[177Lu]Lu-PSMA-617 plus enzalutamide in patients with metastatic castration-resistant prostate cancer (ENZA-p): an open-label, multicentre, randomised, phase 2 trial.

BACKGROUND: Enzalutamide and lutetium-177 [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 both improve overall survival in patients with metastatic castration-resistant prostate cancer. Androgen and PSMA receptors have a close intracellular relationship, with data suggesting complementary benefit if targeted concurrently. In this study, we assessed the activity and safety of enzalutamide plus adaptive-dosed [177Lu]Lu-PSMA-617 versus enzalutamide alone as first-line treatment for metastatic castration-resistant prostate cancer. METHODS: ENZA-p was an open-label, randomised, controlled phase 2 trial done at 15 hospitals in Australia. Participants were men aged 18 years or older with metastatic castration-resistant prostate cancer not previously treated with docetaxel or androgen receptor pathway inhibitors for metastatic castration-resistant prostate cancer, gallium-68 [68Ga]Ga-PSMA-PET-CT (PSMA-PET-CT) positive disease, Eastern Cooperative Oncology Group performance status of 0-2, and at least two risk factors for early progression on enzalutamide. Participants were randomly assigned (1:1) by a centralised, web-based system using minimisation with a random component to stratify for study site, disease burden, use of early docetaxel, and previous treatment with abiraterone acetate. Patients were either given oral enzalutamide 160 mg daily alone or with adaptive-dosed (two or four doses) intravenous 7·5 GBq [177Lu]Lu-PSMA-617 every 6-8 weeks dependent on an interim PSMA-PET-CT (week 12). The primary endpoint was prostate-specific antigen (PSA) progression-free survival, defined as the interval from the date of randomisation to the date of first evidence of PSA progression, commencement of non-protocol anticancer therapy, or death. The analysis was done in the intention-to-treat population, using stratified Cox proportional hazards regression. This trial is registered with ClinicalTrials.gov, NCT04419402, and participant follow-up is ongoing. FINDINGS: 162 participants were randomly assigned between Aug 17, 2020, and July 26, 2022. 83 men were assigned to the enzalutamide plus [177Lu]Lu-PSMA-617 group, and 79 were assigned to the enzalutamide group. Median follow-up in this interim analysis was 20 months (IQR 18-21), with 32 (39%) of 83 patients in the enzalutamide plus [177Lu]Lu-PSMA-617 group and 16 (20%) of 79 patients in the enzalutamide group remaining on treatment at the data cutoff date. Median age was 71 years (IQR 64-76). Median PSA progression-free survival was 13·0 months (95% CI 11·0-17·0) in the enzalutamide plus [177Lu]Lu-PSMA-617 group and 7·8 months (95% CI 4·3-11·0) in the enzalutamide group (hazard ratio 0·43, 95% CI 0·29-0·63, p<0·0001). The most common adverse events (all grades) were fatigue (61 [75%] of 81 patients), nausea (38 [47%]), and dry mouth (32 [40%]) in the enzalutamide plus [177Lu]Lu-PSMA-617 group and fatigue (55 [70%] of 79), nausea (21 [27%]), and constipation (18 [23%]) in the enzalutamide group. Grade 3-5 adverse events occurred in 32 (40%) of 81 patients in the enzalutamide plus [177Lu]Lu-PSMA-617 group and 32 (41%) of 79 patients in the enzalutamide group. Grade 3 events that occurred only in the enzalutamide plus [177Lu]Lu-PSMA-617 group included anaemia (three [4%] of 81 participants) and decreased platelet count (one [1%] participant). No grade 4 or 5 events were attributed to treatment on central review in either group. INTERPRETATION: The addition of [177Lu]Lu-PSMA-617 to enzalutamide improved PSA progression-free survival providing evidence of enhanced anticancer activity in patients with metastatic castration-resistant prostate cancer with risk factors for early progression on enzalutamide and warrants further evaluation of the combination more broadly in metastatic prostate cancer. FUNDING: Prostate Cancer Research Alliance (Movember and Australian Federal Government), St Vincent's Clinic Foundation, GenesisCare, Roy Morgan Research, and Endocyte (a Novartis company).

Development of a Visually Calculated SUVmean (HIT Score) on Screening PSMA PET/CT to Predict Treatment Response to 177Lu-PSMA Therapy: Comparison with Quantitative SUVmean and Patient Outcomes.

