A Somatically Acquired Enhancer of the Androgen Receptor Is a Noncoding Driver in Advanced Prostate Cancer.

Increased androgen receptor (AR) activity drives therapeutic resistance in advanced prostate cancer. The most common resistance mechanism is amplification of this locus presumably targeting the AR gene. Here, we identify and characterize a somatically acquired AR enhancer located 650 kb centromeric to the AR. Systematic perturbation of this enhancer using genome editing decreased proliferation by suppressing AR levels. Insertion of an additional copy of this region sufficed to increase proliferation under low androgen conditions and to decrease sensitivity to enzalutamide. Epigenetic data generated in localized prostate tumors and benign specimens support the notion that this region is a developmental enhancer. Collectively, these observations underscore the importance of epigenomic profiling in primary specimens and the value of deploying genome editing to functionally characterize noncoding elements. More broadly, this work identifies a therapeutic vulnerability for targeting the AR and emphasizes the importance of regulatory elements as highly recurrent oncogenic drivers.

Atg7 cooperates with Pten loss to drive prostate cancer tumor growth.

Understanding new therapeutic paradigms for both castrate-sensitive and more aggressive castrate-resistant prostate cancer is essential to improve clinical outcomes. As a critically important cellular process, autophagy promotes stress tolerance by recycling intracellular components to sustain metabolism important for tumor survival. To assess the importance of autophagy in prostate cancer, we generated a new autochthonous genetically engineered mouse model (GEMM) with inducible prostate-specific deficiency in the Pten tumor suppressor and autophagy-related-7 (Atg7) genes. Atg7 deficiency produced an autophagy-deficient phenotype and delayed Pten-deficient prostate tumor progression in both castrate-naïve and castrate-resistant cancers. Atg7-deficient tumors display evidence of endoplasmic reticulum (ER) stress, suggesting that autophagy may promote prostate tumorigenesis through management of protein homeostasis. Taken together, these data support the importance of autophagy for both castrate-naïve and castrate-resistant growth in a newly developed GEMM, suggesting a new paradigm and model to study approaches to inhibit autophagy in combination with known and new therapies for advanced prostate cancer.

Abiraterone and enzalutamide in the first line therapy of metastatic castration resistant prostate cancer.

Background: The aim was to assess therapeutic outcomes and tolerance in patients with metastatic castration resistant prostate cancer (mCRPC) treated with androgen receptor targeted agents (ARTA) treatment at one oncological center in the Czech Republic. Materials and methods: Retrospective analysis of 64 patients with mCRPC treated with abiraterone (50 patients) and enzalutamide (14 patients) in the first line of this disease was conducted. Kaplan-Meier analysis was used to calculate progression free survival (PFS) and overall survival (OS). We performed a multivariate analysis of risk factors for treatment outcomes (PFS, OS) by Cox regression analysis. Results: The median follow-up was 28.4 months. The median PFS was 15.4 months [95% confidence interval (CI): 12.3-18.5], median OS was 38.2 months (95% CI: 19.9-56.5). Regression analysis demonstrated a favorable prognostic effect on PFS in patients with reduction of PSA ≥ 50 %, in patients with early reduction of prostate-specific antigen (PSA) ≥ 50% within 3 months, in patients younger than 74 years and in overall performance status (PS) 0. Regression analysis demonstrated a favorable prognostic effect on OS in patients with reduction of PSA ≥ 50 %, in patients with early reduction of PSA ≥ 50 % within 3 months and in patients with overall PS 0. Adverse effects grade 3-4 were reported in 17 (27.9%) patients in abirateron arm and in 1 (7.1%) patient in enzalutamide arm. Conclusion: The analysis of patients with mCRPC treated with ARTA in the first line showed that ARTA represents an effective and safe therapy and contributes to longer survival.

Dynamic assessment of serum chromogranin A and treatment response with abiraterone acetate in metastatic castration-resistant prostate cancer.

