Safety and efficacy of apalutamide in Japanese patients with metastatic castration-sensitive prostate cancer receiving androgen deprivation therapy: Final report for the Japanese subpopulation analysis of the randomized, placebo-controlled, phase III TITAN study

Changes in the treatment landscape of metastatic hormone-sensitive prostate cancer following approval of upfront androgen receptor signaling inhibitors: A multicenter study

BACKGROUND

A multicenter database was utilized to examine the current treatment landscape and clinical outcomes among patients with metastatic hormone-sensitive prostate cancer (mHSPC) following approval of upfront androgen receptor signaling inhibitors (ARSIs).

METHODS

We retrospectively analyzed patients with mHSPC who commenced treatment between February 2018 and June 2023. The Kaplan-Meier method was used to assess oncological outcomes, including time to castration-resistant prostate cancer (CRPC), progression-free survival 2 (PFS2, duration from initial treatment to tumor progression during second-line treatment), cancer-specific survival (CSS), and overall survival (OS). Cox regression analyses were performed to determine the impact of treatment choices on oncological outcomes. In addition, the incidence rate of adverse events was assessed.

RESULTS

In total, 829 patients were analyzed; 42.5% received ARSIs with androgen deprivation therapy (ADT), 44.0% received combined androgen blockade (CAB), and 13.5% received ADT alone. Kaplan-Meier curves and multivariate Cox regression analyses indicated higher rates of CRPC and shorter PFS2 in patients treated with CAB versus ARSIs with ADT. By contrast, CSS and OS were not significantly different between the ARSI with ADT group and the CAB group. Grades 3-4 adverse events occurred in 1.9% of patients receiving CAB and 6.0% of those receiving ARSIs with ADT.

CONCLUSIONS

Initial treatment with ARSIs in combination with ADT resulted in a longer time to CRPC and longer PFS2 compared to CAB. Although CAB and ADT alone were associated with fewer adverse events, ARSIs with ADT should be considered a first-line treatment option given its superior oncological outcomes.

Clinical Outcomes and Risk Stratification in Patients With Metastatic Hormone-Sensitive Prostate Cancer Treated With New-Generation Androgen Receptor Signaling Inhibitors

BACKGROUND

Optimal drug selection for metastatic hormone-sensitive prostate cancer (mHSPC) remains unclear. We therefore assessed the clinical outcomes of mHSPC treated with new-generation androgen receptor pathway inhibitors (ARSIs) and identified risk factors associated with the prognosis of mHSPC.

METHODS

We retrospectively reviewed 324 patients with mHSPC who were treated with ARSIs, including abiraterone acetate, enzalutamide, and apalutamide, between January 2018 and December 2022. In addition to assessing the prostate-specific antigen (PSA) response and overall survival (OS) during ARSI treatment, we investigated several potential risk factors for a poor OS in patients with mHSPC.

RESULTS

Patients with a ≥ 90% PSA reduction (hazard ratio [HR]: 0.24, 95% confidence interval [CI], 0.10-0.58; P = .002) and those whose PSA declined to ≤ 0.2 ng/mL (HR: 0.22, 95% CI, 0.08-0.63; P = .005) showed significantly better OS than other patients. Gleason grade group 5 (GG5), presence of liver metastasis, and an LDH ≥ 250 U/L were identified as prognostic factors significantly associated with a poor OS, with HRs of 2.31 (95% CI, 1.02-5.20; P = .044), 7.87 (95% CI, 2.61-23.8; P < .001) and 3.21 (95% CI, 1.43-7.23; P = .005).

CONCLUSION

We identified GG5, the presence of liver metastasis, and elevated LDH at the diagnosis as significant factors predicting the OS of mHSPC, but the choice of ARSIs did not affect the prognosis. The potential prognostic impact of these markers requires further investigation.

Clinical Outcomes of Patients with High-risk Metastatic Hormone-naïve Prostate Cancer: A 3-year Interim Analysis of the Observational J-ROCK Study

BACKGROUND

Androgen deprivation therapy (ADT), administered alone, as combined androgen blockade (CAB) or as ADT plus androgen receptor signalling inhibitors (ARSIs) or ADT plus docetaxel, is the standard treatment for metastatic hormone-naïve prostate cancer (mHNPC) in Japanese real-world practice.

