Radiographic Progression-free Survival Research Articles

The impact of progression-directed therapy on survival in metastatic castration-refractory prostate cancer: MEDCARE phase 3 trial.

Metastatic castration-refractory prostate cancer (mCRPC) presents a therapeutic challenge despite advancements in treatment. Once mCRPC is attained, patients face limited survival prospects. Next-line systemic treatment (NEST) is the standard of care for progressive mCRPC, encompassing various therapeutic options with associated toxicity and costs. In patients with oligoprogressive mCRPC, data suggest that progression-directed therapy (PDT), such as metastasectomy or stereotactic body radiotherapy, delays the initiation of NEST. The MEDCARE phase III trial aims to assess the impact of PDT on overall survival (OS) in oligoprogressive mCRPC. In this multicentric, randomised, prospective trial, we aim to randomise 246 patients in 1:1 allocation ratio between the standard-of-care therapy (surveillance or NEST) or PDT while continuing the current systemic treatment. Patients will be stratified based on number of progressive lesions (one vs ≥one), location of progressive lesions (local recurrence, N or M1a vs M1b or M1c) and previous systemic therapy (palliative androgen-deprivation therapy [pADT] vs pADT + androgen receptor-targeted agent or patients who received docetaxel in the past). The primary endpoint is OS, and the secondary endpoints include quality of life, radiographic progression-free survival (PFS), modified PFS, prostate cancer-specific survival and PDT-induced toxicity. This is the first randomised phase 3 trial in the setting of PDT in patients with oligoprogressive mCRPC with OS as the primary endpoint.

Phase II trial of multi-tyrosine kinase inhibitor ESK981 in combination with PD-1 inhibitor nivolumab in patients with metastatic castration-resistant prostate cancer.

Increasing the response rates of immune checkpoint inhibitors in patients with metastatic castration-resistant prostate cancer (mCRPC) presents a significant challenge. ESK981 is a multi-tyrosine kinase and PIKfyve lipid kinase inhibitor that augments immunotherapeutic responses. In this phase II study, ESK981 was combined with the PD-1 blocking monoclonal antibody nivolumab to test for potentially improved response rates in patients with mCRPC who have progressed on androgen receptor (AR)-targeted agents and chemotherapy. Eligible patients received ESK981 orally once daily for five consecutive days, followed by a two-day break. Patients were also treated with nivolumab intravenously on Day 1 of each 28-day cycle. The primary endpoints were a 50% reduction in prostate-specific antigen (PSA50), and safety. Secondary endpoints included radiographic progression free survival (rPFS) and overall survival (OS). Additional investigations included whole exome sequencing in patients. Ten patients were enrolled. The maximum PSA decline from baseline of 14% was achieved in only one patient. Grade 3 treatment-related adverse events (AEs) included fatigue, anemia, and lymphopenia. There were no Grade 4 events. The median rPFS was 3.7 months (95% CI, 1.6-8.4). The median OS was 9.6 months (95% CI, 1.8-22.4). The study was terminated due to futility after 10 patients. Whole exome sequencing identified AR amplification in 63% of patients (5/8). ESK981 + nivolumab showed no antitumor activity in patients with AR-positive (AR+) mCRPC. Further evaluation of ESK981 combined with the PD-1 inhibitor nivolumab in AR + mCRPC patients is not warranted. (Trial registration: ClinicalTrials.gov NCT04159896. Registration date: November 12, 2019.).

P123 Exploring the relationship Between radiographic progression-free survival and overall survival in first-line metastatic castration-resistant prostate cancer

P123 Exploring the relationship Between radiographic progression-free survival and overall survival in first-line metastatic castration-resistant prostate cancer

Multivariable models of outcomes with [177Lu]Lu-PSMA-617: analysis of the phase 3 VISION trial

