Trials In Prostate Cancer Research Articles

Diversity, equity, and inclusion in genitourinary clinical trials leading to FDA novel drug approval: An assessment of the FDA center for drug evaluation and research drug trials snapshot

To determine the distribution of race and ethnicity among genitourinary oncology trial participants leading to FDA approval of novel molecular entities/biologics. Secondarily, we evaluated whether the proportion of Black participants in clinical trials increased over time. We quired the FDA Center for Drug Evaluation and Research Drug Trials Snapshot (DTS) between 2015 and 2020 for urologic oncology clinical trials leading to FDA approval of novel drugs. Enrollment data was stratified by race and ethnicity. Cochran-Armitage Trend tests were used to examine changes in Black patient participation over years. Nine clinical trials were identified that led to FDA approval of 5 novel molecular entities for prostate and 4 molecular entities for urothelial carcinoma treatment. Trials for prostate cancer included 5202 participants of which 69.8% were White, 4.0% Black, 11.0% Asian, 3.6% Hispanic, <1% American Indian/Alaska Native or Native Hawaiian/Pacific Islander, 3% other. Trials in urothelial carcinoma had 704 participants of which 75.1% were male, 80.8% White, 2.3% Black, 2.4% Hispanic, <1% American Indian/Alaska Native or Native Hawaiian/Pacific Islander, 5% other. Black participation rates over time did not change for urothelial (P=0.59) or the combined cancer cohort (P=0.29). Prostate cancer enrollment trends among Black participant declined over time (P=0.03). Participants in genitourinary clinical trials leading to FDA approval of novel drugs are overwhelmingly white. Involving stakeholders who represent the needs and interests of underrepresented populations in the design and implementation of clinical trials of novel agents may be a strategy to increase diversity, equity, and inclusion among genitourinary clinical trials.

BET Inhibition Sensitizes Immunologically Cold Rb-Deficient Prostate Cancer to Immune Checkpoint Blockade.

Non-T-cell-inflamed immunologically "cold" tumor microenvironments (TME) are associated with poor responsiveness to immune checkpoint blockade (ICB) and can be sculpted by tumor cell genomics. Here, we evaluated how retinoblastoma (Rb) tumor-suppressor loss-of-function (LOF), one of the most frequent alterations in human cancer and associated with lineage plasticity, poor prognosis, and therapeutic outcomes, alters the TME, and whether therapeutic strategies targeting the molecular consequences of Rb loss enhance ICB efficacy. We performed bioinformatics analysis to elucidate the impact of endogenous Rb LOF on the immune TME in human primary and metastatic tumors. Next, we used isogenic murine models of Rb-deficient prostate cancer for in vitro and in vivo mechanistic studies to examine how Rb loss and bromodomain and extraterminal (BET) domain inhibition (BETi) reprograms the immune landscape, and evaluated in vivo therapeutic efficacy of BETi, singly and in combination with ICB and androgen deprivation therapy. Rb loss was enriched in non-T-cell-inflamed tumors, and Rb-deficient murine tumors demonstrated decreased immune infiltration in vivo. The BETi JQ1 increased immune infiltration into the TME through enhanced tumor cell STING/NF-κB activation and type I IFN signaling within tumor cells, resulting in differential macrophage and T-cell-mediated tumor growth inhibition and sensitization of Rb-deficient prostate cancer to ICB. BETi can reprogram the immunologically cold Rb-deficient TME via STING/NF-κB/IFN signaling to sensitize Rb-deficient prostate cancer to ICB. These data provide the mechanistic rationale to test combinations of BETi and ICB in clinical trials of Rb-deficient prostate cancer.

CLO23-025: Comparison of Outcomes Using NCCN Classification in Two Concurrent Phase III Trials in Intermediate and High Risk Prostate Cancer: Long-Term Data

"CLO23-025: Comparison of Outcomes Using NCCN Classification in Two Concurrent Phase III Trials in Intermediate and High Risk Prostate Cancer: Long-Term Data" published on 31 Mar 2023 by National Comprehensive Cancer Network.

