Sequential [177Lu]Lu-PSMA-617 and docetaxel versus docetaxel in patients with metastatic hormone-sensitive prostate cancer (UpFrontPSMA): a multicentre, open-label, randomised, phase 2 study.

BACKGROUND: Lutetium-177 [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 improves survival and quality of life in patients with metastatic castration-resistant prostate cancer, but whether it confers a benefit in hormone-sensitive disease is unknown. We aimed to evaluate [177Lu]Lu-PSMA-617 before docetaxel treatment in patients with de-novo high-volume metastatic hormone-sensitive prostate cancer. METHODS: UpFrontPSMA was an investigator-initiated, multicentre, open-label, randomised, phase 2 trial done at 11 Australian hospitals. Eligible patients had prostate adenocarcinoma without clinically significant neuroendocrine differentiation or small-cell histology, were aged 18 years or older, had less than 4 weeks on androgen deprivation therapy, had an Eastern Cooperative Oncology Group performance status of 0-2, and had high-volume PSMA-avid disease on [68Ga]Ga-PSMA-11 PET-CT with no major discordance on 2-[18F] fluorodeoxyglucose-PET-CT. Patients were randomly assigned (1:1) to the experimental treatment ([177Lu]Lu-PSMA-617 followed 6 weeks later by docetaxel) or standard-of-care treatment (docetaxel alone) using computer-based block randomisation with random block sizes, stratified by disease volume by conventional imaging and duration of androgen deprivation therapy at the time of registration. Neither patients nor investigators were masked to treatment assignment. Patients in the experimental group received two cycles of [177Lu]Lu-PSMA-617 7·5 GBq every 6 weeks intravenously, followed 6 weeks later by six cycles of docetaxel 75 mg/m2 every 3 weeks intravenously, whereas patients in the standard-of-care treatment group received six cycles of docetaxel 75 mg/m2 every 3 weeks intravenously. All patients received continuous androgen deprivation therapy. The primary endpoint was undetectable prostate-specific antigen (≤0·2 ng/mL) at 48 weeks, assessed using a modified intention-to-treat analysis. The trial is registered with ClinicalTrials.gov, NCT04343885. FINDINGS: Between May 5, 2020, and April 18, 2023, 130 patients were randomly assigned, 63 (48%) to [177Lu]Lu-PSMA-617 plus docetaxel and 67 (52%) to docetaxel alone. All patients were male and no race or ethnicity data were collected. Median follow-up was 2·5 years (IQR 1·8-3·0). Four patients in the docetaxel alone group withdrew consent after randomisation and no data beyond screening were collected. An additional four patients were not evaluable for the primary endpoint at 48 weeks (two in each group). 25 (41%) of 61 patients (95% CI 30-54) in the [177Lu]Lu-PSMA-617 plus docetaxel group had undetectable PSA at 48 weeks compared with ten (16%) of 61 patients (9-28) in the docetaxel alone group (OR 3·88, 95% CI 1·61-9·38; p=0·0020). The most common grade 3 or 4 treatment-related adverse events were febrile neutropenia (seven [11%] of 63 patients in the [177Lu]Lu-PSMA-617 plus docetaxel group vs six [10%] of 63 patients in the docetaxel alone group) and diarrhoea (four [6%] of 63 patients vs none). Serious adverse events occurred in 16 (25%) patients in the [177Lu]Lu-PSMA-617 plus docetaxel group (none were definitely related to [177Lu]Lu-PSMA-617) and 16 (25%) patients in the docetaxel alone group. No treatment-related deaths occurred. INTERPRETATION: [177Lu]Lu-PSMA-617 followed by docetaxel improved antitumour activity in patients with de-novo high-volume metastatic hormone-sensitive prostate cancer compared with docetaxel alone, without increased toxic effects. Our data potentially support a role for [177Lu]Lu-PSMA-617 in metastatic hormone-sensitive prostate cancer. FUNDING: Prostate Cancer Research Alliance (Movember Foundation and Australian Government Medical Research Future Fund), US Department of Defence Impact Award-Clinical Trials, Endocyte/Advanced Accelerator Applications (a Novartis company), Australian Nuclear Science and Technology Organization, Victorian Cancer Agency, University of Melbourne, and Peter MacCallum Cancer Foundation.

Overall survival with [177Lu]Lu-PSMA-617 versus cabazitaxel in metastatic castration-resistant prostate cancer (TheraP): secondary outcomes of a randomised, open-label, phase 2 trial.

