Efficacy and safety of abiraterone acetate plus prednisone in Japanese patients with newly diagnosed, metastatic hormone-naive prostate cancer: final subgroup analysis of LATITUDE, a randomized, double-blind, placebo-controlled, phase 3 study

Prognostic outcomes in Japanese patients with metastatic castration-sensitive prostate cancer: Comparative assessments between conventional androgen deprivation therapy (ADT) and ADT with novel androgen receptor signal inhibitor

OBJECTIVE

The objective of this study was to compare the prognostic outcomes between metastatic castration-sensitive prostate cancer (mCSPC) patients receiving conventional androgen deprivation therapy (ADT) and those receiving ADT plus a novel androgen-receptor signaling inhibitor (ARSI) in routine clinical practice in Japan.

METHODS

This was conducted as a retrospective multicenter study including 581 mCSPC patients, consisting of 305 receiving ADT alone or in combination with bicalutamide (group 1) and 276 receiving ADT plus one of the following ARSIs: abiraterone acetate, apalutamide, or enzalutamide (group 2). Prognostic outcomes between these 2 groups were comprehensively compared.

RESULTS

In the entire cohort, prostate-specific antigen-progression-free survival (PSA-PFS) in group 2 was significantly longer than that in group 1, while no significant difference was noted in overall survival (OS) between the two groups. In patients corresponding to the LATITUDE high-risk group, however, both PSA-PFS and OS in group 2 were significantly longer than those in group 1. Of several factors examined, the following were identified as independent predictors of poor PSA-PFS in the entire cohort as well as the LATITUDE high-risk group: high C-reactive protein, high lactate dehydrogenase, high alkaline phosphatase, high Gleason score, and group 1. Furthermore, it was possible to precisely classify both the entire cohort and LATITUDE high-risk group into 3 risk groups regarding PSA-PFS according to the positive numbers of independent factors: positive for ≤1 factor, favorable; 2 factors, intermediate; and ≥3 factors, poor.

CONCLUSION

Combined use of ARSIs with ADT could improve the prognostic outcomes of mCSPC patients, particularly those in the LATITUDE high-risk group, in real-world clinical practice in Japan.

A territory-wide real-world efficacy and toxicity analysis of abiraterone acetate versus docetaxel in 574 Asian patients with metastatic hormone-sensitive prostate cancer

INTRODUCTION

Abiraterone acetate (ABI) or docetaxel (DOC), in addition to androgen-deprivation therapy (ADT), are current treatment options for metastatic hormone-sensitive prostate cancer (mHSPC). No randomized head-to-head trial has compared these 2 mHSPC treatments, and real-world data regarding their outcomes in Asian patients are lacking.

PATIENTS AND METHODS

The medical records of mHSPC patients who began upfront ABI or DOC treatment in addition to ADT at seven public oncology centers in Hong Kong between 2015 and 2021 were reviewed. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), prostate-specific antigen (PSA) response, and toxicities. Kaplan-Meier and multivariate Cox regression analyses were performed.

RESULTS

A total of 574 patients were included, of whom 419 received DOC and 155 received ABI. The median follow-up duration was 22.4 (DOC group: 23.8; ABI group: 17.3) months. The ABI group demonstrated significantly better PFS than the DOC group (not reached vs. 15.1 months: hazard ratio = 0.37; 95% confidence interval = 0.28-0.50; P < .001). No significant OS difference was observed (P = .58). Failure to achieve a ≥ 90% decline in PSA level at 3 months and failure to achieve an undetectable PSA nadir were each associated with unfavorable PFS and OS. Patients who received DOC had a higher rate of febrile neutropenia, whereas those who received ABI had higher rates of grade ≥ 3 hypokalemia and elevated alanine transaminase. Treatment discontinuation due to toxicities was more common in the DOC (3.6%) than the ABI (0.6%) group.

CONCLUSION

In Asian mHSPC patients, upfront ABI + ADT was associated with better PFS than DOC + ADT, with no significant OS difference. PSA kinetics may help stratify the prognosis for treatment intensification. Toxicity profiles were different, with a higher rate of toxicity-related treatment discontinuation in the DOC group.

Adverse cognitive effects of glucocorticoids: A systematic review of the literature

OBJECTIVES

Glucocorticoids as a drug class are widely used in the treatment of many conditions including more recently as one of the mainstay treatments for the SARS-CoV-2 infection. The physiological adverse effects are well described. However, less is known and understood about the potentially deleterious neuro-cognitive effects of this class of medication.