Meta-Analysis of Candidate Surrogate End Points in Advanced Prostate Cancer

BackgroundThe Intermediate Clinical Endpoints in Cancer of the Prostate (ICECaP) working group identified metastasis-free survival as a valid surrogate end point for overall survival (OS) for patients with localized prostate cancer. No comparably validated surrogate end points exist in advanced prostate cancer.MethodsWe searched for trials in advanced prostate cancer, defined as node-positive, metastatic castration-sensitive, nonmetastatic, or metastatic castration-resistant prostate cancer. Eligible randomized trials reported OS and one or more intermediate clinical end points, including biochemical failure (BF), clinical failure, biochemical failure–free survival (BFS), progression-free survival (PFS), and radiographic PFS. Candidacy for surrogacy was assessed by using the second condition of the meta-analytic approach; R2 was weighted by the inverse variance of the log intermediate clinical end point hazard ratio and defined as R2>0.70.ResultsA total of 143 randomized trials (n=75,601 patients) were included. No candidate end points met the criteria for surrogacy (R2 BF [n=28,922], 0.42 [95% confidence interval (CI), 0.18 to 0.64]; BFS [n=25,741], 0.57 [95% CI, 0.37 to 0.73]; clinical failure [n=22,616], 0.31 [95% CI, 0.075 to 0.56]; PFS [n=52,639], 0.50 [95% CI, 0.35 to 0.63]; and radiographic PFS [n=52,548], 0.50 [95% CI, 0.35 to 0.63]). Within preplanned subgroups according to castration-sensitive or castration-resistant disease or according to treatment type, neither BFS nor PFS consistently met criteria for surrogacy. Sensitivity analyses showed that candidacy for surrogacy of all end points tested did not change over time.ConclusionsOur aggregate screening method for surrogate end points in advanced prostate cancer showed that commonly used clinical end points are not clear valid surrogate end points for OS. (Funded by the Prostate Cancer Foundation and the National Cancer Institute.)

Randomized phase II trial in prostate cancer with hormone-sensitive OligometaSTatic relapse: Combining stereotactic ablative radiotherapy and durvalumab (POSTCARD GETUG P13): Study protocol

BackgroundAs in other solid tumors, increasing evidence indicates that patients diagnosed with a limited number of prostate cancer metastases, so-called oligometastases, have a better prognosis than patients with extensive metastatic disease. Stereotactic body radiotherapy (SBRT) is now considered an option in this population.Programmed death-1 (PD-1) and its ligands (PD-L1) are targeted by immune checkpoint inhibitors. Preclinical studies have shown that the tumor immune microenvironment changes when combining radiotherapy with immunotherapy, especially with hypofractionated radiotherapy.The oligometastatic setting appears to be the most relevant clinical situation for evaluating the immune response generated by radiotherapy and immune checkpoint inhibitors in patients with an intact immune system.We hypothesize that durvalumab will enhance the immune response following SBRT targeting oligometastatic lesions. Our purpose is to demonstrate, via a randomized 2:1 phase II trial, that SBRT (3 fractions) with durvalumab in oligometastatic hormone-sensitive prostate cancer patients would improve progression-free survival in patients with prostate cancer with up to 5 metastases compared to patients who exclusively received SBRT. MethodsThis is a multicentric randomized phase II study in French academic hospitals. Patients with prostate cancer and up to 5 metastases (lymph node and/or bone) were randomized into a 2:1 ratio between Arm A (experimental group), corresponding to durvalumab and SBRT to the metastases, and Arm B (control group), corresponding to SBRT alone to the metastases. The study aims to accrue a total of 96 patients within 3 years. The primary endpoint is two-year progression-free survival and secondary endpoints include androgen deprivation therapy-free survival, quality of life, toxicity, prostate cancer specific survival, overall survival, and immune response. DiscussionThe expected benefit for the patients in the experimental arm is longer life expectancy with acceptable toxicity. We also expect our study to provide data for better understanding the synergy between immunotherapy and radiotherapy in oligometastatic prostate cancer.