OBJECTIVE: Elevated serum chromogranin A (CGA) is associated with intrinsic or treatment-related neuroendocrine differentiation (NED) in men with metastatic castration-resistant prostate cancer (mCRPC). Fluctuations in serum CGA during treatment of mCRPC have had conflicting results. We analyzed the impact of (i) rising serum CGA and (ii) baseline CGA/PSA ratio during treatment to identify associations with abiraterone acetate (AA) therapy. METHODS: Between June 2013 and August 2015, 92 men with mCRPC were enrolled in a prospective trial with uniform serum CGA processing performed before initiating abiraterone acetate/prednisone (AA/P) and serially after 12 weeks of AA/P treatments. Serum CGA was measured using a homogenous automated immunofluorescent assay. Patients receiving proton pump inhibitors or with abnormal renal function were excluded due to possible false elevations of serum CGA (n = 21 excluded), therefore 71 patients were analyzed. All patients underwent a composite response assessment at 12-weeks. Kaplan-Meier estimates and Cox Regression models were used to calculate the association with time-to-treatment failure analyses and overall survival. RESULTS: An increase in chromogranin was associated with a lower risk of treatment failure (hazard ratio [HR]: 0.52, p = 0.0181). The median CGA/PSA ratio was 7.8 (2.6-16.0) and an elevated pretreatment CGA/PSA ratio above the median was associated with a lower risk of treatment failure (HR: 0.54 p value = 0.0185). An increase in CGA was not found to be associated with OS (HR: 0.71, 95% CI: 0.42-1.21, p = 0.207). An elevated baseline CGA/PSA ratio was not associated with OS (HR: 0.62, 95% CI: 0.37-1.03, p = 0.062). An increase in PSA after 12 weeks of treatment was associated with an increased risk of treatment failure (HR: 4.14, CI: 2.21-7.73, p = < 0.0001) and worse OS (HR: 2.93, CI: 1.57-4.45, p = < 0.0001). CONCLUSIONS: We show that an increasing chromogranin on AA/P and an elevated baseline CGA/PSA in patients with mCRPC were associated with a favorable response to AA/P with no changes in survival. There may be limited clinical utility in serum CGA testing to evaluate for lethal NED as AA/P did not induce lethal NED in this cohort. This highlights that not all patients with an increasing CGA have a worse OS.

Implications of metastatic stage at presentation in docetaxel naïve metastatic castrate resistant prostate cancer.

BACKGROUND: We performed a secondary analysis of ACIS study to determine if synchronous versus metachronous metastatic presentation has any association with survival and treatment response to dual androgen receptor axis-targeted therapy (ARAT) in docetaxel naïve metastatic castrate resistant prostate cancer (mCRPC). METHODOLOGY: In this phase III randomized controlled trial, docetaxel naïve mCRPC patients were randomized to either apalutamide or placebo combined with abiraterone and prednisone. Multivariable Cox regression models were applied to determine the adjusted association of M-stage with radiographic progression-free survival (rPFS) and overall survival (OS). To determine the heterogeneity of treatment effect based on metastatic stage (M-stage) at presentation, Cox regression was applied with interaction terms between M-stage and treatment. RESULTS: Among 972 patients, 432 had M0, 334 had M1, while M-stage at presentation was unknown in 206. There was no association of M-stage at presentation with rPFS in patients with prior local therapy (LT) (hazard ratio for M1-stage: 1.22 [95% confidence interval: 0.82-1.82]; unknown: 1.03 [0.77-1.38]) or without prior LT (M1-stage: 0.87 [0.64-1.19]; unknown: 1.15 [0.77-1.72]) with no significant heterogeneity. Similarly, there was no association of M-stage with OS in patients with prior LT (M1-stage: 1.04 [0.81-1.33]; unknown: 0.98 [0.79-1.21]) or without prior LT (M1-stage: 0.95 [0.70-1.29]; unknown: 1.17 [0.80-1.71]) with no significant heterogeneity. Based on M-stage at presentation, we did not find any significant heterogeneity in treatment effect on rPFS (interaction p = 0.13), and OS (interaction p = 0.87). CONCLUSION: M-stage at presentation had no association with survival in chemotherapy-naïve mCRPC. We did not find any statistically significant heterogeneity in efficacy of dual ARAT based on synchronous versus metachronous presentation.

Black Patients with Metastatic Castrate-Resistant Prostate Cancer Have a Shorter Time Interval Between PSA and Clinical Progression on Novel Hormonal Therapies plus Avelumab.

