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Preclinical evidence has suggested an interplay between the androgen receptor, which largely drives the growth of prostate cancer cells, and poly(ADP-ribose) polymerase. This association provides a rationale for their co-inhibition for the treatment of metastatic castration-resistant prostate cancer (mCRPC), an area of unmet medical need. The phase 3 TALAPRO-2 study investigated combining the poly(ADP-ribose) polymerase inhibitor talazoparib with enzalutamide versus enzalutamide alone as first-line treatment of mCRPC. Patients were prospectively assessed for tumor alterations in DNA damage response genes involved in homologous recombination repair (HRR). Two cohorts were enrolled sequentially: an all-comers cohort that was enrolled first (cohort 1; N = 805 (169 were HRR-deficient)), followed by an HRR-deficient-only cohort (cohort 2; N = 230). We present results from the alpha-controlled primary analysis for the combined HRR-deficient population (N = 399). Patients were randomized in a 1:1 ratio to talazoparib or placebo, plus enzalutamide. The primary endpoint, radiographic progression-free survival, was met (median not reached at the time of the analysis for the talazoparib group versus 13.8 months for the placebo group; hazard ratio, 0.45; 95% confidence interval, 0.33 to 0.61; P < 0.0001). Data for overall survival, a key secondary endpoint, are immature but favor talazoparib (hazard ratio, 0.69; 95% confidence interval, 0.46 to 1.03; P = 0.07). Common adverse events in the talazoparib group were anemia, fatigue and neutropenia. Combining talazoparib with enzalutamide significantly improved radiographic progression-free survival in patients with mCRPC harboring HRR gene alterations, supporting talazoparib plus enzalutamide as a potential first-line treatment for these patients. ClinicalTrials.gov Identifier: NCT03395197 ., (© 2023. The Author(s).)

Purpose: Biomarkers are needed in patients with non-clear cell renal cell carcinomas (NC-RCC) to inform treatment selection but also to identify novel therapeutic targets. We thus sought to profile circulating angiokines in the context of a randomized treatment trial of everolimus versus sunitinib., Patients and Methods: ASPEN (NCT01108445) was an international, randomized, open-label phase II trial of patients with metastatic papillary, chromophobe, or unclassified NC-RCC with no prior systemic therapy. Patients were randomized to everolimus or sunitinib and treated until disease progression or unacceptable toxicity. The primary endpoint was radiographic progression-free survival (PFS) defined by RECIST 1.1. Plasma angiokines were collected at baseline, cycle 3, and progression and associated with PFS and overall survival (OS)., Results: We enrolled 108 patients, 51 received sunitinib and 57 everolimus; of these, 99 patients had evaluable plasma for 23 angiokines. At the final data cutoff, 94 PFS and 64 mortality events had occurred. Angiokines that were independently adversely prognostic for OS were osteopontin (OPN), TIMP-1, thrombospondin-2 (TSP-2), hepatocyte growth factor (HGF), and VCAM-1, and these were also associated with poor-risk disease. Stromal derived factor 1 (SDF-1) was associated with improved survival. OPN was also significantly associated with worse PFS. No statistically significant angiokine-treatment outcome interactions were observed for sunitinib or everolimus. Angiopoeitin-2 (Ang-2), CD-73, HER-3, HGF, IL6, OPN, PIGF, PDGF-AA, PDGF-BB, SDF-1, TGF-b1-b2, TGFb-R3, TIMP-1, TSP-2, VCAM-1, VEGF, and VEGF-R1 levels increased with progression on everolimus, while CD-73, ICAM-1, IL6, OPN, PlGF, SDF-1, TGF-b2, TGFb-R3, TIMP-1, TSP-2, VEGF, VEGF-D, and VCAM-1 increased with progression on sunitinib., Conclusions: In patients with metastatic NC-RCC, we identified several poor prognosis angiokines and immunomodulatory chemokines during treatment with sunitinib or everolimus, particularly OPN., (©2021 American Association for Cancer Research.)