Role of Bromodomain and Extraterminal (BET) Proteins in Prostate Cancer

Introduction The bromodomain and extraterminal (BET) family of proteins are epigenetic readers of acetylated histones and are critical activators of oncogenic networks across many cancers. Therapeutic targeting of BET proteins has been an attractive area of clinical development for metastatic castration-resistant prostate cancer. In recent years, many structurally diverse BET inhibitors have been discovered and tested. Preclinical studies have demonstrated significant antiproliferative activity of BET inhibitors against prostate cancer. However, their clinical success as monotherapies has been limited by treatment-associated toxicities, primary and acquired drug resistance, and a lack of predictive biomarkers of benefit. Areas covered This review provides an overview of advancements in BET inhibitor design, preclinical research, and conclusions from clinical trials in prostate cancer. We speculate on incorporating BET inhibitors into combination regimens with other agents to improve the therapeutic index of BET inhibition in treating prostate cancer. Expert opinion The therapeutic potential of BET inhibitors for prostate cancer has been demonstrated in preclinical studies. However, further research is needed to identify biomarkers that can predict sensitivity to BET inhibitors and to develop novel, highly selective inhibitors to reduce toxicities. Finally, BET inhibitors are likely to hold the most clinical potential in combination with other agents.

Difficulties in Defining Oligometastatic Prostate Cancer: Implications for Clinical Trial Accrual and Community Practice Adoption of Metastasis-Directed Therapy Approaches

Metastasis-directed therapy is widely utilized for oligometastatic prostate cancer patients, but standard imaging does not always identify metastases definitively and, even with PSMA PET, there may be equivocal findings. Not all clinicians have access to detailed imaging review, particularly outside of academic cancer centers, and PET scan access is also limited. We sought to understand how imaging interpretation impacted recruitment to a clinical trial for oligometastatic prostate cancer. IRB approval was obtained to review medical records from all patients screened for the institutional IRB-approved clinical trial for men with oligometastatic prostate cancer involving androgen deprivation plus stereotactic radiation to all metastatic sites, as well as radium223 (NCT03361735). Clinical trial inclusion required at least one bone metastatic lesion and no more than five total sites of metastasis, including soft tissue sites. Tumor board discussion records were reviewed, along with results from additional radiology studies ordered or confirmatory biopsies performed. Clinical characteristics such as PSA level and Gleason score were studied for association with likelihood of oligometastatic disease confirmation. At the time of data analysis, 18 subjects were deemed eligible and 20 were not eligible. The most common reasons for ineligibility were no confirmed bone metastasis in 16 patients (59%) and too many metastatic sites in 3 (11%). The median PSA of eligible subjects was 3.28 (range 0.4-45.5), whereas the median PSA of those found to be ineligible was 10.45 (range 3.7-26.3) when there were too many metastases identified, and 2.7 (range 0.2-34.5) when metastases were unconfirmed. PET imaging (PSMA or fluciclovine PET) increased the number of metastases, while MRI resulted in downstaging to non-metastatic disease. This research suggests that additional imaging (i.e., at least two independent imaging modalities of a possible metastatic lesion) or tumor board adjudication of imaging findings may be critical to correctly identify patients appropriate for enrollment in oligometastatic protocols. This should be considered as trials of metastasis-directed therapy for oligometastatic prostate cancer accrue and results are translated to broader oncology practice.

107P Censoring imbalance in ACIS trial for prostate cancer

107P Censoring imbalance in ACIS trial for prostate cancer

New treatment approaches for and ongoing trials in metastatic hormone-sensitive prostate cancer

