Metastatic Hormone-sensitive Prostate Cancer Research Articles

Network meta-analysis of combination strategies in metastatic hormone-sensitive prostate cancer.

This study compared different doublet and triplet therapies for efficacy and safety in metastatic hormone-sensitive prostate cancer (mHSPC). PubMed, EMBASE, and the Cochrane Library were comprehensively searched for eligible randomized controlled trials (RCTs) published from inception to October 2023. Interventions included abiraterone, apalutamide, enzalutamide, docetaxel, darolutamide, and androgen deprivation therapy (ADT), either as doublet or triplet therapies. The outcomes examined were overall survival (OS), progression-free survival (PFS), castration-resistant prostate cancer (CRPC)-free survival, time to symptomatic skeletal event (SSE), and toxicity. The surface under the cumulative ranking curve (SUCRA) was determined to identify the preferred treatments. Ten RCTs were included. The combination of darolutamide, docetaxel, and ADT had the highest SUCRA of 84.3 for OS, followed by combined abiraterone, docetaxel, and ADT (SUCRA = 71.6). The highest SUCRAs for PFS were observed for triplet therapies (abiraterone, docetaxel, and ADT [SUCRA = 74.9], followed by enzalutamide, docetaxel, and ADT [SUCRA = 74.3]) and other androgen receptor axis-targeted therapy-based doublet therapies (SUCRAs: 26.5-59.3). Darolutamide, docetaxel, and ADT had the highest SUCRAs, i.e., 80.8 and 84.0 regarding CRPC-free survival and time to SSE, respectively. Regarding Grade >3 adverse events (AEs), the SUCRAs of triplet therapies (SUCRAs: 14.8-31.5) were similar to that of docetaxel and ADT (SUCRA = 39.5). Three studies had a low risk of bias in all categories; the remaining studies had at least an unclear risk of bias in at least one category. Triplet therapy demonstrated potentially enhanced effectiveness than doublet therapy in mHSPC, with acceptable safety concerns. Darolutamide might be the optimal option for triplet therapy in combination with docetaxel and ADT.

Impact of Circulating Tumor Cell-Expressed Prostate-Specific Membrane Antigen and Prostate-Specific Antigen Transcripts in Different Stages of Prostate Cancer.

Prostate-specific membrane antigen (PSMA)-based images, which visually quantify PSMA expression, are used to determine prostate cancer micrometastases. This study evaluated whether a circulating tumor cell (CTC)-based transcript platform, including PSMA mRNA, could help identify potential prognostic markers in prostate cancer. We prospectively enrolled 21 healthy individuals and 247 patients with prostate cancer [localized prostate cancer (LPCa), n = 94; metastatic hormone-sensitive prostate cancer (mHSPC), n = 44; and metastatic castration-resistant prostate cancer (mCRPC), n = 109]. The mRNA expression of six transcripts [PSMA, prostate-specific antigen (PSA), AR, AR-V7, EpCAM, and KRT 19] from CTCs was measured, and their relationship with biochemical recurrence (BCR) in LPCa and mCRPC progression-free survival (PFS) rate in mHSPC was assessed. PSA-PFS and radiological-PFS were also calculated to identify potential biomarkers for predicting androgen receptor signaling inhibitor (ARSI) and taxane-based chemotherapy resistance in mCRPC. CTC detection rates were 75.5%, 95.3%, and 98.0% for LPCa, mHSPC, and mCRPC, respectively. In LPCa, PSMA [hazard ratio (HR), 3.35; P = 0.028) and PSA mRNA (HR, 1.42; P = 0.047] expressions were associated with BCR. Patients with mHSPC with high PSMA (HR, 4.26; P = 0.020) and PSA mRNA (HR, 3.52; P = 0.042) expressions showed significantly worse mCRPC-PFS rates than those with low expression. Increased PSA and PSMA mRNA expressions were significantly associated with shorter PSA-PFS and radiological PFS in mCPRC, indicating an association with drug resistance. PSMA and PSA mRNA expressions are associated with BCR in LPCa. In advanced prostate cancer, PSMA and PSA mRNA can also predict rapid progression from mHSPC to mCRPC and ARSI or taxane-based chemotherapy resistance.

Impact of disease volume on survival efficacy of triplet therapy for metastatic hormone-sensitive prostate cancer: a systematic review, meta-analysis, and network meta-analysis.

Triplet therapy, androgen receptor signaling inhibitors (ARSIs) plus docetaxel plus androgen-deprivation therapy (ADT), is a novel guideline-recommended treatment for metastatic hormone-sensitive prostate cancer (mHSPC). However, the optimal selection of the patient most likely to benefit from triplet therapy remains unclear. We performed a systematic review, meta-analysis, and network meta-analysis to assess the oncologic benefit of triplet therapy in mHSPC patients stratified by disease volume and compare them with doublet treatment regimens. Three databases and meeting abstracts were queried in March 2023 for randomized controlled trials (RCTs) evaluating patients treated with systemic therapy for mHSPC stratified by disease volume. Primary interests of measure were overall survival (OS). We followed the PRISMA guideline and AMSTAR2 checklist. Overall, eight RCTs were included for meta-analyses and network meta-analyses (NMAs). Triplet therapy outperformed docetaxel plus ADT in terms of OS in both patients with high-(pooled HR: 0.73, 95%CI 0.64-0.84) and low-volume mHSPC (pooled HR: 0.71, 95%CI 0.52-0.97). There was no statistically significant difference between patients with low- vs. high-volume in terms of OS benefit from adding ARSI to docetaxel plus ADT (p = 0.9). Analysis of treatment rankings showed that darolutamide plus docetaxel plus ADT (90%) had the highest likelihood of improved OS in patients with high-volume disease, while enzalutamide plus ADT (84%) had the highest in with low-volume disease. Triplet therapy improves OS in mHSPC patients compared to docetaxel-based doublet therapy, irrespective of disease volume. However, based on treatment ranking, triplet therapy should preferably be considered for patients with high-volume mHSPC while those with low-volume are likely to be adequately treated with ARSI + ADT.