BACKGROUND: Black men are at higher risk for prostate cancer death. Previous studies showed a benefit of different therapies, including immune-based therapy, for Black men with metastatic prostate cancer. We sought to explore the efficacy of the PD-L1 inhibitor avelumab in Black men with metastatic castrate-resistant prostate cancer (mCRPC) progressing after abiraterone or enzalutamide. METHODS: This pilot phase II study enrolled self-identified Black patients who developed mCRPC on next-generation hormonal therapies (NHTs) abiraterone acetate or enzalutamide (NCT03770455). Enrolled patients received avelumab 10mg/kg IV every 2 weeks while remaining on the same NHTs. The primary endpoint of our study was ≥ 50% reduction in prostate specific antigen (PSA) at ≥8 weeks. RESULTS: A total of eight patients were enrolled. The median duration on NHTs prior to enrollment was 364 days (95% CI, 260.9-467.1). The median time to initiate avelumab was 8 days (3-14). With a median follow-up of 196 days, no patients achieved the primary endpoint. The median time to PSA progression was 35 days (95 CI%, 0-94.8) and the median time to radiographic and/or clinical progression was 44 days (95 CI%, 0-118.5). The study was closed prematurely due to safety concerns related to the rapid clinical progression observed in the patients enrolled on study. CONCLUSION: In conclusion, the addition of avelumab to NHT did not demonstrate clinical activity in Black men with new mCRPC. The unexpected short interval between PSA and radiographic and/or clinical progression observed in this study has potential clinical implications.ClinicalTrials.gov Identifier: NCT03770455 (IND number 139559).

The Value of Phenotypic Precision Medicine in Prostate Cancer.

Prostate cancer is the most common cancer among men and the second leading cause of cancer-related death. For patients who develop metastatic disease, tissue-based and circulating-tumor-based molecular and genomic biomarkers have emerged as a means of improving outcomes through the application of precision medicine. However, the benefit is limited to a minority of patients. An additional approach to further characterize the biology of advanced prostate cancer is through the use of phenotypic precision medicine, or the identification and targeting of phenotypic features of an individual patient's cancer. In this review article, we will discuss the background, potential clinical benefits, and limitations of genomic and phenotypic precision medicine in prostate cancer. We will also highlight how the emergence of image-based phenotypic medicine may lead to greater characterization of advanced prostate cancer disease burden and more individualized treatment approaches in patients.

YAP1 inhibits RSL3-induced castration-resistant prostate cancer cell ferroptosis by driving glutamine uptake and metabolism to GSH.

High levels of YAP1 and ferroptosis activation in castration-resistant prostate cancer (CRPC) can inhibit CRPC progression and improve its sensitivity toward chemotherapeutics drugs. However, whether YAP1 regulates ferroptosis in CRPC cells and the underlying mechanisms are unknown. The protein levels of YAP1, SLC1A5, and GLS1 in benign prostatic hyperplasia (BPH), prostate cancer (PCa) that did not progress to CRPC, and CRPC tissue samples were evaluated using western blotting. In PC-3 and DU-145 cells, YAP1 overexpression vector, small-interfering RNA, specific inhibitor verteporfin, ferroptosis-inducer RSL3, SLC1A5-inhibitor V-9302, and GLS1-inhibitor CB-839 were used. Immunofluorescence, flow cytometry, dual-luciferase reporter gene, and related kits were used to investigate the effect of YAP1 on the ferroptosis activity in CRPC cells and its underlying mechanisms. YAP1 promoted extracellular glutamine uptake and subsequent production of glutamate and glutathione (GSH), and increases the GPX4 activity. For the activation of ferroptosis by RSL3, YAP1 decreased the levels of reactive oxygen species, malondialdehyde, and lipid peroxidation, and the proportion of dead cells. Mechanistically, YAP1 promoted the expression of SCL1A5 and GLS1 and further increased the GSH levels and GPX4 activity. Thus, inhibiting SLC1A5 or GLS1 activity could alleviate the antagonistic effect of YAP1 on the ferroptosis of RSL3-induced CRPC cells. In CRPC, the YAP1 level is high, which enters the nucleus and promotes the expressions of SLC1A5 and GLS1, thereby promoting cellular glutamine uptake and metabolism to generate glutamate and further synthesizing GSH, increasing GPX4 activity, improving cellular antioxidant capacity, and inhibiting cell death.