177Lu-PSMA therapy is an effective treatment in patients with metastatic castration-resistant prostate cancer. SUVmean is a valuable screening biomarker to assess the suitability for 177Lu-PSMA therapy but requires quantitative software. This study aims to develop a simple, clinically applicable prostate-specific membrane antigen PET/CT score that encompasses the elements of SUVmean without requiring additional quantification. Methods: Datasets from ethics-approved trials of patients with metastatic castration-resistant prostate cancer after androgen receptor signaling inhibition and taxane chemotherapy (or unfit for taxane), who were treated with 177Lu-PSMA-617 and 177Lu-PSMA I&T with a pretreatment screening with 68Ga-PSMA-11 PET/CT, and clinical outcome data, including a prostate-specific antigen (PSA) 50% response rate (PSA50), PSA progression-free survival (PSA-PFS), and overall survival (OS), were included. The screening 68Ga-PSMA-11 PET/CT of all participants was analyzed both semiquantitatively and visually. Semiquantitative analysis was used to derive the SUVmean Visual analysis of the 68Ga-PSMA-11 PET/CT images involved a binary visual heterogeneity assessment (homogeneous or heterogeneous), allocating a tumor SUVmax range (<15, 15-29, 30-49, 50-79, or ≥80). A 4-category score incorporating both heterogeneity and intensity of tumors (HIT) was then developed as a combination of heterogeneity and intensity (SUVmax range). The SUVmax was less than 15 for score 1, 15-79 with heterogeneous intensity for score 2, 15-79 with homogeneous intensity for score 3, and 80 or greater for score 4. This score was evaluated according to clinical outcomes (PSA50, PSA-PFS, and OS) and compared with SUVmean Results: Data from 139 participants were analyzed. In total, 75 (54%) patients achieved a PSA50 with a median PSA-PFS of 5.5 mo (95% CI, 4.1-6.0 mo) and an OS of 13.5 mo (95% CI, 11.1-17.9 mo). SUVmean was associated with PSA50 and survival outcomes when analyzed as a continuous variable or as quartiles. The PSA50 for HIT scores 1-4 was 0%, 39%, 65%, and 76%, respectively. The HIT score was strongly related to PSA-PFS and OS (log-rank test, P < 0.001 and P = 0.002). The median PSA-PFS for HIT scores 1-4 was 1.0, 4.1, 6.0, and 8.5, respectively, and the median OS was 7.6, 12.0, 18.5, and 16.9 mo, respectively. Cohen κ between readers for the HIT score was 0.71. Conclusion: A prostate-specific membrane antigen PET/CT score incorporating HIT derived from tools on a standard PET workstation is comparable with quantitative SUVmean as a prognostic tool following 177Lu-PSMA therapy.

Circulating Tumour DNA Biomarkers Associated with Outcomes in Metastatic Prostate Cancer Treated with Lutetium-177-PSMA-617.

Background: Lutetium-177-prostate-specific membrane antigen- 617 (Lu-PSMA) is an effective therapy for metastatic castration-resistant prostate cancer (mCRPC). However, treatment responses are heterogeneous despite stringent positron emission tomography (PET)-based imaging selection criteria. Molecularly based biomarkers have potential to refine patient selection and optimise outcomes. Objective: To identify circulating tumour DNA (ctDNA) features associated with treatment outcomes for men treated with Lu-PSMA. Design setting and participants: ctDNA from men treated with Lu-PSMA in combination with idronoxil for progressive mCRPC were analysed using an 85-gene customised sequencing assay. ctDNA fractions, molecular profiles, and the presence of alterations in aggressive-variant prostate cancer (AVPC) genes were analysed at baseline, cycle 3 and at disease progression. Intervention: Men received Lu-PSMA with idronoxil every 6 wk for up to six cycles. Outcome measurements and statistical analysis: Baseline and exit PSMA and fluorodeoxyglucose PET/computed tomography (CT) imaging was conducted at baseline and study exit. Single-photon emission CT (SPECT) scans were performed 24 h after Lu-PSMA. Blood samples were collected at baseline,cycle 3 and at disease progression. Cox proportional-hazards models were used to assess associations and derive hazard ratios (HRs) and confidence intervals (CIs) for associations between molecular factors, imaging features, and clinical outcomes. Results and limitations: Sixty samples from 32 men were sequenced (32 at baseline, 24 at cycle 3, four from patients with disease progression); two samples (baseline, on-treatment) from one individual were excluded from analysis owing to poor quality of the baseline sequencing data. Alterations in AVPC genes were associated with shorter prostate-specific antigen (PSA) progression-free survival (PFS) and overall survival (OS) in univariate (HR 3.4, 95% CI 1.5-7.7; p = 0.0036; and HR 3.3, 95% CI 1.4-7.7; p = 0.0063, respectively) and multivariate analyses (HR 4.8, 95% CI 1.8-13; p = 0.0014; and HR 4.1, 95% CI 1.6-11; p = 0.004). Conclusions: ctDNA alterations in AVPC genes were associated with shorter PSA PFS and OS among men treated with Lu-PSMA and intermittent idronoxil. These candidate molecular biomarkers warrant further study to determine whether they have predictive value and potential to guide synergistic combination strategies to enhance outcomes for men treated with Lu-PSMA for mCRPC. Patient summary: Certain DNA/gene changes detected in the blood of men with advanced prostate cancer were associated with shorter benefit from lutetium PSMA, a targeted radioactive therapy. This information may be useful in determining which men may benefit most from this treatment, but additional research is needed.

The Tyr Phenomenon: A Hypocalcemic Response in High-Volume Treatment Responders to 177Lu-Prostate-Specific Membrane Antigen Therapy.