Abstract LB110: Impact of circulating tumor cell-expressed prostate-specific membrane antigen and prostate-specific antigen transcripts in various stages of prostate cancer

Abstract PurposeProstate-specific membrane antigen (PSMA)-based images, which visually quantify PSMA expression, are used to determine prostate cancer (PCa) micrometastases. This study evaluated whether a circulating tumor cell (CTCs-based transcript platform, including PSMA mRNA, could help identify potential prognostic markers in PCa. Experimental design We prospectively enrolled 21 healthy individuals and 247 patients with PCa (localized PCa [LPCa]: 94; metastatic hormone-sensitive PCa [mHSPC]: 44; and metastatic castration-resistant PCa [mCRPC]: 109). The mRNA expression of six transcripts (PSMA, prostate-specific antigen [PSA], AR, AR-V7, EpCAM, and KRT 19) from CTCs was measured, and their relationship with biochemical recurrence (BCR) in LPCa and mCRPC progression-free survival (PFS) rate in mHSPC was assessed. PSA-PFS and radiological-PFS were also calculated to identify potential biomarkers for predicting androgen receptor signaling inhibitor (ARSI) and taxane-based chemotherapy resistance in mCRPC. Results CTC detection rates were 75.5%, 95.3%, and 98% for LPCa, mHSPC, and mCRPC, respectively. In LPCa, PSMA (hazard ratio [HR]: 3.35; P=0.028) and PSA mRNA (HR: 1.42; P=0.047) expression was associated with BCR. mHSPC patients with high PSMA (HR: 4.26; P=0.020) and PSA mRNA (HR: 3.52; P=0.042) expression showed significantly worse mCRPC-PFS rates than those with low expression. Increased PSA and PSMA mRNA expression was significantly associated with shorter PSA-PFS and radiological PFS in mCPRC, indicating an association with drug resistance. Conclusion PSMA and PSA mRNA expression is associated with BCR in LPCa. In advanced PCa, PSMA and PSA mRNA can also predict rapid progression from mHSPC to mCRPC and ARSI or taxane-based chemotherapy resistance. Citation Format: Hyungseok Cho, Seok-Soo Byun, Nak-Hoon Son, Jae Il Chung, Won Ik Seo, Chan Ho Lee, Todd M Morgan, Ki-Ho Han, Jae-Seung Chung. Impact of circulating tumor cell-expressed prostate-specific membrane antigen and prostate-specific antigen transcripts in various stages of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB110.

Abstract CT232: Intense exercise for survival among men with metastatic prostate cancer: 12-month feasibility results from the INTERVAL-GAP4 trial pilot site at Edith Cowan University, Australia

Abstract Introduction: Men with prostate cancer undertaking moderate-to-vigorous exercise have a marked reduction of 30-60% in all-cause and cancer-related mortality based on observational studies. In 2016, the Intense Exercise for Survival among Men with Metastatic Prostate Cancer (INTERVAL-GAP4) was launched to determine if supervised exercise improves overall survival in men with metastatic prostate cancer. Here, we describe the demographic characteristics, completion rates, exercise adherence, and safety of the first 12 months of the intervention at the pilot site, Edith Cowan University in Perth, Australia. Methods: INTERVAL-GAP4 is a multi-center global randomized controlled phase III trial. Patients are randomly allocated (1:1) to: (intervention) a high intensity combined resistance and aerobic exercise supervised program for 1 year tapering to self-management in year 2; or (control) self-directed unsupervised exercise with print materials. Patients were stratified by site and by disease/treatment status (metastatic hormone-sensitive prostate cancer [mHSPC] or metastatic castration-resistant prostate cancer [mCRPC] and if the latter, treatment modality). The study did not meet recruitment goals and closed to further enrollment in February 2023. Results: 240 participants were evaluated between April 2016-Feb 2023, 60 patients were consented, 52 participants were randomized, and two patients did not receive the allocation, resulting in 50 participants (27 intervention and 23 control). Main reasons for exclusion were not meeting clinical criteria (N=81), time commitment (N=24), unable to contact (N=22), not interested (N=19), and poor physical function (N=13). Median age at randomization was 72 years (IQR: 68, 77), median body mass index (BMI) was 31.7 kg/m2 (IQR: 27.5, 35.7), 94% identified as white, and time since diagnosis was 5 years (IQR: 1, 9). 13 participants (26%) had mHSPC and 37 (74%) had mCRPC. Completion rates were the following at 6 months: 84% completed surveys, 62% exercise testing, and 66% biological samples. Of 42 alive at 12 months: 85% completed surveys, 73% testing, and 73% biological samples. Median exercise adherence was 90% (IQR: 78, 97) for the first 12 months of the study. Adherence was not significantly different for those with mCRPC vs. mHSPC status. There were 10 SAEs in first 12 months; all (100%) were unrelated to the intervention. Conclusions: Exercise training was feasible and safe in men with metastatic prostate cancer with no difference observed in exercise session adherence by disease status. Survey completion was high, while in-person completion rates were affected by the COVID-19 pandemic. Additional analysis of the entire study population (N=145) is ongoing and will be compared with the pilot site. Citation Format: Stacey A. Kenfield, Nicolas H. Hart, Jennette Sison, June M. Chan, Kerry S. Courneya, Fred Saad, Robert U. Newton. Intense exercise for survival among men with metastatic prostate cancer: 12-month feasibility results from the INTERVAL-GAP4 trial pilot site at Edith Cowan University, Australia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT232.