METHODS

We carried out a systematic review of the literature using two separate search strategies. The first focussed on the rates of reporting of adverse cognitive effects of glucocorticoid use in randomised controlled trials. The second looked at those studies focussing directly on adverse cognitive effects associated with the use of glucocorticoids. MEDLINE, Embase and Cochrane Library was searched for randomised controlled trials utilising glucocorticoids as a part of a treatment regimen. Additionally, these databases were also used to search for articles looking directly at the adverse cognitive effects of glucocorticoids.

RESULTS

Of the forty-three RCTs included as a part of the first search strategy, only one (2.3%) included specific documentation pertaining to cognitive side effects. As a part of the twenty studies included in the second search strategy, eleven of the included studies (55%) were able to demonstrate a correlation between glucocorticoid use and decreased cognition. Most studies within this strategy showed that GCs predominately affected hippocampus-dependent functions such as memory, while sparing executive function and attention.

CONCLUSIONS

Overall, the data reporting of adverse clinical effects of glucocorticoid use is poor in recent RCTs. Given the demonstrable effect on predominately hippocampal-dependent cognitive functions evident within the literature, more thorough documentation is needed within clinical research to fully appreciate the potentially widespread nature of these effects.

Japanese subgroup analysis of EV-301: An open-label, randomized phase 3 study to evaluate enfortumab vedotin versus chemotherapy in subjects with previously treated locally advanced or metastatic urothelial carcinoma

BACKGROUND

Enfortumab vedotin (EV) is an antibody-drug conjugate showing significant overall survival (OS) benefit versus chemotherapy for patients with previously treated locally advanced or metastatic urothelial carcinoma (la/mUC) in EV-301. This subgroup analysis was conducted to further analyze the efficacy and safety in a Japanese population.

METHODS

In the open-label, phase 3 EV-301 trial, patients with la/mUC were randomized 1:1 to EV 1.25 mg/kg on Days 1, 8, and 15 for 28-day cycles or investigator-preselected standard chemotherapy (SC; docetaxel or paclitaxel for patients in Japan) on Day 1 of each 21-day cycle. Primary endpoint was OS and secondary efficacy endpoints included progression-free survival (PFS) and overall response rate (ORR). Safety/tolerability was also evaluated.

RESULTS

As of the July 15, 2020 cut-off date for the interim analysis, the Japanese subgroup included 86 patients (EV: n = 36; SC: n = 50). Median OS was 15.18 months for EV and 10.55 months for SC (HR: 0.437 [95% CI: 0.209, 0.914]). Median PFS was 6.47 months for EV and 5.39 months for SC (HR: 0.464 [95% CI: 0.258, 0.835]). Confirmed ORR was 34.4% for EV and 21.3% for SC. A higher proportion of patients receiving SC versus EV had treatment-related adverse events (TRAEs; 97.9% vs. 91.7%, respectively), including grade ≥ 3 TRAEs (75.0% vs. 63.9%).

CONCLUSIONS

This subgroup analysis confirmed that EV, with consistent efficacy and safety/tolerability in the EV-301 Japanese subgroup and overall study population, represents an important treatment option for previously treated patients with la/mUC.

Novel hormonal therapies in the management of advanced prostate cancer: extrapolating Asian findings to Southeast Asia

There is a paucity of information on the use of novel hormonal agents in Southeast Asian patients. We reviewed the clinical roles of novel hormonal therapy (NHT), namely abiraterone acetate (AA), enzalutamide, apalutamide and darolutamide, in the management of advanced prostate cancer, and data on its use in Asian patients, in order to extrapolate these findings to the Southeast Asian patient population. There are some differences in the molecular features between the NHTs, which influenced their respective permeabilities through the blood-brain barrier. The Asian sub-analyses of the landmark studies of each NHT were limited. The primary endpoints of the Asian sub-analyses generally reflect the efficacy outcomes of the respective landmark study. Hypertension, fatigue, musculoskeletal disorders, rash, and hot flushes were among the common toxicities observed in Asian patients. Real-world data on AA in the Asian setting is favourable, but data is limited for enzalutamide, apalutamide and darolutamide. Based on the sub-analyses and real-world data, the efficacy and safety of NHTs in the Asian patients showed a similar trend to the respective landmark studies. The lack of clinical trials in the Southeast Asian region hampers the ability to make a robust conclusion on any specific efficacy or safety differences that may be present; clinicians must assume that the broader Asian sub-analyses and real-world data reflects Southeast Asian patients' outcomes.