[177Lu]Lu-PSMA-617 (177Lu-PSMA-617) prolonged life in patients with metastatic castration-resistant prostate cancer (mCRPC) in VISION (NCT03511664). However, distinguishing between patients likely and unlikely to respond remains a clinical challenge. We present the first multivariable models of outcomes with 177Lu-PSMA-617 built using data from VISION, a large prospective phase 3 clinical trial powered for overall survival. Adults with progressive post androgen receptor pathway inhibitor and taxane prostate-specific membrane antigen (PSMA)-positive mCRPC received 177Lu-PSMA-617 plus protocol-permitted standard of care (SoC) or SoC alone. In this post hoc analysis, multivariable Cox proportional hazards models of overall survival (OS) and radiographic progression-free survival (rPFS), and a logistic regression model of prostate-specific antigen response (≥50% decline; PSA50) were constructed and evaluated using C-index or receiver operating characteristic (ROC) analyses with bootstrapping validation. Nomograms were constructed for visualisation. Patients were randomised between June 2018 and October 2019. Data from all 551 patients in the 177Lu-PSMA-617 arm were analysed in multivariable modelling. The OS nomogram (C-index, 0.73; 95% confidence interval [CI], 0.70-0.76) included whole-body maximum standardised uptake value (SUVmax), time since diagnosis, opioid analgesic use, aspartate aminotransferase, haemoglobin, lymphocyte count, presence of PSMA-positive lesions in lymph nodes, lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and neutrophil count. The rPFS nomogram (C-index, 0.68; 0.65-0.72) included SUVmax, time since diagnosis, opioid analgesic use, lymphocyte count, presence of liver metastases by computed tomography, LDH, and ALP. The PSA50 nomogram (area under ROC curve, 0.72; 95% CI, 0.68-0.77) included SUVmax, lymphocyte count and ALP. Performances of the OS and rPFS models were maintained when they were reconstructed excluding SUVmax. These models of outcomes with 177Lu-PSMA-617 are the first built using prospective phase 3 data. They show that a combination of pretreatment laboratory, clinical, and imaging parameters, reflecting both patient and tumour status, influences outcomes. These models are important for aiding treatment selection, patient management, and clinical trial design. Novartis.

Investigating High-risk Factors, Precise Diagnosis, and Treatment of Castration- Resistant Prostate Cancer (CRPC).

The treatment of metastatic castration-resistant prostate cancer (mCRPC) in the actual world currently presents difficulties. In light of this, it is crucial to investigate high-risk factors for the progression of advanced prostate cancer and to identify methods for delaying the onset of CRPC. This study aimed to explore the high-risk factors that impact the progression of prostate cancer and emphasize the significance of precise diagnosis and treatment based on etiological classification in the clinical management of castration-resistant prostate cancer. A retrospective analysis was conducted on 277 newly diagnosed cases of PCa treated with endocrine therapy. A follow-up was done on prostate-specific antigen (PSA) levels and testosterone. Additionally, a prospective analysis was performed on the clinical data of 60 patients with CRPC. Following the principle of "4W1H", 30 patients were included in the precision treatment group for a second biopsy and related tests, while another 30 patients were included in the conventional treatment group. The therapeutic effect and prognosis of the two groups were observed. Distant metastasis (HR = 1.879, 95% CI: 1.311 ~ 2.694, P = 0.001), PSA nadir > 0.2 ng/mL (HR = 1.843, 95% CI: 1.338 ~ 2.540, P = 0.001), testosterone nadir > 20 ng/dL (HR = 1.403, 95% CI: 1.035 ~ 1.904, P = 0.029), and time to testosterone nadir > 6 months (HR = 1.919, 95% CI: 1.364 ~ 2.701, P = 0.001) were risk factors for the progression to CRPC. Patients in the CRPC group were treated with precision therapy and conventional therapy based on their molecular subtyping. The precision treatment group showed a significantly prolonged median PSA progression-free survival compared to the conventional treatment group (16.0 months vs. 13.0 months, P=0.025). The median radiographic progression-free survival was also significantly extended in the precision treatment group compared to the conventional treatment group (21.0 months vs. 16.0 months, P=0.042). Patients with prostate cancer diagnosed with distant metastasis at initial presentation require early intervention. Close monitoring of PSA and serum testosterone changes is necessary during the process of endocrine therapy. After entering the CRPC stage, the etiological classification precision treatment can improve the therapeutic effect and improve the prognosis of patients.

Regression and growth rates in androgen deprivation therapy for advanced castration-sensitive prostate cancer.