Bone marrow dosimetry in low volume mHSPC patients receiving Lu-177-PSMA therapy using SPECT/CT

BackgroundBone marrow toxicity in advanced prostate cancer patients who receive [177Lu]Lu-PSMA-617 is a well-known concern. In early stage patients; e.g. low volume metastatic hormone sensitive prostate cancer (mHSPC) patients, prevention of late bone marrow toxicity is even more crucial due to longer life expectancy. To date, bone marrow dosimetry is primarily performed using blood sampling. This method is time consuming and does not account for possible active bone marrow uptake. Therefore other methodologies are investigated. We calculated the bone marrow absorbed dose for [177Lu]Lu-PSMA-617 in mHSPC patients using SPECT/CT imaging and compared it to the blood sampling method as reference.MethodsEight mHSPC patients underwent two cycles (3 and 6 GBq) of [177Lu]Lu-PSMA-617 therapy. After each cycle, five time point (1 h, 1 day, 2 days, 3 days, 7 days) SPECT/CT was performed at kidney level. Bone marrow dosimetry was performed using commercial software by drawing ten 1.5 cm diameter spheres in the lowest ten vertebrae to determine the time-integrated activity. Simplified protocols using only 2 imaging time points and 3 vertebrae were also compared. Blood-based dosimetry was based on the blood sampling method according to the EANM guideline.ResultsMean bone marrow absorbed dose was significantly different (p < 0.01) for the imaging based method (25.4 ± 8.7 mGy/GBq) and the blood based method (17.2 ± 3.4 mGy/GBq), with an increasing absorbed dose ratio between both methods over time. Bland Altman analysis of both simplification steps showed that differences in absorbed dose were all within the 95% limits of agreement.ConclusionThis study showed that bone marrow absorbed dose after [177Lu]Lu-PSMA-617 can be determined using an imaging-based method of the lower vertebrae, and simplified using 2 time points (1 and 7 days) and 3 vertebrae. An increasing absorbed dose ratio over time between the imaging-based method and blood-based method suggests that there might be specific bone marrow binding of [177Lu]Lu-PSMA-617.

Patient-reported Quality of Life and Survival Outcomes in Prostate Cancer: Analysis of the ECOG-ACRIN E3805 Chemohormonal Androgen Ablation Randomized Trial (CHAARTED)

BackgroundChemohormonal therapy with androgen deprivation therapy and docetaxel (ADT + D) improves overall survival (OS) and quality of life (QOL) at 12 mo versus androgen deprivation therapy (ADT) alone in men with metastatic hormone-sensitive prostate cancer (mHSPC). However, the prognostic role of QOL is unknown in this population. ObjectiveTo study the relationship between QOL, disease characteristics, and OS in men with mHSPC. Design, setting, and participantsIn this exploratory post hoc analysis, 790 patients with mHSPC completed the QOL instruments Functional Assessment of Cancer Therapy—Prostate (FACT-P), Functional Assessment of Chronic Illness Therapy—Fatigue (FACIT-F), and Brief Pain Inventory (BPI). Outcome measurements and statistical analysisLog-rank test and Cox proportional hazard models tested the association between QOL and OS by clinical and disease characteristics. Results and limitationsBaseline higher FACT-P trended toward improved survival after accounting for clinical variables (hazard ratio [HR] 0.80 [0.62, 1.04], p = 0.09), while higher 3-mo FACT-P was independently associated with better survival (HR 0.76 [0.58, 1.0], p = 0.05). Patients with the poorest QOL (bottom quartile) at baseline and 3 mo had longer survival if they received ADT + D rather than ADT alone (median OS 45.2 vs 34.4 mo, HR 0.75 [0.53, 1.05], p = 0.09, and 48.3 vs 29.3 mo, HR 0.69 [0.48, 0.99], p = 0.05 respectively). In contrast, patients with the best QOL (top quartile) at baseline and 3 mo had comparable survival irrespective of whether or not docetaxel was added (median OS 72.1 vs 51.7 mo, HR 0.92 [0.63, 1.36], p = 0.69, and 69.9 vs 68.9 mo, HR 1.11 [0.73, 1.67], p = 0.63, respectively). Survival was linked with baseline FACIT-F (HR 0.76 [0.57, 1.0], p = 0.05), but not BPI (HR 0.98 [0.75, 1.28], p = 0.90). ConclusionsThree-month QOL had a stronger independent association with survival. The most symptomatic patients had longer survival with the addition of docetaxel; conversely, the least symptomatic patients did not appear to benefit. Consideration of QOL may enhance decision-making and patient selection when choosing chemohormonal treatment in mHSPC. Patient summaryQuality of life independently forecasted the survival of men with metastatic hormone-sensitive prostate cancer in the CHAARTED study. Close tracking of quality of life could help patients and clinicians make decisions about the appropriate treatment in this setting.