177Lu-prostate-specific membrane antigen (PSMA) is an effective treatment for metastatic castration-resistant prostate cancer. Rarer treatment-related adverse events have not yet been described. Methods: We present case reviews of 2 men with a marked hypocalcemic osteosclerotic response to 177Lu-PSMA-I&T therapy. A clinical dataset of 177Lu-PSMA-I&T therapy was evaluated to estimate the incidence and clinical association with hypocalcemia. Results: Forty-one of the 127 men (32%) had a serum calcium drop, and 6 (5%) developed clinical hypocalcemia during 177Lu-PSMA therapy. The baseline total tumor volume was significantly higher in those who developed hypocalcemia (median, 3,249 cm3 [interquartile range, 1,856-3,852] vs. 465 [interquartile range 135-1,172]; P = 0.002). The mean prostate-specific antigen response in those with hypocalcemia was 78% (SD, 24%). Conclusion: Hypocalcemia may occur in response to 177Lu-PSMA-I&T, particularly with both high-volume bone metastases and a significant prostate-specific antigen response, and may be severe, requiring corticosteroids. Further evaluation of 177Lu-PSMA-induced hypocalcemia is required to better understand mechanisms, optimal treatments, and repercussions from any subsequent osteosclerotic response.

Patient outcomes following a response biomarker-guided approach to treatment using 177Lu-PSMA-I&T in men with metastatic castrate-resistant prostate cancer (Re-SPECT).

Background: 177LuPSMA is an effective treatment in metastatic castrate-resistant prostate cancer with trials adopting a standardised dose interval. Adjusting treatment intervals utilising early response biomarkers may improve patient outcomes. Objective: This study evaluated progression-free survival (PFS) and overall survival (OS) based on treatment interval adjustment utilising 177LuPSMA 24-h SPECT/CT (177Lu-SPECT) and early prostate-specific antigen (PSA) response. Design: Retrospective analysis of a clinical 177Lu-PSMA-I&T treatment programme. Methods: In all, 125 men were treated with 6-weekly 177LuPSMA-I&T [median 3 cycles, interquartile range (IQR): 2-4], median dose 8.0 GBq [95% confidence interval (CI): 7.5-8.0]. Imaging screening involved 68GaPSMA-11 PET/diagnostic CT. 177Lu-SPECT/diagnostic CT was acquired following each therapy, and clinical assessments 3-weekly. Following dose 2 (week 6), a composite PSA and 177Lu-SPECT/CT imaging response [partial response (PR), stable disease (SD), and progressive disease (PD)] determined ongoing management. Response group (RG) 1 (marked reduction in PSA/imaging PR) break in treatment until subsequent PSA rise, then re-treatment. RG 2 (stable or reduced PSA and/or imaging SD) 6-weekly treatments until six doses, or no longer clinically benefitting. RG 3 (rise in PSA and/or imaging PD) recommended for an alternative treatment. Results: Overall PSA50% response rate (PSARR) was 60% (75/125), median PSA-PFS 6.1 months (95%CI: 5.5-6.7), and median OS 16.8 months (95%CI: 13.5-20.1). 35% (41/116) were classified as RG 1, 34% (39/116) RG 2, and 31% (36/116) RG 3. PSARRs by RG were 95% (38/41), 74% (29/39), and 8% (3/36); median PSA-PFS rates were 12.1 months (95%CI: 9.3-17.4), 6.1 months (95%CI: 5.8-9.0), and 2.6 months (95%CI: 1.6-3.1); and OS rates were 19.2 months (95%CI: 16.8-20.7), 13.2 months (95%CI: 12.0-18.8), and 11.2 months (95%CI: 8.7-15.6) for RG 1, 2, and 3, respectively. The median months of 'treatment holiday' for RG 1 was 6.1 months (IQR: 3.4-8.7). Nine men had received prior 177LuPSMA-617 and were retreated with 177LuPSMA-I&T, with a PSARR of 56% on re-treatment. Conclusion: Personalising dosing regimens using early response biomarkers with 177LuPSMA has the potential to achieve similar treatment responses to continuous dosing while allowing treatment breaks or intensification. Further evaluation of early response biomarker-guided treatment regimens in prospective trials is warranted. Plain Language Summary: Lutetium-PSMA therapy is a new therapy for metastatic prostate cancer that is well tolerated and effective. However, not all men respond equally, with some responding very well and others progressing early. Personalising treatments require tools that can accurately measure treatment responses, preferably early in the treatment course, so adjustments to treatment can be made. Lutetium-PSMA can measure tumour sites after each therapy by taking whole body 3D images at 24 h using a small radiation wave from the treatment itself. This is called a SPECT scan. Previous work has shown that both prostate-specific antigen (PSA) response and changes in tumour volume on a SPECT scan can predict how patients will respond to treatment as early as dose 2. This study demonstrates that stratifying how men are treated based on the results of the 6-week SPECT scan and PSA response potentially allows a third of men to have break in treatment and that these men have both longer time to disease progression and OS. Men with an increase in tumour volume and increase in PSA early in treatment (6 weeks) had shorter time to disease progression and OS. Men with early biomarker disease progression were offered alternative treatments early in an attempt to allow the opportunity to allow a more effective potential therapy, if one was available. The study is an analysis of a clinical programme, and was not a prospective trial. As such, there are potential biases that could influence results. Hence, while the study is encouraging for the use of early response biomarkers to guide better treatment decisions, this must be validated in a well-designed clinical trial.

The Prognostic Value of Posttreatment 68Ga-PSMA-11 PET/CT and 18F-FDG PET/CT in Metastatic Castration-Resistant Prostate Cancer Treated with 177Lu-PSMA-617 and NOX66 in a Phase I/II Trial (LuPIN).