Retrospective validation of bone risk stratification criteria for men with de novo metastatic hormone-naive prostate cancer in China

Background

Bone metastasis has been suggested to be a significant impactor on the prognosis of newly diagnosed de novo metastatic hormone-sensitive prostate cancer (mHSPC), and some risk stratification models have been proposed on the basis of this hypothesis. However, the effectiveness of these risk stratification criteria has not been fully evaluated in China. This study aimed to evaluate the effectiveness of the risk stratification models in China.

Methods

A total of 140 patients who were newly diagnosed with metastatic prostate cancer followed by primary androgen deprivation-based therapy from January 2008 to June 2021 at our institution were enrolled in this study. The patients were divided into different groups on the basis of high- and low-volume disease (H/LVD) criteria, high-and low-risk disease (H/LRD) criteria, extremity bone metastasis criteria (EBM), and extent of disease (EOD) criteria. The area under the receiver operating characteristic (ROC) curve (AUC) and decision curve analysis (DCA) were used to compare the validity and net benefit of these models. Using the Cox proportional hazards model, we performed univariable and multivariable analyses of the factors influencing overall survival (OS) and the time of progression to metastatic castration-resistant prostate cancer (CRPC).

Results

The median patient age was 72 years. Most patients had a Gleason score ≥8 (102 cases, 72.9%) and clinical T stage >2 (75 cases, 53.6%). The median follow-up time was 25 months (range, 2-95 months). Ninety-two patients progressed to CRPC and fifty-seven patients died during the follow-up. The AUC of OS and CRPC showed that the EOD model had higher validity than the other risk stratification models. DCA shows that the net benefit of the EOD model on OS was better than that of the other risk stratification models. As for CRPC, the net benefit of the EOD model was second only to that of the H/LRD model when the threshold was <0.5; however, when the threshold was >0.5, the EOD model outperformed the other models. The effectiveness of EOD as an independent prognostic variable was verified through univariable and multivariable analyses.

Conclusion

The EOD model yields reasonable risk stratification for use in Chinese mHSPC patients, providing further evidence supporting its role in clinical decision-making.

Efficacy and safety of therapies for advanced prostate cancer in Asia: Evidence from a systematic literature review

OBJECTIVES

Several therapies are available for the treatment of advanced/metastatic prostate cancer (PC). However, the systematic assessment of evidence pertaining to the use of these therapies in Asian patients is lacking.

METHODS

A systematic literature review (SLR) was conducted using PubMed/Medline search in May 2021 to identify the randomized/nonrandomized controlled trials (RCTs/non-RCTs) and real-world observational studies (prospective/retrospective). Only studies published as full manuscripts in English were included if reporting the efficacy, effectiveness, and/or safety of treatments in Asian patients with advanced/metastatic PC.

RESULTS

Of the 1,898 retrieved publications, 24 studies were included. These studies had patients with nonmetastatic castration-resistant PC (n = 2), metastatic castration-sensitive PC (n = 4), and metastatic castration-resistant PC (n = 18). Study designs included RCTs (n = 7), non-RCTs (n = 2), and real-world studies (n = 15). Treatments used in included studies were abiraterone acetate plus prednisone (AAP; n = 6), enzalutamide, lutetium-177 prostate-specific membrane antigen (177Lu-PSMA; n = 4 each), docetaxel (n = 3), apalutamide, radium-223 (n = 2 each), darolutamide, cabazitaxel, and pembrolizumab (n = 1 each). The evidence from RCTs (i.e., ARAMIS, SPARTAN, ARCHES, TITAN, LATITUDE, PREVAIL) demonstrated the clinical benefits of apalutamide, darolutamide, enzalutamide, and AAP in terms of overall, disease-free, and metastasis-free survival in Asian patients. These treatments were reported to be well tolerated, with no new safety signals identified in Asian population. The efficacy and safety profiles in Asian patients were consistent with the overall trial population. Data from real-world studies supported the effectiveness and tolerability of AAP, enzalutamide, radium-223, docetaxel, cabazitaxel, 177Lu-PSMA, and pembrolizumab in patients with advanced/metastatic PC.