BACKGROUND: The TheraP study reported improved prostate-specific antigen responses with lutetium-177 [177Lu]Lu-PSMA-617 versus cabazitaxel in men with metastatic castration-resistant prostate cancer progressing after docetaxel. In this Article, we report the secondary outcome of overall survival with mature follow-up, and an updated imaging biomarker analysis. We also report the outcomes of participants excluded due to ineligibility on gallium-68 [68Ga]Ga-PSMA-11 and 2-[18F]fluoro-2-deoxy-D-glucose (2-[18F]FDG) PET-CT. METHODS: TheraP was an open-label, randomised phase 2 trial at 11 centres in Australia. Eligible participants had metastatic castration-resistant prostate cancer progressing after docetaxel, and PET imaging with [68Ga]Ga-PSMA-11 and 2-[18F]FDG that showed prostate-specific membrane antigen (PSMA)-positive disease and no sites of metastatic disease with discordant 2-[18F]FDG-positive and PSMA-negative findings. Participants were randomly assigned (1:1) to treatment with [177Lu]Lu-PSMA-617 (every 6 weeks for a maximum of six cycles; starting at 8·5 GBq, decreasing by 0.5 GBq to 6·0 GBq for the sixth cycle) versus cabazitaxel (20 mg/m2 every 3 weeks, maximum of ten cycles). Overall survival was analysed by intention-to-treat and summarised as restricted mean survival time (RMST) to account for non-proportional hazards, with a 36-month restriction time corresponding to median follow-up. This trial is registered with ClinicalTrials.gov, NCT03392428, and is complete. FINDINGS: 291 men were registered from Feb 6, 2018, to Sept 3, 2019; after study imaging, 200 were eligible and randomly assigned to treatment with [177Lu]Lu-PSMA-617 (n=99) or cabazitaxel (n=101). After completing study treatment, 20 (20%) participants assigned to cabazitaxel and 32 (32%) assigned to [177Lu]Lu-PSMA-617 were subsequently treated with the alternative regimen. After a median follow-up of 35·7 months (IQR 31·1 to 39·2), 77 (78%) participants had died in the [177Lu]Lu-PSMA-617 group and 70 (69%) participants had died in the cabazitaxel group. Overall survival was similar among those assigned to [177Lu]Lu-PSMA-617 versus those assigned to cabazitaxel (RMST 19·1 months [95% CI 16·9 to 21·4] vs 19·6 months [17·4 to 21·8]; difference -0·5 months [95% CI -3·7 to 2·7]; p=0·77). No additional safety signals were identified with the longer follow-up in this analysis. 80 (27%) of 291 men who were registered after initial eligibility screening were excluded after [68Ga]Ga-PSMA-11 and 2-[18F]FDG PET. In the 61 of these men with follow-up available, RMST was 11·0 months (95% CI 9·0 to 13·1). INTERPRETATION: These results support the use of [177Lu]Lu-PSMA-617 as an alternative to cabazitaxel for PSMA-positive metastatic castration-resistant prostate cancer progressing after docetaxel. We did not find evidence that overall survival differed between the randomised groups. Median overall survival was shorter for men who were excluded because of low PSMA expression or 2-[18F]FDG-discordant disease. FUNDING: Australian and New Zealand Urogenital and Prostate Cancer Trials Group, Prostate Cancer Foundation of Australia, Endocyte (a Novartis company), Australian Nuclear Science and Technology Organization, Movember, It's a Bloke Thing, CAN4CANCER, and The Distinguished Gentleman's Ride.

Talazoparib plus enzalutamide in men with first-line metastatic castration-resistant prostate cancer (TALAPRO-2): a randomised, placebo-controlled, phase 3 trial.

BACKGROUND: Co-inhibition of poly(ADP-ribose) polymerase (PARP) and androgen receptor activity might result in antitumour efficacy irrespective of alterations in DNA damage repair genes involved in homologous recombination repair (HRR). We aimed to compare the efficacy and safety of talazoparib (a PARP inhibitor) plus enzalutamide (an androgen receptor blocker) versus enzalutamide alone in patients with metastatic castration-resistant prostate cancer (mCRPC). METHODS: TALAPRO-2 is a randomised, double-blind, phase 3 trial of talazoparib plus enzalutamide versus placebo plus enzalutamide as first-line therapy in men (age ≥18 years [≥20 years in Japan]) with asymptomatic or mildly symptomatic mCRPC receiving ongoing androgen deprivation therapy. Patients were enrolled from 223 hospitals, cancer centres, and medical centres in 26 countries in North America, Europe, Israel, South America, South Africa, and the Asia-Pacific region. Patients were prospectively assessed for HRR gene alterations in tumour tissue and randomly assigned (1:1) to talazoparib 0·5 mg or placebo, plus enzalutamide 160 mg, administered orally once daily. Randomisation was stratified by HRR gene alteration status (deficient vs non-deficient or unknown) and previous treatment with life-prolonging therapy (docetaxel or abiraterone, or both: yes vs no) in the castration-sensitive setting. The sponsor, patients, and investigators were masked to talazoparib or placebo, while enzalutamide was open-label. The primary endpoint was radiographic progression-free survival (rPFS) by blinded independent central review, evaluated in the intention-to-treat population. Safety was evaluated in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov (NCT03395197) and is ongoing. FINDINGS: Between Jan 7, 2019, and Sept 17, 2020, 805 patients were enrolled and randomly assigned (402 to the talazoparib group and 403 to the placebo group). Median follow-up for rPFS was 24·9 months (IQR 21·9-30·2) for the talazoparib group and 24·6 months (14·4-30·2) for the placebo group. At the planned primary analysis, median rPFS was not reached (95% CI 27·5 months-not reached) for talazoparib plus enzalutamide and 21·9 months (16·6-25·1) for placebo plus enzalutamide (hazard ratio 0·63; 95% CI 0·51-0·78; p<0·0001). In the talazoparib group, the most common treatment-emergent adverse events were anaemia, neutropenia, and fatigue; the most common grade 3-4 event was anaemia (185 [46%] of 398 patients), which improved after dose reduction, and only 33 (8%) of 398 patients discontinued talazoparib due to anaemia. Treatment-related deaths occurred in no patients in the talazoparib group and two patients (<1%) in the placebo group. INTERPRETATION: Talazoparib plus enzalutamide resulted in clinically meaningful and statistically significant improvement in rPFS versus standard of care enzalutamide as first-line treatment for patients with mCRPC. Final overall survival data and additional long-term safety follow-up will further clarify the clinical benefit of the treatment combination in patients with and without tumour HRR gene alterations. FUNDING: Pfizer.

