Impact of Comorbidities and Drug Interactions in Patients With Metastatic Castration-Resistant Prostate Cancer Receiving Androgen Receptor Pathway Inhibitors.

PURPOSE: Androgen receptor pathway inhibitors (ARPIs) are widely prescribed in metastatic castration-resistant prostate cancer (mCRPC). Real-world frequencies and potential impacts of comorbidities and concomitant medication (conmed) interactions with ARPIs are not well described. METHODS: Patients receiving ARPIs for mCRPC were identified from the electronic Prostate Cancer Australian Database (ePAD). Demographics, clinicopathologic characteristics, and outcome data were extracted. Conmeds and comorbidities were collected from medical records. Potential interacting comorbidities were defined from trial and post-trial data. Clinically significant drug-drug interactions (DDIs) were identified using UpToDate Lexicomp and Stockley's databases. Patient characteristics, comorbidity interactions, DDIs, and outcomes were analyzed. RESULTS: Two hundred thirty-five patients received first- or second-line ARPIs for mCRPC from 2012 to 2021, with a median follow-up of 27 months. One hundred sixteen received abiraterone acetate (AAP) and 135 received enzalutamide (ENZ). The median age was 74 years, and the median number of conmeds was 4. Clinically significant DDIs occurred in 55 (47%) AAP patients and 90 (67%) ENZ patients. Only 5% of DDIs were predicted to affect ARPI pharmacokinetics (PK) or pharmacodynamics, whereas 95% were predicted to impact conmed PK or increase toxicity risk. In patients receiving ENZ, DDIs were associated with lower PSA50 (50% v 74%, P = .04) and poorer overall survival (28 v 45 months, P = .04), although statistical significance was not maintained on multivariate analysis. No significant survival differences were seen with DDIs in patients receiving AAP. Potential interactions between comorbidities and ARPI were present in 72% on AAP and 14% on ENZ with no significant associated survival differences. CONCLUSION: DDIs and drug-comorbidity interactions in real-world patients receiving ARPIs for mCRPC are common and may affect outcomes. Ongoing clinician education regarding DDIs is necessary to optimize patient outcomes.

Treatment patterns and outcomes in older adults with castration-resistant prostate cancer: Analysis of an Australian real-world cohort.

INTRODUCTION: Prostate cancer (PC) is the second commonest malignancy and fifth leading cause of cancer death in men worldwide. Older men are more likely to develop PC but are underrepresented in pivotal clinical trials, leading to challenges in treatment selection in the real-world setting. We aimed to examine treatment patterns and outcomes in older Australians with metastatic castration-resistant prostate cancer (mCRPC). MATERIALS AND METHODS: We identified 753 men with mCRPC within the electronic CRPC Australian Database (ePAD). Clinical data were analysed retrospectively to assess outcomes including time to treatment failure (TTF), overall survival (OS), PSA doubling time (PSADT), PSA50 response rate, and pre-defined adverse events of special interest (AESIs). Descriptive statistics were used to report baseline characteristics, stratified by age groups (<75y, 75-85y and >85y). Groups were compared using Kruskal-Wallis and Chi-square analyses. Time-to-event analyses were performed using Kaplan-Meier methods and compared through log-rank tests. Cox proportional hazards univariate and multivariate analyses were performed to evaluate the influence of variables on OS. RESULTS: Fifty-seven percent of men were aged <75y, 31% 75-85y, and 12% >85y. Patients ≥75y more frequently received only one line of systemic therapy (40% of <75y vs 66% 75-85y vs 68% >85y; P < 0.01). With increasing age, patients were more likely to receive androgen receptor signalling inhibitors (ARSIs) as initial therapy (42% of <75y vs 70% of 75-85y vs 84% of >85y; p < 0.01). PSA50 response rates or TTF did not significantly differ between age groups for chemotherapy or ARSIs. Patients >85y receiving enzalutamide had poorer OS but this was not an independent prognostic variable on multivariate analysis (hazard ratio [HR] 0.93(0.09-9.35); p = 0.95). PSADT >3 months was an independent positive prognostic factor for patients receiving any systemic therapy. Older patients who received docetaxel were more likely to experience AESIs (18% in <75y vs 37% 75-85y vs 33% >85y, p = 0.038) and to stop treatment as a result (21% in <75y vs 39% in 75-85y; p = 0.011). DISCUSSION: In our mCRPC cohort, older men received fewer lines of systemic therapy and were more likely to cease docetaxel due to adverse events. However, treatment outcomes were similar in most subgroups, highlighting the importance of individualised assessment regardless of age.