#30. Fractures in metastatic hormone-sensitive prostate cancer (mHSPC). Results from two phase 3 trials from the STAMPEDE platform

#30. Fractures in metastatic hormone-sensitive prostate cancer (mHSPC). Results from two phase 3 trials from the STAMPEDE platform

Recomendaciones de tratamiento en el cáncer de próstata hormonosensible metastásico: selección de pacientes

The standard treatment for metastatic hormone-sensitive prostate cancer (mHSPC) is now a combination of androgen deprivation therapy plus an androgen receptor-targeted therapy (abiraterone, apalutamide, enzalutamide or darolutamide), with or without chemotherapy (docetaxel). The selection of suitable patients for each therapeutic approach has become a determining factor to ensure efficacy and minimize side effects. This article combines recent clinical evidence with the accumulated experience of experts in medical oncology, radiation oncology and urology, to provide a comprehensive view and therapeutic recommendations for mHSPC.

Multidisciplinary Team Approach in Prostate-Specific Membrane Antigen Theranostics for Prostate Cancer: A Narrative Review

In managing prostate cancer, the integration of multidisciplinary team (MDT) with prostate-specific membrane antigen (PSMA) theranostics marks a significant advancement, addressing the disease's spectrum from indolent forms to aggressive metastatic stages. MDTs, comprising urology, oncology, radiation oncology, pathology, radiology, and nuclear medicine experts, are pivotal in delivering tailored, evidence-based care, essential for the varied clinical presentations of prostate cancer. The introduction of PSMA-targeted theranostics and PSMA positron emission tomography imaging has impacted the approach to diagnosis and treatment, offering enhanced precision in disease localization and enabling more nuanced management strategies for conditions such as oligometastatic prostate cancer, metastatic hormone-sensitive prostate cancer, and metastatic castration-resistant prostate cancer. The collaborative approach of MDTs in utilizing PSMA-targeted radioligand therapy emphasizes meticulous patient selection, predictive assessment of therapy response, and careful management of therapy-related toxicities. Additionally, recent strategies, including combination therapies from ENZA-P and Lu-PARP trials, show potential for improving treatment efficacy. This unified approach showcases the critical role of MDTs in optimizing treatment outcomes, underscoring the importance of collaboration in advancing the treatment of prostate cancer with PSMAtargeted therapies, thereby setting a new paradigm in personalized prostate cancer management.

Abstract 3812: Treatment guideline concordance for patients with metastatic hormone-sensitive prostate cancer (mHSPC) in the United States in IRONMAN, the International Registry for Men with Advanced Prostate Cancer

Abstract Background: Treatment intensification strategies with an androgen receptor pathway inhibitor (ARPI) and/or docetaxel chemotherapy in addition to androgen deprivation therapy (ADT) are guideline recommended treatment options for patients with metastatic hormone-sensitive prostate cancer (mHSPC). Prevalence of guideline concordant care for mHSPC patients in the US and its changes over time are not well characterized. Methods: The International Registry for Men with Advanced Prostate Cancer (IRONMAN) is a prospective cohort study of patients with newly diagnosed mHSPC and castration-resistant prostate cancer (CRPC). Therapies are captured by site personnel and by directly capturing data from treating physicians via physician questionnaires (PQ). We included all US patients with mHSPC enrolled from 2018 to January 1, 2023 with a completed PQ at enrollment. We examined patient characteristics, first-line treatments for mHSPC, and guideline concordance of first-line treatments. Guideline concordance was defined as a treatment regimen listed in the first National Comprehensive Cancer Network guidelines version for the year prior to treatment. Patients enrolled in clinical trials were excluded from analysis of treatment guideline concordance. Results: Among the 636 US participants with mHSPC, physicians completed PQs for 458 participants (72%). Participants had a median age of 68 years (interquartile range 62 - 75). Three hundred eight (78%) were White, 72 (18%) were Black, 13 (3%) were other races/ethnicities: 65 did not report race. First-line treatment for mHSPC based on the PQ was most commonly ADT + ARPI (59%) followed by ADT + docetaxel (17%), ADT monotherapy (14%), ADT + first-generation antiandrogen (3%), ADT + ARPI + docetaxel (3%), and other treatments (5%). Overall, 384 (86%) participants received first-line treatment that was guideline concordant at the time of treatment. Treatment guideline concordance was highest in 2018 (99%) when ADT monotherapy was considered as guideline concordant but then decreased to 80% in 2019 and remained largely stable from 2019 to 2022 (85%). Overall, rates of guideline concordance were similar when stratified by race (88% for White patients vs 85% for Black patients), age (90% for patients &amp;lt;65 years old vs 85% for patients ≥65 years old), and treatment at a Comprehensive Cancer Center (CCC) (87% at CCC vs 86% at non-CCC). Conclusion: Among patients with mHSPC treated in the US at 38 cancer centers, proportions of guideline concordant first-line treatment were high and remained stable over time, despite changes in approved therapies. Future efforts to understand reasons for treatment decisions will be important to better understand the relatively uncommon situations in which guidelines and actually received treatments differ for patients with mHSPC. Citation Format: Hannah Dzimitrowicz McManus, Lauren Howard, Kerri-Anne Crowell, Terry Hyslop, Jake Vinson, Dana E. Rathkopf, Philip Kantoff, Lorelei A. Mucci, Daniel George, Konrad Stopsack. Treatment guideline concordance for patients with metastatic hormone-sensitive prostate cancer (mHSPC) in the United States in IRONMAN, the International Registry for Men with Advanced Prostate Cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3812.