177Lu-PSMA-617 therapy has shown high prostate-specific antigen (PSA) response rates in men with metastatic castration-resistant prostate cancer. However, early treatment resistance is common. This LuPIN substudy aimed to determine the prognostic value of posttreatment quantitative PET for PSA progression-free survival (PFS) and overall survival (OS) with 177Lu-PSMA-617 therapy. Methods: Fifty-six men with progressive metastatic castration-resistant prostate cancer were enrolled in the LuPIN trial and received up to 6 doses of 177Lu-PSMA-617 and a radiation sensitizer (NOX66). 68Ga-PSMA-11 and 18F-FDG PET/CT, diagnostic CT, and bone scanning were performed at study entry and exit. Quantitative analysis tracked change in total tumor volume (TTV) and SUV. Univariable and multivariable analyses were conducted to examine the association of change in TTV (continuous and >30%), SUVmax, PSA, and radiographic progression with PSA PFS and OS. Results: All men (37/56) who underwent both screening and posttreatment molecular imaging were analyzed; 70% (26/37) had a PSA response of more than 50%. Median PSA PFS was 8.6 mo, and median OS was 22 mo. Clinical progression had occurred at trial exit in 54% (20/37). In response to treatment, a reduced PSMA SUVmax was demonstrated in 95% (35/37) and a reduced PSMA TTV in 68% (25/37). An increase in PSMA TTV by at least 30% was associated with worse OS (median, 10.2 vs. 23.6 mo; P = 0.002). Change in PSMA SUVmax was not associated with PSA PFS or OS. 18F-FDG SUVmax was reduced in 51% (18/35) and 18F-FDG TTV in 67% (22/35). An increased 18F-FDG SUVmax was associated with worse OS (median, 20.7 vs. 25.7 mo; P < 0.01). An 18F-FDG TTV increase by more than 30% was associated with a short PSA PFS (median, 3.5 vs. 8.6 mo; P < 0.001) but not OS. Both PSA and radiographic progression were associated with shorter OS (median, 14.5 vs. 25.7 mo [P < 0.001] and 12.2 vs. 23.6 mo [P = 0.002]). On multivariable analysis, only increased PSMA TTV and PSA progression remained independently prognostic of OS (hazard ratio, 5.1 [95% CI, 1.5-17.1; P = 0.008] and 3.5 [95% CI, 1.1-10.9; P = 0.03], respectively). Conclusion: Change in quantitative PSMA TTV has strong potential as a prognostic biomarker with 177Lu-PSMA-617 therapy, independent of 18F-FDG PET parameters, PSA, or radiographic progression. Further research into the value of posttreatment PET as an imaging biomarker is warranted.

Evaluation of 177Lu-PSMA-617 SPECT/CT Quantitation as a Response Biomarker Within a Prospective 177Lu-PSMA-617 and NOX66 Combination Trial (LuPIN).

177Lu-PSMA-617 is an effective and novel treatment in metastatic castration-resistant prostate cancer (mCRPC). Our ability to assess response rates and therefore efficacy may be improved using predictive tools. This study investigated the predictive value of serial 177Lu-PSMA-617 SPECT/CT (177Lu SPECT) imaging in monitoring treatment response. Methods: Fifty-six men with progressive mCRPC previously treated with chemotherapy and novel androgen signaling inhibitor were enrolled into the LuPIN trial and received up to 6 doses of 177Lu-PSMA-617 and a radiation sensitizer (3-(4-hydroxyphenyl)-2H-1-benzopyran-7-ol [NOX66]). 68Ga-PSMA-11 and 18F-FDG PET/CT were performed at study entry and exit, and 177Lu SPECT from vertex to mid thighs was performed 24 h after each treatment. SPECT quantitative analysis was undertaken at cycles 1 (baseline) and 3 (week 12) of treatment. Results: Thirty-two of the 56 men had analyzable serial 177Lu SPECT imaging at both cycle 1 and cycle 3. In this subgroup, median prostate-specific antigen (PSA) progression-free survival (PFS) was 6.3 mo (95% CI, 5-10 mo) and median overall survival was 12.3 mo (95% CI, 12-24 mo). The PSA 50% response rate was 63% (20/32). 177Lu SPECT total tumor volume (SPECT TTV) was reduced in 68% (22/32; median, -0.20 m3 [95% CI, -1.4 to -0.001]) and increased in 31% (10/32; median, 0.36 [95% CI, 0.1-1.4]). Any increase in SPECT TTV was associated with shorter PSA PFS (hazard ratio, 4.1 [95% CI, 1.5-11.2]; P = 0.006). An increase of 30% or more in SPECT TTV was also associated with a shorter PSA PFS (hazard ratio, 3.3 [95% CI, 1.3-8.6]; P =0.02). Tumoral SUVmax was reduced in 91% (29/32) and SUVmean in 84% (27/32); neither was associated with PSA PFS or overall survival outcomes. PSA progression by week 12 was also associated with a shorter PSA PFS (hazard ratio, 26.5 [95% CI, 5.4-131]). In the patients with SPECT TTV progression at week 12, 50% (5/10) had no concurrent PSA progression (median PSA PFS, 4.5 mo [95% CI, 2.8-5.6 mo]), and 5 of 10 men had both PSA and SPECT TTV progression at week 12 (median PSA PFS, 2.8 mo [95% CI, 1.8-3.7 mo]). Conclusion: Increasing SPECT TTV on quantitative 177Lu SPECT predicts a short PFS and may play a future role as an imaging response biomarker.

