LBA25 Final overall survival (OS) analysis from ARCHES: A phase III, randomized, double-blind, placebo (PBO)-controlled study of enzalutamide (ENZA) + androgen deprivation therapy (ADT) in men with metastatic hormone-sensitive prostate cancer (mHSPC)

Cost-Effectiveness Analysis of Systemic Therapy for Intensification of Treatment in Metastatic Hormone-Sensitive Prostate Cancer in India

BACKGROUND AND OBJECTIVE

Androgen-deprivation therapy is the mainstay of treatment for patients with newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC). However, the intensification of treatment with either docetaxel or novel anti-androgens (abiraterone-acetate plus prednisone [AAP], enzalutamide, and apalutamide) is being recommended based on the improved clinical outcomes and quality of life among patients. This study aimed to determine the most cost-effective drug for treatment intensification for patients with mHSPC in India.

METHODS

A Markov model was developed with four health states: progression-free survival, progressive disease, best supportive care, and death. Lifetime costs and consequences were estimated for four treatment sequences: AAP-first, enzalutamide-first, apalutamide-first, and docetaxel-first. Incremental cost per quality-adjusted life-year (QALY) gained with a given treatment option was compared against the next best alternative and assessed for cost effectiveness using a willingness to pay threshold of 1 × per capita gross domestic product in India.

RESULTS

We estimated that the total lifetime cost per patient was ₹1,367,454 (US$17,487), ₹2,168,885 (US$27,735), ₹7,678,501 (US$98,190), and ₹1,358,746 (US$17,375) in the AAP-first, enzalutamide-first, apalutamide-first, and docetaxel-first treatment sequence, respectively. The mean quality-adjusted life-years lived per patient were 4.78, 5.03, 3.22, and 2.61, respectively. The AAP-first sequence incurs an incremental cost of ₹4014 (US$51) per quality-adjusted life-year gained as compared with the docetaxel-first sequence, with a 87% probability of being cost effective at the willingness-to-pay threshold of 1 × per-capita gross domestic product of India. The use of AAP-first also incurs an incremental net monetary benefit of ₹396,491 (US$5070) as compared with the docetaxel-first treatment sequence. Nearly a 48% reduction in the price of enzalutamide is required to make it a cost-effective treatment sequence as compared with AAP-first in India.

CONCLUSIONS

We concur with the inclusion of standard-dose AAP in India's publicly financed health insurance scheme for the intensification of treatment in mHSPC as it is the only cost-effective sequence among the various novel anti-androgens when compared with the docetaxel-first treatment sequence. Furthermore, a systematic reduction in the price of enzalutamide would further help to improve clinical outcomes among patients with mHSPC.

Radiographic Progression-Free Survival and Clinical Progression-Free Survival as Potential Surrogates for Overall Survival in Men With Metastatic Hormone-Sensitive Prostate Cancer

PURPOSE

Despite major increases in the longevity of men with metastatic hormone-sensitive prostate cancer (mHSPC), most men still die of prostate cancer. Phase III trials assessing new therapies in mHSPC with overall survival (OS) as the primary end point will take approximately a decade to complete. We investigated whether radiographic progression-free survival (rPFS) and clinical PFS (cPFS) are valid surrogates for OS in men with mHSPC and could potentially be used to expedite future phase III clinical trials.

METHODS

We obtained individual patient data (IPD) from 9 eligible randomized trials comparing treatment regimens (different androgen deprivation therapy [ADT] strategies or ADT plus docetaxel in the control or research arms) in mHSPC. rPFS was defined as the time from random assignment to radiographic progression or death from any cause whichever occurred first; cPFS was defined as the time from random assignment to the date of radiographic progression, symptoms, initiation of new treatment, or death, whichever occurred first. We implemented a two-stage meta-analytic validation model where conditions of patient-level and trial-level surrogacy had to be met. We then computed the surrogate threshold effect (STE).

RESULTS

IPD from 6,390 patients randomly assigned from 1994 to 2012 from 13 units were pooled for a stratified analysis. The median OS, rPFS, and cPFS were 4.3 (95% CI, 4.2 to 4.5), 2.4 (95% CI, 2.3 to 2.5), and 2.3 years (95% CI, 2.2 to 2.4), respectively. The STEs were 0.80 and 0.81 for rPFS and cPFS end points, respectively.