CONCLUSIONS

This SLR of the Asian data on therapies for advanced PC from the pivotal and real-world studies confirms similar efficacy and safety outcomes, consistent with the results from the pivotal clinical trials. These findings will help clinicians make better treatment decisions in clinical practice for patients with advanced/metastatic PC.

Androgen receptor axis‑targeted agents are not superior to conventional hormonal therapy for treatment of metastatic prostate cancer

The present study aimed to use real-world Japanese data to compare the treatment outcome of conventional hormonal therapy to that of using androgen receptor axis-targeted (ARAT) agents for patients with metastatic castration-resistant prostate cancer. The overall survival between the conventional hormonal therapy group and the ARAT agent therapy group was compared using a group of 75 Japanese patients who were treated for metastatic castration-resistant prostate cancer. A subgroup analysis was carried out and the risk factors that affected overall survival (OS) were determined. The median OS from the time of prostate-specific antigen recurrence was 73.1 months in the ARAT group and 45.2 months in the conventional treatment group (P=0.414). Although OS tended to be slightly longer in the ARAT group, the difference between the groups was not significant. Subgroup analysis suggested that the therapeutic outcome of using ARAT agents tended to be less beneficial in patients who were older, and in those with a higher tumor volume or low Gleason grade. In conclusion, use of ARAT agents did not impart a significant survival benefit to patients with metastatic castration-resistant prostate cancer when compared with survival rates in response to conventional therapy. However, there was some clinical benefit when ARAT agents were used after patients developed castration-resistant prostate cancer. These findings suggest that up-front therapy using ARAT agents at the time of the initial hormone therapy can impart clinical benefit in Japanese patients with metastatic prostate cancer.

Comparison of Abiraterone and Combined Androgen Blockade Therapy for High-Risk Metastatic Hormone-Sensitive Prostate Cancer: A Propensity Score-Matched Analysis

This study aimed to compare the effects of abiraterone acetate plus prednisone (AAP) with androgen deprivation therapy (ADT) with those of combined androgen blockade (CAB) therapy in patients with high-risk metastatic hormone-sensitive prostate cancer (mHSPC). This study retrospectively identified 163 patients with high-risk mHSPC at Kindai University and affiliated hospitals between January 2014 and December 2020. Kaplan-Meier analysis was used to summarize progression-free survival (PFS) and overall survival (OS). Multivariate Cox proportional hazard modeling was used to identify the prognostic factors in the overall cohort. Propensity score matching was used to adjust the clinical characteristics, and log-rank test was applied to these propensity score–matched cohorts. Seventy-four patients who received AAP with ADT and 89 patients who received CAB were included in this study. The median follow-up duration was 27 months (range, 2–89 months). The median PFS and OS were not reached by the AAP+ADT group and 15 and 79 months, respectively, in the CAB group. The Eastern Cooperative Oncology Group (ECOG) performance status (PS) score and AAP+ADT were significant prognostic factors for PFS, whereas ECOG PS score, visceral metastasis, and AAP+ADT were significant prognostic factors for OS. The 2-year PFS was 76.1% in the AAP+ADT group and 38.6% in the CAB group (P < 0.0001), and the 2-year OS was 90.2% in the AAP+ADT group and 84.8% in the CAB group (P = 0.015). In conclusion, AAP+ADT had better PFS and OS than CAB in patients with high-risk mHSPC.

Comparison of clinical outcomes between androgen deprivation therapy with up-front abiraterone and bicalutamide for Japanese patients with LATITUDE high-risk prostate cancer in a real-world retrospective analysis

BACKGROUND

Combining abiraterone (Abi) with androgen deprivation therapy (ADT) improves overall survival, compared to ADT only, in patients with metastatic castration-sensitive prostate cancer (mCSPC). In Japan, bicalutamide (Bica) and ADT (combined androgen blockade: CAB) is frequently provided for mCSPC. Because these two treatments have not been compared, mCSPC patients who received either treatment were retrospectively analyzed.

METHODS

Of 178 patients with LATITUDE high-risk mCSPC, 103 had received ADT plus upfront Abi (Abi group) and 75 had received ADT plus Bica (Bica group) in multiple institutions of the Tokai Urologic Oncology Research Seminar. Kaplan-Meir curves were used to retrospectively analyze survival and cancer recurrence. Univariate and multivariate Cox regression analyses identified potential prognostic factors for progression-free survival (PFS).