Objectives: To investigate the uptake, safety and efficacy of docetaxel chemotherapy in hormone-naïve metastatic prostate cancer (mPC) in the first year of use outside of a clinical trial., Patients and Methods: Patients in the West of Scotland Cancer Network with newly diagnosed mPC were identified from the regional multidisciplinary team meetings and their treatment details were collected from electronic patient records. The rate of febrile neutropenia, hospitalisations, time to progression, and overall survival were compared between those patients who received docetaxel and androgen-deprivation therapy (ADT), or ADT alone using survival analysis., Results: Of the 270 eligible patients, 103 received docetaxel (38.1%). 35 patients (34%) were hospitalised and there were 17 episodes of febrile neutropenia (16.5%). Two patients (1.9%) died within 30 days of chemotherapy. Patients who received ADT alone had an increased risk of progression (hazard ratio [HR] 2.03, 95% confidence interval [CI] 1.27-3.25; log-rank test, P = 0.002) and had an increased risk of death (HR 5.88, 95% CI: 2.52-13.72; log-rank test, P = 0.001) compared to the docetaxel group. The risk of febrile neutropenia was nine-times greater if chemotherapy was started within 3 weeks of ADT initiation (95% CI: 1.22-77.72; P = 0.032)., Conclusion: Docetaxel chemotherapy in hormone-naïve mPC has significant toxicities, but has a similar effect on time to progression and overall survival as seen in randomised trials. Chemotherapy should be started at ≥3 weeks after ADT., (© 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.)

Objective: To assess the efficacy and safety of sorafenib dose escalation in metastatic renal cell carcinoma (mRCC)., Patients and Methods: Intra-patient dose escalation may enhance the clinical benefit of targeted anticancer agents in metastatic disease. In this non-randomised, open-label, Phase 2b study, treatment-naïve patients with mRCC were initially treated with the standard oral sorafenib dose [400 mg twice daily (BID)]. Two dose escalations were planned, each 200 mg BID after 28 days at the prior level. Dose reductions, interruptions, or delayed escalations were used to manage adverse events (AEs). The primary endpoint was objective response rate (ORR) in the modified intent-to-treat (mITT) population, which comprised patients with ≥6 months of treatment including ≥4 months of therapy at their highest tolerated dose. Secondary endpoints included progression-free survival (PFS) and safety., Results: In all, 83 patients received sorafenib. The dose received for the longest duration was 400, 600, and 800 mg BID in 48.2%, 15.7%, and 24.1% of patients, respectively. The ORR was 44.4% [n = 8/18; 95% confidence interval (CI) 21.5-69.2] and 17.9% (n = 12/67; 95% CI 9.6-29.2) in the mITT and ITT populations, respectively. The median (95% CI) PFS was 7.4 (6.0-11.7) months (ITT). The most common AEs of any grade were hand-foot skin reaction (66.3%) and diarrhoea (63.9%)., Conclusion: Sorafenib demonstrated clinical benefit in treatment-naïve patients with mRCC. However, relatively few patients could sustain doses of >400 mg BID. There was evidence that, where tolerated, escalation from the standard sorafenib dose may have enhanced clinical benefit. However, this study does not support dose escalation for most patients with treatment-naïve mRCC. Alternative protocols for sorafenib dose escalation could be explored., (© 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.)

