[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).

ENZA-p trial protocol: a randomized phase II trial using prostate-specific membrane antigen as a therapeutic target and prognostic indicator in men with metastatic castration-resistant prostate cancer treated with enzalutamide (ANZUP 1901).

OBJECTIVES: To determine the activity and safety of lutetium-177 (177 Lu)-prostate-specific membrane antigen (PSMA)-617 in men with metastatic castration-resistant prostate cancer (mCRPC) commencing enzalutamide, who are at high risk of early progression, and to identify potential prognostic and predictive biomarkers from imaging, blood and tissue. PARTICIPANTS AND METHODS: ENZA-p (ANZUP 1901) is an open-label, randomized, two-arm, multicentre, phase 2 trial. Participants are randomly assigned (1:1) to treatment with enzalutamide 160 mg daily alone or enzalutamide plus 177 Lu-PSMA-617 7.5 GBq on Days 15 and 57. Two additional 177 Lu-PSMA-617 doses are allowed, informed by Day-92 Gallium-68 (68 Ga)-PSMA positron emission tomography (PET; up to four doses in total). The primary endpoint is prostate-specific antigen (PSA) progression-free survival (PFS). Other major endpoints include radiological PFS, PSA response rate, overall survival, health-related quality of life, adverse events and cost-effectiveness. Key eligibility criteria include: biochemical and/or clinical progression; 68 Ga-PSMA PET-avid disease; no prior androgen signalling inhibitor, excepting abiraterone; no prior chemotherapy for mCRPC; and ≥2 high-risk features for early enzalutamide failure. Assessments are 4 weekly during study treatment, then 6 weekly until radiographic progression. Response Evaluation Criteria in Solid Tumours (RECIST) are used to assess imaging conducted every 12 weeks, 68 Ga-PSMA PET at baseline, Days 15 and 92, and at progression, and 18 F-fluorine deoxyglucose (18 F-FDG) PET at baseline and progression. Translational samples include blood (and optional biopsies) at baseline, Day 92, and first progression. Correlative studies include identification of prognostic and predictive biomarkers from 68 Ga-PSMA and 18 F-FDG PET/CT, circulating tumour cells and circulating tumour DNA. The trial will enrol 160 participants, providing 80% power with a two-sided type-1 error rate of 5% to detect a hazard ratio of 0.625 assuming a median PSA-PFS of 5 months with enzalutamide alone. RESULTS AND CONCLUSION: The combination of 177 Lu-PSMA-617 and enzalutamide may be synergistic. ENZA-p will determine the safety and efficacy of the combination in addition to developing predictive and prognostic biomarkers to better guide treatment decisions.

Durvalumab with first-line chemotherapy in previously untreated malignant pleural mesothelioma (DREAM): a multicentre, single-arm, phase 2 trial with a safety run-in.

BACKGROUND: There is a strong unmet need to improve systemic therapy in mesothelioma. Chemotherapy with cisplatin and pemetrexed improves survival in malignant pleural mesothelioma, and immune checkpoint inhibitors are an emerging treatment in this disease. We aimed to evaluate the activity of durvalumab, an anti-PD-L1 antibody, given during and after first-line chemotherapy with cisplatin and pemetrexed in patients with advanced malignant pleural mesothelioma. METHODS: DREAM was a multicentre, single-arm, open-label, phase 2 trial done in nine hospitals in Australia. Eligible patients were aged 18 years or older and had histologically confirmed malignant pleural mesothelioma considered unsuitable for cancer-directed surgery, an Eastern Cooperative Oncology Group performance status of 0 or 1, and measurable disease as per the modified Response Evaluation Criteria in Solid Tumors version 1.0 (mRECIST) for mesothelioma that was previously untreated with systemic therapy. All histological subtypes were eligible. The first six participants were treated for two cycles in a safety run-in. All participants received cisplatin 75 mg/m2, pemetrexed 500 mg/m2, and durvalumab 1125 mg intravenously on day 1 of a 3-weekly schedule for a maximum of six cycles. Change from cisplatin to carboplatin with an area under the curve of 5 was permitted. Durvalumab was continued for a maximum of 12 months. The primary endpoint was progression-free survival at 6 months, measured according to mRECIST for malignant pleural mesothelioma and analysed in the intention-to-treat population. Safety analyses included all participants who receive at least one dose of any study drug. This study is registered with the Australia New Zealand Clinical Trials Registry, ACTRN12616001170415. FINDINGS: Between Dec 28, 2016, and Sept 27, 2017, 55 participants were enrolled. 54 patients were eligible and were followed up for a median of 28·2 months (IQR 26·5-30·2). 31 (57%; 95% CI 44-70) of 54 patients were alive and progression-free at 6 months. The most common grade 3-4 adverse events were neutropenia (seven [13%] patients), nausea (six [11%]), and anaemia (four [7%]). A total of 60 serious adverse events occurred in 29 participants, five of which were considered possibly related to durvalumab. Five patients died during the study treatment; none of these five deaths were attributed to study treatment. INTERPRETATION: The combination of durvalumab, cisplatin, and pemetrexed has promising activity and an acceptable safety profile that warrants further investigation in a randomised phase 3 trial. FUNDING: AstraZeneca.

Trials with patient-reported outcomes registered on the Australian New Zealand Clinical Trials Registry (ANZCTR).

AIMS: It is important to understand the number, types and regions of trials that include patient-reported outcomes (PROs) to appreciate how patient experiences have been considered in studies of health and interventions. Twenty-seven percent of trials registered with ClinicalTrials.gov (2007-2013) included PROs; however, a regional breakdown was not provided and no reviews have been conducted of the Australia New Zealand Clinical Trials Registry (ANZCTR). We aimed to identify trials registered with ANZCTR with PRO endpoints and describe their characteristics. METHODS: ANZCTR was systematically searched from inception (2005) to 31 March 2017 for trials with PRO endpoints. Search terms included PRO measures listed in Patient-Reported Outcomes Quality of Life Instrument Database and Grid-Enabled Measures, as well as generic PRO terms (e.g. "quality of life" (QOL)). Trial endpoints were individually coded using an established framework to identify trials with PROs for the analysis. RESULTS: Of 13,666 registered trials, 6168 (45.1%) included a PRO. The proportion of studies including PROs increased between 2006 and 2016 (r = 0.74, p = 0.009). Among the 6168 trials, there were 17,961 individual PRO endpoints, including symptoms/functional outcomes/condition-specific QOL (65.6%), generic QOL (13.2%), patient-reported experiences (9.9%), patient-reported behaviours (7.9%). Mental health was the most common category (99.8% included PROs), followed by physical medicine/rehabilitation (65.6%), musculoskeletal (63.5%), public health (63.1%), and cancer (54.2%). DISCUSSION: Our findings suggest growing use of PROs in the assessment of health and interventions in ANZ. Our review identifies trial categories with limited patient-reported information and provides a basis for future work on the impact of PRO findings in clinical care.

Correction to: Trials with patient-reported outcomes registered on the Australian New Zealand Clinical Trials Registry (ANZCTR).

In the original publication of the article, the sentence "The ANZCTR is the fifth largest trial registry internationally, with 21,330 registered trials as at January 2018 [5]" in the Introduction section was published incorrectly.