No study has compared cancer regression (d) and growth (g) rates in patients with advanced castration-sensitive prostate cancer (CSPC) treated with androgen deprivation therapy. The comparison of d and g rates provides insight into the differential impact of ADT regimens on tumor dynamics, potentially guiding more personalized treatment strategies. Therefore, we aimed to estimate these rates and evaluate their impact on survival outcomes. Sequential prostate-specific antigen (PSA) data was obtained from the KYUCOG-1401 trial including patients with advanced CSPC randomized to gonadotropin-releasing hormone (GnRH) antagonist (group A) and GnRH agonist plus bicalutamide (group B). d and g rates were estimated by applying mathematical models and were compared in subgroups. PSA-progression-free survival (PSA-PFS), radiographic progression-free survival (rPFS), and overall survival (OS) were compared by lower and higher than the median of these rates. Patients with higher PSA and higher extent of disease score at enrollment presented higher d rates (0.03965 vs. 0.03546, p = 0.0006) and (0.03947 vs. 0.03587, p = 0.0113) for groups A and B, respectively. The median d rate was lower for group A than group B (0.03306 vs. 0.039965, respectively [p = 0.0002]). The median g rate was higher for group A than group B (0.00016 vs. 0.00002, respectively [p = 0.0014]). The g rate, but not the d rate discriminated PSA-PFS, rPFS, and OS. Our results suggest that GnRH agonist plus bicalutamide reduced PSA level faster and suppressed PSA rising longer than GnRH antagonist. Moreover, measuring the g rate can predict PSA-PFS, rPFS, and OS in patients with advanced CPSC treated with androgen deprivation therapy. These findings suggest that incorporating g rate measurements into clinical practice could improve prognostic accuracy and guide treatment decisions in advanced CSPC.

Assessing the predictive value of intraductal carcinoma of the prostate (IDC-P) in determining abiraterone efficacy for metastatic hormone-sensitive prostate cancer (mHSPC) patients.

This study explored the value of intraductal carcinoma of the prostate (IDC-P) in predicting the efficacy of abiraterone treatment in metastatic hormone-sensitive prostate cancer (mHSPC) patients. A retrospective study of 925 patients who underwent prostate biopsies to detect IDC-P was conducted, with participants divided into two cohorts. The first cohort of 165 mHSPC patients receiving abiraterone treatment was analyzed to compare therapeutic effectiveness between IDC-P positive and negative cases. Utilizing propensity score matching (PSM) to reduce bias, outcomes such as PSA response, progression-free survival (PSA-PFS), radiographic progression-free survival (rPFS), and overall survival were assessed. Additionally, the second cohort of 760 mHSPC patients compared the efficacy of abiraterone with conventional hormone therapy, focusing on differences between IDC-P positive and negative individuals. After PSM, our first cohort included 108 patients with similar baseline characteristics. Among them, 50% (54/108) were diagnosed with IDC-P, with 22.2% (12/54) having IDC-P pattern 1 and 77.8% (42/54) with IDC-P pattern 2. While no notable difference was seen in PSA responses between IDC-P positive and negative patients, IDC-P presence linked to worse clinical outcomes (PSA-PFS: 18.6 months vs. not reached [NR], p = 0.009; rPFS: 23.6 months vs. NR, p = 0.020). Further analysis showed comparable outcomes for IDC-P pattern 1 but significantly worse prognosis for IDC-P pattern 2 (PSA-PFS: 18.6 months vs. NR, p = 0.002; rPFS: 22.4 months vs. NR, p = 0.010). Subgroup analysis revealed IDC-P pattern 2 consistently predicted poorer outcomes across patient subgroups. Remarkably, both IDC-P positive and negative patients gained more from androgen deprivation therapy with abiraterone than conventional treatment, with IDC-P negative patients showing a more significant survival advantage, supported by better hazard ratios (0.47 and 0.66). This study found that IDC-P, especially pattern 2, predicts poor prognosis in mHSPC patients on abiraterone therapy. Also, abiraterone's advantage over hormone therapy is reduced in cases with IDC-P compared to those without.

Prostate Cancer, Pathophysiology and Recent Developments in Management: A Narrative Review.