177Lu-PSMA SPECT Quantitation at 6 Weeks (Dose 2) Predicts Short Progression-Free Survival for Patients Undergoing 177Lu-PSMA-I&T Therapy.

177Lu-PSMA is an effective treatment in metastatic castration-resistant prostate cancer (mCRPC). Our ability to assess response rates and adjust treatment may be improved using predictive tools. This study aimed to evaluate change in 177Lu-PSMA SPECT quantitative parameters to monitor treatment response. Methods: One hundred twenty-seven men with progressive mCRPC previously treated with androgen-signaling inhibition (99%) and chemotherapy (71%) received a median of 3 (interquartile range [IQR], 2-5) 8-GBq (IQR, 8-8.5 GBq) doses of 177Lu-PSMA-I&T. Imaging included 68Ga-PSMA-11 PET/CT (SUVmax > 15 at a single site and > 10 at all sites > 2 cm), diagnostic CT, and 177Lu SPECT/CT from vertex to mid thigh (24 h after treatment). 177Lu SPECT/CT quantitative analysis was undertaken at cycles 1 (baseline) and 2 (week 6) of treatment. Clinical and biochemical results were assessed to evaluate prostate-specific antigen (PSA) progression-free survival (PFS) and overall survival (OS). Results: A PSA reduction of more than 50% was seen in 58% (74/127). The median PSA PFS was 6.1 mo (95% CI, 5.5-6.7), and OS was 16.8 mo (95% CI, 13.5-20.1). At the time of analysis, 41% (52/127) were deceased. At baseline and week 6, 76% (96/127) had analyzable serial 177Lu SPECT/CT imaging. SPECT total tumor volume (TTV) was reduced between baseline and week 6 in 74% (71/96; median, -193; IQR, -486 to -41). Any increase in SPECT TTV between baseline and week 6 was associated with significantly shorter PSA PFS (hazard ratio, 2.5; 95% CI, 1.5-4.2; P = 0.0008) but not OS. Median PSA PFS in those with an increase in SPECT TTV was 3.7 mo (95% CI, 2.8-6.8), compared with 6.7 mo (95% CI, 5.8-10.6) in those with no increase in SPECT TTV. An increase in SPECT TTV greater than 20% was also associated with PSA PFS (hazard ratio, 1.9; 95% CI, 1.2-3.0; P = 0.008) but less significantly than any change in SPECT TTV. There was a significant difference in PSA PFS between patients with both increased PSA and SPECT TTV and patients with reduced SPECT TTV and PSA (median, 2.8 vs. 9.0 mo; P < 0.0001). Conclusion: Increasing PSMA SPECT TTV on quantitative 177Lu SPECT/CT predicts short progression-free survival and may play a future role as an imaging response biomarker, identifying when to cease or intensify 177Lu-PSMA therapy.

The cell-free DNA methylome captures distinctions between localized and metastatic prostate tumors.

Metastatic prostate cancer remains a major clinical challenge and metastatic lesions are highly heterogeneous and difficult to biopsy. Liquid biopsy provides opportunities to gain insights into the underlying biology. Here, using the highly sensitive enrichment-based sequencing technology, we provide analysis of 60 and 175 plasma DNA methylomes from patients with localized and metastatic prostate cancer, respectively. We show that the cell-free DNA methylome can capture variations beyond the tumor. A global hypermethylation in metastatic samples is observed, coupled with hypomethylation in the pericentromeric regions. Hypermethylation at the promoter of a glucocorticoid receptor gene NR3C1 is associated with a decreased immune signature. The cell-free DNA methylome is reflective of clinical outcomes and can distinguish different disease types with 0.989 prediction accuracy. Finally, we show the ability of predicting copy number alterations from the data, providing opportunities for joint genetic and epigenetic analysis on limited biological samples.

Expansion of Lymphocytes from Prostatic Adenocarcinoma and Adjacent Nonmalignant Tissue.

Background: The evaluation of tumour-infiltrating lymphocytes (TILs) in solid malignancies has yielded insights into immune regulation within the tumour microenvironment and has also led to the development and optimisation of adoptive T cell therapies. Objectives: This study examined the in vitro expansion of TILs from prostate adenocarcinoma, as a preliminary step to evaluate the potential of TILs for adoptive T cell therapy. Design, Setting, and Participants. Malignant and adjacent nonmalignant tissues were obtained from fifteen men undergoing radical prostatectomy. Interventions. There were no study interventions. Outcome Measurements and Statistical Analysis. Expanded cells were analysed by flow cytometry, and the data was assessed for associations between cell subpopulations and expansion rate. Results: Tumour-infiltrating lymphocytes could be expanded to numbers that would be needed to generate a therapeutic infusion product from nine of 15 malignant specimens (60%). The CD4+ T cells predominated over CD8+ T cells (median 56.8% CD4+, 30.0% CD8+), and furthermore, faster TIL expansion was associated with a higher proportion of CD4+ T cells (median 69.8% in faster-growing cultures; 36.8% in slower-growing cultures). A higher proportion of CD3-CD56+ cells versus CD3+ cells was associated with slower TIL expansion in cultures from malignant specimens (median 13.3% in slower-growing cultures versus 2.05% in faster-growing cultures), but not from nonmalignant specimens. Conclusions: The expansion of TILs for potential therapeutic use is feasible. Our findings also indicate that further examination of TILs from prostate adenocarcinomas may yield insights into mechanisms of regulation of T cells within the tumour microenvironment. Further research is required to evaluate their therapeutic potential.