For many years, therapy for metastatic hormone-sensitive prostate cancer (mHSPC) was dominated by monotherapy using androgen deprivation therapy (ADT). With the demonstration of survival benefit with intensified systemic therapy from the CHAARTED and STAMPEDE trials, this has fundamentally changed. We analyzed the phaseIII trials that led to the change in therapy in mHSPC. In addition, we summarized ongoing trials in mHSPC. The ongoing studies and current data on systemic therapy in mHSPC were analyzed. Monotherapy with ADT is no longer considered the standard therapy for mHSPC. Combination therapy with ADT and novel androgen receptor targeting agents (ARTAs: abiraterone, apalutamide, enzalutamide) is now the established standard option. The added value of further intensification of therapy was demonstrated in the first trials of triple therapy with ADT + docetaxel + darolutamide or abiraterone in mHSPC. Current studies are also investigating new forms of therapy. Lutetium177-PSMA radioligand therapy is an established standard in metastatic castration-resistant prostate cancer (mCRPC) and is currently being evaluated in combination with ADT + ARTA in mHSPC. The use of PARP inhibitors (PARPi) have been established in mCRPC. Current studies are showing early evidence of benefit from novel combination therapies of PARPi + ARTA, which represent afurther expansion of the therapeutic landscape. Experimental therapies are testing another combination, such as an AKT inhibitor with ARTA in patients with PTEN (phosphatase and tensin homolog) loss. Based on the proof of principle in mCRPC, this combination is now being evaluated in earlier stage mHSPC. Other experimental therapies in clinical testing include inhibitors of cyclin dependent kinases (CDK). Combination therapies are the current standard of care for mHSPC, with the combination of ADT + ARTA dominating. Preliminary results underline the importance of further intensification of therapy by means of triple therapy. However, novel combinations with radioligand therapy or PARP inhibitors are also promising in the treatment of mHSPC. Preliminary results show the principle efficacy of AKT inhibitors in patients with PTEN loss, which similar to therapy with CDK4/6 inhibitors still have to prove their clinical relevance in randomized trials.

Effects of docetaxel on circulating immune cell subsets and association with outcomes in metastatic castration-sensitive prostate cancer.

207 Background: Docetaxel with androgen deprivation therapy (ADT) has been shown to improve survival in metastatic castration-sensitive prostate cancer (mCSPC). There is limited data on the immunologic effects of docetaxel in mCSPC. Greater knowledge of the immune impact of docetaxel could inform future trials in prostate cancer. Methods: A clinical trial in mCSPC evaluated sequencing docetaxel and ADT with Prostvac, a poxviral vaccine targeting prostate-specific antigen (PSA). Eligibility criteria included mCSPC within 4 months of ADT and ECOG performance status 0-2. Patients given 6 cycles of docetaxel 75mg/m2 with ADT alone for mCSPC were included in this analysis. Peripheral blood mononuclear cells (PBMCs) were sampled at baseline and at 3 weeks after commencing docetaxel. Immune cell subsets analyzed included CD4+ and CD8+ T-cells, T regulatory cells (Tregs), natural killer (NK) cells, dendritic cells (DCs) and myeloid-derived suppressor cells (MDSCs). Analyses were performed to determine if the baseline immune status or immune changes induced by therapy associate with PSA at 2 years. Results: Fifteen patients were evaluated for peripheral immune responses in this study. Median age was 63 years (range 50-73). Fourteen were white and 1 was black. ECOG performance status was 0 in 11 patients, 1 in 4 patients. Disease volume was high in 7 and low in 8 patients. Among 158 immune cell subsets assessed, only changes in Tregs and activated NK cells with a lytic and cytokine producing phenotype (CD16+ CD56br) were noted after initiation of docetaxel in addition to ADT. Patients with PSA ≤0.2 at 2 years had higher baseline frequencies of total CD4+ T cells, several activated CD4+ T-cell subsets, plasmacytoid DCs, and CD49d- Tregs. They also had lower baseline frequencies of total CD8+ T cells, naïve CD8+ T cells, and CD73+CD8+ T-cells. Patients with PSA ≤0.2 at 2 years also had greater percent increases in CD8+ effector memory (EM) PD-1+ T-cells after treatment. Conclusions: This is the first study to demonstrate increases in activated NK cells with lytic and cytokine producing potential after treatment with docetaxel. Given that NK cells are associated with clinical outcomes in prostate cancer (Zhao SG, JNCI, 2019) and that increased NK cells were seen after treatment with enzalutamide as well (Madan, JITC, 2021), developing immunotherapy combinations to capitalize on NK cell activity may be a path forward for developing immunotherapy in prostate cancer. Clinical trial information: NCT02649855 . [Table: see text]

Transdermal square-wave testosterone therapy: A pilot trial in metastatic castration-resistant prostate cancer.