Updates in the Treatment of Non-Metastatic Castrate-Resistant Prostate Cancer: The Benefit of Second-Generation Androgen Receptor Antagonists.

OBJECTIVE: To review pharmacology, efficacy, safety, and considerations for use, of second-generation androgen receptor (AR) antagonists in treatment of nonmetastatic castrate-resistant prostate cancer (M0CRPC). DATA SOURCES: Conducted search in PubMed and Google scholar (January, 1, 2002-December 31, 2022), using relevant terms. STUDY SELECTION AND DATA EXTRACTION: Relevant English-language studies, conducted in humans evaluating second-generation AR antagonists for M0CRPC, and additional articles and package inserts were considered. DATA SYNTHESIS: Apalutamide, darolutamide, and enzalutamide are effective in delaying the time to development of metastatic prostate cancer in men with M0CRPC with a rapid prostate-specific antigen (PSA) doubling time (<10 months). No head-to-head, randomized, clinical trials have been conducted. The most common adverse effects include fatigue and hypertension, and quality of life is maintained in most patients. Cost is similar among the agents (~$15,000/month). Drug-drug interactions vary among these agents and should be considered, when selecting therapy as well as likely adherence. Darolutamide is administered twice daily with the others once daily. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: Second-generation AR antagonists are effective in reducing time to development of metastatic disease and prolonging overall survival in patients with M0CRPC and a PSA doubling time of <10 months. Recent imaging advances may alter how we evaluate outcomes. CONCLUSIONS: Second-generation AR antagonists improve disease control and overall survival. Generally, they are well tolerated and QOL is maintained. Selection of the best agent is based on the adverse effect profile, potential for drug- and disease-interactions, administration, cost, and patient preference.

Real-world outcomes for first line next-generation hormonal agents in metastatic prostate cancer: a systematic review.

Aim: This review aims to summarize published evidence on the real-world (RW) outcomes of abiraterone or enzalutamide in first-line metastatic castration-resistant prostate cancer. Materials & methods: Studies reporting on RW effectiveness, safety, economic and/or health-related quality of life outcomes were identified by systematic literature review (2011-2021, incl. Embase®, MEDLINE®) and presented in a qualitative synthesis. Risk of bias was assessed using ROBINS-I or the Molinier checklist. Results: 88 studies (n = 83,427 patients) were included. Median progression-free (40 studies) and overall survival (38 studies) ranged from 3.7 to 20.9 months and 9.8 to 45 months, respectively. Survival, safety and economic outcomes were similar across individual treatments, while limited health-related quality of life evidence suggested improvements with abiraterone. Risk of bias was moderate to high. Conclusion: RW outcomes in first-line metastatic castration-resistant prostate cancer remain poor despite treatment, highlighting an unmet need for new regimens. This review was supported by AstraZeneca and Merck Sharp & Dohme.

Crystal structure determination, molecular docking, and molecular dynamics of arylal dimedones as potential inhibitors for castrate-resistant prostate cancer.

Increased androgen receptor (AR) signaling brought on by higher intratumoral androgen production and AR amplification is associated with castrate-resistant prostate cancer (CRPC). Cell proliferation in this case continues even during low expression of testosterone in the body. Aldo-keto reductase family 1 member C3 (AKR1C3) is one of the most elevated genes in CRPC and catalyzes the formation of powerful AR ligands from inactive forms. The current work aimed to use the x-ray method to investigate the ligand's crystal structure while also conducting molecular docking and molecular dynamics tests on the synthesized molecules against AKR1C3. As per the results obtained, the MM-PBSA binding energies of inhibitors 2,2'-((4-methoxyphenyl)methylene)bis(3,4-hydroxy-5,5-dimethylcyclohex-2-en-1-one is -132.456 kJ mol-1 and 2,2'-(phenylmethylene)bis(3-hydroxy-5,5-dimethylcyclohex-2-en-1-one is -81.017 kJ mol-1 . These results create a promising approach to drug design based on its fit to the structures of the receptor site rather than basing it on analogies to other active structures.

Bench to Bedside Development of [18F]Fluoromethyl-(1,2-2H4)choline ([18F]D4-FCH).