RESULTS

Significant differences in major clinicopathological characteristics between the two groups were not observed. The rate of castration-resistant development was higher in the Bica compared to Abi group (50.6 vs. 25.2%, p < 0.001). The median PFS in the Bica group was 13.6 months {95% confidence interval [CI] 9.2-22.2}; however, in the Abi group, PFS did not reach the median {95% CI 18.5-not assessed [NA]; p < 0.001}. Time to second progression for the Abi group was superior (p = 0.07). Univariate and multivariate analyses revealed Gleason pattern 5, high alkaline phosphatase levels, and conventional CAB using Bica as significant prognostic factors for short PFS.

CONCLUSIONS

In patients with LATITUDE high-risk mCSPC, upfront use of Abi combined with ADT resulted in favorable prognostic outcomes compared with conventional ADT with Bica.

Prognostic Factors in Hormone-sensitive Prostate Cancer Patients Treated With Combined Androgen Blockade: A Consecutive 15-year Study at a Single Japanese Institute

BACKGROUND/AIM

There are several treatment options for metastatic hormone-sensitive prostate cancer (mHSPC) in the world. In recent years, the use of docetaxel, abiraterone, enzalutamide, and apalutamide has been used for mHSPC, but combined androgen blockade (CAB) therapy using first-generation antiandrogens has been widely used in Japan. There is a background. We performed a consecutive study of patients who received combined androgen blockade (CAB) at a single institute to determine the prognostic factors for mHSPC.

PATIENTS AND METHODS

We conducted a consecutive study of 237 mHSPC patients treated with CAB from 2003 to 2017 at the Gunma University Hospital. Prostate-specific antigen progression-free survival (PSA-PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. The associations between pre-treatment risk factors and the PSA response 3 months after starting CAB, PSA-PFS, and OS were evaluated by the Cox proportional hazards model.

RESULTS

Among the 237 cases, the median PSA-PFS and OS times were 63.0 and 91.4 months, respectively. The median PSA-PFS and OS times of M1 cases (174 cases, 73.4% of all 237 cases) were 36.1 and 75.9 months, respectively. The Eastern Cooperative Oncology Group performance status (ECOG PS) score, hemoglobin (Hb), lactate dehydrogenase, extent of disease, visceral metastasis (no vs. yes), and PSA response after 3 months were significant predictors of OS according to Cox regression analysis of prognostic factors in M1 patients. The ECOG PS, Hb, visceral metastasis (no vs. yes), and PSA response after 3 months predicted OS high-risk patients in LATITUDE criteria. The OS was 92.1 months in the low-risk group (0-1 risk factors), 48.2 months in the intermediate-risk group (2 risk factors), and 16.9 months in the high-risk group (3-4 risk factors).

CONCLUSION

CAB should be considered as a treatment option for strictly selected patients with mHSPC, even though novel treatments are available.

Impact of pretreatment anemia on upfront abiraterone acetate therapy for metastatic hormone-sensitive prostate cancer: a multicenter retrospective study

Background

Anemia has been a known prognostic factor in metastatic hormone-sensitive prostate cancer (mHSPC). We therefore examined the effect of anemia on the efficacy of upfront abiraterone acetate (ABI) in patients with mHSPC.

Methods

We retrospectively evaluated 66 mHSPC patients with high tumor burden who received upfront ABI between 2018 and 2020 (upfront ABI group). We divided these patients into two groups: the anemia-ABI group (hemoglobin < 13.0 g/dL, n = 20) and the non-anemia-ABI group (n = 46). The primary objective was to examine the impact of anemia on the progression-free survival (PFS; clinical progression or PC death before development of castration resistant PC) of patients in the upfront ABI group. Secondary objectives included an evaluation of the prognostic significance of upfront ABI and a comparison with a historical cohort (131 mHSPC patients with high tumor burden who received androgen deprivation therapy (ADT/complete androgen blockade [CAB] group) between 2014 and 2019).

Results

We found that the anemia-ABI group had a significantly shorter PFS than the non-anemia-ABI group. A multivariate Cox regression analysis showed that anemia was an independent prognostic factor of PFS in the upfront ABI group (hazard ratio, 4.66; P = 0.014). Patients in the non-anemia-ABI group were determined to have a significantly longer PFS than those in the non-anemia-ADT/CAB group (n = 68) (P < 0.001). However, no significant difference was observed in the PFS between patients in the anemia-ABI and the anemia-ADT/CAB groups (n = 63). Multivariate analyses showed that upfront ABI could significantly prolong the PFS of patients without anemia (hazard ratio, 0.17; P < 0.001), whereas ABI did not prolong the PFS of patients with anemia.