Objective: Prostate-specific antigen (PSA) decline by 50 % from the baseline to 12 weeks (PSA50w12) is currently used to predict response to treatment and clinical outcome of patients with metastatic castration-resistant prostate cancer (mCRPC). We evaluated the association between PSA changes at 4 weeks and clinical outcome., Patients and Methods: Eligible patients had PSA levels assessed at baseline, and monthly during enzalutamide treatment. Early PSA increase was defined as an increased PSA level at 4 weeks ≥20 % (PSA + 20w4) from baseline. Early PSA decline was defined as a PSA response at 4 weeks ≥30 % (PSA30w4) and ≥50 % (PSA50w4) from baseline. Progression-free survival (PFS), overall survival (OS) and their 95 % confidence intervals (CI) were evaluated by the Kaplan-Meier method and compared with the log-rank test. The impact of early PSA increase and decline on PFS and OS was evaluated by Cox regression analyses., Results: We assessed 193 patients with median age of 73 years (range 43-91 years). The median follow-up was 11.7 months (range 0.5-27.4 months). PSA + 20w4 predicted both PFS and OS [HR 6.50 (95 % CI 2.63-16.07; p < 0.0001) and HR 10.54 (95 % CI 4.02-27.64; p < 0.0001), respectively], whereas PSA30w4 and PSA50w4 predicted only PFS [HR 0.37 (95 % CI 0.21-0.67; p = 0.0009) and HR 0.34 (95 % CI 0.19-0.60; p = 0.0003), respectively]., Conclusions: An early PSA increase, defined as a PSA level at 4 weeks ≥20 % (PSA + 20w4), could be useful to quickly identify patients unlikely to benefit from enzalutamide. Larger studies are needed to confirm PSA + 20W4 as an early biomarker of primary resistance to enzalutamide.

Background: ASP9521 is a first-in-class orally available inhibitor of the enzyme 17 β-hydroxysteroid dehydrogenase type 5 (17 βHSD5; AKR1C3), catalysing the conversion of dehydroepiandrosterone and androstenedione into 5-androstenediol and testosterone. It has demonstrated anti-tumour activity in in vitro and in vivo preclinical models., Material and Methods: This first-in-man phase I/II study utilised a 3 + 3 dose escalation design starting at 30 mg ASP9521/day, with the aim of defining a maximum tolerated dose, as defined by the incidence of dose-limiting toxicities. Eligible patients received ASP9521 orally for 12 weeks. Safety, tolerability, pharmacokinetics (PK), pharmacodynamics and anti-tumour activity were assessed., Results: Thirteen patients (median age: 68 years; range 52-76) with metastatic castration-resistant prostate cancer (mCRPC) progressing after chemotherapy were included; 12 patients discontinued treatment at or before week 13, mainly due to disease progression. The most common adverse events were grade 1/2 and included asthenia (N = 5), constipation (N = 4), diarrhoea (N = 3), back pain (N = 3) and cancer pain (N = 3). PK demonstrated a half-life (t1/2) ranging from 16 to 35 h, rapid absorption and dose proportionality. No biochemical or radiological responses were identified; neither endocrine biomarker levels nor circulating tumour cell counts were altered by ASP9521. Given the lack of observable clinical activity, the study was terminated without implementing a planned 12-week dose expansion part at selected doses or a planned food-effect study part., Conclusions: In patients with mCRPC, ASP9521 demonstrated dose-proportional increase in exposure over the doses evaluated, with an acceptable safety and tolerability profile. However, the novel androgen biosynthesis inhibitor showed no relevant evidence of clinical activity.

Simple Summary: Urothelial carcinoma (UC) is a common type of bladder cancer. Patients with UC that has not improved after previous treatment or has spread to other parts of the body need new treatment options. Ibrutinib is a drug approved for the treatment of blood cancers and chronic graft-versus-host disease. It works by blocking Bruton's tyrosine kinase, an enzyme important for cancer cell survival. Other drugs, pembrolizumab and paclitaxel, are considered standard treatments for UC. This study aimed to understand if ibrutinib alone or combined with pembrolizumab or paclitaxel could lessen disease in patients with UC and help them live longer without their disease getting worse. More patients previously treated for UC had disease