188 Background: Metastatic castration-resistant prostate cancer (mCRPC) becomes resistant to anti-androgen therapies due to a variety of adaptive mechanisms. Intramuscular bipolar androgen therapy (BAT) which alternates between high and low testosterone (T) levels is therapeutically active in mCRPC and confers sensitivity to second-generation androgen receptor antagonists such as enzalutamide (ENZA). We hypothesized that transdermal T with sustained supraphysiologic T levels would lead to high response rates to ENZA in mCRPC. We also hypothesized Square-wave transdermal T therapy would be a safe alternative to BAT due to the ability to quickly withdraw therapy in the setting of symptoms. Methods: This was an open-label, single-site, phase 2 feasibility trial in men with asymptomatic mCRPC who had not previously received ENZA. Transdermal T was administered at a dose of 100 mg/day for a minimum of 12 weeks and until disease progression. Therapy was then switched to ENZA 160 mg/day until next disease progression. Patients who initially responded to T could receive a second course of transdermal T followed by ENZA, remaining on study until progression on both T and ENZA, or for the 12-month study duration, whichever was sooner. ADT was continued throughout. The primary endpoint of the study was feasibility. T dose was adjusted to achieve T levels between 900-1500 ng/dL. Secondary end points included PSA50 response rate (50% decline in PSA) and safety. Results: Fifteen patients were enrolled. Ten (66.7%) had Gleason &gt;8 disease. Thirteen (86.7%) patients had bone metastases. Median baseline PSA was 11.73 ng/mL. Primary endpoint of feasibility based on patient recruitment and retention was met. The median testosterone level on T was 901.3 ng/dL (Range: 645.2 to 1171.1). Median time on therapy was 15.9 weeks on T and 25.9 weeks on ENZA. PSA50 was 13.3% on initial T therapy and 66.7% after switching to ENZA. Three (20%) patients did not initiate ENZA after T progression. Two desired to avoid androgen-related side effects and 1 initiated chemotherapy. No Grade 3 or higher adverse events (AEs) occurred on T and the most common AEs were weight gain, rash, and nipple sensitivity. Conclusions: Square-wave transdermal T alternating with ENZA is feasible and achieves adequate T levels in the treatment of asymptomatic mCRPC. Given the acceptable safety profile and quick reversibility, transdermal T warrants further exploration, and we have expanded enrollment to include higher risk patient populations. Clinical trial information: NCT03734653 .

CDK12 pathogenic mutations in African American and White patients with prostate cancer.

38 Background: African American (AA) men are underrepresented in prostate cancer (PC) trials but have a greater probability of both developing and dying from prostate cancer (PC) than other populations. CDK12 mutations in PC are associated with aggressive disease, increased metastasis, and decreased overall survival. Some preliminary data has suggested that CDK12 mutations may be more common in AA men. This study reports data from next-generation sequencing (NGS) of tissue from a large population of patients with PC in the real-world setting to investigate frequency of pathogenic CDK12 mutations in AA men and White men. Methods: De-identified records from patients with primary PC who underwent NGS with Tempus xT (solid tumor, 648 genes, 500× coverage, full transcriptome RNAseq for a subset of patients) were analyzed to characterize the frequency and types of pathogenic CDK12 mutations, and co-mutation in other assessed genes. Results were compared between patients identified as AA and White. Patients were excluded if they were Microsatellite Instability high (MSI-H), Tumor Mutational Burden (TMB) ≥10, or Mismatch Repair deficient (MMR-d). Results: Genomic profiles were analyzed from tissue samples of 6121 unique patients; of 3,555 patients with known race, 646 (18%) were AA, 2657 (75%) were White, and 252 (7%) were of other races. Of these patients, 3026 were AA or White after excluding 277 patients with known MSI-H, TMB≥10, or MMR-d status. AA were younger at diagnosis than Whites (median 63 vs 66 years; p&lt;0.001). Tissue samples from AA men were significantly more likely than those from Whites to express a pathogenic CDK12 mutation (42 [7.2%] vs 93 [3.8%], p&lt;0.001). The majority of the variants identified were truncating mutations. There were no differences in truncating vs. non-truncating alterations between White and AA men, nor were there differences in the prevalence or distribution of co-mutations between the two populations. Conclusions: AA men with PC show a higher frequency of pathogenic CDK12 mutations than Whites in a large real-world population. Co-mutations did not vary by race, and the alterations were most likely to be truncating mutations in both races.