Conclusion

Pretreatment anemia was a prognostic factor among mHSPC patients who received upfront ABI. Although the upfront ABI significantly improved the PFS of mHSPC patients without anemia, its efficacy in patients with anemia might be limited.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08206-8.

Enzalutamide with androgen deprivation therapy in Japanese men with metastatic hormone-sensitive prostate cancer: A subgroup analysis of the phase III ARCHES study

Objective

To evaluate the efficacy and safety of enzalutamide plus androgen deprivation therapy in Japanese men with metastatic hormone‐sensitive prostate cancer.

Methods

A post‐hoc analysis of the Japanese subgroup in the phase III, randomized, multinational ARCHES study (NCT02677896) was carried out. Patients with metastatic hormone‐sensitive prostate cancer were randomized to receive enzalutamide or a placebo, plus androgen deprivation therapy, stratified by disease volume and prior docetaxel therapy. The primary end‐point was radiographic progression‐free survival. Secondary end‐points included time to prostate‐specific antigen progression and overall survival.

Results

Of 1150 patients, 92 Japanese patients were randomized to enzalutamide (n = 36) or a placebo (n = 56), plus androgen deprivation therapy; none received prior docetaxel. Enzalutamide plus androgen deprivation therapy reduced the risk of radiographic progression or death in Japanese patients by 61% versus the placebo, similar to the overall population. Similar results were observed with secondary end‐points, showing clinical benefit of enzalutamide plus androgen deprivation therapy in Japanese patients. Overall survival data were immature. Grade 3–4 adverse events were reported in 47% and 25% of the enzalutamide and placebo groups, respectively. Nasopharyngitis, hypertension and abnormal hepatic function were reported more frequently in Japanese patients versus the overall population.

Conclusions

Enzalutamide plus androgen deprivation therapy has clinical benefit with a tolerable safety profile in Japanese men with metastatic hormone‐sensitive prostate cancer, consistent with the overall population.

Cabazitaxel versus abiraterone or enzalutamide in metastatic castration-resistant prostate cancer: post hoc analysis of the CARD study excluding chemohormonal therapy for castrate-naive disease

Background

In the CARD study (NCT02485691), cabazitaxel significantly improved clinical outcomes versus abiraterone or enzalutamide in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel and the alternative androgen-signalling-targeted inhibitor. However, some patients received docetaxel or the prior alternative androgen-signalling-targeted inhibitor in the metastatic hormone-sensitive (mHSPC) setting. Therefore, the CARD results cannot be directly translated to a Japanese population.

Methods

Patients (N = 255) received cabazitaxel (25 mg/m² IV Q3W, prednisone, G-CSF) versus abiraterone (1000 mg PO, prednisone) or enzalutamide (160 mg PO) after prior docetaxel and progression ≤12 months on the alternative androgen-signalling-targeted inhibitor. Patients who received combination therapy for mHSPC were excluded (n = 33) as docetaxel is not approved in this setting in Japan.

Results

A total of 222 patients (median age 70 years) were included in this subanalysis. Median number of cycles was higher for cabazitaxel versus androgen-signalling-targeted inhibitors (7 versus 4). Clinical outcomes favoured cabazitaxel over abiraterone or enzalutamide including, radiographic progression-free survival (rPFS; median 8.2 versus 3.4 months; P < 0.0001), overall survival (OS; 13.9 versus 11.8 months; P = 0.0102), PFS (4.4 versus 2.7 months; P < 0.0001), confirmed prostate-specific antigen response (37.0 versus 14.4%; P = 0.0006) and objective tumour response (38.9 versus 11.4%; P = 0.0036). For cabazitaxel versus androgen-signalling-targeted inhibitor, grade ≥ 3 adverse events occurred in 55% versus 44% of patients, with adverse events leading to death on study in 2.7% versus 5.7%.

Conclusions

Cabazitaxel significantly improved outcomes including rPFS and OS versus abiraterone or enzalutamide and are reflective of the Japanese patient population. Cabazitaxel should be considered the preferred treatment option over abiraterone or enzalutamide in this setting.