Statin and metformin use and outcomes in patients with castration-resistant prostate cancer treated with enzalutamide: A meta-analysis of AFFIRM, PREVAIL and PROSPER.

BACKGROUND: Statins and metformin are commonly prescribed for patients, including those with prostate cancer. Preclinical and epidemiologic studies of each agent have suggested anti-cancer properties. METHODS: Patient data from three randomised, double-blind, placebo-controlled, phase III studies evaluating enzalutamide (AFFIRM, PREVAIL and PROSPER) in patients with castration-resistant prostate cancer were included in this analysis. This post hoc, retrospective study examined the association of statin and metformin on radiographic progression-free survival (rPFS), metastasis-free survival (MFS), toxicity and overall survival (OS). After adjusting for available clinical prognostic variables, multivariate analyses were performed on pooled data from AFFIRM and PREVAIL, all three trials pooled, and each trial individually, to assess differential efficacy in these end-points associated with the baseline use of these medications. RESULTS: In the multivariate analysis of the individual trials, OS and rPFS/MFS were not significantly influenced by statin or metformin use in AFFIRM or PROSPER. However, in PREVAIL, OS was significantly influenced by statin (hazard ratio [HR] 0.72; 95% confidence interval [CI] 0.59-0.89) and rPFS was significantly influenced by metformin (HR, 0.48; 95% CI 0.34-0.70). In pooled analyses, improved OS was significantly associated with statin use but not metformin use for AFFIRM+PREVAIL trials (HR 0.83; 95% CI 0.72-0.96) and AFFIRM+PREVAIL+PROSPER (HR 0.75; 95% CI 0.66-0.85). CONCLUSIONS: The association between statin or metformin use and rPFS, MFS and OS was inconsistent across three trials. Analyses of all three trials pooled and AFFIRM+PREVAIL pooled revealed that statin but not metformin use was significantly associated with a reduced risk of death in enzalutamide-treated patients. Additional prospective, controlled studies are warranted. CLINICAL TRIAL REGISTRATION: AFFIRM (NCT00974311), PREVAIL (NCT01212991) and PROSPER (NCT02003924).

GUIDE: a randomised non-comparative phase II trial of biomarker-driven intermittent docetaxel versus standard-of-care docetaxel in metastatic castration-resistant prostate cancer (clinical trial protocol).

Objective: To determine the efficacy and safety of intermittent docetaxel chemotherapy guided by circulating methylated glutathione S-transferase Pi-1 (mGSTP1) in men with metastatic castration-resistant prostate cancer (CRPC). Patients and Methods: GUIDE (NCT04918810) is a randomised, two-arm, non-comparative phase-2 trial recruiting 120 patients at six Australian centres. Patients with Prostate Cancer Working Group-3 defined metastatic CRPC who are commencing docetaxel 75 mg/m2 q3w will be pre-screened for detectable mGSTP1 at baseline ± following two cycles of treatment. Those with detectable plasma mGSTP1 at baseline that becomes undetectable after two cycles of chemotherapy will be eligible for GUIDE. Prior to Cycle 4 of docetaxel, these patients are randomised 2:1 to one of two treatment arms: Arm A (cease docetaxel and reinstitute if mGSTP1 becomes detectable) or Arm B (continue docetaxel 75 mg/m2 q3w in accordance with clinician's usual practice). The primary endpoint is radiographic progression-free survival. Secondary endpoints include time on treatment holidays, safety, patient-reported outcomes, overall survival, health resource use, and cost associated with treatment. Enrolment commenced November 2021. Results and Conclusion: The results of this trial will generate data on the clinical utility of mGSTP1 as a novel biomarker to guide treatment de-escalation in metastatic CRPC.

Combined impact of lipidomic and genetic aberrations on clinical outcomes in metastatic castration-resistant prostate cancer.