CONCLUSION

Both rPFS and cPFS appear to be promising surrogate end points for OS. The STE of 0.80 or higher makes it viable for either rPFS or cPFS to be used as the primary end point that is surrogate for OS in phase III mHSPC trials with testosterone suppression alone as the backbone therapy and would expedite trial conduct.

Feasibility of Next-generation Sequencing of Liquid Biopsy (Circulating Tumor DNA) Samples and Tumor Tissue from Patients with Metastatic Prostate Cancer in a Real-world Clinical Setting in Germany

BACKGROUND AND OBJECTIVE

With European Medicines Agency approval of PARP inhibitors in metastatic castration-resistant prostate cancer and ongoing trials in metastatic hormone-sensitive prostate cancer, detection of genetic alterations in BRCA1/2 and other homologous recombination repair genes has gained an important role. Our aim was to investigate the feasibility and comparability of comprehensive next-generation sequencing (NGS) of liquid biopsy (LB; circulating tumor DNA) and tumor tissue (TT) samples in a real-world clinical setting.

METHODS

The study cohort consisted of 50 patients with metastatic prostate cancer (mPC) who had TT NGS performed for BRCA1/2 alterations and consent for additional LB NGS. The Oncomine Comprehensive Assay v3 (Thermo Fisher Scientific, Waltham, MA, USA) was used for TT NGS. The Guardant360 83-gene assay (Guardant Health, Palo Alto, CA, USA) was used for LB NGS, including all types of somatic alterations, microsatellite instability, and blood tumor mutational burden. We calculated BRCA1/2 alteration rates and the negative percentage agreement (NPA) and positive percentage agreement (PPA) between TT and LB results.

KEY FINDINGS AND LIMITATIONS

TT NGS was successful in 44/50 patients (88%), with pathogenic BRCA1/2 alterations detected in four (9%). LB NGS was successful in all 50 patients (100%), with BRCA1/2 alterations detected in ten (20%). In a subgroup analysis for the 44 patients with successful TT NGS, NPA was 85% and PPA was 50%. The median time between TT sample collection and blood sampling for NGS was 132 wk (IQR 94-186). The limited sample size and differences in the time of NGS assessment are limitations.

CONCLUSIONS AND CLINICAL IMPLICATIONS

LB NGS resulted in a higher detection rate for BRCA1/2 alterations in comparison to conventional TT NGS (20% vs 9%). Ideally, BRCA1/2 testing should be based on both approaches to identify all patients with mPC eligible for PARP inhibitor therapy.

PATIENT SUMMARY

Our study shows that genetic tests for both tumor tissue and blood samples results in higher rates of detection of BRCA1/2 gene alterations in patients with metastatic prostate cancer.

Novel androgen receptor inhibitors for metastatic hormone-sensitive prostate cancer: Current application and future perspectives

Androgen receptor (AR) signaling is essential in prostate cancer treatment. For many years, androgen deprivation therapy (ADT) has been primarily applied to manage advanced prostate cancer. However, most individuals with metastatic hormone-sensitive prostate cancer (mHSPC) administered ADT alone are at risk of developing metastatic castration-resistant prostate cancer (mCRPC) in less than two years. New approaches employing novel AR inhibitors (ARi) as intensified upfront systemic treatment in mHSPC have recently demonstrated substantial benefits in delaying disease progression and prolonging overall survival. Administration of novel ARi has become the new standard of care in mHSPC. The new landscape simultaneously makes treatment choice more challenging. This review provides comprehensive data on molecular structure, pharmaceutical properties, and efficacy and safety profiles reported by pivotal clinical trials. We also discuss future directions with ongoing Phase III trials of novel ARi in mHSPC. Considering these biological and clinical insights, this review aimed to provide a comprehensive understanding of differences in the development and applications of novel ARi for mHSPC, which may be helpful in designing strategies for first-line treatment choices.

Testosterone suppression plus enzalutamide versus testosterone suppression plus standard antiandrogen therapy for metastatic hormone-sensitive prostate cancer (ENZAMET): an international, open-label, randomised, phase 3 trial

BACKGROUND

The interim analysis of the ENZAMET trial of testosterone suppression plus either enzalutamide or standard nonsteroidal antiandrogen therapy showed an early overall survival benefit with enzalutamide. Here, we report the planned primary overall survival analysis, with the aim of defining the benefit of enzalutamide treatment in different prognostic subgroups (synchronous and metachronous high-volume or low-volume disease) and in those who received concurrent docetaxel.