Malignant transformation is characterised by aberrant phospholipid metabolism of cancers, associated with the upregulation of choline kinase alpha (CHKα). Due to the metabolic instability of choline radiotracers and the increasing use of late-imaging protocols, we developed a more stable choline radiotracer, [18F]fluoromethyl-[1,2-2H4]choline ([18F]D4-FCH). [18F]D4-FCH has improved protection against choline oxidase, the key choline catabolic enzyme, via a 1H/2D isotope effect, together with fluorine substitution. Due to the promising mechanistic and safety profiles of [18F]D4-FCH in vitro and preclinically, the radiotracer has transitioned to clinical development. [18F]D4-FCH is a safe positron emission tomography (PET) tracer, with a favourable radiation dosimetry profile for clinical imaging. [18F]D4-FCH PET/CT in lung and prostate cancers has shown highly heterogeneous intratumoral distribution and large lesion variability. Treatment with abiraterone or enzalutamide in metastatic castrate-resistant prostate cancer patients elicited mixed responses on PET at 12-16 weeks despite predominantly stable radiological appearances. The sum of the weighted tumour-to-background ratios (TBRs-wsum) was associated with the duration of survival.

Preclinical Study of Therapeutic Efficacy of a New Russian Radiopharmaceutical 177Lu-DOTA-PSMA.

The therapeutic efficacy of a Russian radiopharmaceutical 177Lu-DOTA-PSMA was studied in vivo using male BALB/c nu/nu (nude) mice with prostate carcinoma 22Rv1 xenografts by tumor growth inhibition criterion. The mean tumor volumes in mice treated with 177Lu-DOTA-PSMA were significantly lower than in animals of the control group. There were no significant differences in the values of tumor growth inhibition between the groups of animals receiving 3.7 or 7.4 MBq of 177Lu-DOTA-PSMA.

NPRL2 reduces the niraparib sensitivity of castration-resistant prostate cancer via interacting with UBE2M and enhancing neddylation.

In this study, we explored the regulatory effects of nitrogen permease regulator 2-like (NPRL2) on niraparib sensitivity, a PARP inhibitor (PARPi) in castrate-resistant prostate cancer (CRPC). Data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) program were retrospectively examined. Gene-set enrichment analysis (GSEA) was conducted between high and low NRPL2 expression prostate adenocarcinoma (PRAD) cases in TCGA. CCK-8 assay, Western blot analysis of apoptotic proteins, and flow cytometric analysis of apoptosis were applied to test niraparib sensitivity. Immunofluorescent (IF) staining and co-immunoprecipitation (co-IP) were conducted to explore the proteins interacting with NPRL2. Results showed that the upregulation of a canonical protein-coding transcript of NPRL2 (ENST00000232501.7) is associated with an unfavorable prognosis. Bioinformatic analysis predicts a physical interaction between NPRL2 and UBE2M, which is validated by a following Co-IP assay. This interaction increases NPRL2 stability by reducing polyubiquitination and proteasomal degradation. Depletion of NPRL2 or UBE2M significantly increases the niraparib sensitivity of CRPC cells and enhances niraparib-induced tumor growth inhibition in vivo. NPRL2 cooperatively enhances UBE2M-mediated neddylation and facilitates the degradation of multiple substrates of Cullin-RING E3 ubiquitin ligases (CRLs). In conclusion, this study identified a novel NPRL2-UBE2M complex in modulating neddylation and niraparib sensitivity of CRPC cells. Therefore, targeting NPRL2 might be considered as an adjuvant strategy for PARPi therapy.

Independent prognostic impact of plasma NCOA2 alterations in metastatic castration-resistant prostate cancer.