Abstract 688: Radium-223 in combination with darolutamide exhibits synergistic antitumor efficacy in LNCaP prostate cancer models

Abstract Radium-223 dichloride (radium-223) is a targeted alpha therapy that binds to newly formed abnormal bone in bone metastases and induces DNA double-strand breaks (DSBs) in cancer cells, osteoblasts and osteoclasts. Radium-223 is used for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC). Darolutamide is an androgen receptor inhibitor indicated for patients with metastatic hormone-sensitive prostate cancer or non-metastatic CRPC. We studied the antitumor effects of radium-223 in combination with darolutamide using LNCaP human prostate cancer cells in vitro and an intratibial LNCaP model mimicking prostate cancer metastasized to bone. The in vitro antiproliferative effects of radium-223 and darolutamide were determined using LNCaP cells. Gene set enrichment analysis (GSEA) was conducted on RNA sequencing data from LNCaP cells treated with the synthetic androgen R1881 alone or in combination with darolutamide. LNCaP cells were inoculated into the right tibia of male NOD.scid mice. The mice (n=7-9/group) were randomized based on serum prostate-specific antigen (PSA) and treated with vehicle, radium-223 (330 kBq/kg, Q4Wx2, i.v.), darolutamide (100 mg/kg, BID, p.o.), or with a combination of radium-223 and darolutamide, for 41 days. PSA and the bone turnover markers PINP and CTX-I were measured every second week in serum. Tumor-induced abnormal bone area, bone formation rate and radium-223 uptake in tumor-bearing tibiae were determined by X-ray, histomorphometry and gamma counter, respectively. The combination of radium-223 and darolutamide showed synergistic antiproliferative effects with combination indexes between 0.69-0.75 in vitro. GSEA demonstrated a prominent darolutamide-induced downregulation of DNA damage response (DDR) signaling pathways. In vivo, the combination treatment showed synergistic antitumor efficacy (p=0.04) as demonstrated by lower PSA concentrations when compared with the vehicle, radium-223 or darolutamide monotherapies (p=0.004, p=0.011 and p=0.002, respectively). In the vehicle and combination treatment groups, the mean serum PSA was 541% and 95.9% of the pre-treatment level, respectively. Furthermore, radium-223 alone or in combination with darolutamide inhibited increased bone turnover, tumor-induced abnormal bone growth and trabecular bone formation when compared to vehicle. Concurrent administration of darolutamide did not affect radium-223 uptake in tibiae. Radium-223 in combination with darolutamide exhibited synergistic antitumor efficacy both in vitro and in vivo. The synergistic effects could be due to the radiosensitization of cancer cells by darolutamide-induced downregulation of DDR pathways. Our results suggest that the combination of targeted alpha therapy with an androgen receptor inhibitor is a promising treatment strategy for mCRPC. Citation Format: Christoph A. Schatz, Mari I. Suominen, Andreas Schlicker, Matias Knuuttila, Esa Alhoniemi, Sanna-Maria Käkönen, Bernard Haendler, Urs B. Hagemann, Arne Scholz. Radium-223 in combination with darolutamide exhibits synergistic antitumor efficacy in LNCaP prostate cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 688.

Abstract 3410: Financial toxicity among patients with advanced prostate cancer in the United States

Abstract Background: Advanced prostate cancer is defined as metastatic hormone-sensitive prostate cancer (mHSPC) or castration-resistant prostate cancer (CRPC). Newer and aggressive treatments are leading to increasing lifespans in this population. As such, studying quality of life could have a large impact on the survivorship experience. An important component of quality of life is financial toxicity, defined as the financial burden and distress that can arise for patients and their families because of cancer treatment. Objectives: To understand the prevalence and predictors of financial toxicity in advanced prostate cancer. Methods: IRONMAN (International Registry of Men with Advanced Prostate Cancer) is a prospective cohort of patients with newly diagnosed mHSPC or CRPC enrolling in 15 countries. Financial toxicity was collected using the EORTC QLQ-C30 (“has your physical condition or medical treatment caused you financial difficulties?”) at enrollment and every three months thereafter. For this analysis, we studied 997 patients cared for at 37 US sites enrolled from 7/2017 to 7/2023. We examined baseline and longitudinal reports of financial toxicity across clinical and demographic factors: age at enrollment, race and ethnicity, disease state, marital status, education, employment, military status, and type of health center. We conducted adjusted risk difference analysis and multivariable regression modeling to identify predictors of financial toxicity using a generalized estimating equations approach to calculate odds ratios (OR and 95% confidence intervals, CI). Results: At enrollment, 125 (13%) patients reported experiencing “quite a bit” or “very much” financial toxicity. 21% of Black patients experienced toxicity compared to 10% of White patients. Even after incorporating all other predictors, Black patients experienced 5% (95% CI: 0, 11) greater toxicity than White patients. Independently of other predictors, patients &amp;gt;75 experienced 11% (CI: -17, -4) lower toxicity compared to those &amp;lt;65 years (while patients in the 65-74 group experienced 6% less, CI: -12, 1). Toxicity was 6% greater in patients with mHSPC (CI: 2, 10) than in patients with CRPC, and disabled or unemployed patients were at substantially higher risk. In the multivariable longitudinal analyses, older age (&amp;gt; 75) remained associated with significantly lower odds for financial toxicity (OR: 0.30, 0.15-0.61) while mHSPC (OR: 1.91, 1.14-3.20) and being unemployed (OR: 2.69, 1.03-6.99) or disabled (OR: 5.14, 2.29-11.6) were associated with higher odds. Conclusions: Financial toxicity is prevalent in advanced prostate cancer, especially in patients who are Black, younger than 75, diagnosed with mHSPC, or unemployed/disabled. These results may inform identification of patients at high risk for financial toxicity to support delivery of patient-situation-informed care by clinicians and targeted aid for patients at highest risk. Citation Format: Isani Singh, Bailey Vaselkiv, Emily Rencsok, Karen Autio, Deborah Enting, Alicia Morgans, Joel Nowak, Kevin Kensler, David Nanus, Robert Dreicer, Brian Lewis, Oliver Sartor, Elisabeth Heath, Phillip Kantoff, Deborah Kaye, Daniel George, Lorelei Mucci. Financial toxicity among patients with advanced prostate cancer in the United States [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3410.