Phase 2 randomized total eradication of metastatic lesions following definitive radiation to the prostate in de novo oligometastatic prostate cancer (TERPs) trial.

TPS275 Background: It is now recognized that some patients with “oligo,” or few sites of metastases, may have the potential to completely eradicate their disease with aggressive local therapy. There are recent encouraging randomized prospective data for total consolidation of macroscopic metastases through treatment intensification involving metastasis-directed therapy (MDT). Hypotheses include that radiation to primary prostate tumor and metastatic sites affects the natural history of metastasis by virtue of radiation effects on cancer cell autonomous pathways and tumor microenvironment/normal tissue pathways. This study aims to evaluate the utility of the addition of MDT to the evolving standard of care treatment for de novo low volume metastatic prostate cancer (PCa) patients. This study will evaluate the efficacy of best systemic therapy (BST) and primary prostate radiation (XRT) versus BST, XRT and stereotactic ablative radiation therapy (SABR) MDT. Discovery correlatives associated with clinical outcome will be assessed by collection of including, but not limited to: circulating tumor cells, immunologic biomarkers, microbiota and radiomics. Methods: This study is a multi-site, non-blinded, randomized Phase II trial in patients with oligometastatic PCa. Men with de novo histologically confirmed (at any site) oligometastatic PCa (&lt;3 metastases on standard imaging or &lt;5 on Axumin/Choline/PSMA-PET/CT) will be randomized (1:1) to BST + XRT versus BST + XRT + SABR MDT. BST and XRT will be administered for all men in the first 3-months, and radiation treatment will be completed within the first 150 days. A range of XRT treatment approaches are permitted but must deliver an EQD2 &gt;75.6 Gy to the prostate. BST will allow standard and intensified androgen blockade. The trial will evaluate the addition of SABR MDT and explore several translational and imaging correlatives. Subjects who meet eligibility criteria and qualify for enrollment will be stratified according to: (i) hormonal therapy vs intensified hormonal therapy; (ii) XRT vs XRT + primary prostate boost, and (iii) absence vs presence of bone metastasis. This study has been approved and began accrual on October 3rd, 2022, the Clinicaltrials.gov. Identifier: NCT05223803. We assume an accrual time of 24 months, with 24 months of additional follow-up time, and will randomize a total of 122 patients (61 patients in each arm). The primary endpoint with be to assess 2-year failure-free survival (FFS). Secondary endpoints will include toxicity, quality of life (QoL), time to locoregional progression, time to distant progression, time to new metastasis, radiographic progression-free survival, and duration of response. Clinical trial information: NCT05223803 .

Antibody-Drug Conjugates in Prostate Cancer: A Systematic Review.

The prognosis in the setting of metastatic castration-resistant prostate cancer patients (mCRPC) remains limited. Therefore, novel treatment strategies remain an unmet need. Antibody-drug conjugates (ADC) emerged as a new drug concept with the potential to deliver a cytotoxic payload with limited off-target toxicity and potentially bystander effect. Following the success of ADCs in breast cancer and urothelial tumours, their activity in prostate cancer is now under investigation. Thus, the aim of this systematic review was to identify published and ongoing prospective clinical trials regarding ADC treatment in prostate cancer. A systematic search of PubMed, MEDLINE, and Web of Science was conducted as per PRISMA guidelines to identify prospective clinical trials of ADCin prostate cancer. Trials are currently ongoing on ClinicalTrials.gov and in the EU. The Clinical Trials Register was also identified. Abstracts, publications in languages other than English, review articles, retrospective analyses, and phase I trials were excluded. A total of six phase I/II prospective clinical trials already published were included. Seven ongoing trials were also identified. All studies were in the refractory/advanced tumour setting, and two included only mCRPC patients. The ADC targets were prostate-specific membrane antigen (PSMA), trophoblast cell surface antigen-2 (TROP-2), six-transmembrane epithelial antigen of prostate-1 (STEAP-1), tissue factor (TF), delta-like protein 3 (DLL-3), B7-H3 family of proteins (B7-H3), and human epidermal growth factor receptor 2 (HER2). Regarding the efficacy of PSMA ADC treatment in the second-line or beyond mCRPC setting, a PSA ≥ 50% decline rate in 14% of all treated patients was reported. One patient achieved a complete response with TROP-2 ADC. Overall, a wide range of safety issues were raised, particularly in connection with neuropathy and hematologic toxicity. Novel therapies have been changing the scope of treatment in mCRPC. ADCs seem to provide efficacy benefits, even with potential toxicity. The results of most prospective ongoing studies are still awaited, and a longer follow-up time is warranted to evaluate the real impact of ADCs in PCa.