OBJECTIVE

To investigate treatment patterns and clinical outcomes in LATITUDE criteria high-risk mHNPC.

DESIGN, SETTING, AND PARTICIPANTS

The longitudinal, multicentre, J-ROCK registry study enrolled patients initiating ADT in Japan after May 2019, and categorised them as cohort 1 (ADT or CAB) or cohort 2 (ADT plus ARSIs or docetaxel).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Prostate-specific antigen (PSA) response, progression-free survival (PFS), time to castrate-resistant prostate cancer (CRPC), overall survival (OS), and safety were evaluated. PFS, time to CRPC, and OS were estimated via the Kaplan-Meier method and between-cohort comparisons via multivariate Cox regression models.

RESULTS AND LIMITATIONS

In total, 974 patients were included (cohort 1: 38.1%, cohort 2: 61.9%). CAB was preferred (67.4%) to ADT alone in cohort 1, and abiraterone acetate plus prednisolone was used most frequently in cohort 2 (59.4%). The proportion of patients with ≥50%/≥90% PSA decline or who achieved PSA ≤0.2/≤0.1 ng/ml tended to be higher in cohort 2. PFS (adjusted hazard ratio 0.42; 95% confidence interval [CI] 0.31-0.55), time to CRPC (0.28; 95% CI 0.23-0.36), and OS (0.54; 95% CI 0.35-0.82) were longer in cohort 2. In cohorts 1 and 2, adverse drug reactions of special interest (ADRSIs) occurred in 1.3% and 15.1%, and fatal adverse events occurred in 1.9% and 1.7%, respectively. Limitations included nonrandomised design, varying time since marketing authorisation for ARSIs, and limited safety assessments.

CONCLUSIONS

ADT plus ARSIs or docetaxel was used more frequently to treat high-risk mHNPC than standard ADT/CAB and was associated with more favourable clinical outcomes. Although ADRSIs were reported more in cohort 2, the safety profile was considered tolerable.

PATIENT SUMMARY

Although many treatment options are available for high-risk metastatic prostate cancer, there are limited reports on real-world clinical experience with different therapies outside of the clinical trial setting. In this study, we compared clinical and safety outcomes with different treatment regimens, using a large series of patients with high-risk metastatic hormone-naïve prostate cancer across Japan. We found that androgen deprivation therapy in combination with newer androgen receptor signalling inhibitors resulted in improved response compared with androgen deprivation therapy alone or in combination with a first-generation antiandrogen.

Real-world prostate-specific antigen response and progression to castration-resistant prostate cancer among men with metastatic castration-sensitive prostate cancer treated with apalutamide: a multi-institutional study in the Chu-shikoku Japan Urological Consortium

BACKGROUND

Japanese men receiving apalutamide often experience skin-adverse events (AEs), possibly requiring treatment interruption or dose reduction. However, concerns have arisen regarding the impact of these adjustments on the efficacy of apalutamide. Our study evaluated the efficacy, safety, and persistence of apalutamide in men with metastatic castration-sensitive prostate cancer (mCSPC).

METHODS

We retrospectively reviewed the medical records of 108 men with mCSPC from 14 Japanese institutions. The primary outcomes were the efficacy of apalutamide: prostate-specific antigen (PSA) response (50%, 90% and < 0.2 decline) and progression to castration-resistant prostate cancer (CRPC). The secondary outcomes were the skin-AE and compliance of apalutamide.

RESULTS

PSA50%, PSA90% and PSA < 0.2 declines were observed in 89.8, 84.3 and 65.7%, and the median time to CRPC progression was not reached. PSA < 0.2 decline and an initial full dose of apalutamide were significantly associated with a longer time to CRPC. The most common AE was skin-AE (50.9%), and there was no association between the occurrence of skin-AE and the time to CRPC (P = 0.72). The median apalutamide persistence was 29 months, which was longer in the initial full dose recipients than in the reduced dose recipients. The dosage is reduced in about 60% of patients within the first year of treatment in the initial full dose recipients.

CONCLUSIONS

Our findings indicate the effectiveness of apalutamide in Japanese men with mCSPC, despite a substantial portion requiring dose reduction within a year among the initial full dose recipients.