Abstract 6857: Evolution of myeloid-mediated mechanisms of immunotherapy resistance at single-cell resolution with prostate cancer progression

Abstract Background: Patients with metastatic castration-resistant prostate cancer (mCRPC) are largely refractory to immune checkpoint inhibitors (ICIs). This resistance is, in part, attributed to the presence of immunosuppressive myeloid cells in tumors. However, attempts to target these cells broadly, such as CSF1R antagonism, have thus far failed clinically primarily due to their heterogeneous nature. Thus, we hypothesized that a more comprehensive understanding of immunosuppressive myeloid subsets and their molecular mechanisms at the single-cell level is critical to enhance the effectiveness of immunotherapy. Methods: We performed single-cell profiling of patient biopsies with either localized, metastatic hormone-sensitive prostate cancer, or mCRPC. We then reverse translated these findings in a syngeneic mouse model of CRPC, where we performed multi-omic single-cell assessment and conducted studies to assess tumor efficacy and gain mechanistic insights. Results: We identified a specific subset of tumor-associated macrophages with elevated hypoxia signatures, including higher SPP1 transcript levels (SPP1hi-TAMs). These macrophages become significantly more abundant as the disease advances, expressing elevated immunosuppressive molecular programs. Notably, CSF1R transcripts were significantly reduced in SPP1hi-TAMs, suggesting their potential role in the clinical ineffectiveness of CSF1R blockade. In a syngeneic mouse CRPC model, we identified an analogous macrophage subset through single-cell profiling and flow cytometry. These macrophages possess the ability to suppress T cell activity in co-culture. Consistent with these findings, adoptive transfer of Spp1hi-TAMs into CRPC promoted ICI resistance and worsened survival in vivo. Importantly, these macrophages proved resistant to anti-CSF1R treatment, underscoring the need to target their immunosuppressive signals as a potential therapeutic approach. Pathway analysis revealed enrichment of gene signatures associated with adenosine signaling in SPP1hi-TAMs both in patients and in mice, implicating this pathway as their immunosuppressive mechanism. Indeed, blocking adenosine signaling using antibodies or pharmacologic inhibitors resulted in a significant reduction in T cell suppression mediated by Spp1hi-TAMs in culture. Furthermore, pharmacologic blockade of adenosine receptors in vivo significantly decreased tumor growth and enhanced the responsiveness of tumor cells to ICI therapies. Conclusions: Our studies demonstrate that SPP1hi-TAMs become prevalent as the disease progresses. They are resistant to CSF1R blockade and play a key role in mediating immunotherapeutic resistance in vivo by activating adenosine signaling pathways. These findings highlight the potential of the associated signals as promising targets for therapeutic intervention. Citation Format: Aram Lyu, Zenghua Fan, Diamond Luong, Ali Setayesh, Alec Starzinski, Laura Valderrábano, Eliezer Van Allen, Lawrence Fong. Evolution of myeloid-mediated mechanisms of immunotherapy resistance at single-cell resolution with prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6857.