Addition of endocrine therapy to dual anti-HER2 targeted therapy in initial treatment of HER2 + /HR + metastatic breast cancer.

PURPOSE: Dual anti-HER2 targeted therapy and chemotherapy is the current first-line standard of care for HER2 + metastatic breast cancer (MBC), with endocrine therapy (ET) the backbone of treatment in hormone receptor positive (HR +) disease. The potential ET benefit in HER2 + /HR + patients is unknown as pivotal dual anti-HER2 clinical trials precluded ET use. METHODS: Real-world data from a multi-site registry of consecutive HER2 + MBC patients treated at clinician discretion were examined. Patients that were HR + (ER + and/or PR +) and had received first-line chemotherapy alongside trastuzumab and pertuzumab were explored. Of 362 patients in the registry, 215 were excluded due to being HR- (n = 210) or not receiving chemotherapy (n = 5). RESULTS: Of the 147 patients included, 91 (62%) received concurrent ET and 56 (38%) had not. Comparing the groups, there were no significant differences in age, performance status, metastatic sites, use of previous therapy and de novo metastatic disease. More patients with ER + PR + disease versus those with ER + PR- or ER-PR + received ET (73 vs 45%). The addition of ET was associated with significantly improved 5-year PFS (HR 0.58, CI 0.37-0.89, p = 0.014) and OS (HR 0.52, CI 0.31-0.90, p = 0.018), with no increase in adverse events noted. CONCLUSION: The addition of ET to first-line dual anti-HER2 therapy post chemotherapy in patients with HER2 + /HR + MBC was associated with major gains in PFS and OS with no safety concerns evident. Further studies of this combination are justified, along with studies of how best to integrate other agents that are active in this patient subset, including CDK4/6 inhibitors.

Real-world clinical outcomes and cost estimates of metastatic castration-resistant prostate cancer treatment: does sequencing of taxanes and androgen receptor-targeted agents matter?

INTRODUCTION: Health economic outcomes of real-world treatment sequencing of androgen receptor-targeted agents (ARTA) and docetaxel (DOC) remain unclear. MATERIAL AND METHODS: Data from the electronic Castration-resistant Prostate cancer Australian Database (ePAD) were analyzed including median overall survival (mOS) and median time-to-treatment failure (mTTF). Mean total costs (mTC) and incremental cost-effectiveness ratios (ICER) of treatment sequences were estimated using the average sample method and Zhao and Tian estimator. RESULTS: Of 752 men, 441 received ARTA, 194 DOC, and 175 both sequentially. Of participants treated with both, first-line DOC followed by ARTA was the more common sequence (n = 125, 71%). mOS for first-line ARTA was 8.38 years (95% CI: 3.48, not-estimated) vs. 3.29 years (95% CI: 2.92, 4.02) for DOC. mTTF was 15.7 months (95% CI: 14.2, 23.7) for the ARTA-DOC sequence and 18.2 months (95% CI: 16.2, 23.2) for DOC-ARTA. In first-line, ARTA cost an additional $13,244 per mTTF month compared to DOC. In second-line, ARTA cost $6726 per mTTF month. The DOC-ARTA sequence saved $2139 per mTTF compared to ARTA-DOC, though not statistically significant. CONCLUSION: ICERs show ARTA had improved clinical benefit compared to DOC but at higher cost. There were no significant cost differences between combined sequences.

Role for a Web-Based Intervention to Alleviate Distress in People With Newly Diagnosed Testicular Cancer: Mixed Methods Study.