Prostate cancer is the second most common cancer in men. The different stages of prostate cancer which include localised (low, intermediate, and high risk) disease, locally advanced, non-metastatic castration-resistant prostate cancer (M0 CRPCa), and metastatic disease. The main treatment of locally advanced disease is external beam radiotherapy with hormonal therapy which are associated with good prognosis. Current treatments for M0 CRPCa include androgen deprivation therapy in combination with apalutamide, darolutamide or enzalutamide, all of which are associated with good metastatic-free survival rates in clinical trials. Hormone-naive metastatic prostate cancer comprises the same treatments as M0 CRPCa, whereas further treatment includes docetaxel and abiraterone. Metastatic castration-resistant prostate cancer treatments include sipuleucel-T, radium-223, abiraterone, enzalutamide and cabazitaxel, which aim to slow down the progression of the disease and to prolong life. This article also provides insight into the development of new drugs recently approved for metastatic castration prostate cancer, which include PARP inhibitors and Lutetium-177 which have shown to have significantly good overall survival and to improve radiographic progression-free survival. In addition, new clinical trials are ongoing to test new medications such as cabozantinb and chimeric-antigen receptor T-cell therapy for the treatment of advanced prostate cancer. With the aim to slow down the progression of the disease and to prolong life, new drug developments are underway to hopefully provide a positive impact on overall survival and improve progression-free survival, especially in advanced prostate cancer.

Ultralow Prostate-Specific Antigen (PSA) Levels and Improved Oncological Outcomes in Metastatic Hormone-Sensitive Prostate Cancer (mHSPC) Patients Treated with Apalutamide: A Real-World Multicentre Study.

Background/Objectives: Androgen receptor-targeted agents have significantly improved the prognosis of metastatic hormone-sensitive prostate cancer (mHSPC). Prostate-specific antigen (PSA) levels are key prognostic markers, with rapid and deep reductions associated with better outcomes. This study aims to assess the association between the new PSA cut-offs and survival in mHSPC patients treated with Apalutamide. Methods: We conducted a multicentre, retrospective analysis of mHSPC patients treated with Apalutamide between March 2021 and January 2023. Overall survival (OS) and radiographic progression-free survival (rFPS) were analyzed and stratified by the following PSA ranges: <0.02 ng/mL (ultralow), 0.02-0.2 ng/mL, and >0.2 ng/mL. Cox regression was applied to identify variables associated with OS and rPFS. Results: Among 193 patients, 34.2% had de novo mHSPC, with the majority classified as M1b. A total of 58.2% (110) of our cohort achieved ultralow PSA levels, with 20.6% between 0.02 and 0.2 ng/mL, and 21.2% of PSA levels > 0.2 ng/mL. Most patients reached ultralow PSA within six months. Low-volume, metachronous, and M1a subgroups displayed a higher prevalence of patients reaching ultralow PSA levels. At 18 months, OS was 100% in the ultralow PSA group, 94.4% for the 0.02-0.2 ng/mL group, and 67.7% in the >0.2 ng/mL group. Similarly, rPFS at 18 months was 100%, 93.5%, and 50.7%, respectively. Cox regression revealed that both ultralow PSA levels and ISUP grade had a significant impact on OS (HR of 8.256 and 0.164, respectively). For rPFS, only ultralow PSA levels had a significant impact (HR = 0.085). Conclusions: This real-world study of mHSPC patients treated with Apalutamide plus ADT revealed that achieving ultralow PSA levels is strongly associated with better oncological outcomes.

Preliminary Efficacy, Tolerability, and Safety Analysis of Darolutamide for Metastatic Castration-Resistant Prostate Cancer: A Single-Center, Open-Label Study

Introduction: Darolutamide is a structurally unique second-generation androgen receptor antagonist that has been approved for indications in patients with non-metastatic castration-resistant prostate cancer (nmCRPC) and metastatic hormone-sensitive prostate cancer (mHSPC). The aim was to assess the efficacy and safety of Darolutamide for mCRPC. Methods: In this single-center, open-label study, patients with previously untreated mCRPC were enrolled and received androgen deprivation therapy (goserelin acetate 3.6 mg every 28 days) and docetaxel (75 mg per square meter of body surface area every 21 days) with Denosumab (120 mg every 28 days) for bone metastases, Darolutamide (300 mg orally twice daily) in the experimental group, and the control group received the corresponding of placebo. Serum PSA changes were detected and recorded, and imaging changes and adverse events (AEs) were evaluated. The primary endpoints were safety, tolerability, and antitumor efficacy, and the second endpoint was radiographic progression-free survival (rPFS). Results: Thirty-seven patients with mCRPC were enrolled. The median time to PSA50 in the Darolutamide group was 1.5 months (95% CI: 0.2619–0.9545), significantly lower than that in the placebo group (3.0 months [95% CI: 1.048–3.818], p = 0.0259). The median time to PSA90 in the experimental group was 4 months (95% CI: 0.3094–1.437), 2 months shorter than that in the placebo group (6.0 months [95% CI: 0.6961–3.232]). With the median follow-up of 6 months, the median decrease in serum PSA was −81.8% (range −60.4 to −99.9%) in the Darolutamide group and −69.4% (range −50.3 to −89.6%) in the placebo group. Tumor-related pain and AEs were not increased, and the median rPFS was not reached. Conclusions: The combination of Darolutamide and docetaxel was well tolerated with more clinically beneficial than docetaxel alone in previously untreated mCRPC. Darolutamide rapidly reduced PSA levels and prolonged rPFS and did not increase the incidence of AEs.