Abiraterone acetate in combination with androgen deprivation therapy compared to androgen deprivation therapy only for metastatic hormone-sensitive prostate cancer

BACKGROUND

Systemic androgen deprivation therapy (ADT), also referred to as hormone therapy,àhas long been the primary treatment for metastatic prostate cancer. Additional agents have been reserved for the castrate-resistant disease stage when ADT start becoming less effective. Abiraterone is an agent with an established role in that disease stage, which has only recently been evaluated in the hormone-sensitive setting.

OBJECTIVES

To assess the effects of early abiraterone acetate, in combination with systemic ADT, for newly diagnosed metastatic hormone-sensitive prostate cancer.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, six other databases, two trials registries, grey literature, and conference proceedings, up to 15 May 2020. We applied no restrictions on publication language or status.

SELECTION CRITERIA

We included randomized trials, in which men diagnosed with hormone-sensitive prostate cancer were administered abiraterone acetate and prednisolone with ADT or ADTàalone.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies and abstracted data from the included studies. We performed statistical analyses using a random-effects model. We rated the quality of evidence according to the GRADE approach.

MAIN RESULTS

The search identified two randomized controlled trials (RCT), with 2201 men, who were assigned to receive either abiraterone acetate 1000 mg once daily and low dose prednisone (5mg) in addition to ADT, or ADT alone. In the LATITUDE trial, the median age and range of men in the intervention group was 68 (38 to 89) years, and 67 (33 to 92) years in the control group. Nearly all of the men in thisàstudy (97.6%) had prostate cancer with a Gleason score of at least 8 (ISUP grade group 4). Primary outcomes The addition of abiraterone acetate to ADT reduces the probability of death from any cause compared to ADT alone (hazard ratio [HR] 0.64, 95% confidence interval [CI] 0.56 to 0.73; 2 RCTs, 2201 men; high certainty of evidence); this corresponds to 163 fewer deaths per 1000 men with hormone-sensitive metastaticàprostate cancerà(210 fewer to 115 fewer) at five years. Abiraterone acetate in addition to ADT probably results in little to no differenceàin quality of life compared to ADT alone, measured with the Functional Assessment of Cancer Therapy-prostate total score (FACT-P; range 0 to 156; higher values indicates better quality of life),àat 12 months (mean difference [MD] 2.90 points, 95% CI 0.11 to 5.60; 1 RCT, 838 men; moderate certainty of evidence). Secondary outcomes Abiraterone plus ADT increases the risk of grades III to V adverse events compared to ADT alone (risk ratio [RR] 1.34, 95% CI 1.22 to 1.47; 1 RCT, 1199 men; high certainty of evidence); this corresponds to 162 more grade III to Vàevents per 1000 men with hormone-sensitive metastaticàprostate cancerà(105 more to 224 more) at a median follow-up of 30àmonths. Abiraterone acetate in addition to ADT probably reduces the probability of death due to prostate cancer compared to ADT alone (HR 0.58, 95% CI 0.50 to 0.68; 2 RCTs, 2201 men; moderate certainty of evidence). This corresponds to 120 fewer death from prostate cancer per 1000 men with hormone-sensitive metastaticàprostate cancerà(95% CI 145 fewer to 90 fewer) afteràa median follow-up of 30 months. The addition of abiraterone acetate to ADT probably decreases the probability of disease progression compared to ADT alone (HR 0.35, 95%CI 0.26 to 0.49; 2 RCTs, 2097 men; moderate certainty of evidence). This corresponds to 369 fewer incidences of disease progression per 1000 men with hormone-sensitive metastaticàprostate cancerà(456 fewer to 256 fewer)àafter a median follow-up of 30 months. The addition of abiraterone acetate to ADT probably increases the risk of discontinuing treatment due to adverse events compared to ADT alone (RR 1.50, 95% CI 1.17 to 1.92; 1 RCT, 1199 men; moderate certainty of evidence). This corresponds to 51 more men (95% CI 17 more to 93 more) discontinuing treatment because of adverse events per 1000 men treated with abiraterone acetate and ADT compared to ADT alone afteràa median follow-up of 30 months.

AUTHORS' CONCLUSIONS

The addition of abiraterone acetate to androgen deprivation therapy improves overall survival but probably not quality of life. Itàprobably also extends disease-specific survival, and delays disease progression compared to androgen deprivation therapy alone. However, the risk of grades III to V adverse events is increased, and probably, so is the risk of discontinuing treatment due to adverse events.