BACKGROUND: Distress is common immediately after diagnosis of testicular cancer. It has historically been difficult to engage people in care models to alleviate distress because of complex factors, including differential coping strategies and influences of social gender norms. Existing support specifically focuses on long-term survivors of testicular cancer, leaving an unmet need for age-appropriate and sex-sensitized support for individuals with distress shortly after diagnosis. OBJECTIVE: We evaluated a web-based intervention, Nuts & Bolts, designed to provide support and alleviate distress after diagnosis of testicular cancer. METHODS: Using a mixed methods design to evaluate the acceptability, feasibility, and impact of Nuts & Bolts on distress, we randomly assigned participants with recently diagnosed testicular cancer (1:1) access to Nuts & Bolts at the time of consent (early) or alternatively, 1 week later (day 8; delayed). Participants completed serial questionnaires across a 4- to 5-week period to evaluate levels of distress (measured by the National Comprehensive Cancer Network Distress Thermometer [DT]; scored 0-10), anxiety, and depression (Hospital Anxiety and Depression Score [HADS]-Anxiety and HADS-Depression; each scored 0-21). The primary end point was change in distress between consent and day 8. Secondary end points of distress, anxiety, and depression were assessed at defined intervals during follow-up. Optional, semistructured interviews occurring after completion of quantitative assessments were thematically analyzed. RESULTS: Overall, 39 participants were enrolled in this study. The median time from orchidectomy to study consent was 14.8 (range 3-62) days. Moderate or high levels of distress evaluated using DT were reported in 58% (23/39) of participants at consent and reduced to 13% (5/38) after 1 week of observation. Early intervention with Nuts & Bolts did not significantly decrease the mean DT score by day 8 compared with delayed intervention (early: 4.56-2.74 vs delayed: 4.47-2.74; P=.85), who did not yet have access to the website. A higher baseline DT score was significantly predictive of reduction in DT score during this period (P<.001). Median DT, HADS-Anxiety, and HADS-Depression scores reduced between orchidectomy and 3 weeks postoperatively and then remained stable throughout the observation period. Thematic analysis of 16 semistructured interviews revealed 4 key themes, "Nuts & Bolts is a helpful tool," "Maximizing benefits of the website," "Whirlwind of diagnosis and readiness for treatment," and "Primary stressors and worries," as well as multiple subthemes. CONCLUSIONS: Distress is common following the diagnosis of testicular cancer; however, it decreases over time. Nuts & Bolts was considered useful, acceptable, and relevant by individuals diagnosed with testicular cancer, with strong support for the intervention rendered by thematic analyses of semistructured interviews. The best time to introduce support, such as Nuts & Bolts, is yet to be determined; however, it may be most beneficial as soon as testicular cancer is strongly suspected or diagnosed.

Leveraging Comprehensive Cancer Registry Data to Enable a Broad Range of Research, Audit and Patient Support Activities.

Traditional cancer registries have often been siloed efforts, established by single groups with limited objectives. There is the potential for registry data to support a broad range of research, audit and education initiatives. Here, we describe the establishment of a series of comprehensive cancer registries across the spectrum of common solid cancers. The experience and learnings of each registry team as they develop, implement and then use collected data for a range of purposes, that informs the conduct and output of other registries in a virtuous cycle. Each registry is multi-site, multi-disciplinary and aims to collect data of maximal interest and value to a broad range of enquiry, which would be accessible to any researcher with a high-quality proposal. Lessons learnt include the need for careful and continuous curation of data fields, with regular database updates, and the need for a continued focus on data quality. The registry data as a standalone resource has supported numerous projects, but linkage with external datasets with patients in common has enhanced the audit and research potential. Multiple projects have linked registry data with matched tissue specimens to support prognostic and predictive biomarker studies, both validation and discovery. Registry-based biomarker trials have been successfully supported, generating novel and practice-changing data. Registry-based clinical trials, particularly randomised studies exploring the optimal use of available therapy options are now complementing the research conducted in traditional clinical trials. More recent projects supported by the registries include health economic studies, personalised patient education material, and increased consumer engagement, including consumer entered data.