BACKGROUND: The androgen receptor (AR) pathway-associated gene nuclear receptor coactivator 2 (NCOA2) has an established oncogenic role in early prostate cancer and likewise is a driver of metastatic disease and castration-resistant prostate cancer. However, its significance as a biomarker in metastatic castration-resistant prostate cancer (mCRPC), both alone and in conjunction with co-occurring AR alterations using a liquid biopsy approach has not been investigated. METHODS: Ninety-one patients were included in this study, (n = 68 receiving an androgen receptor pathway inhibitor and n = 23 receiving taxane chemotherapy). Up to 30 ml of peripheral blood was collected before commencing treatment from each patient. Plasma cell-free DNA, along with a matched germline sample, underwent targeted next-generation sequencing using a validated, highly sensitive in-house prostate cancer panel. Variants in AR and NCOA2 were identified and correlated with clinical outcomes. RESULTS: Plasma AR and NCOA2 aberrations were identified in 35% and 13% of the cohort, respectively, whilst 8% had concurrent AR and NCOA2 alterations. NCOA2 copy number gain and any NCOA2 aberration predicted for lower prostate-specific antigen (PSA) response rates. Likewise, median overall survival was shorter for NCOA2 gain (10.1 vs. 18.3 months; p = .004), remaining significant after adjusting for covariates including circulating tumor DNA fraction and tumor suppressor gene alterations. Importantly, dual AR and NCOA2 aberrations were also associated with inferior outcomes, including no PSA responses in patients treated with AR pathway inhibitors (0% vs. 64%; p = .02). CONCLUSIONS: These data highlight the importance of identifying multiple markers of AR pathway modulation in mCRPC and represent the first instance of the assessment of plasma NCOA2 status as a prognostic biomarker for standard-of-care therapies. Further assessment is warranted to determine if NCOA2 aberrations are a marker of primary resistance to AR pathway inhibitors.

Combined 177 Lu-PSMA-617 PRLT and abiraterone acetate versus 177 Lu-PSMA-617 PRLT monotherapy in metastatic castration-resistant prostate cancer: An observational study comparing the response and durability.

OBJECTIVE: The aim of present study was to determine and compare the overall response rates, progression-free survival (PFS), overall survival (OS), and clinical toxicity of the combination of 177Lu-PSMA-617 radioligand therapy (PRLT) and abiraterone acetate (AA) versus 177Lu-PSMA-617 PRLT as monotherapy in metastatic castration-resistant prostate cancer (mCRPC) patients. MATERIALS AND METHODS: The mCRPC patients who received at least one cycle of 177 Lu-PSMA-617 PRLT with or without AA therapy, were included and analyzed in the present study. The patients were divided into two major groups. Group 1 received only 177 Lu-PSMA PRLT and Group 2 received combined 177 Lu-PSMA PRLT + AA therapy. Therapeutic dose of 177 Lu-PSMA-617 PRLT was 4.4-5.55 GBq per patient per cycle administered at intervals of 10-12 weeks in both groups. The Group 2 patients additionally received a dose of 1000 mg of AA once daily and 5 mg of prednisone twice daily. Treatment response in two groups was evaluated under four broad categories (a) symptomatic, (b) biochemical (serum prostate-specific antigen level), (c) objective molecular imaging (68 Ga-PSMA-11 and 18 F-FDG PET/CT), and (d) objective anatomical imaging (computed tomography). For assessing treatment response, patients in two groups were categorized into responders (complete response [CR], partial response [PR], and stable disease [SD]) and nonresponders (progressive disease [PD]). The Kaplan-Meier product-limit method was used to calculate PFS and OS following first 177 Lu-PSMA PRLT in the two groups. Univariate analysis was used to compare the patients' characteristics in two groups using a χ2 or Fisher exact test. The Kaplan-Meier curves of PFS and OS between two groups were compared by using the log-rank test (p < 0.05 significant). RESULTS: A total of 58 mCRPC patients (Group 1, 38 patients and Group 2, 20 patients) were included in this study analysis. The clinical and demographic characteristics of these patients (age, Gleason score, FDG avid disease, metastatic disease burden, and average number of 177 Lu-PSMA PRLT cycles) in two groups were compared and found to be similar (p > 0.05). Post-treatment, symptomatic, biochemical, molecular, and anatomic imaging responders were found in 22 patients (58%) and 17 patients (85%), 22 patients (58%) and 16 patients (80%), 19 patients (54%) and 14 patients (78%), and 19 patients (54%) and 14 patients (78%) in Group 1 and Group 2, respectively. The median PFS of 7 months and median OS of 8 months were documented in Group 1, whereas median PFS was not reached and median OS of 16 months registered in Group 2. Transient hematological toxicity of Grades 1 and 2 was found in total seven patients (five patients in Group 1 and two patients in Group 2). On comparison of the treatment outcome between two groups, significant p value was found for symptomatic responders (58% in Group 1 vs. 85% in Group 2), median PFS (7 months in Group 1 vs. not reached in Group 2), and median OS (8 months in Group 1 vs. 16 months in Group 2), with better outcome in Group 2 patients for these variables. CONCLUSION: In the present study, the combination of 177 Lu-PSMA-617 PRLT and AA therapy showed significant improvement in mCRPC patients' symptomatic response, PFS, and OS as compared to 177 Lu-PSMA-617 PRLT monotherapy.