Abstract 6875: PIM kinases alter the prostate tumor immune microenvironment

Abstract Prostate cancer is the second leading cause of cancer-related deaths in American men. While prostate cancer patients typically respond to androgen-deprivation therapy, androgen receptor signaling inhibitor (ARSI), and/or taxane chemotherapy, patients inevitably develop resistance, and the disease progresses to an untreatable and lethal form known as castrate resistant prostate cancer (CRPC). Immunotherapy has changed the treatment paradigm for many types of cancer; however, immune checkpoint inhibitors have not shown clinical benefits in CRPC. Clinical and preclinical evidence indicates that this lack of efficacy can largely be attributed to the immunosuppressive tumor microenvironment. Tumor associated macrophages (TAMs) secrete factors that promote tumor progression and suppress antitumor immunity, making them a promising therapeutic target. The Proviral Integration site for Moloney murine leukemia virus (PIM) kinases are serine/threonine kinases that are overexpressed in prostate cancer. PIM regulates many signaling pathways that promote cell proliferation and survival. However, how PIM kinase alters the prostate tumor immune microenvironment and impacts immunotherapy resistance is not well understood. We analyzed primary prostate and metastatic lymph node samples from treatment-naive metastatic hormone-sensitive prostate cancer patients. Prostate cancer samples with PIM1/PIM2/PIM3-high and -low expression were classified by top and bottom quartile, respectively. PIM high tumors had higher expression of immunostimulatory genes (IL1β, TNF, and TNFSF13), increased infiltration of M2 macrophages, B cells, and NK Cells, and a higher T cell inflamed score compared to PIM-low tumors. Our results demonstrate that PIM overexpressing prostate tumors display increased inflammation and infiltration of immunosuppressive immune cells, including M2 macrophages. Due to the changes observed in inflammation, we hypothesized that PIM kinase may regulate macrophage inflammatory signaling. We treated bone marrow derived macrophages with a PIM kinase inhibitor and showed that PIM inhibition suppresses inflammasome signaling and the release of the pro-inflammatory cytokine, IL-1β. Chronic inflammation can lead to the recruitment of TAMs, further promoting resistance to immune checkpoint inhibitors. Utilizing a syngeneic mouse model of prostate cancer, we demonstrated that PIM inhibition in combination with immune checkpoint blockade synergistically decreased tumor growth. Furthermore, immunoprofiling demonstrated that combination treatment enhances T cell activity. Overall, our results suggest that PIM kinase plays an important role in regulating the prostate tumor immune microenvironment and that PIM kinase may be a potential target to enhance the efficacy of immunotherapy for the treatment of prostate cancer. Citation Format: Amber N. Clements, Kai Sutterby, Sachin Kumar Deshmukh, Sharon Wu, Joanne Xiu, Alex Farrell, Milan Radovich, Chadi Nabhan, Elisabeth I. Heath, Rana R. McKay, Alejandro Recio-Boiles, Noel A. Warfel. PIM kinases alter the prostate tumor immune microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6875.

Three- and Seven-month Prostate-specific Antigen Levels as Prognostic Markers for Overall Survival in Metastatic Hormone-sensitive Prostate Cancer: Results from SWOG S1216, a Phase 3 Randomized Trial of Androgen Deprivation Plus Orteronel or Bicalutamide

BackgroundA robust decrease in prostate-specific antigen (PSA) in response to androgen deprivation therapy (ADT) has been evaluated as a prognostic factor in patients with metastatic hormone-sensitive prostate cancer (mHSPC) since 2006, but the treatment of mHSPC has since evolved to include intensified therapy. ObjectiveWe assessed the association of PSA levels at 3 (PSA-3mo) and 7 (PSA-7mo) mo with overall survival (OS) in patients with mHSPC treated with ADT combined with either bicalutamide or orteronel in the S1216 phase 3 clinical trial. Design, setting, and participantsPSA responses to treatment of patients in the S1216 trial were categorized as: complete response (CR) if PSA was ≤0.2 ng/ml, partial response if PSA was >0.2 and ≤4 ng/ml, and no response (NR) if PSA was >4 ng/ml. Outcome measurements and statistical analysisA Cox analysis (adjusted for treatment arm and three stratification factors: performance status, severity of disease, and early vs late induction) was used for OS association. While PSA-7mo association was a prespecified objective, PSA-3mo association was also evaluated. Results and limitationsA total of 1251 and 1231 patients from the S1216 study were evaluable for PSA-3mo and PSA-7mo, respectively. A PSA-7mo CR was associated with improved OS compared with NR (HR: 0.20; p < 0.0001). A PSA-3mo CR showed a similar association to NR (HR: 0.34; p < 0.0001). The association of a PSA response with survival did not differ by treatment arm at either time point. ConclusionsThe PSA-3mo and PSA-7mo responses were strongly associated with OS; taken with other emerging prognostic biomarkers, these markers may allow for early identification of patients at the highest risk of death, aid with counseling in clinical practice, and permit design of future clinical trials targeting these patients. Patient summaryA low prostate-specific antigen level at 3 or 7 mo after starting treatment for metastatic hormone-sensitive prostate cancer predicts longer survival regardless of the first treatment given with androgen deprivation therapy.

Radiographic Progression at Castration-Resistant Prostate Cancer Diagnosis: A Prognostic Indicator of Metastatic Hormone-Sensitive Prostate Cancer

BackgroundThe critical role of radiographic assessment at the time of castration-resistant prostate cancer (CRPC) diagnosis is underscored by this study. We performed a retrospective analysis of radiographic changes in metastasis from the time of diagnosis of metastatic hormone-sensitive prostate cancer (mHSPC) to CRPC diagnosis. We also explored its impact on prognosis post-CRPC. Materials and MethodsWe retrospectively analyzed 98 men who underwent radiographic examinations (bone scans and computed tomography [CT]) at the time of CRPC diagnosis. When radiographic studies demonstrated progression at CRPC diagnosis, patients were assigned to the radiographic progressive disease (rPD) group. The remaining patients were placed in the "non-rPD" group. The overall survival (OS) post-CRPC was compared between the 2 groups. ResultsThe median OS post-CRPC was significantly shorter in the rPD group (n = 50) compared to the non-rPD group (n = 48) (32 months vs. not reached, P = .0124). Multivariate analysis showed that radiographic progression and shorter time to CRPC were associated with a shorter OS post-CRPC (hazard ratio [HR] = 3.14; 95% confidence interval [CI], 1.21-8.12, P = .019). ConclusionRadiographic progression at the point of CRPC diagnosis independently predicts a shorter OS post-CRPC in patients with mHSPC. Therefore, assessing radiographic changes at the time of CRPC diagnosis could be instrumental in managing CRPC in patients with mHSPC.