Real-World Outcomes in Patients With Brain Metastases Secondary to HER2-Positive Breast Cancer: An Australian Multi-centre Registry-based Study.

BACKGROUND: The development of brain metastases occurs commonly in HER2-positive metastatic breast cancer and is associated with a poorer prognosis. The advent of HER2-targeted therapy has improved overall survival, but the benefit in patients with brain metastases is unclear, as these patients are often excluded from clinical trials. This study aimed to explore real-world outcomes in patients with brain metastases in HER2-positive MBC. MATERIALS & METHODS: Data was extracted from the TABITHA registry, which consists of patient data collected prospectively from 16 Australian sites from 24th February 2015 to 31st October 2021. Data analysed included characteristics of brain metastases, treatment received and survival outcomes. RESULTS: A total of 135 (37%) of 361 patients with HER2-positive MBC were diagnosed with brain metastases during their clinical course, including 45 (12%) with brain metastases at time of MBC diagnosis. 61 (45%) had ≥4 brain lesions. The most common local therapy given was whole brain radiation therapy (WBRT) (36%) followed by multi-modality treatment with both surgery and radiation therapy (27%). The majority of patients received first-line HER2-targeted treatment with trastuzumab and pertuzumab followed by second-line trastuzumab emtansine (T-DM1) but third-line therapy was heterogenous. The median overall survival in patients who developed brain metastases was significantly shorter than those who did not develop brain metastases (58.9 vs. 96.1 months, P = .02). CONCLUSION: Real-world patients diagnosed with brain metastases in HER2-positive MBC have a relatively poor prognosis, despite advances in HER2-targeted treatment. As the range of HER2-targeted treatment expands, it is important to pursue clinical trials that focus on patients with brain metastases.

Phase 2 Study of Neoadjuvant FGFR Inhibition and Androgen Deprivation Therapy Prior to Prostatectomy.

BACKGROUND: Disease recurrence is common following prostatectomy in patients with localised prostate cancer with high-risk features. Although androgen deprivation therapy increases the rates of organ-confined disease and negative surgical margins, there is no significant benefit on disease recurrence. Multiple lines of evidence suggest that (Fibroblast Growth Factor/Fibroblast Growth Factor Receptor) FGF/FGFR-signalling is important in supporting prostate epithelial cell survival in hostile conditions, including acute androgen deprivation. Given the recent availability of oral FGFR inhibitors, we investigated whether combination therapy could improve tumour response in the neo-adjuvant setting. METHODS: We conducted an open label phase II study of the combination of erdafitinib (3 months) and androgen deprivation therapy (4 months) in men with localised prostate cancer with high-risk features prior to prostatectomy using a Simon's 2 stage design. The co-primary endpoints were safety and tolerability and pathological response in the prostatectomy specimen. The effect of treatment on residual tumours was explored by global transcriptional profiling with RNA-sequencing. RESULTS: Nine patients were enrolled in the first stage of the trial. The treatment combination was poorly tolerated. Erdafitinib treatment was discontinued early in six patients, three of whom also required dose interruptions/reductions. Androgen deprivation therapy for 4 months was completed in all patients. The most common adverse events were hyperphosphataemia, taste disturbance, dry mouth and nail changes. No patients achieved a complete pathological response, although patients who tolerated erdafitinib for longer had smaller residual tumours, associated with reduced transcriptional signatures of epithelial cell proliferation. CONCLUSIONS: Although there was a possible enhanced anti-tumour effect of androgen deprivation therapy in combination with erdafitnib in treatment naïve prostate cancer, the poor tolerability in this patient population prohibits the use of this combination in this setting.

Real-world first-line systemic therapy patterns in metastatic castration-resistant prostate cancer.