METHODS

ENZAMET is an international, open-label, randomised, phase 3 trial conducted at 83 sites (including clinics, hospitals, and university centres) in Australia, Canada, Ireland, New Zealand, the UK, and the USA. Eligible participants were males aged 18 years or older with metastatic, hormone-sensitive prostate adenocarcinoma evident on CT or bone scanning with ^99mTc and an Eastern Cooperative Oncology Group performance status score of 0-2. Participants were randomly assigned (1:1), using a centralised web-based system and stratified by volume of disease, planned use of concurrent docetaxel and bone antiresorptive therapy, comorbidities, and study site, to receive testosterone suppression plus oral enzalutamide (160 mg once per day) or a weaker standard oral non-steroidal antiandrogen (bicalutamide, nilutamide, or flutamide; control group) until clinical disease progression or prohibitive toxicity. Testosterone suppression was allowed up to 12 weeks before randomisation and for up to 24 months as adjuvant therapy. Concurrent docetaxel (75 mg/m² intravenously) was allowed for up to six cycles once every 3 weeks, at the discretion of participants and physicians. The primary endpoint was overall survival in the intention-to-treat population. This planned analysis was triggered by reaching 470 deaths. This study is registered with ClinicalTrials.gov, NCT02446405, ANZCTR, ACTRN12614000110684, and EudraCT, 2014-003190-42.

FINDINGS

Between March 31, 2014, and March 24, 2017, 1125 participants were randomly assigned to receive non-steroidal antiandrogen (n=562; control group) or enzalutamide (n=563). The median age was 69 years (IQR 63-74). This analysis was triggered on Jan 19, 2022, and an updated survival status identified a total of 476 (42%) deaths. After a median follow-up of 68 months (IQR 67-69), the median overall survival was not reached (hazard ratio 0·70 [95% CI 0·58-0·84]; p<0·0001), with 5-year overall survival of 57% (0·53-0·61) in the control group and 67% (0·63-0·70) in the enzalutamide group. Overall survival benefits with enzalutamide were consistent across predefined prognostic subgroups and planned use of concurrent docetaxel. The most common grade 3-4 adverse events were febrile neutropenia associated with docetaxel use (33 [6%] of 558 in the control group vs 37 [6%] of 563 in the enzalutamide group), fatigue (four [1%] vs 33 [6%]), and hypertension (31 [6%] vs 59 [10%]). The incidence of grade 1-3 memory impairment was 25 (4%) versus 75 (13%). No deaths were attributed to study treatment.

INTERPRETATION

The addition of enzalutamide to standard of care showed sustained improvement in overall survival for patients with metastatic hormone-sensitive prostate cancer and should be considered as a treatment option for eligible patients.

FUNDING

Astellas Pharma.

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.

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.

[New S3 guideline prostate cancer 2021 (version 6.2)-What has changed in advanced prostate cancer?]

There have been numerous new findings from clinical trials in recent years regarding the treatment of metastatic hormone-sensitive or castration-resistant prostate cancer. The newly approved treatment options make therapy planning and therapy sequencing more challenging. In addition, local therapy of metastatic prostate cancer is becoming increasingly important. In the new German guidelines on prostate cancer (version 6.2, October 2021), new developments in the recommendations for the treatment of mHSPC and mCRPC were implemented, and their most important resulting recommendations for the clinical practice are presented in this review.

Treatments for Metastatic Hormone-sensitive Prostate Cancer: Systematic Review, Network Meta-analysis, and Benefit-harm assessment

CONTEXT

Multiple treatments for metastatic, hormone-sensitive prostate cancer (mHSPC) are available, but their effects on health-related quality of life (HRQoL) and benefit-harm balance remain unclear.

OBJECTIVE

To assess clinical effectiveness regarding survival and HRQoL, safety, and benefit-harm balance of mHSPC treatments.

EVIDENCE ACQUISITION

We searched MEDLINE, EMBASE, CENTRAL, and ClinicalTrials.gov until March 1, 2022. Randomized controlled trials (RCTs) comparing docetaxel, abiraterone, enzalutamide, apalutamide, darolutamide, and radiotherapy combined with androgen deprivation therapy (ADT) mutually or with ADT alone were eligible. Three reviewers independently performed screening, data extraction, and risk of bias assessment in duplicate.