BACKGROUND: Both changes in circulating lipids represented by a validated poor prognostic 3-lipid signature (3LS) and somatic tumour genetic aberrations are individually associated with worse clinical outcomes in men with metastatic castration-resistant prostate cancer (mCRPC). A key question is how the lipid environment and the cancer genome are interrelated in order to exploit this therapeutically. We assessed the association between the poor prognostic 3-lipid signature (3LS), somatic genetic aberrations and clinical outcomes in mCRPC. METHODS: We performed plasma lipidomic analysis and cell-free DNA (cfDNA) sequencing on 106 men with mCRPC commencing docetaxel, cabazitaxel, abiraterone or enzalutamide (discovery cohort) and 94 men with mCRPC commencing docetaxel (validation cohort). Differences in lipid levels between men ± somatic genetic aberrations were assessed with t-tests. Associations between the 3LS and genetic aberrations with overall survival (OS) were examined using Kaplan-Meier methods and Cox proportional hazard models. RESULTS: The 3LS was associated with shorter OS in the discovery (hazard ratio [HR] 2.15, 95% confidence interval [CI] 1.4-3.3, p < 0.001) and validation cohorts (HR 2.32, 95% CI 1.59-3.38, p < 0.001). Elevated plasma sphingolipids were associated with AR, TP53, RB1 and PI3K aberrations (p < 0.05). Men with both the 3LS and aberrations in AR, TP53, RB1 or PI3K had shorter OS than men with neither in both cohorts (p ≤ 0.001). The presence of 3LS and/or genetic aberration was independently associated with shorter OS for men with AR, TP53, RB1 and PI3K aberrations (p < 0.02). Furthermore, aggressive-variant prostate cancer (AVPC), defined as 2 or more aberrations in TP53, RB1 and/or PTEN, was associated with elevated sphingolipids. The combination of AVPC and 3LS predicted for a median survival of ~12 months. The relatively small sample size of the cohorts limits clinical applicability and warrants future studies. CONCLUSIONS: Elevated circulating sphingolipids were associated with AR, TP53, RB1, PI3K and AVPC aberrations in mCRPC, and the combination of lipid and genetic abnormalities conferred a worse prognosis. These findings suggest that certain genotypes in mCRPC may benefit from metabolic therapies.

Patterns of care and outcomes of men with germ cell tumors in a high-volume Australian center.

AIM: To evaluate disease presentation, treatment practices, and outcomes of patients with germ cell tumor (GCT) treated in a high-volume cancer center in Australia. METHODS: This is a retrospective analysis of 609 patients diagnosed with GCT in the Sydney West Cancer Network between 1990 and 2013. Cause and date of death, and second malignancy information was sourced from The Centre for Health Record Linkage. RESULTS: The median age was 33 years (range, 14-85). Primary site was testis in 590 (96.9%), mediastinum in nine (1.5%), and retroperitoneum in nine (1.5%). History of undescended testis was present in 48 (7.9%). Pure seminoma was seen in 334 (54.8%), with 274 (82.0%) being stage I. There was a decline in use of adjuvant radiotherapy from 83% in 1990-1997 to 29% in 2006-2013. Nonseminoma GCT (NSGCT) was diagnosed in 275 (45.2%), with 162 (58.9%) being stage 1. Active surveillance has increased as the initial treatment, from 58% between 1990 and 1997 to 89% between 2006 and 2013. Metastatic disease at presentation was seen in 162 (26.6%): 55 (34.0%) seminoma and 107 (66.0%) NSGCT. With median of 15-year follow-up, 18 (3.0%) have died from GCT and 70 (11.5%) from all causes. Ten-year overall survival was 93% and GCT-specific survival was 97%. Forty patients developed a secondary malignancy, with 38 receiving chemotherapy, radiotherapy, or both. CONCLUSIONS: This large Australian series illustrates a changing pattern of care and outcomes and compares them favorably with other series. This serves as a basis for future comparison of outcomes for this malignancy.

Vigilance for carcinoid heart disease is still required in the era of somatostatin analogues: Lessons from a case series.

AIM: Carcinoid heart disease (CHD) is a well-documented complication of neuroendocrine tumors (NETs) due to secreted hormones causing fibrosis. Somatostatin analogues (SSAs) can decrease hormonal secretion and inhibit tumor growth. The reported incidence of CHD has decreased as SSA use has increased. We describe a series of patients who have developed CHD even though they were treated with SSA therapy. METHODS: Nine patients were seen in four centers in Australia and New Zealand. The average duration of follow-up from diagnosis was 39 months. RESULTS: Three patients had Grade 1 and six Grade 2 disease by World Health Organization 2010 criteria. All patients had no CHD symptoms at baseline and started SSA therapy soon after diagnosis, yet developed significant, symptomatic cardiac dysfunction in their disease course. The median time from NET diagnosis to SSA initiation was 1 month, and median time from NET diagnosis to CHD diagnosis was 23 months (range 4-52). All patients who were tested had persistently increased hormonal levels (chromogranin A, urinary 5-hydroxyindolacetic acid). CONCLUSIONS: The good symptomatic control afforded by SSAs should not lead to reduced vigilance in screening for CHD, especially in patients with persistently elevated hormonal assays. Clinicians should consider regular echocardiographic screening in patients with a secretory syndrome.

177Lu-PSMA-617 and Idronoxil in Men with End-Stage Metastatic Castration-Resistant Prostate Cancer (LuPIN): Patient Outcomes and Predictors of Treatment Response in a Phase I/II Trial.