Introduction: Several systemic therapies have demonstrated a survival advantage in metastatic castration resistant prostate cancer (mCRPC). Access to these medications varies significantly worldwide. In Australia until recently, patients must have received docetaxel first, unless unsuitable for chemotherapy, despite no evidence suggesting superiority over androgen receptor signalling inhibitors (ARSIs). Our study investigated real-world systemic treatment patterns in Australian patients with mCRPC. Methods: The electronic CRPC Australian Database (ePAD) was interrogated to identify mCRPC patients. Clinicopathological features, treatment and outcome data, stratified by first-line systemic therapies, were extracted. Comparisons between groups utilised Kruskal-Wallis tests and Chi-Square analyses. Time-to-event data were calculated using Kaplan-Meier methods and groups compared using log-rank tests. Factors influencing overall survival (OS) and time to treatment failure (TTF) were analysed through Cox proportional hazards regression models. Results: We identified 578 patients who received first-line systemic therapy for mCRPC. Enzalutamide (ENZ) was most commonly prescribed (n = 240, 41%), followed by docetaxel (DOC, n = 164, 28%) and abiraterone (AA, n = 100, 17%). Patients receiving ENZ or AA were older (79, 78.5 years respectively) compared with DOC (71 years, p = 0.001) and less likely to have ECOG performance status 0 (45%, 44%, 59% in ENZ, AA and DOC groups respectively p < 0.0001). Median TTF was significantly higher in those receiving ENZ (12.4 months) and AA (11.9 months) compared to DOC (8.3 months, p < 0.001). PSA50 response rates and OS were not statistically different. Time to developing CRPC > 12 months was independently associated with longer TTF (HR 0.67, p < 0.001) and OS (HR 0.49, p = 0.002). Conclusion: In our real-world population, ENZ and AA were common first-line systemic therapy choices, particularly among older patients and those with poorer performance status. Patients receiving ENZ and AA demonstrated superior TTF compared to DOC, while OS was not statistically different. Our findings highlight the important role of ARSIs, given the variability of access worldwide.

Molecular classification of hormone-sensitive and castration-resistant prostate cancer, using nonnegative matrix factorization molecular subtyping of primary and metastatic specimens.

BACKGROUND: Despite the rapidly evolving therapeutic landscape, immunotherapy has demonstrated limited activity in prostate cancer. A greater understanding of the molecular landscape, particularly the expression of immune-related pathways, will inform future immunotherapeutic strategies. Consensus nonnegative matrix factorization (cNMF) is a novel model of molecular classification analyzing gene expression data, focusing on biological interpretation of metagenes and selecting meaningful clusters. OBJECTIVE: We aimed to identify molecular subtypes of prostate cancer using cNMF and correlate these with existing biomarkers to inform future immunotherapeutic strategies. METHODS: A cohort of archival tumor specimens from hormone-sensitive and castration-resistant disease was studied. Whole transcriptomic profiles were generated using TruSeq RNA Access technology and subjected to cNMF. Comprehensive genomic profiling was performed with the FoundationOne assay. NMF subtypes were characterized by gene expression pathways, genomic alterations and correlated with clinical data, then applied to The Cancer Genome Atlas data set. RESULTS: We studied 164 specimens, including 52 castration-resistant and 13 paired primary/metastatic specimens. cNMF identified four distinct subtypes. NMF1 (19%) is enriched for immune-related and stromal-related pathways with transforming growth factor ß (TGFß) signature. NMF2 (36%) is associated with FOXO-mediated transcription signature and AKT signaling, NMF3 (26%) is enriched for ribosomal RNA processing, while NMF4 (19%) is enriched for cell cycle and DNA-repair pathways. The most common gene alterations included TMPRSS22 (42%), TP53 (23%), and DNA-repair genes (19%), occurring across all subtypes. NMF4 is significantly enriched for MYC and Wnt-signaling gene alterations. TMB, CD8 density, and PD-L1 expression were low overall. NMF1 and NMF4 were NMF2 was associated with superior overall survival. CONCLUSIONS: Using cNMF, we identified four molecularly distinct subtypes which may inform treatment selection. NMF1 demonstrates the most inflammatory signature with asuppressive TGFß signature, suggesting potential benefit with immunotherapy combination strategies targeting TGFß and PD-(L)1. Prospective studies are required to evaluate the use of this novel model to molecularly stratify patients for optimal treatment selection.