EVIDENCE SYNTHESIS

Across ten RCTs, we found relevant survival benefits for ADT + docetaxel (high certainty according to the Grading of Recommendations, Assessment, Development and Evaluation [GRADE]), ADT + abiraterone (moderate certainty), ADT + enzalutamide (low certainty), ADT + apalutamide (high certainty), and ADT + docetaxel + darolutamide (high certainty) compared with ADT alone. ADT + radiotherapy appeared effective only in low-volume de novo mHSPC. We found a short-term HRQoL decrease lasting 3-6 mo for ADT + docetaxel (moderate certainty) and a potential HRQoL benefit for ADT + abiraterone up to 24 mo of follow-up (moderate certainty) compared with ADT alone. There was no difference in HRQoL for ADT + enzalutamide, ADT + apalutamide, or ADT + radiotherapy over ADT alone (low-high certainty). Grade 3-5 adverse effect rates were increased with all systemic combination treatments. A benefit-harm assessment showed high probabilities (>60%) for a net clinical benefit with ADT + abiraterone, ADT + enzalutamide, and ADT + apalutamide, while ADT + docetaxel and ADT + docetaxel + darolutamide appeared unlikely (<40%) to be beneficial.

CONCLUSIONS

Despite substantial survival benefits, no systemic combination treatment showed a clear HRQoL improvement compared with ADT alone. We found evidence for a short-term HRQoL decline with ADT + docetaxel and a higher net clinical benefit with ADT + abiraterone, ADT + apalutamide and ADT + enzalutamide. While individualized decision-making remains important and economic factors need to be considered, the evidence may support a general preference for the combination of ADT with androgen receptor axis-targeted therapies over docetaxel-containing strategies.

PATIENT SUMMARY

We assessed different combination treatments for metastatic hormone-sensitive prostate cancer. While survival was better with all systemic combination treatments, there was no clear improvement in health-related quality of life compared with androgen deprivation therapy alone. Novel hormonal combination treatments had a more favorable benefit-harm balance than combination treatments that include chemotherapy.

Addition of androgen receptor targeted agents to androgen deprivation therapy and docetaxel in metastatic hormone-sensitive prostate cancer: a systematic review and meta-analysis

Background

Androgen-deprivation therapy (ADT) historically represented the milestone for the treatment of metastatic hormone-sensitive prostate cancer (mHSPC). Recently, combining androgen receptor-targeted agents (ARTA) or docetaxel with ADT significantly improved clinical outcomes in this setting. The efficacy of the combined use of an ARTA with docetaxel and ADT (triplet), however, was unknown, and often conflicting data derived from subgroup analysis of randomized phase III trials. In order to better define the benefits and risks of the triplet in mHSPC, we carried out a systematic review and meta-analysis of available clinical trials.

Methods

A literature search with no data restriction using Medline/PubMed, the Cochrane Library, and American Society of Clinical Oncology/European Society for Medical Oncology (ASCO/ESMO) Meeting abstracts was carried out up to April 2022. The meta-analysis was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statements. Overall survival (OS) was the primary endpoint; progression-free survival (PFS) and safety were secondary endpoints. For OS and PFS, summary hazard ratios (HRs) were calculated; for safety, risk ratio (RR) was assessed. Random- or fixed-effects models were used, depending on studies heterogeneity.

Results

Five randomized clinical trials fulfilled the prespecified inclusion criteria. The triplet significantly improved OS (fixed-effect, HR = 0.74; P < 0.00001) and PFS (fixed-effect; HR = 0.50 for clinical PFS, HR = 0.49 for radiological PFS; P < 0.0001) compared with docetaxel plus ADT. We did not show heterogeneity between treatment efficacy and the disease burden, metachronous versus synchronous presentation, concomitant versus sequential strategy. Compared with docetaxel + ADT, the triplet did not increase the risk of adverse events (AEs) (RR = 1.00, P = 0.27 for any-grade AEs; RR = 1.13, P = 0.14 for severe AEs), except for severe hypertension (RR = 1.73, P = 0.001).

Conclusions

Emerging evidence supports the combination of an ARTA plus docetaxel and ADT in mHSPC patients. Given the availability of several strategies in this setting, clinical characteristics and drug safety profile may help clinicians select the appropriate treatment for mHSPC patients who are more likely to benefit from treatment intensification.