Correlation of PSA and survival in metastatic hormone-sensitive prostate cancer treated with rezvilutamide plus ADT in the CHART trial.

This exploratory analysis of the CHART trial (ClinicalTrials.gov: NCT03520478) investigated prostate-specific antigen (PSA) kinetics and the correlation between PSA and survival outcomes in high-volume, metastatic, hormone-sensitive prostate cancer (mHSPC). A total of 654 patients were randomized 1:1 to receive either rezvilutamide plus androgen deprivation therapy (ADT; n= 326) or bicalutamide plus ADT (n= 328). PSA kinetics were evaluated, and the correlation between survival and the achievement of undetectable PSA (≤0.2ng/mL) or ≥90% PSA reduction (PSA90) was assessed. The rezvilutamide group exhibited higher proportions of ≥50% PSA reduction (PSA50; 98.2% vs. 87.5%), PSA90 (88.7% vs. 63.1%), and undetectable PSA (38.3% vs. 17.7%) responses compared to the bicalutamide group by 3months. The rezvilutamide group demonstrated superior efficacy in delaying PSA progression compared to the bicalutamide group (hazard ratio [HR] 0.21, 95% confidence interval 0.16-0.27). The achievement of undetectable PSA and PSA90 by 6months in the rezvilutamide group was associated with prolonged overall survival (undetectable PSA, HR= 0.34; PSA90, HR= 0.22), radiographic progression-free survival (HR= 0.36, HR= 0.26), time to PSA progression (HR= 0.25, HR= 0.17), and time to castration resistance (HR= 0.34, HR= 0.23) compared to those who did not achieve these PSA milestones. Stratification by baseline PSA level revealed consistent survival improvements with rezvilutamide plus ADT across quartiles. PSA kinetics is a valuable prognostic factor in mHSPC treated with rezvilutamide plus ADT, and the achievement of undetectable PSA and PSA90 is associated with improved survival. These findings highlight the importance of monitoring PSA kinetics in the management of mHSPC. This study was funded by Jiangsu Hengrui Pharmaceuticals Co., Ltd.

China ARCHES: A Phase 3 Trial of Enzalutamide vs Placebo in Metastatic Hormone-Sensitive Prostate Cancer

Purpose: This study evaluated the efficacy and safety of enzalutamide vs placebo, both combined with androgen deprivation therapy, in Chinese men with metastatic hormone-sensitive prostate cancer. Materials and Methods: Patients were randomized 2:1 to enzalutamide 160 mg/day or placebo, both in combination with androgen deprivation therapy. The primary trial end point was the time to prostate-specific antigen progression. Selected secondary end points included radiographic progression-free survival, time to castration resistance, time to initiation of new antineoplastic therapy, undetectable prostate-specific antigen (&lt;0.2 ng/mL) rate among patients with detectable levels at baseline, and safety. Results: From September 11, 2019, to November 18, 2022, 180 patients were randomized to treatment (enzalutamide: n = 120; placebo: n = 60). Baseline characteristics were balanced between the treatment arms. Median treatment duration in the enzalutamide vs the placebo arm was 25.66 vs 15.11 months. After 63 prostate-specific antigen progression events (enzalutamide: n = 23; placebo: n = 40), enzalutamide significantly reduced the hazard for prostate-specific antigen progression by 87% (hazard ratio: 0.130; 95% confidence interval: 0.076, 0.222; P &lt; .0001) vs placebo. Radiographic progression-free survival, time to castration resistance, and achievement of undetectable prostate-specific antigen levels were increased with enzalutamide vs placebo, while treatment-emergent adverse event rates were similar. Serious and grade 3 to 4 treatment-emergent adverse events occurred in 35.3% and 52.1%, respectively, of enzalutamide recipients vs 20.3% and 39.0%, respectively, of placebo recipients. Conclusions: In Chinese men with metastatic hormone-sensitive prostate cancer, enzalutamide significantly reduced the hazard for prostate-specific antigen progression vs placebo when combined with androgen deprivation therapy. The China ARCHES (NCT04076059) results were consistent with those of the global ARCHES study (NCT02677896).