Enzalutamide in metastatic hormone-sensitive prostate cancer: A plain language summary of the ARCHES and ENZAMET follow-up studies.

WHAT IS THIS SUMMARY ABOUT?: This summary includes information from the ARCHES and ENZAMET follow-up studies. Both studies looked at enzalutamide treatment for people with metastatic hormone-sensitive prostate cancer (known as mHSPC). In ARCHES, researchers compared the medications enzalutamide + androgen deprivation therapy (known as ADT) with placebo + ADT. In ENZAMET, researchers compared enzalutamide + ADT with standard treatment + ADT. Some people in ENZAMET also took enzalutamide with docetaxel (a chemotherapy treatment). In both studies, researchers wanted to find out if enzalutamide helps people with mHSPC live longer. WHAT ARE THE KEY TAKEAWAYS?: In both studies, researchers found that people with mHSPC who took enzalutamide lived longer than people who did not. People who took enzalutamide also lived longer without their cancer getting worse. The results were mostly similar in groups of people dependingon when and where their cancer was found. Researchers did not find any new safety concerns. WHAT WERE THE MAIN CONCLUSIONS?: People with mHSPC may benefit from long-term treatment with enzalutamide + ADT. They may also benefit from taking enzalutamide with other treatments, like docetaxel. It may be better for people with mHSPC to have enzalutamide treatment before their cancer gets worse, rather than waiting. These people and their doctors should carefully consider the benefits and risks of each treatment to make a joint decision for treating mHSPC.Clinical Trial Registration: NCT02677896 (ARCHES), NCT02446405 (ENZAMET) (ClinicalTrials.gov).

TALAPRO-3 clinical trial protocol: phase III study of talazoparib plus enzalutamide in metastatic castration-sensitive prostate cancer.

Poly(ADP-ribose) polymerase inhibitors in combination with androgen-receptor signaling inhibitors are a promising therapeutic option for patients with metastatic castration-sensitive prostate cancer (mCSPC) and homologous recombination repair (HRR) gene alterations. Here, we describe the design and rationale of the multinational, phase III, TALAPRO-3 study comparing talazoparib plus enzalutamide versus placebo plus enzalutamide in patients with mCSPC and HRR gene alterations. The primary end point is investigator-assessed radiographic progression-free survival (rPFS) per RECIST 1.1 in soft tissue, or per PCWG3 criteria in bone. The TALAPRO-3 study will demonstrate whether the addition of talazoparib can improve the efficacy of enzalutamide as assessed by rPFS in patients with mCSPC and HRR gene alterations undergoing androgen deprivation therapy. Clinical Trial Registration:NCT04821622 (ClinicalTrials.gov) Registry Name: Study of Talazoparib With Enzalutamide in Men With DDR Gene Mutated mCSPC. Date of Registration: 29 March 2021.

The TALAPRO-3 study design: a plain language summary.

WHAT IS THIS SUMMARY ABOUT?: This summary is about the ongoing research study called TALAPRO-3. This study is testing the use of two medicines called talazoparib and enzalutamide. The two medicines are being used together as a treatment for patients with a type of cancer called metastatic castration-sensitive prostate cancer and changes in specific DNA repair genes within their tumors. The study began in May 2021, and includes 599 patients from 27 countries. WHAT IS METASTATIC CASTRATION-SENSITIVE PROSTATE CANCER?: Metastatic castration-sensitive prostate cancer is known as mCSPC for short. It is cancer that has started in the prostate and spread to other body parts. The prostate is a gland below the bladder and helps make semen (the liquid that contains sperm). Castration-sensitive means that the cancer responds to treatments that lower testosterone in the blood. WHICH MEDICINES ARE BEING TESTED?: In this study, some patients will take talazoparib plus enzalutamide while others will take a placebo plus enzalutamide. Talazoparib and enzalutamide are two different cancer medicines. Talazoparib is not currently used to treat patients with mCSPC. Enzalutamide is used to treat patients with prostate cancer. Talazoparib plus enzalutamide is being compared with a placebo plus enzalutamide to see if patients live longer without their cancer getting worse, or them dying, when taking talazoparib plus enzalutamide or when taking a placebo plus enzalutamide. WHAT ARE THE AIMS OF THE TALAPRO-3 STUDY?: This study aims to find out if treatment with talazoparib plus enzalutamide increases the length of time the patients in the study live without their cancer getting worse, or them dying, compared with treatment with a placebo plus enzalutamide. The study will also measure how long the patients in the study live, the number and types of side effects they have, their general health and quality of life, and whether there are changes in how patients report their pain.Clinical Trial Registration: NCT03395197 (TALAPRO-2) (ClinicalTrials.gov).