177Lu-PSMA-617 is an effective therapy for metastatic castration-resistant prostate cancer (mCRPC). However, treatment resistance occurs frequently, and combination therapies may improve outcomes. We report the final safety and efficacy results of a phase I/II study combining 177Lu-PSMA-617 with idronoxil (NOX66), a radiosensitizer, and examine potential clinical, blood-based, and imaging biomarkers. Methods: Fifty-six men with progressive mCRPC previously treated with taxane chemotherapy and novel androgen signaling inhibitor (ASI) were enrolled. Patients received up to 6 doses of 177Lu-PSMA-617 (7.5 GBq) on day 1 in combination with a NOX66 suppository on days 1-10 of each 6-wk cycle. Cohort 1 (n = 8) received 400 mg of NOX66, cohort 2 (n = 24) received 800 mg, and cohort 3 (n = 24) received 1,200 mg. 68Ga-PSMA and 18F-FDG PET/CT were performed at study entry, and semiquantitative imaging analysis was undertaken. Blood samples were collected for analysis of blood-based biomarkers, including androgen receptor splice variant 7 expression. The primary outcomes were safety and tolerability; secondary outcomes included efficacy, pain scores, and xerostomia. Regression analyses were performed to explore the prognostic value of baseline clinical, blood-based, and imaging parameters. Results: Fifty-six of the 100 men screened were enrolled (56%), with a screening failure rate of 26% (26/100) for PET imaging criteria. All men had received prior treatment with ASI and docetaxel, and 95% (53/56) had received cabazitaxel. Ninety-six percent (54/56) of patients received at least 2 cycles of combination NOX66 and 177Lu-PSMA-617, and 46% (26/56) completed 6 cycles. Common adverse events were anemia, fatigue, and xerostomia. Anal irritation attributable to NOX66 occurred in 38%. Forty-eight of 56 had a reduction in prostate-specific antigen (PSA) level (86%; 95% CI, 74%-94%); 34 of 56 (61%; 95% CI, 47%-74%) had a PSA reduction of at least 50%. Median PSA progression-free survival was 7.5 mo (95% CI, 5.9-9 mo), and median overall survival was 19.7 mo (95% CI, 9.5-30 mo). A higher PSMA SUVmean correlated with treatment response, whereas a higher PSMA tumor volume and prior treatment with ASI for less than 12 mo were associated with worse overall survival. Conclusion: NOX66 with 177Lu-PSMA-617 is a safe and feasible strategy in men being treated with third-line therapy and beyond for mCRPC. PSMA SUVmean, PSMA-avid tumor volume, and duration of treatment with ASI were independently associated with outcome.

Relationship between Circulating Lipids and Cytokines in Metastatic Castration-Resistant Prostate Cancer.

Circulating lipids or cytokines are associated with prognosis in metastatic castration-resistant prostate cancer (mCRPC). This study aimed to understand the interactions between lipid metabolism and immune response in mCRPC by investigating the relationship between the plasma lipidome and cytokines. Plasma samples from two independent cohorts of men with mCRPC (n = 146, 139) having life-prolonging treatments were subjected to lipidomic and cytokine profiling (290, 763 lipids; 40 cytokines). Higher baseline levels of sphingolipids, including ceramides, were consistently associated with shorter overall survival in both cohorts, whereas the associations of cytokines with overall survival were inconsistent. Increasing levels of IL6, IL8, CXCL16, MPIF1, and YKL40 correlated with increasing levels of ceramide in both cohorts. Men with a poor prognostic 3-lipid signature at baseline had a shorter time to radiographic progression (poorer treatment response) if their lipid profile at progression was similar to that at baseline, or their cytokine profile at progression differed to that at baseline. In conclusion, baseline levels of circulating lipids were more consistent as prognostic biomarkers than cytokines. The correlation between circulating ceramides and cytokines suggests the regulation of immune responses by ceramides. The association of treatment response with the change in lipid profiles warrants further research into metabolic interventions.

Overcoming enzalutamide resistance in metastatic prostate cancer by targeting sphingosine kinase.

BACKGROUND: Intrinsic resistance to androgen receptor signalling inhibitors (ARSI) occurs in 20-30% of men with metastatic castration-resistant prostate cancer (mCRPC). Ceramide metabolism may have a role in ARSI resistance. Our study's aim is to investigate the association of the ceramide-sphingosine-1-phosphate (ceramide-S1P) signalling axis with ARSI resistance in mCRPC. METHODS: Lipidomic analysis (∼700 lipids) was performed on plasma collected from 132 men with mCRPC, before commencing enzalutamide or abiraterone. AR gene aberrations in 77 of these men were identified by deep sequencing of circulating tumour DNA. Associations between circulating lipids, radiological progression-free survival (rPFS) and overall survival (OS) were examined by Cox regression. Inhibition of ceramide-S1P signalling with sphingosine kinase (SPHK) inhibitors (PF-543 and ABC294640) on enzalutamide efficacy was investigated with in vitro assays, and transcriptomic and lipidomic analyses of prostate cancer (PC) cell lines (LNCaP, C42B, 22Rv1). FINDINGS: Men with elevated circulating ceramide levels had shorter rPFS (HR=2·3, 95% CI=1·5-3·6, p = 0·0004) and shorter OS (HR=2·3, 95% CI=1·4-36, p = 0·0005). The combined presence of an AR aberration with elevated ceramide levels conferred a worse prognosis than the presence of only one or none of these characteristics (median rPFS time = 3·9 vs 8·3 vs 17·7 months; median OS time = 8·9 vs 19·8 vs 34·4 months). SPHK inhibitors enhanced enzalutamide efficacy in PC cell lines. Transcriptomic and lipidomic analyses indicated that enzalutamide combined with SPHK inhibition enhanced PC cell death by SREBP-induced lipotoxicity. INTERPRETATION: Ceramide-S1P signalling promotes ARSI resistance, which can be reversed with SPHK inhibitors. FUNDING: None.