A boost or a redundancy? on the value of combination of androgen receptor signal inhibitor and PARP inhibitor for advanced prostate cancer

AbstractPoly (ADP-ribose) polymerase (PARP) inhibitor (PARPi), as a novel endocrine therapy, has been investigated in patients with metastatic castration-resistant prostate cancer (mCRPC) in recent years. Multiple large-scale clinical trials have consistently demonstrated that various PARP inhibitors, including olaparib, rucaparib, niraparib, and talazoparib, confer longer radiographic progression-free survival (rPFS) compared to new hormonal agents (NHA) in mCRPC patients with homologous recombination deficiency (HRD). Moreover, the incidence of grade 3 and above adverse events did not significantly increase. Additionally, when combined with androgen receptor signaling inhibitors (ARSI), olaparib, niraparib, and talazoparib have shown significant extension of rPFS but also an increased occurrence of serious adverse events in HRD-positive patients. Only PROpel yielded positive results among the homologous recombination repair (HRR) mutation negative population. Therefore, it remains uncertain whether ARSI-PARPi combination therapy should be considered as first-line treatment for mCRPC patients without HRR mutations. In this review article, we aim to elucidate the necessity and feasibility of combination therapy versus monotherapy specifically within the HRR mutant population while exploring its potential applicability to other non-HRR mutant subtypes. Furthermore, we conducted a comprehensive search on registered clinical trials at present to summarize the research progress of PARP inhibitors in prostate cancer patients at different disease stages.

Nivolumab in patients with metastatic castration-resistant prostate cancer with and without DNA repair defects.

Despite the success of immune checkpoint inhibitors (ICIs) across various cancers, their efficacy in metastatic castration-resistant prostate cancer (mCRPC) is modest, except for a subset of patients who experience significant, yet unpredictable, benefits. DNA repair defects (DRD) are associated with higher neoantigen load, which may predict response. Our study explored the potential of DRD for enhanced responsiveness to the ICI nivolumab. We conducted a phase II, multi-center, single-arm trial evaluating nivolumab in post-docetaxel mCRPC patients. DRD was assessed using circulating tumor DNA (ctDNA). The primary endpoint was PSA50 response. Secondary endpoints included objective response rate (ORR), radiographic progression-free survival (rPFS), and overall survival (OS). Also, exploratory comprehensive genomic profiling was performed via whole-exome sequencing (WES) of tumor samples and matched normal tissue, alongside PD-L1 expression evaluation. Among the 38 enrolled patients, DRD was identifiable in 30.5% (11/36) through ctDNA and/or WES analysis. The overall PSA50 response rate was 10.5% (4/38). PSA50 response and ORR did not significantly differ between patients with and without DRD (18.2% vs. 8%; p = 0.57 and 50% vs. 17.6%, p= 0.27, respectively). Median PSA-PFS (1.9 vs. 2.8 months, p=0.52) and rPFS (3.4 vs. 5.5 months, p=0.7) were not statistically different between patients with and without DRD. Grade ≥ 3 adverse events were reported in 47.3% of participants. Nivolumab has clinical activity in a subset of mCRPC patients, however, DRD do not predicted response.These results highlight the necessity of identifying new biomarkers to more accurately determine mCRPC patients who might respond to ICIs.

177Lu-PSMA-617 versus a change of androgen receptor pathway inhibitor therapy for taxane-naive patients with progressive metastatic castration-resistant prostate cancer (PSMAfore): a phase 3, randomised, controlled trial.