The TALAPRO-3 study design: a plain language summary.

WHAT IS THIS SUMMARY ABOUT?: This summary is about the ongoing research study called TALAPRO-3. This study is testing the use of two medicines called talazoparib and enzalutamide. The two medicines are being used together as a treatment for patients with a type of cancer called metastatic castration-sensitive prostate cancer and changes in specific DNA repair genes within their tumors. The study began in May 2021, and includes 599 patients from 27 countries. WHAT IS METASTATIC CASTRATION-SENSITIVE PROSTATE CANCER?: Metastatic castration-sensitive prostate cancer is known as mCSPC for short. It is cancer that has started in the prostate and spread to other body parts. The prostate is a gland below the bladder and helps make semen (the liquid that contains sperm). Castration-sensitive means that the cancer responds to treatments that lower testosterone in the blood. WHICH MEDICINES ARE BEING TESTED?: In this study, some patients will take talazoparib plus enzalutamide while others will take a placebo plus enzalutamide. Talazoparib and enzalutamide are two different cancer medicines. Talazoparib is not currently used to treat patients with mCSPC. Enzalutamide is used to treat patients with prostate cancer. Talazoparib plus enzalutamide is being compared with a placebo plus enzalutamide to see if patients live longer without their cancer getting worse, or them dying, when taking talazoparib plus enzalutamide or when taking a placebo plus enzalutamide. WHAT ARE THE AIMS OF THE TALAPRO-3 STUDY?: This study aims to find out if treatment with talazoparib plus enzalutamide increases the length of time the patients in the study live without their cancer getting worse, or them dying, compared with treatment with a placebo plus enzalutamide. The study will also measure how long the patients in the study live, the number and types of side effects they have, their general health and quality of life, and whether there are changes in how patients report their pain.Clinical Trial Registration: NCT03395197 (TALAPRO-2) (ClinicalTrials.gov).

Plain language summary of the results from the TALAPRO-2 study: Talazoparib plus enzalutamide versus placebo plus enzalutamide for patients with advanced prostate cancer.

WHAT IS THIS SUMMARY ABOUT?: This summary describes the results from the TALAPRO-2 research study (also known as a clinical trial). The TALAPRO-2 study tested the combination of two medicines called talazoparib plus enzalutamide. This combination of medicines was used as the first treatment for adult patients with metastatic castration-resistant prostate cancer. The combination of talazoparib plus enzalutamide was compared with a placebo plus enzalutamide. WHAT IS METASTATIC CASTRATION-RESISTANT PROSTATE CANCER?: Metastatic castration-resistant prostate cancer is a type of cancer that starts in the prostate and has spread to other parts of the body. Castration-resistant means that the cancer continues to grow even when testosterone levels in the blood are reduced to very low levels. Taking medicines to lower testosterone levels in the blood is a standard treatment for men with advanced prostate cancer. WHAT ARE THE AIMS OF THE TALAPRO-2 TRIAL?: TALAPRO-2 looked at if combining talazoparib plus enzalutamide would increase the length of time patients lived before their cancer got worse or they died compared with a placebo plus enzalutamide. Researchers looked at how treatment affected the size and number of tumors and the length of time before patients needed to change to a new cancer medicine. Researchers also looked at any side effects patients had during the study. WHAT ARE THE KEY TAKEAWAYS?: A total of 805 patients with metastatic castration-resistant prostate cancer took part in the study. Compared with patients who took a placebo plus enzalutamide, the group of patients who took talazoparib plus enzalutamide had a 37% reduced risk of their cancer getting worse or dying. Some patients had tumors that at the start of the study could be measured with scans. Sixty-two percent of patients who took talazoparib plus enzalutamide had their tumors decrease or shrink to the point that they could no longer be seen on scans versus 44% of patients who took a placebo plus enzalutamide. Patients who took talazoparib plus enzalutamide were more likely to have a longer time before they needed to change to a new cancer medicine. The most common side effects of talazoparib plus enzalutamide were low levels of red blood cells (66% of patients) and neutrophils (36% of patients), and excessive tiredness or exhaustion (34% of patients).Clinical Trial Registration: NCT03395197 (TALAPRO-2) (ClinicalTrials.gov).

Future directions in systemic treatment of metastatic hormone-sensitive prostate cancer.

The landscape of advanced prostate cancer treatment has evolved tremendously in past decades. The treatment paradigm has shifted from androgen deprivation therapy (ADT) alone to doublet combinations comprising ADT with docetaxel or an androgen receptor inhibitor, and now triplet therapy involving all 3 classes of agents. Robust clinical data has demonstrated survival benefits with this strategy of upfront treatment intensification. Subgroup analysis has alluded to the importance of tailoring treatment according to metastatic disease burden. However, defining the volume of disease is becoming increasingly controversial due to the advent of next generation molecular imaging. Several trials testing established agents in the castrate-resistant setting are now underway in metastatic hormone sensitive prostate cancer patients. As the treatment milieu is enriched earlier in the disease trajectory, future studies should elucidate biomarkers to further define specific patient populations who will benefit most from treatment intensification and/or de-escalation, with what agents and for what duration.