•

The addition of ARTA or docetaxel to ADT improved survival in mHSPC.

•

Recently, the combination of ARTA plus docetaxel and ADT (triplet) versus docetaxel plus ADT has been investigated.

•

The triplet prolonged OS and PFS compared with docetaxel plus ADT and represents a potential practice-changing treatment.

•

Clinical characteristics and drug safety profile may help clinicians to select the appropriate treatment for mHSPC.

The Treatment of Metastatic, Hormone-Sensitive Prostatic Carcinoma

BACKGROUND

For many years, the standard treatment of metastatic, hormone-sensitive prostatic carcinoma (mHSPC) was androgen deprivation therapy (ADT) alone. By lowering the testosterone level into the castration range, ADT deprives the tumor of a key growth factor.

METHODS

For this article, we evaluated the treatment recommendations contained in national and international guidelines (German S3 guidelines and those of the European Society for Medical Oncology [ESMO], European Association of Urology [EAU], and National Comprehensive Cancer Network [NCCN]), as well as pertinent publications revealed by a PubMed search and the congress abstracts of the ESMO and of the American Society of Clinical Oncology [ASCO].

RESULTS

The past few years have witnessed fundamental changes in the treatment of mHSPC. Treatment intensification with docetaxel or with the new drugs directed against the androgen receptor signal pathway (abiraterone, apalutamide and enzalutamide) has been found to lower mortality by 19-40% and is now an integral component of first-line therapy. Relevant new findings have also been obtained with threefold combinations of ADT, docetaxel, and abiraterone or darolutamide. For patients with a light tumor burden, local radiotherapy of the primary tumor improves the probability of survival at 3 years by 8% (45.4 versus 49.1 months, difference 3.6 months; 95% confidence interval, 1.0 to 6.2 months).

CONCLUSION

The treatment of mHSPC is constantly changing. Phase III trials that are now in the recruitment stage, as well as our continually improving understanding of the underlying molecular-pathological mechanisms, will be altering the treatment landscape still further in the years to come.

Androgen Receptor Signaling Inhibitors in Addition to Docetaxel with Androgen Deprivation Therapy for Metastatic Hormone-sensitive Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

Recent randomized controlled trials (RCTs) examined the role of adding androgen receptor signaling inhibitors (ARSIs), including abiraterone acetate (ABI), apalutamide, darolutamide (DAR), and enzalutamide (ENZ), to docetaxel (DOC) and androgen deprivation therapy (ADT) in patients with metastatic hormone-sensitive prostate cancer (mHSPC).

OBJECTIVE

To analyze the oncologic benefit of triplet combination therapies using ARSI + DOC + ADT, and comparing them with available treatment regimens in patients with mHSPC.

EVIDENCE ACQUISITION

Three databases and meetings abstracts were queried in April 2022 for RCTs analyzing patients treated with first-line combination systemic therapy for mHSPC. The primary interests of measure were overall survival (OS) and progression-free survival (PFS). Subgroup analyses were conducted to assess the differential outcomes in patients with low- and high-volume disease as well as de novo and metachronous metastasis.

EVIDENCE SYNTHESIS

Overall, 11 RCTs were included for meta-analyses and network meta-analyses (NMAs). We found that the triplet combinations outperformed DOC + ADT in terms of OS (pooled hazard ratio [HR]: 0.74, 95% confidence interval [CI]: 0.65-0.84) and PFS (pooled HR: 0.49, 95% CI: 0.42-0.58). There was no statistically significant difference between patients with low- and high-volume disease in terms of an OS benefit from adding an ARSI to DOC +ADT (both HR: 0.79; p = 1). Based on NMAs, triplet therapy also outperformed ARSI + ADT in terms of OS (DAR + DOC + ADT: pooled HR: 0.74, 95% CI: 0.55-0.99) and PFS (ABI + DOC + ADT: HR: 0.68, 95% CI: 0.51-0.91, and ENZ + DOC + ADT: HR: 0.70, 95% CI: 0.53-0.93). An analysis of treatment ranking among de novo mHSPC patients showed that triplet therapy had the highest likelihood of improved OS in patients with high-volume disease; however, doublet therapy using ARSI + ADT had the highest likelihood of improved OS in patients with low-volume disease.