Oligometastatic carcinoma prostate - An overview of the last decade

Introduction

Oligometastatic prostate cancer (OMPC) has gained profound interest lately due to its different tumor biology and our ability to use multimodality therapy for cure or prolonged survival. Selecting the appropriate patient for treatment has become the aim of treating urologists, medical oncologists, and radiation oncologists. Through this review, we try to highlight the management of OMPC in light of recent literature.

Methods

Literature search was performed on Pubmed, Scopus and Embase using keywords "Oligometastatic", " Prostate Cancer" using operators such as "And" & "Or". Relevant articles were screened and all the latest articles on this emerging entity were included in this review.

Results

All trials relevant to oligometastatic prostate cancer defining the role of surgery, radiotherapy and systemic therapy were included and appropriate inferences were drawn. Relevant studies were compiled in tabular form for this article.

Conclusion

The current standard of care of management for OMPC remains systemic therapy on the lines of hormone-sensitive metastatic prostate cancer. The evolving role of surgery, and radiotherapy along with systemic therapy is highlighted in this article.

Effects of apalutamide dose reduction on skin-related adverse events in patients with advanced prostate cancer: A multicenter retrospective study

BACKGROUND

We aimed to evaluate the effects of apalutamide dose reduction on skin-related adverse events (AEs) and castration-resistant prostate cancer (CRPC)-free survival in patients with advanced prostate cancer (PC).

METHODS

We retrospectively evaluated 35 patients with nonmetastatic CRPC and 72 patients with treatment-naïve metastatic castration-sensitive PC (mCSPC) who were treated with apalutamide. The primary outcome was the effect of apalutamide dose reduction on skin-related AEs. The secondary outcomes were the effect of apalutamide dose reduction on skin-related AEs in patients with small body size, postskin AE apalutamide discontinuation rate, and CRPC-free survival in patients with mCSPC treated with upfront apalutamide plus androgen deprivation therapy.

RESULTS

Of the 107 patients, 65 (60.7%) and 42 (39.3%) were treated with full and reduced doses of apalutamide, respectively. The skin-related AE rate was not significantly different between the groups (55% vs. 43%, p = 0.761). In the group receiving reduced apalutamide dose, the incidence of skin-related AEs was significantly lower in patients with small body sizes (body weight <67 kg and body mass index <24 kg/m² ) than in those with other body sizes. The postskin AE apalutamide discontinuation rate was significantly differed between patients receiving the full (50%) and reduced (16.7%) doses. In the 72 patients with mCSPC, CRPC-free survival was not significantly different between the full and reduced dose groups.

CONCLUSION

Apalutamide dose reduction was not significantly associated with the incidence of skin-related AEs. However, dose reduction in patients with small body sizes may alleviate skin-related AEs without sacrificing oncological outcomes.

Emergence of triplet therapy for metastatic castration-sensitive prostate cancer: An updated systematic review and network meta-analysis

INTRODUCTION

There have been a growing number of treatment options available for men with metastatic castration-sensitive prostate cancer. Not only have newer agents entered the clinical landscape, there is a trend toward treatment intensification by combining multiple agents simultaneously. We aim to assess the best contemporary treatment option for men with mCSPC.

MATERIALS AND METHODS

We perform an updated systematic review and network meta-analysis of randomized control trials that evaluated systemic therapies in men with castration-sensitive prostate cancer. We searched multiple databases up to April 2022. We included all randomized trials assessing the effect of systemic agents. We performed subgroup analyses based on disease volume and timing of presentation. Statistical analysis was performed with Bayesian methods.

RESULTS

We found 10 eligible trials with 10,065 patients who were included in this analysis. Triplet therapy with darolutamide or abiraterone with docetaxel and ADT improved overall survival. In the sensitivity analysis, the respective hazard ratios for triplet therapy was HR 0.70 (95%CI 0.61-0.80) compared to docetaxel+ADT and 0.77 (95%CI 0.65-0.91) compared to androgen receptor pathway inhibitors+ADT combinations. It was estimated that there was 96% chance that one of the triplet therapy combinations were the best treatment option from an OS perspective. Triplet therapy also improved progression-free survival. These benefits were pronounced in men with high-volume disease burden and those with de novo metastatic disease.

CONCLUSION

The finding suggest that triplet therapy is likely the most efficacious available option in men with metastatic, castration-sensitive prostate cancer, especially in those with high-volume disease burden.