improvement with the combinations of ibrutinib and pembrolizumab or ibrutinib and paclitaxel than with pembrolizumab, paclitaxel or ibrutinib alone or compared to historical data. Based on these results, additional studies of ibrutinib combinations in UC are needed. Ibrutinib is a first-in-class Bruton's tyrosine kinase inhibitor approved for the treatment of various B-cell malignancies and chronic graft-versus-host disease. We evaluated the safety and efficacy of ibrutinib, alone or combined with standard-of-care regimens, in adults with advanced urothelial carcinoma (UC). Once-daily ibrutinib was administered orally at 840 mg (single-agent or with paclitaxel) or at 560 mg (with pembrolizumab). Phase 1b determined the recommended phase 2 dose (RP2D) of ibrutinib, and phase 2 assessed progression-free survival (PFS), overall response rate (ORR), and safety. Thirty-five, eighteen, and fifty-nine patients received ibrutinib, ibrutinib plus pembrolizumab, and ibrutinib plus paclitaxel at the RP2D, respectively. Safety profiles were consistent with those of the individual agents. The best-confirmed ORRs were 7% (two partial responses) with single-agent ibrutinib and 36% (five partial responses) with ibrutinib plus pembrolizumab. Median PFS was 4.1 months (range, 1.0–37.4+) with ibrutinib plus paclitaxel. The best-confirmed ORR was 26% (two complete responses). In previously treated patients with UC, ORR was higher with ibrutinib plus pembrolizumab than with either agent alone (historical data in the intent-to-treat population). ORR with ibrutinib plus paclitaxel was greater than historical values for single-agent paclitaxel or ibrutinib. These data warrant further evaluation of ibrutinib combinations in UC. [ABSTRACT FROM AUTHOR]

Combination chemotherapy regimens can improve survival in patients with advanced gastric and oesophageal adenocarcinoma. Docosahexaenoic acid (DHA)-paclitaxel is a novel conjugate formed by the covalent linkage of the fatty acid DHA to paclitaxel and may result in increased tumour exposure to paclitaxel without increased toxicity. In this single arm, phase II study of DHA-paclitaxel, eligible patients with previously untreated, inoperable locally advanced or metastatic adenocarcinoma of the oesophagus, oesophago-gastric junction or stomach were treated with DHA-paclitaxel (1,100 mg/m2) administered by 2-h intravenous infusion every 21 days. Fifty-four patients were recruited of whom 53 were evaluable for toxicity, and 48 for response. There were five confirmed partial responses (9.4%) by the RECIST criteria. The median duration of response was 87 days (range 49–97 days), the median time to progression was 84 days (95% CI 78–124 days), and median overall survival was 262 days (95% CI 205–357 days). Grade ≥3 neutropaenia occurred in 93% of patients, and febrile neutropaenia in 17% of patients. DHA-paclitaxel has modest activity in patients with oesophago-gastric cancer and with haematological toxicity that is comparable to paclitaxel and docetaxel. [ABSTRACT FROM AUTHOR]

This detailed analysis further characterizes the safety profile of talazoparib plus enzalutamide in the ongoing randomized, phase III TALAPRO-2 study in patients with metastatic castration-resistant prostate cancer (mCRPC). In both the all-comers and homologous recombination repair (HRR)-deficient populations, talazoparib plus enzalutamide significantly improved radiographic progression-free survival compared with placebo plus enzalutamide. The talazoparib plus enzalutamide safety populations in TALAPRO-2 included 398 patients from cohort 1 (all-comers, unselected for HRR gene alterations) and 198 patients from the combined HRR-deficient population (patients from the all-comers population with HRR gene alterations plus subsequently enrolled patients with HRR gene alterations; cohort 2). Patients received talazoparib 0.5 mg (0.35 mg, moderate renal impairment) and enzalutamide 160 mg once daily. Safety analyses evaluated common treatment-emergent adverse events (TEAE), their type, severity, timing, seriousness, and relationship to study treatment. In the all-comers (n = 398) and HRR-deficient populations (n = 198), all-cause grade 3/4 (G3/4) TEAEs with talazoparib plus enzalutamide were reported in 71.9 % and 66.2 % of patients, respectively. Most common G3/4 hematologic TEAEs were anemia (46.7 % and 40.9 %, respectively), neutropenia (18.3 % and 18.7 %), and thrombocytopenia (7.3 % and 7.1 %). Median time to event was 3.3 and 3.3 months for G3/4 anemia, 2.3 and 2.3 months for G3/4 neutropenia, and 2.3 and 1.5 months for G3/4 thrombocytopenia. Maximum hemoglobin reduction occurred after 13 and 15 weeks of treatment. 