Beyond cabazitaxel: Late line treatments in metastatic castration resistant prostate cancer: A retrospective multicentre analysis.

AIMS: Multiple life-prolonging therapies are available for metastatic castration-resistant prostate cancer (mCRPC). However, the optimal treatment strategy following progression through standard treatment with docetaxel, androgen receptor signaling inhibitor (ARSI) and cabazitaxel, remains unclear. We aimed to describe treatment patterns in men with mCRPC following progression on standard treatments and determine whether subsequent treatment choice impacts overall survival. METHODS: Clinicopathologic and treatment data were extracted from the electronic CRPC Australian Database (ePAD) for patients who had received docetaxel, ARSIs and cabazitaxel in any order. Data were analyzed to compare groups that did versus did not receive subsequent systemic therapy. Treatment sequences, median duration of treatment, and median overall survival (mOS) were reported for each treatment group. RESULTS: Ninety-eight eligible patients were identified, with 51 receiving subsequent systemic therapy. Those who received further treatment were younger (68 vs. 71 years, p < .01) but did not have any other differences in clinicopathologic features compared to those who received no further treatment. Patients who received upfront docetaxel were more likely to proceed to subsequent treatment (p = .02). Subsequent systemic therapies varied, the most common being carboplatin-based regimens (n = 13, 25.5%) and many patients were rechallenged with ARSI (n = 10, 19.6%) or docetaxel (n = 6, 11.8%). There was no difference in mOS according to subsequent systemic therapy (p = .09). CONCLUSION: This retrospective multicenter analysis demonstrates the variation in treatment sequences used for mCRPC in the real-world setting. In the absence of high quality, prospective evidence, our results suggest that subsequent treatment choice does not influence survival outcomes and the optimal choice is guided by individual patient and disease-related factors.

Uptake of bone-modifying agents in patients with HER2+ metastatic breast cancer with bone metastases - prospective data from a multi-site Australian registry.

BACKGROUND: International practice guidelines recommend administration of bone-modifying agents (BMA) in metastatic breast cancer (MBC) patients with bone metastases to reduce skeletal-related events (SRE). Optimal delivery of BMA in routine clinical practice, including agent selection and prescribing intervals, remains unclear. AIM: To describe real-world practice of Australian breast oncologists. METHODS: Prospective data from February 2015 to July 2020 on BMA delivery to MBC patients with bone metastases was analysed from Treatment of Advanced Breast Cancer in the Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Australian Patient (TABITHA), a multi-site Australian HER2+ MBC registry. RESULTS: Of 333 HER2+ MBC patients, 171 (51%) had bone metastases at diagnosis, with a mean age of 58.1 years (range, 32-87). One hundred and thirty (76%) patients received a BMA, with 90 (69%) receiving denosumab and 40 (31%) receiving a bisphosphonate. Patients who received a BMA were more likely to have received concurrent first-line systemic anti-HER2 therapy (95% vs 83%; P = 0.04), to present with bone-only metastases at diagnosis (24% vs 7%; P = 0.02) and less likely to have visceral metastases (51% vs 71%; P = 0.03). Ten of 40 (25%) bisphosphonate patients and 45 of 90 (50%) denosumab patients received their BMA at the recommended 4-weekly interval. Prescribing intervals varied over time. Adverse events reported were consistent with clinical trial data. CONCLUSION: Three-quarters of Australian HER2+ MBC patients with bone metastases receive a BMA, often at different schedules than guidelines recommend. Further studies, including all MBC subtypes, are warranted to better understand clinicians' prescribing rationale and potential consequences of current prescribing practice on SRE incidence.

Avelumab Combined with Stereotactic Ablative Body Radiotherapy in Metastatic Castration-resistant Prostate Cancer: The Phase 2 ICE-PAC Clinical Trial.