CONCLUSIONS

We found that the triplet combination therapy improves survival endpoints in mHSPC patients compared with currently available doublet treatment regimens. Our findings need to be confirmed in further head-to-head trials with longer follow-up and among various patient populations.

PATIENT SUMMARY

Our study suggests that triplet therapy with androgen receptor signaling inhibitor, docetaxel, androgen deprivation therapy prolongs survival in patients with metastatic hormone-sensitive prostate cancer compared with the current standard doublet therapy.

Addition of Docetaxel to Androgen Receptor Axis-targeted Therapy and Androgen Deprivation Therapy in Metastatic Hormone-sensitive Prostate Cancer: A Network Meta-analysis

CONTEXT

Randomized controlled trials (RCTs) have shown that addition of docetaxel or androgen receptor axis-targeted therapy (ARAT) to androgen deprivation therapy (ADT) or addition of ARAT to ADT and docetaxel improves overall survival (OS) in metastatic hormone-sensitive prostate cancer (mHSPC). However, it is unknown whether docetaxel, when given as part of triplet therapy, has an independent OS benefit.

OBJECTIVE

To compare the efficacy of ADT plus ARAT with the triplet of ADT, ARAT, and docetaxel through a network meta-analysis (NMA) of RCTs in mHSPC.

EVIDENCE ACQUISITION

Bibliographic databases and conference proceedings were searched in March 2022 for RCTs that evaluated the addition of docetaxel, ARAT, or both to ADT in mHSPC. The primary endpoint was OS. Standard random-effect NMA and Bayesian analyses were performed to compare ADT plus ARAT with triplet therapy.

EVIDENCE SYNTHESIS

Eleven RCTs (n = 11 546) were eligible. Compared with ADT plus ARAT, the triplet had a nonsignificant OS benefit (hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.68-1.16), while ADT plus docetaxel (HR 1.16 [0.94-1.43]) and ADT alone (HR 1.46 [1.30-1.64]) had an increased risk of death. By P-score ordering, the triplet was the most effective treatment strategy (P score = 0.936) followed by ADT plus ARAT (P score = 0.704). The triplet had a 77% likelihood of being the best treatment strategy compared with a 23% likelihood for ADT plus ARAT.

CONCLUSIONS

The triplet of ADT, ARAT, and docetaxel was the highest ranked treatment strategy, but it did not confer a statistically significant OS benefit over ADT plus ARAT. This NMA provides the highest-level comparative evidence for these treatment approaches in the initial management of mHSPC.

PATIENT SUMMARY

We synthesized the available evidence from clinical trials conducted in newly diagnosed metastatic prostate cancer to compare the survival of patients receiving triplet therapy (androgen receptor axis-targeted therapy [ARAT], androgen deprivation therapy [ADT], and docetaxel) with those receiving only ARAT and ADT. We conclude that the triplet is a somewhat more effective treatment approach.

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.

Abiraterone plus prednisone added to androgen deprivation therapy and docetaxel in de novo metastatic castration-sensitive prostate cancer (PEACE-1): a multicentre, open-label, randomised, phase 3 study with a 2 × 2 factorial design

BACKGROUND

Current standard of care for metastatic castration-sensitive prostate cancer supplements androgen deprivation therapy with either docetaxel, second-generation hormonal therapy, or radiotherapy. We aimed to evaluate the efficacy and safety of abiraterone plus prednisone, with or without radiotherapy, in addition to standard of care.

METHODS

We conducted an open-label, randomised, phase 3 study with a 2 × 2 factorial design (PEACE-1) at 77 hospitals across Belgium, France, Ireland, Italy, Romania, Spain, and Switzerland. Eligible patients were male, aged 18 years or older, with histologically confirmed or cytologically confirmed de novo metastatic prostate adenocarcinoma, and an Eastern Cooperative Oncology Group performance status of 0-1 (or 2 due to bone pain). Participants were randomly assigned (1:1:1:1) to standard of care (androgen deprivation therapy alone or with intravenous docetaxel 75 mg/m² once every 3 weeks), standard of care plus radiotherapy, standard of care plus abiraterone (oral 1000 mg abiraterone once daily plus oral 5 mg prednisone twice daily), or standard of care plus radiotherapy plus abiraterone. Neither the investigators nor the patients were masked to treatment allocation. The coprimary endpoints were radiographic progression-free survival and overall survival. Abiraterone efficacy was first assessed in the overall population and then in the population who received androgen deprivation therapy with docetaxel as standard of care (population of interest). This study is ongoing and is registered with ClinicalTrials.gov, NCT01957436.