18.8 % and 10.1 % of patients discontinued talazoparib. TEAEs were managed with dose interruption (62.1 % and 57.6 %), reduction (52.8 % and 52.0 %), hematologic supportive care (13.1 % and 10.6 %), and packed red blood cell transfusions (39.2 % and 35.9 %). Talazoparib plus enzalutamide had a generally manageable safety profile in patients with mCRPC within the all-comers and the HRR-deficient populations. NCT03395197 • We present detailed safety analyses of talazoparib plus enzalutamide from TALAPRO-2. • Anemia, neutropenia, and fatigue were the most common any-grade adverse events. • Median time to grade 3/4 myelosuppression-related events ranged from 1.5–3.3 months. • Anemia was managed with dose modifications and hematologic supportive care. • Talazoparib plus enzalutamide for mCRPC has a generally manageable safety profile. [ABSTRACT FROM AUTHOR]

PTEN loss and aberrations in PI3K/AKT signaling kinases associate with poorer response to abiraterone acetate (AA) in metastatic castration-resistant prostate cancer (mCRPC). In this study, we assessed antitumor activity of the AKT inhibitor capivasertib combined with enzalutamide in mCRPC with prior progression on AA and docetaxel. This double-blind, placebo-controlled, randomized phase 2 trial, recruited men ≥ 18 years with progressing mCRPC and performance status 0–2 from 15 UK centers. Randomized participants (1:1) received enzalutamide (160 mg orally, once daily) with capivasertib (400 mg)/ placebo orally, twice daily on an intermittent (4 days on, 3 days off) schedule. Primary endpoint was composite response rate (RR): RECIST 1.1 objective response, ≥ 50 % PSA decrease from baseline, or circulating tumor cell count conversion (from ≥ 5 at baseline to < 5 cells/7.5 mL). Subgroup analyses by PTEN IHC status were pre-planned. Overall, 100 participants were randomized (50:50); 95 were evaluable for primary endpoint (47:48); median follow-up was 43 months. RR were 9/47 (19.1 %) enzalutamide/capivasertib and 9/48 (18.8 %) enzalutamide/placebo (absolute difference 0.4 % 90 %CI −12.8 to 13.6, p = 0.58), with similar results in the PTEN IHC loss subgroup. Irrespective of treatment, OS was significantly worse for PTEN IHC loss (10.1 months [95 %CI: 4.6–13.9] vs 14.8 months [95 %CI: 10.8–18]; p = 0.02). Most common treatment-emergent grade ≥ 3 adverse events for the combination were diarrhea (13 % vs 2 %) and fatigue (10 % vs 6 %). Combined capivasertib/enzalutamide was well tolerated but didn't significantly improve outcomes from abiraterone pre-treated mCRPC. • RE-AKT is a multicentre, randomized, double-blinded phase II trial in mCRPC. • Combined capivasertib and enzalutamide did not increase enzalutamide's antitumour activity in mCRPC. • Albeit well tolerated, capivasertib exposure is reduced when enzalutamide is given. [ABSTRACT FROM AUTHOR]

Background: Men with high-risk non-metastatic prostate cancer are treated with androgen-deprivation therapy (ADT) for 3 years, often combined with radiotherapy. We analysed new data from two randomised controlled phase 3 trials done in a multiarm, multistage platform protocol to assess the efficacy of adding abiraterone and prednisolone alone or with enzalutamide to ADT in this patient population.Methods: These open-label, phase 3 trials were done at 113 sites in the UK and Switzerland. Eligible patients (no age restrictions) had high-risk (defined as node positive or, if node negative, having at least two of the following: tumour stage T3 or T4, Gleason sum score of 8-10, and prostate-specific antigen [PSA] concentration ≥40 ng/mL) or relapsing with high-risk features (≤12 months of total ADT with an interval of ≥12 months without treatment and PSA concentration ≥4 ng/mL with a doubling time of <6 months, or a PSA concentration ≥20 ng/mL, or nodal relapse) non-metastatic prostate cancer, and a WHO performance status of 