PSMA and FDG-PET as predictive and prognostic biomarkers in patients given [177Lu]Lu-PSMA-617 versus cabazitaxel for metastatic castration-resistant prostate cancer (TheraP): a biomarker analysis from a randomised, open-label, phase 2 trial.

BACKGROUND: Previously, results from the TheraP trial showed that treatment with lutetium-177 [177Lu]Lu-PSMA-617 improved frequency of prostate-specific antigen (PSA) response rate and progression-free survival compared with cabazitaxel in men with metastatic castration-resistant prostate cancer. In this study, we aimed to analyse gallium-68 [68Ga]Ga-PSMA-11 PET (PSMA-PET) and 2-[18F]fluoro-2-deoxy-D-glucose PET (FDG-PET) imaging parameters as predictive and prognostic biomarkers in this patient population. METHODS: TheraP was a multicentre, open-label, randomised phase 2 trial that recruited men with metastatic castration-resistant prostate cancer after treatment with docetaxel who were suitable for cabazitaxel from 11 hospitals in Australia. Participants were required to be 18 years old or older; have adequate haematological, renal, and liver function; and an Eastern Cooperative Oncology Group performance status of 0-2. Participants were randomly assigned (1:1) using a centralised system using minimisation with a random component and that stratified patients by disease burden, previous treatment with enzalutamide or abiraterone, and study site. Patients were either given cabazitaxel (20 mg/m2 intravenously every 3 weeks for up to ten cycles) or [177Lu]Lu-PSMA-617 (6·0-8·5 GBq intravenously every 6 weeks for up to six cycles). The primary study endpoint, analysed previously, was PSA response rate. The prespecified tertiary study endpoint was association between total tumour quantitative parameters on PSMA-PET, FDG-PET, and baseline characteristics with clinical outcomes. A SUVmean of 10 or higher on PSMA-PET was evaluated as a predictive biomarker for response to [177Lu]Lu-PSMA-617 versus cabazitaxel. A metabolic tumour volume (MTV) of 200 mL or higher on FDG-PET was tested as a prognostic biomarker. Both cutoff points were prespecified. The analysis was intention-to-treat, using logistic regression. This trial is registered with ClinicalTrials.gov, NCT03392428. FINDINGS: 200 patients were randomly assigned between Feb 6, 2018, and Sept 3, 2019. 101 men were assigned to the cabazitaxel group and 99 were assigned to the [177Lu]Lu-PSMA-617 group. The median follow-up at data cutoff of July 20, 2020, was 18·4 months (IQR 12·8-21·8). 35 (35%) of 99 men who were assigned [177Lu]Lu-PSMA-617 and 30 (30%) of 101 men who were assigned cabazitaxel had high PSMA uptake (SUVmean of ≥10). Odds of PSA response to [177Lu]Lu-PSMA-617 versus cabazitaxel were significantly higher for men with SUVmean of 10 or higher compared with those with SUVmean of less than 10 (odds ratio [OR] 12·19 [95% CI 3·42-58·76] vs 2·22 [1·11-4·51]; padj=0·039 for treatment-by-SUVmean interaction). PSA response rate for [177Lu]Lu-PSMA-617 compared with cabazitaxel was 32 (91% [95% CI 76-98]) of 35 men versus 14 (47% [29-65]) of 30 men in patients with SUVmean of 10 or higher, and 33 (52% [39-64]) of 64 men versus 23 (32% [22-45]) of 71 men in those with SUVmean of less than 10. High-volume disease on FDG-PET (MTV ≥200 mL) was seen in 30 (30%) of 99 men who were assigned [177Lu]Lu-PSMA-617 and 30 (30%) of 101 men who were assigned cabazitaxel. PSA response rate for both treatment groups combined for FDG-PET MTV of 200 mL or higher versus FDG-PET MTV of less than 200 mL was 23 (38% [95% CI 26-52]) of 60 men versus 79 (56% [48-65]) of 140 men (OR 0·44, 95% CI 0·23-0·84; padj=0·035). INTERPRETATION: In men with metastatic castration-resistant prostate cancer, PSMA-PET SUVmean was predictive of higher likelihood of favourable response to [177Lu]Lu-PSMA-617 than cabazitaxel, which provides guidance for optimal [177Lu]Lu-PSMA-617 use. High FDG-PET MTV was associated with lower responses regardless of randomly assigned treatment, warranting further research for treatment intensification. A strength of this analysis is the validation of pre-specified cutpoints within a multicentre, randomised, controlled trial. Quantitative PET parameters used, however, require specialised software and are not yet routinely available in most clinics. FUNDING: Prostate Cancer Foundation of Australia, Endocyte (a Novartis Company), Australian Nuclear Science and Technology Organisation, Movember Foundation, It's a Bloke Thing, CAN4CANCER, The Distinguished Gentleman's Ride.

Safety, pharmacokinetic, pharmacodynamic and clinical activity of molibresib for the treatment of nuclear protein in testis carcinoma and other cancers: Results of a Phase I/II open-label, dose escalation study.