Automated quantification of PET/CT skeletal tumor burden in prostate cancer using artificial intelligence: The PET index

PurposeConsistent assessment of bone metastases is crucial for patient management and clinical trials in prostate cancer (PCa). We aimed to develop a fully automated convolutional neural network (CNN)-based model for calculating PET/CT skeletal tumor burden in patients with PCa.MethodsA total of 168 patients from three centers were divided into training, validation, and test groups. Manual annotations of skeletal lesions in [18F]fluoride PET/CT scans were used to train a CNN. The AI model was evaluated in 26 patients and compared to segmentations by physicians and to a SUV 15 threshold. PET index representing the percentage of skeletal volume taken up by lesions was estimated.ResultsThere was no case in which all readers agreed on prevalence of lesions that the AI model failed to detect. PET index by the AI model correlated moderately strong to physician PET index (mean r = 0.69). Threshold PET index correlated fairly with physician PET index (mean r = 0.49). The sensitivity for lesion detection was 65–76% for AI, 68–91% for physicians, and 44–51% for threshold depending on which physician was considered reference.ConclusionIt was possible to develop an AI-based model for automated assessment of PET/CT skeletal tumor burden. The model’s performance was superior to using a threshold and provides fully automated calculation of whole-body skeletal tumor burden. It could be further developed to apply to different radiotracers. Objective scan evaluation is a first step toward developing a PET/CT imaging biomarker for PCa skeletal metastases.

Novel radionuclide therapy combinations in prostate cancer.

Prostate cancer remains the commonest cancer diagnosed in males and a leading cause of cancer-related death. Men with metastatic castration-resistant prostate cancer (mCRPC) who have progressed on chemotherapy and androgen receptor pathway inhibitors (ARPI) have limited treatment options, significant morbidity, and poor outcomes. Prostate-specific membrane antigen (PSMA)-directed radionuclide therapy (RNT) is emerging as an efficacious and well-tolerated therapy; however, disease progression is universal. Several ongoing RNT trials focus on combination strategies to improve efficacy and durability of treatment response, including combinations with ARPIs, chemotherapy, immunotherapy, and targeted therapies. Further, efforts are underway to expand the role of PSMA-directed RNT to earlier stages of disease including hormone-sensitive and localized prostate cancer. In this review, we discuss the rationale and ongoing RNT combination therapeutic trials in prostate cancer and summarize the efficacy and toxicity associated with RNT.

Pharmaceutical industry funding and chemotherapy trials for prostate cancer: A systematic review