Examining the ability of the Cancer and Aging Research Group tool to predict toxicity in older men receiving chemotherapy or androgen-receptor-targeted therapy for metastatic castration-resistant prostate cancer.

BACKGROUND: Because multiple treatments are available for metastatic castrate-resistant prostate cancer (mCRPC) and most patients are elderly, the prediction of toxicity risk is important. The Cancer and Aging Research Group (CARG) tool predicts chemotherapy toxicity in older adults with mixed solid tumors, but has not been validated in mCRPC. In this study, its ability to predict toxicity risk with docetaxel chemotherapy (CHEMO) was validated, and its utility was examined in predicting toxicity risk with abiraterone or enzalutamide (A/E) among older adults with mCRPC. METHODS: Men aged 65+ years were enrolled in a prospective observational study at 4 Canadian academic cancer centers. All clinically relevant grade 2 to 5 toxicities over the course of treatment were documented via structured interviews and chart review. Logistic regression was used to identify predictors of toxicity. RESULTS: Seventy-one men starting CHEMO (mean age, 73 years) and 104 men starting A/E (mean age, 76 years) were included. Clinically relevant grade 3+ toxicities occurred in 56% and 37% of CHEMO and A/E patients, respectively. The CARG tool was predictive of grade 3+ toxicities with CHEMO, which occurred in 36%, 67%, and 91% of low, moderate, and high-risk groups (P = .003). Similarly, grade 3+ toxicities occurred among A/E users in 23%, 48%, and 86% with low, moderate, and high CARG risk (P < .001). However, it was not predictive of grade 2 toxicities with either treatment. CONCLUSIONS: There is external validation of the CARG tool in predicting grade 3+ toxicity in older men with mCRPC undergoing CHEMO and demonstrated utility during A/E therapy. This may aid with treatment decision-making.

FDA Approval Summary: Rucaparib for the Treatment of Patients with Deleterious BRCA-Mutated Metastatic Castrate-Resistant Prostate Cancer.

The U.S. Food and Drug Administration (FDA) granted accelerated approval to rucaparib in May 2020 for the treatment of adult patients with deleterious BRCA mutation (germline and/or somatic)-associated metastatic castrate-resistant prostate cancer (mCRPC) who have been treated with androgen receptor-directed therapy and a taxane. This approval was based on data from the ongoing multicenter, open-label single-arm trial TRITON2. The primary endpoint, confirmed objective response rate, in the 62 patients who met the above criteria, was 44% (95% confidence interval [CI]: 31%-57%). The median duration of response was not estimable (95% CI: 6.4 to not estimable). Fifty-six percent of patients had a response duration of >6 months and 15% >12 months. The safety profile of rucaparib was generally consistent with that of the class of poly-(ADP-ribose) polymerase enzyme inhibitors and other trials of rucaparib in the treatment of ovarian cancer. Deaths due to adverse events (AEs) occurred in 1.7% of patients, and 8% discontinued rucaparib because of an AE. Grade 3-4 AEs occurred in 59% of patients. No patients with prostate cancer developed myelodysplastic syndrome or acute myeloid leukemia. The trial TRITON3 in patients with mCRPC is ongoing and is planned to verify the clinical benefit of rucaparib in mCRPC. This article summarizes the FDA thought process and data supporting this accelerated approval. IMPLICATIONS FOR PRACTICE: The accelerated approval of rucaparib for the treatment of adult patients with deleterious BRCA mutation (germline and/or somatic)-associated metastatic castrate-resistant prostate cancer who have been treated with androgen receptor-directed therapy and a taxane represents the first approved therapy for this selected patient population. This approval was based on a single-arm trial demonstrating a confirmed objective response rate greater than that of available therapy with a favorable duration of response and an acceptable toxicity profile. The ongoing trial TRITON3 is verifying the clinical benefit of this drug.