Molibresib is an orally bioavailable, selective, small molecule BET protein inhibitor. Results from a first time in human study in solid tumors resulted in the selection of a 75 mg once daily dose of the besylate formulation of molibresib as the recommended Phase 2 dose (RP2D). Here we present the results of Part 2 of our study, investigating safety, pharmacokinetics, pharmacodynamics and clinical activity of molibresib at the RP2D for nuclear protein in testis carcinoma (NC), small cell lung cancer, castration-resistant prostate cancer (CRPC), triple-negative breast cancer, estrogen receptor-positive breast cancer and gastrointestinal stromal tumor. The primary safety endpoints were incidence of adverse events (AEs) and serious AEs; the primary efficacy endpoint was overall response rate. Secondary endpoints included plasma concentrations and gene set enrichment analysis (GSEA). Molibresib 75 mg once daily demonstrated no unexpected toxicities. The most common treatment-related AEs (any grade) were thrombocytopenia (64%), nausea (43%) and decreased appetite (37%); 83% of patients required dose interruptions and 29% required dose reductions due to AEs. Antitumor activity was observed in NC and CRPC (one confirmed partial response each, with observed reductions in tumor size), although predefined clinically meaningful response rates were not met for any tumor type. Total active moiety median plasma concentrations after single and repeated administration were similar across tumor cohorts. GSEA revealed that gene expression changes with molibresib varied by patient, response status and tumor type. Investigations into combinatorial approaches that use BET inhibition to eliminate resistance to other targeted therapies are warranted.

[177Lu]Lu-PSMA-617 versus cabazitaxel in patients with metastatic castration-resistant prostate cancer (TheraP): a randomised, open-label, phase 2 trial.

BACKGROUND: Lutetium-177 [177Lu]Lu-PSMA-617 is a radiolabelled small molecule that delivers ß radiation to cells expressing prostate-specific membrane antigen (PSMA), with activity and safety in patients with metastatic castration-resistant prostate cancer. We aimed to compare [177Lu]Lu-PSMA-617 with cabazitaxel in patients with metastatic castration-resistant prostate cancer. METHODS: We did this multicentre, unblinded, randomised phase 2 trial at 11 centres in Australia. We recruited men with metastatic castration-resistant prostate cancer for whom cabazitaxel was considered the next appropriate standard treatment. Participants were required to have adequate renal, haematological, and liver function, and an Eastern Cooperative Oncology Group performance status of 0-2. Previous treatment with androgen receptor-directed therapy was allowed. Men underwent gallium-68 [68Ga]Ga-PSMA-11 and 2-flourine-18[18F]fluoro-2-deoxy-D-glucose (FDG) PET-CT scans. PET eligibility criteria for the trial were PSMA-positive disease, and no sites of metastatic disease with discordant FDG-positive and PSMA-negative findings. Men were randomly assigned (1:1) to [177Lu]Lu-PSMA-617 (6·0-8·5 GBq intravenously every 6 weeks for up to six cycles) or cabazitaxel (20 mg/m2 intravenously every 3 weeks for up to ten cycles). The primary endpoint was prostate-specific antigen (PSA) response defined by a reduction of at least 50% from baseline. This trial is registered with ClinicalTrials.gov, NCT03392428. FINDINGS: Between Feb 6, 2018, and Sept 3, 2019, we screened 291 men, of whom 200 were eligible on PET imaging. Study treatment was received by 98 (99%) of 99 men randomly assigned to [177Lu]Lu-PSMA-617 versus 85 (84%) of 101 randomly assigned to cabazitaxel. PSA responses were more frequent among men in the [177Lu]Lu-PSMA-617 group than in the cabazitaxel group (65 vs 37 PSA responses; 66% vs 37% by intention to treat; difference 29% (95% CI 16-42; p<0·0001; and 66% vs 44% by treatment received; difference 23% [9-37]; p=0·0016). Grade 3-4 adverse events occurred in 32 (33%) of 98 men in the [177Lu]Lu-PSMA-617 group versus 45 (53%) of 85 men in the cabazitaxel group. No deaths were attributed to [177Lu]Lu-PSMA-617. INTERPRETATION: [177Lu]Lu-PSMA-617 compared with cabazitaxel in men with metastatic castration-resistant prostate cancer led to a higher PSA response and fewer grade 3 or 4 adverse events. [177Lu]Lu-PSMA-617 is a new effective class of therapy and a potential alternative to cabazitaxel. FUNDING: Prostate Cancer Foundation of Australia, Endocyte (a Novartis company), Australian Nuclear Science and Technology Organization, Movember, The Distinguished Gentleman's Ride, It's a Bloke Thing, and CAN4CANCER.

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.

Modern paradigms for prostate cancer detection and management.