[177Lu]Lu-PSMA-617 (177Lu-PSMA-617) prolongs radiographic progression-free survival and overall survival in patients with metastatic castration-resistant prostate cancer previously treated with androgen receptor pathway inhibitor (ARPI) and taxane therapy. We aimed to investigate the efficacy of 177Lu-PSMA-617 in patients with taxane-naive metastatic castration-resistant prostate cancer. In this phase 3, randomised, controlled trial conducted at 74 sites across Europe and North America, taxane-naive patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer who had progressed once on a previous ARPI were randomly allocated (1:1) to open-label, intravenous 177Lu-PSMA-617 at a dosage of 7·4 GBq (200 mCi) ± 10% once every 6 weeks for six cycles, or a change of ARPI (to abiraterone or enzalutamide, administered orally on a continuous basis per product labelling). Crossover from ARPI change to 177Lu-PSMA-617 was allowed after centrally confirmed radiographic progression. The primary endpoint was radiographic progression-free survival, defined as the time from randomisation until radiographic progression or death, assessed in the intention-to-treat population. Safety was a secondary endpoint. This study is registered with ClinicalTrials.gov (NCT04689828) and is ongoing. In this primary report of the study, we present primary (first data cutoff) and updated (third data cutoff) analyses of radiographic progression-free survival; all other data are based on the third data cutoff. Overall, of the 585 patients screened, 468 met all eligibility criteria and were randomly allocated between June 15, 2021 and Oct 7, 2022 to receive 177Lu-PSMA-617 (234 [50%] patients) or ARPI change (234 [50%]). Baseline characteristics were mostly similar between groups; median number of 177Lu-PSMA-617 cycles was 6·0 (IQR 4·0-6·0). Of patients assigned to ARPI change, 134 (57%) crossed over to receive 177Lu-PSMA-617. In the primary analysis (median time from randomisation to first data cutoff 7·26 months [IQR 3·38-10·55]), the median radiographic progression-free survival was 9·30 months (95% CI 6·77-not estimable) in the 177Lu-PSMA-617 group versus 5·55 months (4·04-5·95) in the ARPI change group (hazard ratio [HR] 0·41 [95% CI 0·29-0·56]; p<0·0001). In the updated analysis at time of the third data cutoff (median time from randomisation to third data cutoff 24·11 months [IQR 20·24-27·40]), median radiographic progression-free survival was 11·60 months (95% CI 9·30-14·19) in the 177Lu-PSMA-617 group versus 5·59 months (4·21-5·95) in the ARPI change group (HR 0·49 [95% CI 0·39-0·61]). The incidence of grade 3-5 adverse events was lower in the 177Lu-PSMA-617 group (at least one event in 81 [36%] of 227 patients; four [2%] grade 5 [none treatment related]) than the ARPI change group (112 [48%] of 232; five [2%] grade 5 [one treatment related]). 177Lu-PSMA-617 prolonged radiographic progression-free survival relative to ARPI change, with a favourable safety profile. For patients with PSMA-positive metastatic castration-resistant prostate cancer who are being considered for a change of ARPI after progression on a previous ARPI, 177Lu-PSMA-617 may be an effective treatment alternative. Novartis.

Safety and clinical activity of BMS-986365 (CC-94676), a dual androgen receptor ligand-directed degrader and antagonist, in heavily pretreated patients with metastatic castration-resistant prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) that progresses on androgen receptor pathway inhibitors (ARPIs) may continue to be driven by AR signaling. BMS-986365 is an orally administered ligand-directed degrader targeting the AR via a first-in-class dual mechanism of AR degradation and antagonism. CC-94676-PCA-001 (NCT04428788) is a phase I multicenter study of BMS-986365 in patients with progressive mCRPC. Patients who progressed on androgen deprivation therapy, one or more ARPIs, and taxane chemotherapy (unless declined/ineligible) were enrolled. The study included dose escalation (part A) and expansion (part B) of BMS-986365 up to 900 mg twice daily. Primary objectives were safety and tolerability, and to define maximum tolerated dose and/or recommended phase II dose. Key secondary endpoints included decline in prostate-specific antigen ≥50% (PSA50) and radiographic progression-free survival (rPFS). Parts A and B enrolled 27 and 68 patients, respectively. In part B, the median number of prior therapies was 4 (range 2-11). The most common treatment-related adverse events were asymptomatic prolonged corrected QT interval (47%) and bradycardia (34%). Part A maximum tolerated dose was not reached and recommended phase II dose selection is ongoing. Across part B three highest doses (400-900 mg twice daily, n= 60), PSA50 was 32% (n= 19), including 50% (n= 10/20) at 900 mg; median rPFS (95% confidence interval) was 6.3 months (5.3-12.6 months), including 8.3 months (3.8-16.6 months) at 900 mg; and rPFS was longer in patients without versus with prior chemotherapy: 16.5 months (5.5 months-not evaluable) versus 5.5 months (2.7-8.3 months), respectively. Efficacy was observed in patients with mCRPC with AR ligand binding domain (LBD) WT or with AR LBD mutations. BMS-986365 was well tolerated, with a manageable safety profile, and demonstrated activity in heavily pretreated patients with mCRPC with potentially higher benefit in chemotherapy-naive patients. These data show the potential of BMS-986365 to overcome resistance to current ARPIs, regardless of AR LBD mutation status.