FINDINGS

Between Nov 27, 2013, and Dec 20, 2018, 1173 patients were enrolled (one patient subsequently withdrew consent for analysis of his data) and assigned to receive standard of care (n=296), standard of care plus radiotherapy (n=293), standard of care plus abiraterone (n=292), or standard of care plus radiotherapy plus abiraterone (n=291). Median follow-up was 3·5 years (IQR 2·8-4·6) for radiographic progression-free survival and 4·4 years (3·5-5·4) for overall survival. Adjusted Cox regression modelling revealed no interaction between abiraterone and radiotherapy, enabling the pooled analysis of abiraterone efficacy. In the overall population, patients assigned to receive abiraterone (n=583) had longer radiographic progression-free survival (hazard ratio [HR] 0·54, 99·9% CI 0·41-0·71; p<0·0001) and overall survival (0·82, 95·1% CI 0·69-0·98; p=0·030) than patients who did not receive abiraterone (n=589). In the androgen deprivation therapy with docetaxel population (n=355 in both with abiraterone and without abiraterone groups), the HRs were consistent (radiographic progression-free survival 0·50, 99·9% CI 0·34-0·71; p<0·0001; overall survival 0·75, 95·1% CI 0·59-0·95; p=0·017). In the androgen deprivation therapy with docetaxel population, grade 3 or worse adverse events occurred in 217 (63%) of 347 patients who received abiraterone and 181 (52%) of 350 who did not; hypertension had the largest difference in occurrence (76 [22%] patients and 45 [13%], respectively). Addition of abiraterone to androgen deprivation therapy plus docetaxel did not increase the rates of neutropenia, febrile neutropenia, fatigue, or neuropathy compared with androgen deprivation therapy plus docetaxel alone.

INTERPRETATION

Combining androgen deprivation therapy, docetaxel, and abiraterone in de novo metastatic castration-sensitive prostate cancer improved overall survival and radiographic progression-free survival with a modest increase in toxicity, mostly hypertension. This triplet therapy could become a standard of care for these patients.

FUNDING

Janssen-Cilag, Ipsen, Sanofi, and the French Government.

Combination therapy in metastatic hormone-sensitive prostate cancer: is three a crowd?

The mainstay of treatment for metastatic prostate cancer is androgen deprivation therapy (ADT). Outcomes with ADT are variable but control of hormone-sensitive prostate cancer (HSPC) can often be achieved for many years. Death from prostate cancer is usually due to the development of escape variants able to survive and proliferate in the setting of castrate levels of serum androgens (metastatic castration-resistant prostate cancer, mCRPC). Several agents can improve survival for patients with mCRPC, including chemotherapy, agents to reduce androgen receptor signalling, the radioisotope radium-223 dichloride, and cellular immunotherapy with sipuleucel-T. Some of these agents have been moved earlier in the disease course and have shown to improve survival in metastatic HSPC also, often to a much greater degree than when the same agents are used in mCRPC. Specifically, survival of metastatic HSPC can be improved with the addition to ADT of any one of docetaxel, abiraterone acetate/prednisone combination, apalutamide, enzalutamide, or darolutamide in combination with docetaxel. Factors affecting outcomes include the volume or burden of disease, timing of metastases relative to the original diagnosis, and patient factors determining the appropriateness of therapy. Unfortunately, uptake of this information by the clinical community remains suboptimal, with many men potentially suitable for combination therapy still receiving only ADT. Some trials have examined the effects of ‘triplet’ therapies although few were designed specifically to address this question. The best evidence to date suggests that triplet therapy with ADT + abiraterone + docetaxel or ADT + darolutamide + docetaxel, can improve overall survival in metastatic HSPC. Clear opportunities exist to improve survival outcomes for men with metastatic HSPC but need to be balanced against cost, accessibility, toxicity, and patient-specific factors.

[A 2021 inventory in oncology news]

Once again this year, the Editorial Board presents here a summary of the most important advances in treatment and patient care in oncology over the past year. Some of the most important results in breast and gynecological cancers (endometrium and cervix), lung, brain, urologic and digestive cancers. Are also presented progresses in hematological malignancies, pediatric oncology, and of course supportive care essential for our patients.