Early detection and management of prostate cancer has evolved over the past decade, with a focus now on harm minimisation and reducing overdiagnosis and overtreatment, given the proven improvements in survival from randomised controlled trials. Multiparametric magnetic resonance imaging (mpMRI) is now an important aspect of the diagnostic pathway in prostate cancer, improving the detection of clinically significant prostate cancer, enabling accurate localisation of appropriate sites to biopsy, and reducing unnecessary biopsies in most patients with normal magnetic resonance imaging scans. Biopsies are now performed transperineally, substantially reducing the risk of post-procedure sepsis. Australian-led research has shown that prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has superior accuracy in the staging of prostate cancer than conventional imaging (CT and whole-body bone scan). Localised prostate cancer that is low risk (International Society for Urological Pathology [ISUP] grade 1, Gleason score 3 + 3 = 6; and ISUP grade group 2, Gleason score 3 + 4 = 7 with less than 10% pattern 4) can be offered active surveillance, reducing harms from overtreatment. Prostatectomy and definitive radiation remain the gold standard for localised intermediate and high risk disease. However, focal therapy is an emerging experimental treatment modality in Australia in carefully selected patients. The management of advanced prostate cancer treatment has evolved to now include several novel agents both in the metastatic hormone-sensitive and castration-resistant disease settings. Multimodal therapy with androgen deprivation therapy, additional systemic therapy and radiotherapy are often recommended. PSMA-based radioligand therapy has emerged as a treatment option for metastatic castration-resistant prostate cancer and is currently being evaluated in earlier disease states.

Predictors of real-world utilisation of docetaxel combined with androgen deprivation therapy in metastatic hormone-sensitive prostate cancer.

BACKGROUND: Docetaxel has emerged as a standard-of-care for metastatic hormone-sensitive prostate cancer (mHSPC). Uptake of docetaxel for mHSPC in Australia has not previously been reported. AIMS: To investigate the real-world uptake of docetaxel in mHSPC and to identify predictors of utilisation of docetaxel in mHSPC. METHODS: Men diagnosed from June 2014 to December 2018 and enrolled in the Prostate Cancer Outcomes Registry-Victoria (PCOR-Vic) were included. Data collected include demographics, diagnosis method and institution, staging investigations and treatments within 12 months of diagnosis. Wilcoxon rank-sum, Chi-squared and trend tests were used to identify predictors of docetaxel utilisation. All predictors were entered as covariates simultaneously into a multivariable logistic regression model. Statistical significance was set at 0.05 (two sided). RESULTS: In all, 1014 men with mHSPC were analysed, 25% of whom received docetaxel with androgen deprivation therapy. Uptake of docetaxel increased from 20% in 2014 to 33% in 2018. Predictors of higher usage of docetaxel were younger age and treatment in a private hospital, with both remaining significant on multivariable analysis. Notably, the proportion of men aged <70 years receiving docetaxel increased from 54% in 2014-2015 to 64% in 2016-2018, while in men aged ≥70 years the comparative figures were 15% and 22% respectively. CONCLUSIONS: Although docetaxel was not used in the majority of cases, there was a clear increase in docetaxel uptake, especially in younger men following publication of the CHAARTED and STAMPEDE trials. Identifying barriers to real-world implementation of pivotal clinical trial data is critical to improving outcomes in mHSPC.

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

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

UpFrontPSMA: a randomized phase 2 study of sequential 177 Lu-PSMA-617 and docetaxel vs docetaxel in metastatic hormone-naïve prostate cancer (clinical trial protocol).

OBJECTIVE: To assess the activity and safety of sequential lutetium-177 (177 Lu)-PSMA-617 and docetaxel vs docetaxel on a background of androgen deprivation therapy (ADT) in men with de novo metastatic hormone-naïve prostate cancer (mHNPC). PATIENTS AND METHODS: UpFrontPSMA (NCT04343885) is an open-label, randomized, multicentre, phase 2 trial, recruiting 140 patients at 12 Australian centres. Key eligibility criteria include: prostate cancer with a histological diagnosis within 12 weeks of screening commencement; prostate-specific antigen (PSA) >10 ng/mL at diagnosis; ≤4 weeks on ADT; evidence of metastatic disease on computed tomography (CT) and/or bone scan; high-volume prostate-specific membrane antigen (PSMA)-avid disease with a maximum standardized uptake value >15; and absence of extensive discordant fluorodeoxyglcuose (FDG)-positive, PSMA-negative disease. 68 Ga-PSMA-11 and 18 F-FDG positron-emission tomography (PET)/CT undergo central review to determine eligibility. Patients are randomized 1:1 to experimental treatment, Arm A (177 Lu-PSMA-617 7.5GBq q6w × 2 cycles followed by docetaxel 75 mg/m2 q3w × 6 cycles), or standard-of-care treatment, Arm B (docetaxel 75 mg/m2 q3w × 6 cycles). All patients receive continuous ADT. Patients are stratified based on disease volume on conventional imaging and duration of ADT at time of registration. The primary endpoint is the proportion of patients with undetectable PSA (≤0.2 ng/L) at 12 months after study treatment commencement. Secondary endpoints include safety, time to castration resistance, overall survival, PSA and radiographic progression-free survival, objective tumour response rate, early PSMA PET response, health-related quality of life, and frequency and severity of adverse events. Enrolment commenced in April 2020. RESULTS AND CONCLUSIONS: The results of this trial will generate data on the activity and safety of 177 Lu-PSMA-617 in men with de novo mHNPC in a randomized phase 2 design.

Understanding the diagnosis of prostate cancer.