0-2. Local radiotherapy (as per local guidelines, 74 Gy in 37 fractions to the prostate and seminal vesicles or the equivalent using hypofractionated schedules) was mandated for node negative and encouraged for node positive disease. In both trials, patients were randomly assigned (1:1), by use of a computerised algorithm, to ADT alone (control group), which could include surgery and luteinising-hormone-releasing hormone agonists and antagonists, or with oral abiraterone acetate (1000 mg daily) and oral prednisolone (5 mg daily; combination-therapy group). In the second trial with no overlapping controls, the combination-therapy group also received enzalutamide (160 mg daily orally). ADT was given for 3 years and combination therapy for 2 years, except if local radiotherapy was omitted when treatment could be delivered until progression. In this primary analysis, we used meta-analysis methods to pool events from both trials. The primary endpoint of this meta-analysis was metastasis-free survival. Secondary endpoints were overall survival, prostate cancer-specific survival, biochemical failure-free survival, progression-free survival, and toxicity and adverse events. For 90% power and a one-sided type 1 error rate set to 1·25% to detect a target hazard ratio for improvement in metastasis-free survival of 0·75, approximately 315 metastasis-free survival events in the control groups was required. Efficacy was assessed in the intention-to-treat population and safety according to the treatment started within randomised allocation. STAMPEDE is registered with ClinicalTrials.gov, NCT00268476, and with the ISRCTN registry, ISRCTN78818544.Findings: Between Nov 15, 2011, and March 31, 2016, 1974 patients were randomly assigned to treatment. The first trial allocated 455 to the control group and 459 to combination therapy, and the second trial, which included enzalutamide, allocated 533 to the control group and 527 to combination therapy. Median age across all groups was 68 years (IQR 63-73) and median PSA 34 ng/ml (14·7-47); 774 (39%) of 1974 patients were node positive, and 1684 (85%) were planned to receive radiotherapy. With median follow-up of 72 months (60-84), there were 180 metastasis-free survival events in the combination-therapy groups and 306 in the control groups. Metastasis-free survival was significantly longer in the combination-therapy groups (median not reached, IQR not evaluable [NE]-NE) than in the control groups (not reached, 97-NE; hazard ratio [HR] 0·53, 95% CI 0·44-0·64, p<0·0001). 6-year metastasis-free survival was 82% (95% CI 79-85) in the combination-therapy group and 69% (66-72) in the control group. There was no evidence of a difference in metatasis-free survival when enzalutamide and abiraterone acetate were administered concurrently compared with abiraterone acetate alone (interaction HR 1·02, 0·70-1·50, p=0·91) and no evidence of between-trial heterogeneity (I2 p=0·90). Overall survival (median not reached [IQR NE-NE] in the combination-therapy groups vs not reached [103-NE] in the control groups; HR 0·60, 95% CI 0·48-0·73, p<0·0001), prostate cancer-specific survival (not reached [NE-NE] vs not reached [NE-NE]; 0·49, 0·37-0·65, p<0·0001), biochemical failure-free-survival (not reached [NE-NE] vs 86 months [83-NE]; 0·39, 0·33-0·47, p<0·0001), and progression-free-survival (not reached [NE-NE] vs not reached [103-NE]; 0·44, 0·36-0·54, p<0·0001) were also significantly longer in the combination-therapy groups than in the control groups. Adverse events grade 3 or higher during the first 24 months were, respectively, reported in 169 (37%) of 451 patients and 130 (29%) of 455 patients in the combination-therapy and control groups of the abiraterone trial, respectively, and 298 (58%) of 513 patients and 172 (32%) of 533 patients of the combination-therapy and control groups of the abiraterone and enzalutamide trial, respectively. The two most common events more frequent in the combination-therapy groups were hypertension (abiraterone trial: 23 (5%) in the combination-therapy group and six (1%) in control group; abiraterone and enzalutamide trial: 73 (14%) and eight (2%), respectively) and alanine transaminitis (abiraterone trial: 25 (6%) in the combination-therapy group and one (<1%) in control