IntroductionClinical trials are increasingly supported by industries while previous studies have shown that industry-supported studies have more favorable results than studies with other sources of funding. In the present study, we investigated the association of industrial funding on the results of clinical trials regarding chemotherapy in prostate cancer. MethodsA systematic literature search was performed in the Cochrane Library, MEDLINE, and EMBASE to identify clinical trials comparing chemotherapy with treatments such as hormone therapy, surgery, radiotherapy, and placebo in patients with metastatic or non-metastatic prostate cancer. Data were extracted by two reviewers on the financial resources and the positive or negative results of chemotherapy in each study. The quality of articles was evaluated and compared based on Cochrane Critical Appraisal Tool. The trials were divided into two groups; industry funded and those not funded by industry. Association of industry funding and positive outcome was presented as odds ratio. ResultsIn this study, out of the 91 studies, 80.2% were funded by pharmaceutical companies and 19.8% were funded by government agencies. The end result of 61.6% of the studies funded by pharmaceutical companies was an increase in survival due to chemotherapy, whereas only 27.8% of the studies sponsored by government agencies reported positive results (P-value=0.010). In fact, industry-funded trials more often presented statistically significant positive results for survival (OR: 4.17; CI, 1.34–12.99). In general, there was no significant difference in the degree of bias between the two groups. ConclusionAccording to this study, despite of the similar quality of studies funded by pharmaceutical companies and government agencies, positive results were more common in studies related to pharmaceutical companies. Therefore, this point should be taken into account when making a decision on the best treatment approach.

BLIMP1 and NR4A3 transcription factors reciprocally regulate antitumor CAR T cell stemness and exhaustion.

Chimeric antigen receptor (CAR) T cells have not induced meaningful clinical responses in solid tumors. Loss of T cell stemness, poor expansion capacity, and exhaustion during prolonged tumor antigen exposure are major causes of CAR T cell therapeutic resistance. Single-cell RNA-sequencing analysis of CAR T cells from a first-in-human trial in metastatic prostate cancer identified two independently validated cell states associated with antitumor potency or lack of efficacy. Low expression of PRDM1, encoding the BLIMP1 transcription factor, defined highly potent TCF7 [encoding T cell factor 1 (TCF1)]-expressing CD8+ CAR T cells, whereas enrichment of HAVCR2 [encoding T cell immunoglobulin and mucin-domain containing-3 (TIM-3)]-expressing CD8+ T cells with elevated PRDM1 was associated with poor outcomes. PRDM1 knockout promoted TCF7-dependent CAR T cell stemness and proliferation, resulting in marginally enhanced leukemia control in mice. However, in the setting of PRDM1 deficiency, a negative epigenetic feedback program of nuclear factor of activated T cells (NFAT)-driven T cell dysfunction was identified. This program was characterized by compensatory up-regulation of NR4A3 and other genes encoding exhaustion-related transcription factors that hampered T cell effector function in solid tumors. Dual knockout of PRDM1 and NR4A3 skewed CAR T cell phenotypes away from TIM-3+CD8+ and toward TCF1+CD8+ to counter exhaustion of tumor-infiltrating CAR T cells and improve antitumor responses, effects that were not achieved with PRDM1 and NR4A3 single knockout alone. These data underscore dual targeting of PRDM1 and NR4A3 as a promising approach to advance adoptive cell immuno-oncotherapy.

Centralization and prospective audit of cystectomy are necessary: a commentary on the case for centralization, supported by a contemporary series utilizing the ANZUP cystectomy database.

Bladder cancer (BC) outcomes are unacceptably poor. In Australia, BC survival is actually deteriorating. There is an urgent need to improve outcomes in BC patients, which requires a multipronged approach. One area deserving closer scrutiny is radical cystectomy. Audit is necessary to identify areas for improvement and without it, outcomes remain unknown. Evidence convincingly shows high-volume surgeons and centers improve cystectomy outcomes including overall survival, yet centralization has still not occurred. The Australia and New Zealand Urogenital and Prostate (ANZUP) Cancer Trials Group cystectomy database has been established to facilitate cystectomy audit in Australia and New Zealand. We present initial data from the ANZUP cystectomy database from a single high-volume center, discuss the benefits of centralization and its challenges in the Asia-Pacific context.

Reirradiation Options for Previously Irradiated Prostate cancer (RO-PIP): Feasibility study investigating toxicity outcomes following reirradiation with stereotactic body radiotherapy (SBRT) versus high-dose-rate brachytherapy (HDR-BT)

IntroductionRadiotherapy is the most common curative treatment for non-metastatic prostate cancer; however, up to 13% of patients will develop local recurrence within 10 years. Patients can undergo further and potentially...