Is It Premature to Accept Radiographic Progression-Free Survival as a Surrogate End Point in Metastatic Hormone-Sensitive Prostate Cancer?

Is It Premature to Accept Radiographic Progression-Free Survival as a Surrogate End Point in Metastatic Hormone-Sensitive Prostate Cancer?

Treatment Patterns and Survival Outcomes Among Androgen Receptor Pathway Inhibitor-Experienced Patients With Metastatic Castration-Resistant Prostate Cancer

BackgroundThere is limited real-world data regarding subsequent treatment utilization and clinical outcomes following initial androgen receptor pathway inhibitor (ARPI) exposure for the treatment of advanced prostate cancer. This study aimed to address this evidence gap. MethodsElectronic health records during 01/01/2013-07/31/2022 from Flatiron Health were used to identify adults with mCRPC, who had prior exposure to ARPIs (irrespective of the setting) and ≥1 post-ARPI line of therapy (LOT) in the mCRPC setting (index therapy: the first eligible LOT in the mCRPC setting). Treatment patterns and survival outcomes following the initiation of index therapy were reported. ResultsAmong 804 ARPI-experienced mCRPC patients, 459 patients (57.1%) received another ARPI as their index therapy and 192 (23.9%) received chemotherapy as their index therapy. In the overall population, median time on the index therapy and median time from index therapy to next therapy were 4.1 and 6.2 months, respectively. Median overall survival and radiographic progression-free survival from the initiation of index therapy were 15.1 and 7.0 months, respectively. ConclusionsIn this real-world analysis, more than half of patients attempted at least 1 additional ARPI in the mCRPC setting, despite prior treatment with ARPIs. The short treatment duration and survival time highlight the unmet need for additional, effective therapies that may improve clinical outcomes in this population.

Circulating Tumor DNA Assessment for Treatment Monitoring Adds Value to PSA in Metastatic Castration-Resistant Prostate Cancer.

Enzalutamide after abiraterone progression is commonly used in metastatic castration-resistant prostate cancer despite a low rate of clinical benefit. Analyzing IMbassador250, a phase III trial assessing enzalutamide with or without atezolizumab after abiraterone, we hypothesized that baseline and early changes in circulating tumor DNA (ctDNA) tumor fraction (TF) may identify patients more likely to exhibit survival benefit from enzalutamide. ctDNA was quantified from plasma samples using a tissue-agnostic assay without buffy coat sequencing. Baseline ctDNA TF, changes in ctDNA TF from baseline to cycle 3 day 1 (C3D1), and detection at C3D1 alone were compared with overall response rate, radiographic progression-free survival (rPFS), median OS (mOS), and 50% reduction in PSA. ctDNA TF detection at baseline and/or C3D1 was associated with shorter rPFS and OS in 494 evaluable patients. Detection of ctDNA TF at C3D1, with or without detection at cycle 1 day 1, was associated with worse rPFS and mOS than lack of detection. When ctDNA TF and PSA response at C3D1 were discordant, patients with (ctDNA TF undetected/PSA not reduced) had more favorable outcomes than (ctDNA TF detected/PSA reduced; mOS 22.1 vs. 16 months; P < 0.001). In a large cohort of patients with metastatic castration-resistant prostate cancer receiving enzalutamide after abiraterone, we demonstrate the utility of a new tissue-agnostic assay for monitoring molecular response based on ctDNA TF detection and dynamics. ctDNA TF provides a minimally invasive, complementary biomarker to PSA testing and may refine personalized treatment approaches.

High-Dose Intravenous Vitamin C Combined with Docetaxel in Men with Metastatic Castration-Resistant Prostate Cancer: A Randomized Placebo-Controlled Phase II Trial.

This is the first randomized, placebo-controlled, double-blind trial to evaluate HDIVC in cancer treatment. The addition of HDIVC to docetaxel in patients with mCRPC does not improve PSA response, toxicity, or other clinical outcomes compared with docetaxel alone. The routine use of HDIVC in mCRPC treatment is not supported outside of clinical trials.