group; abiraterone and enzalutamide trial: 69 (13%) and four (1%), respectively). Seven grade 5 adverse events were reported: none in the control groups, three in the abiraterone acetate and prednisolone group (one event each of rectal adenocarcinoma, pulmonary haemorrhage, and a respiratory disorder), and four in the abiraterone acetate and prednisolone with enzalutamide group (two events each of septic shock and sudden death).Interpretation: Among men with high-risk non-metastatic prostate cancer, combination therapy is associated with significantly higher rates of metastasis-free survival compared with ADT alone. Abiraterone acetate with prednisolone should be considered a new standard treatment for this population.Funding: Cancer Research UK, UK Medical Research Council, Swiss Group for Clinical Cancer Research, Janssen, and Astellas. [ABSTRACT FROM AUTHOR]

Background: Based on previous findings, we hypothesised that radiotherapy to the prostate would improve overall survival in men with metastatic prostate cancer, and that the benefit would be greatest in patients with a low metastatic burden. We aimed to compare standard of care for metastatic prostate cancer, with and without radiotherapy.Methods: We did a randomised controlled phase 3 trial at 117 hospitals in Switzerland and the UK. Eligible patients had newly diagnosed metastatic prostate cancer. We randomly allocated patients open-label in a 1:1 ratio to standard of care (control group) or standard of care and radiotherapy (radiotherapy group). Randomisation was stratified by hospital, age at randomisation, nodal involvement, WHO performance status, planned androgen deprivation therapy, planned docetaxel use (from December, 2015), and regular aspirin or non-steroidal anti-inflammatory drug use. Standard of care was lifelong androgen deprivation therapy, with up-front docetaxel permitted from December, 2015. Men allocated radiotherapy received either a daily (55 Gy in 20 fractions over 4 weeks) or weekly (36 Gy in six fractions over 6 weeks) schedule that was nominated before randomisation. The primary outcome was overall survival, measured as the number of deaths; this analysis had 90% power with a one-sided α of 2·5% for a hazard ratio (HR) of 0·75. Secondary outcomes were failure-free survival, progression-free survival, metastatic progression-free survival, prostate cancer-specific survival, and symptomatic local event-free survival. Analyses used Cox proportional hazards and flexible parametric models, adjusted for stratification factors. The primary outcome analysis was by intention to treat. Two prespecified subgroup analyses tested the effects of prostate radiotherapy by baseline metastatic burden and radiotherapy schedule. This trial is registered with ClinicalTrials.gov, number NCT00268476.Findings: Between Jan 22, 2013, and Sept 2, 2016, 2061 men underwent randomisation, 1029 were allocated the control and 1032 radiotherapy. Allocated groups were balanced, with a median age of 68 years (IQR 63-73) and median amount of prostate-specific antigen of 97 ng/mL (33-315). 367 (18%) patients received early docetaxel. 1082 (52%) participants nominated the daily radiotherapy schedule before randomisation and 979 (48%) the weekly schedule. 819 (40%) men had a low metastatic burden, 1120 (54%) had a high metastatic burden, and the metastatic burden was unknown for 122 (6%). Radiotherapy improved failure-free survival (HR 0·76, 95% CI 0·68-0·84; p<0·0001) but not overall survival (0·92, 0·80-1·06; p=0·266). Radiotherapy was well tolerated, with 48 (5%) adverse events (Radiation Therapy Oncology Group grade 3-4) reported during radiotherapy and 37 (4%) after radiotherapy. The proportion reporting at least one severe adverse event (Common Terminology Criteria for Adverse Events grade 3 or worse) was similar by treatment group in the safety population (398 [38%] with control and 380 [39%] with radiotherapy).Interpretation: Radiotherapy to the prostate did not improve overall survival for unselected patients with newly diagnosed metastatic prostate cancer.Funding: Cancer Research UK, UK Medical Research Council, Swiss Group for Clinical Cancer Research, Astellas, Clovis Oncology, Janssen, Novartis, Pfizer, and Sanofi-Aventis. [ABSTRACT FROM AUTHOR]