Prostate cancer continues to be the most commonly diagnosed cancer, and the second leading cause of cancer death among Australian men. Prostate-specific antigen testing is personalised (not dichotomous in nature) and its interpretation should take into account the patient's age, symptoms, previous results and medication (eg, 5-α reductase inhibitors such as dutasteride). Multiparametric magnetic resonance imaging of the prostate has been proven to have a 93% sensitivity for detecting clinically significant prostate cancer. It has the potential to decrease unnecessary prostate biopsies by around 27%. International Society of Urological Pathology (ISUP) grade 1 (Gleason score 6) has been shown to have very little, if any, risk of metastasis ISUP grade 1 (Gleason score 3 +3 = 6) and low percentage ISUP grade 2 (Gleason score 3 + 4 [< 10%] = 7) can be offered active surveillance. The goal of active surveillance is to defer treatment but is still curative when required. With better imaging (magnetic resonance imaging and emerging prostate-specific membrane antigen positron emission tomography-computed tomography) and transperineal prostate biopsy, more men can be offered screening after discussion of risks and benefits, knowing that overdiagnosis has been minimised and radical treatment is reserved for only the most aggressive disease.

Optimal sequencing of enzalutamide and abiraterone acetate plus prednisone in metastatic castration-resistant prostate cancer: a multicentre, randomised, open-label, phase 2, crossover trial.

BACKGROUND: Abiraterone acetate plus prednisone and enzalutamide are both used for the treatment of metastatic castration-resistant prostate cancer. We aimed to determine the best sequence in which to use both drugs, as well as their second-line efficacy. METHODS: In this multicentre, randomised, open-label, phase 2, crossover trial done in six cancer centres in British Columbia, Canada, we recruited patients aged 18 years or older with newly-diagnosed metastatic castration-resistant prostate cancer without neuroendocrine differentiation and Eastern Cooperative Oncology Group performance status 2 or less. Patients were randomly assigned (1:1) using a computer-generated random number table to receive either abiraterone acetate 1000 mg orally once daily plus prednisone 5 mg orally twice daily until PSA progression followed by crossover to enzalutamide 160 mg orally once daily (group A), or the opposite sequence (group B). Treatment was not masked to investigators or participants. Primary endpoints were time to second PSA progression and PSA response (≥30% decline from baseline) on second-line therapy, analysed by intention-to-treat in all randomly assigned patients and in patients who crossed over, respectively. The trial is registered with ClinicalTrials.gov, NCT02125357. FINDINGS: Between Oct 21, 2014, and Dec 13, 2016, 202 patients were enrolled and randomly assigned to either group A (n=101) or group B (n=101). At the time of data cutoff, 73 (72%) patients in group A and 75 (74%) patients in group B had crossed over. Time to second PSA progression was longer in group A than in group B (median 19·3 months [95% CI 16·0-30·5] vs 15·2 months [95% CI 11·9-19·8] months; hazard ratio 0·66, 95% CI 0·45-0·97, p=0·036), at a median follow-up of 22·8 months (IQR 10·3-33·4). PSA responses to second-line therapy were seen in 26 (36%) of 73 patients for enzalutamide and three (4%) of 75 for abiraterone (χ2 p<0·0001). The most common grade 3-4 adverse events throughout the trial were hypertension (27 [27%] of 101 patients in group A vs 18 [18%] of 101 patients in group B) and fatigue (six [10%] vs four [4%]). Serious adverse events were reported in 15 (15%) of 101 patients in group A and 20 (20%) of 101 patients in group B. There were no treatment-related deaths. INTERPRETATION: Enzalutamide showed activity as a second-line novel androgen receptor pathway inhibitor, whereas abiraterone acetate did not, leading to a longer time to second PSA progression for the sequence of abiraterone followed by enzalutamide than with the opposite treatment sequence. Our data suggest that using a sequencing strategy of abiraterone acetate followed by enzalutamide provides the greatest clinical benefit. FUNDING: Canadian Cancer Society Research Institute, Prostate Cancer Canada, Movember Foundation, Prostate Cancer Foundation, Terry Fox New Frontiers Program, BC Cancer Foundation, Jane and Aatos Erkko Foundation, Janssen, and Astellas.

Radiotherapy and immunotherapy: a synergistic effect in cancer care.

Radiotherapy is an effective treatment modality commonly used in efforts to cure many localised cancers and in the palliation of symptoms in metastatic cancers. Immunotherapy has revolutionised cancer care by increasing the disease control and overall survival of patients in several cancer types; however, the majority of patients do not respond to currently available therapies based on immune checkpoint inhibitors (ICIs). The benefit of those agents is limited to patients who have a pre-existing active immune microenvironment that can be reactivated by ICIs. It is now recognised that radiotherapy does not only directly kill tumour cells but it also changes the tumour microenvironment, enhancing tumour cell recognition by the immune system and, therefore, acting as an in situ vaccine. Radiotherapy increases expression of tumour-associated antigens, causes the release of cytokines, stimulates recruitment of dendritic cells and, most importantly, stimulates the proliferation and priming of cytotoxic CD8+ T cells in the tumour microenvironment. This immunological cascade specifically generates activated T cells able to induce immunogenic cell death directed against cancer cells bearing those antigens. By its ability to overcome some tumour immune escape mechanisms, radiation provides a non-pharmacological and cost-effective approach to potentially improve the systemic response to immune checkpoints inhibitors.