrials.gov, and major international societies' online proceedings were searched comprehensively until May 15, 2024, for terms related to treatment intensification and sequencing for mCRPC.

KEY FINDINGS AND LIMITATIONS

Overall, 28 clinical trials and 24 ongoing studies of intensification treatments were included in this review. Algorithms of optimal sequencing of approved treatments for mCRPC were outlined according to the use of androgen receptor pathway inhibitors (ARPIs) with or without docetaxel for earlier disease states. In first line, poly(ADP-ribose) polymerase inhibitor + ARPI combinations improve radiographical progression-free survival (rPFS), particularly for those with BRCA1/2 alterations. The AKT inhibitor combination of ipatasertib + abiraterone extends rPFS in those with PTEN loss or PIK3CA/AKT1/PTEN alterations. In those with two or more risk factors for early progression on enzalutamide, radionuclide 177-Lu-PSMA-617 + enzalutamide prolongs progression-free survival. Ongoing research of intensified approaches for mCRPC, and available and potential predictive and prognostic biomarkers are discussed.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Recent approvals and ongoing investigations of single agents and intensification approaches will keep transforming the mCRPC treatment landscape. Improvement of patient profiling applying recognized genomic, molecular, and clinical predictive and prognostic indicators is fundamental to optimize sequential use of available therapies.

Efficacy and safety of interventions for metastatic castration resistant prostate cancer (mCRPC) patients progressing on androgen receptor-axis-targeted (ARAT) therapy: a systematic literature review

BACKGROUND

To review the literature to outline findings from clinical trials assessing interventions for metastatic castration-resistant prostate cancer (mCRPC) in patients who have progressed on androgen receptor-axis-targeted (ARAT) therapies.

METHODS

A systematic literature review was performed to identify trials that assessed the efficacy and safety of interventions used in patients that progressed on prior ARAT therapies. A literature search was conducted using the OVID platform that searched the EMBASE, MEDLINE, and CENTRAL bibliographic databases.

RESULTS

Of the 10,114 citations identified, a total of 36 studies representing 33 unique trials were included in the review. Of the 33 trials, 21 were randomized controlled trials and 12 were single-arm trials. A total of 11 were phase III trials, 13 were phase II trials, and 2 were phase I trials. The majority of included trials were open-label (n = 29) and the remaining were double-blind (n = 4). A total of 16 trials evaluated ARAT based therapies, 7 trials evaluated taxane-based treatments, 10 trials evaluated PARP inhibitors, 8 trials evaluated immunotherapies, and 8 trials evaluated other therapies (i.e. cabozantinib, mitoxantrone, radium-223,177[Lu-177]-PNT2002,177Lu-PSMA-617, samotolisib).

CONCLUSIONS

This systematic review demonstrated there are limited effective treatment options in this patient population. Unlike other cancer types, immunotherapy agents appear to provide little to no benefit. Conversely, agents such as taxane-based chemotherapy (e.g. cabazitaxel) and radionuclide therapy provide the most value in this patient population. Further research is needed to explore new therapies in this disease area and to optimize existing treatment strategies with more effective combination therapies.

Highlighting recent progress in the treatment of men with advanced prostate cancer

PURPOSE OF REVIEW

This review is designed to highlight recent research efforts to optimize treatment strategies in men with advanced prostate cancer.

RECENT FINDINGS

Recent research analyses have suggested an overall survival advantage to treating some men with newly identified metastatic prostate cancer with a "triplet" of androgen deprivation therapy, docetaxel, and an androgen receptor axis-targeted agent (ARAT), but further work remains to refine which men need this aggressive of a treatment approach. Randomized trials have led to the approval of poly(ADP-ribose) polymerase inhibitor/ARAT agent combinations for some men with metastatic castration resistant prostate cancer, but the applicability of this approach to the growing number of men receiving combinations of systemic therapy in the castration-sensitive setting is unclear. Trials to refine use of prostate-specific membrane antigen (PSMA)-directed radiopharmaceuticals are ongoing, while novel treatment approaches targeting mechanisms driving advanced prostate cancer continue to be explored.

SUMMARY

Ongoing research focuses on refining the best combination and sequence of treatments for men with advanced prostate cancer. Future questions remain about use of existing therapies, and novel treatment approaches need to be developed.

Second-line treatment options in metastatic castration-resistant prostate cancer after progression on first-line androgen-receptor targeting therapies: A systematic review and Bayesian network analysis

OBJECTIVE

To summarize and indirectly compare the efficacy and safety of different second-line systematic therapies after first-line androgen-receptor targeting therapies (ARTs) for biomarker-unselected metastatic castration-resistant prostate cancer (mCRPC) patients.

METHODS

Studies published in English up to May 2023 were identified in PubMed, Web of Science and ASCO-GU 2023. Studies accessing the efficacy and safety of second-line systematic therapies after first-line ARTs for biomarker-unselected mCRPC patients were eligible for current systematic review and network meta-analysis (NMA).

RESULTS

Thirty-two studies with 5388 patients and 10 unique treatment modalities met our inclusion criteria. Current evidence suggested that docetaxel (DOC) combined with the same ART as first-line (ART1) (ART1 + DOC) were associated with significantly improved PSA response, PSA progression-free survival (PFS) and clinical or radiographic PFS (rPFS) compared with other reported second-line systematic therapies, including DOC. An increase in toxicity was observed with ART1 + DOC. Our NMA indicated that DOC monotherapy was only inferior to ART1 + DOC in improvement disease outcomes. The incidence of toxicity between patients received second-line DOC and an alternative ART (ART2) was similar.

CONCLUSION

The available evidence reviewed in our work suggested a clinical benefit of DOC nomotherapy and DOC plus ART1 as the second-line systematic therapy for biomarker-unselected mCRPC patients progressed on a first-line ART. More studies and RCTs are needed to evaluate the optimal second-line treatments for mCRPC patients with one prior first-line ART.

Prostate cancer and novel pharmacological treatment options-what's new for 2022?

INTRODUCTION

Androgen deprivation therapy (ADT) plus Androgen Receptor Target Agents (ARTAs) or docetaxel are the actual standard of care in prostate cancer (PC). Several therapeutic options are available for pretreated patients: cabazitaxel, olaparib, and rucaparib for BRCA mutations, Radium-223 for selected patients with symptomatic bone metastasis, sipuleucel T, and 177 LuPSMA-617.

AREAS COVERED

This review the new potential therapeutic approaches and the most impacting recent published trials to provide an overview on the future management of PC.

EXPERT OPINION

Currently, there is a growing interest in the potential role of triplet therapies encompassing ADT, chemotherapy, and ARTAs. These strategies, explored in different settings, appeared to be particularly promising in metastatic hormone-sensitive PC. Recent trials investigating ARTAs plus poly(adenosine diphosphate-ribose) polymerase (PARPi) inhibitor provided helpful insights for patients with metastatic castration resistant disease, regardless of homologous recombination genes status. Otherwise, the publication of the complete data is awaited, and more evidence is required. In advanced settings, several combination approaches are under investigation, to date with contradictory results, such as immunotherapy plus PARPi or chemotherapy. The radionuclide ¹⁷⁷Lu-PSMA-617 proved successful outcomes in pretreated mCRPC patients. Additional studies will better clarify the appropriate candidates to each strategy and the correct treatments' sequence.