Effectiveness and safety of darolutamide as a component of combination therapy in patients with prostate cancer

Prostate cancer is an extremely important problem in current urologic oncology. For a long time, the golden standard of treatment of common forms of prostate cancer at the stage of distant metastases was androgen deprivation therapy directed at suppression of native testosterone level. Combination treatment using long-term androgen deprivation therapy and new generation antiandrogens is currently a scientifically substantiated conceptually new standard of therapy which has replaced treatment paradigm using androgen deprivation therapy as a monotherapy in patients with metastatic hormone-sensitive prostate cancer. The article presents the results of large trials performed in patients with metastatic hormone-sensitive prostate cancer and characterizes the role of one of the most effective and safe drugs, darolutamide, used to treat patients of this subgroup.

Markers of bone metabolism and overall survival in men with bone-metastatic hormone sensitive prostate cancer (HSPC): A subset analysis of SWOG S1216, a phase III trial of androgen deprivation with or without orteronel.

Circulating biomarkers of bone metabolism are significantly associated with overall survival (OS) in men with advanced prostate cancer. In the SWOG S1216 phase III trial, we showed that elevated bone biomarkers are significantly associated with an increased risk of death in hormone-sensitive prostate cancer (HSPC) regardless of the status of bone metastases, identifying three risk groups with differential OS outcomes based on bone biomarker status. Here we report the association of bone biomarkers with OS in men with HSPC and documented skeletal metastases as part of a planned subset analysis of S1216. Bone resorption [C-telopeptide (CTx); Pyridinoline (PYD)] and bone formation markers [C-terminal collagen propeptide (CICP); bone alkaline phosphatase (BAP)] were assessed in blood from men with bone metastatic HSPC. Patients were randomly divided into training (n = 238) and validation (n = 475) sets. In the training set, recursive partitioning that maximizes discrimination of OS was used to identify the dichotomous cut-point for each biomarker and for a combination of biomarker split points to define prognostic groups. In the validation set, Cox proportional hazards models were used to assess the impact of biomarkers on OS, adjusted for patient and tumor characteristics. Of 1279 men, 713 had both baseline bone metastases and evaluable bone biomarkers. Patient characteristics were similar between the overall population and the subset with bone metastases. Elevated levels of CICP, CTX, and PYD were strongly prognostic for OS. Hazard ratios (95% CI) for OS adjusted for treatment arm and baseline clinical variables were: BAP-1.31 (0.93, 1.84), p = 0.12; CICP-1.58 (1.09, 2.29), p < 0.02; CTx - 1.55 (1.12, 2.15), p = 0.008; and PYD-1.66 (1.27, 2.217), p = 0.0002. There was no evidence of interaction between elevated biomarkers and treatment (all p > 0.2). Recursive partitioning algorithms identified four groups of patients with differential OS outcomes based on bone biomarkers, adjusted for baseline clinical variables, with median OS ranging from 2.3 years (highest risk group) to 7.5 years (lowest risk group). In this planned S1216 subset analysis of men with HSPC and bone metastases, elevated serum markers of bone metabolism were significantly associated with worse OS. Bone biomarker levels alone and in combination with patient and tumor characteristics identify unique subsets of men with differential OS outcomes. NCT01809691.

[Palliative surgery for metastatic prostate cancer].

Androgen deprivation in combination with novel hormonal agents, docetaxel, or in combination with abiraterone/prednisone plus docetaxel or darolutamid plus docetaxel represent the standard therapeutic approach in metastatic hormone-sensitive prostate cancer (mHSPC). Patients with low-risk prostate cancer also benefit from additional radiation therapy or radical prostatectomy in terms of progression-free and overall survival. Despite favorable response rates, basically all patients will develop castration resistant prostate cancer (CRPC) within 2.5to 4years. In addition to systemic chemotherapy, second-line hormonal treatment of systemic application of radionuclides such as radium223 or 177Lu-PSMA represent salvage management options. However, nowadays about 50-65% of patients will develop symptoms due to local progression of prostate cancer which is the result of improved oncological outcomes with significantly prolonged survival times due to the new medical treatment options. Management of such symptomatic local progression will become more important in upcoming years so that all uro-oncologists need to be aware of the various surgical management options. Complications of the lower urogenital tract such as recurrent gross hematuria ± bladder clotting and with the necessity for red blood cell transfusions, subvesical obstruction and acute urinary retention, rectourethral or rectovesical fistulas might be managed by palliative surgery such as palliative transurethral resection of the prostate (TURP), radical cystectomy, radical cystoprostatectomy with urinary diversion, and pelvic exenteration. Symptomatic or asymptomatic obstruction of the upper urinary tract might be managed by endoluminal or percutaneous urinary diversion, ureteral reimplantation, ileal ureter replacement, or implantation of the Detour® system (Coloplast GmbH, Hamburg, Germany).