Can post-treatment free PSA ratio be used to predict adverse outcomes in recurrent prostate cancer?

OBJECTIVES: To assess whether free PSA ratio (FPSAR) at biochemical recurrence (BCR) can predict metastasis, castrate-resistant prostate cancer (CRPC), and cancer-specific survival (CSS), following therapy for localised disease. PATIENTS AND METHODS: A single-centre retrospective cohort study (NCT03927287) including a discovery cohort composed of patients with an FPSAR after radical prostatectomy (RP) or radiotherapy (RT) between 2000 and 2017. For validation, an independent Biobank cohort of patients with BCR after RP was tested. Using a defined FPSAR cut-off, the metastasis-free-survival (MFS), CRPC-free survival, and CSS were compared. Multivariable Cox models determined the association between post-treatment FPSAR, metastases, and CRPC. RESULTS: Overall, 822 patients (305 RP- and 363 RT-treated patients and 154 Biobank patients) were analysed. In the RP cohort, a total of 272/305 (89.1%) and 33/305 (10.9%) had a FPSAR test incidentally and reflexively, respectively. In the RT cohort, 155/363 (42.7%) and 208/263 (57.3%) had a FPSAR test incidentally and reflexively, respectively. However, in the prospective Biobank RP cohort, FPSAR testing was done on all samples of patients diagnosed with BCR. A FPSAR cut-off of 0.10 was determined using receiver operating characteristic analyses in both the RP and RT cohorts. A FPSAR of <0.10 resulted in longer median MFS (14.8 vs 9.3 years and 14.8 vs 13 years, respectively), and longer median CRPC-free survival (median not reached vs 9.9 years and 20.7 vs 13.8 years, respectively). Multivariable analyses showed that a FPSAR of ≥0.10 was associated with increased metastasis in the RP cohort (hazard ratio [HR] 1.915, 95% confidence interval [CI] 1.241-2.955) and RT cohort (HR 1.754, 95% CI 1.112-2.769), and increased CRPC in the RP cohort (HR 2.470, 95% CI 1.493-4.088). Findings were validated in the Biobank cohort. CONCLUSIONS: A post-treatment FPSAR of ≥0.10 is associated with more aggressive disease, suggesting a potentially novel role for this biomarker.

Optimizing the management of castration-resistant prostate cancer patients: A practical guide for clinicians.

BACKGROUND: Advanced prostate cancer (PC) patients, especially those with metastatic prostate cancer (mPC), often require complex management pathways. Despite the publication of clinical practice guidelines by leading urological and oncological organizations that provide a substantial and comprehensive framework, there are numerous clinical scenarios that are not always addressed, especially as new treatments become available, new imaging modalities are developed, and advances in genetic testing continue. METHODS: A 14-member expert review panel comprised of urologists and medical oncologists were chosen to provide guidance on addressing specific topics and issues regarding metastatic castration-resistant prostate cancer (mCRPC) patients. Panel members were chosen based upon their experience and expertise in the management of PC patients. Four academic members (two urologists and two medical oncologists) of the panel served as group leaders; the remaining eight panel members were from Large Urology Group Practice Association (LUGPA) practices with proven experience in leading their advanced PC clinics. The panel members were assigned to four separate working groups, each assigned a specific mCRPC topic to review and discuss with the entire panel. RESULTS: This article describes the practical recommendations of an expert panel on the management of mCRPC patients. The target reading audience for this publication is all providers (urologists, medical oncologists, radiation oncologists, or advanced practice providers) who evaluate and manage advanced PC patients, regardless of their practice setting. CONCLUSION: The panel has provided recommendations for managing mCRPC with regard to specific issues: (a) biomarker monitoring and the role of genetic and molecular testing; (b) rationale, current strategies, and optimal sequencing of the various approved therapies, including hormonal therapy, cytotoxic chemotherapy, radiopharmaceuticals and immunotherapy; (c) adverse event management and monitoring; and (d) imaging advanced PC patients. These recommendations seek to complement national guidelines, not replace them, and a discussion of where the panel agreed or disagreed with national guidelines is included.