BACKGROUND: Immune checkpoint inhibitor monotherapy in metastatic castration-resistant prostate cancer (mCRPC) has produced modest results. High-dose radiotherapy may be synergistic with checkpoint inhibitors. OBJECTIVE: To evaluate the efficacy and safety of the PD-L1 inhibitor avelumab with stereotactic ablative body radiotherapy (SABR) in mCRPC. DESIGN, SETTING, AND PARTICIPANTS: From November 2017 to July 2019, this prospective phase 2 study enrolled 31 men with progressive mCRPC after at least one prior androgen receptor-directed therapy. Median follow-up was 18.0 mo. INTERVENTION: Avelumab 10 mg/kg intravenously every 2 wk for 24 wk (12 cycles). A single fraction of SABR (20 Gy) was administered to one or two disease sites within 5 d before the first and second avelumab treatments. OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was the disease control rate (DCR), defined as a confirmed complete or partial response of any duration, or stable disease/non-complete response/non-progressive disease for ≥6 mo (Prostate Cancer Clinical Trials Working Group 3-modified Response Evaluation Criteria in Solid Tumours version 1.1). Secondary endpoints were the objective response rate (ORR), radiographic progression-free survival (rPFS), overall survival (OS), and safety. DCR and ORR were calculated using the Clopper-Pearson exact binomial method. RESULTS AND LIMITATIONS: Thirty-one evaluable men were enrolled (median age 71 yr, 71% with ≥2 prior mCRPC therapy lines, 81% with >5 total metastases). The DCR was 48% (15/31; 95% confidence interval [CI] 30-67%) and ORR was 31% (five of 16; 95% CI 11-59%). The ORR in nonirradiated lesions was 33% (four of 12; 95% CI 10-65%). Median rPFS was 8.4 mo (95% CI 4.5-not reached [NR]) and median OS was 14.1 mo (95% CI 8.9-NR). Grade 3-4 treatment-related adverse events occurred in six patients (16%), with three (10%) requiring high-dose corticosteroid therapy. Plasma androgen receptor alterations were associated with lower DCR (22% vs 71%, p = 0.13; Fisher's exact test). Limitations include the small sample size and the absence of a control arm. CONCLUSIONS: Avelumab with SABR demonstrated encouraging activity and acceptable toxicity in treatment-refractory mCRPC. This combination warrants further investigation. PATIENT SUMMARY: In this study of men with advanced and heavily pretreated prostate cancer, combining stereotactic radiotherapy with avelumab immunotherapy was safe and resulted in nearly half of patients experiencing cancer control for 6 months or longer. Stereotactic radiotherapy may potentially improve the effectiveness of immunotherapy in prostate cancer.

Real-world use of first-generation antiandrogens: impact on patient outcomes and subsequent therapies in metastatic castration-resistant prostate cancer.

OBJECTIVES: To investigate the recent real-world use of first-generation antiandrogens (FGAs) in metastatic castration-resistant prostate cancer (mCRPC) using a retrospective multicentre cohort study. PATIENTS AND METHODS: The electronic CRPC Australian Database (ePAD) was interrogated to identify patients with mCRPC. Clinicopathological features, treatment and outcome data, stratified by FGA use, were retrieved and reported through descriptive statistics. Survival analyses were calculated using the Kaplan-Meier method and groups compared using log-rank tests. Factors influencing overall survival (OS) were analysed using Cox proportional hazards regression model. RESULTS: We identified 634 patients with mCRPC, enrolled in ePAD between January 2016 and March 2019, including 322 (51%) who received FGAs. The median follow-up was 21.9 months. Patients treated with FGAs were more likely to have lower International Society of Urological Pathologists (ISUP) grade group (P = 0.04), longer median time to CRPC (25.6 vs 16.0 months, P < 0.001), and were less likely to have visceral metastases (5.0% vs 11.2%, P = 0.005) or to have received upfront docetaxel (P < 0.001). A ≥50% reduction from pre-treatment prostate-specific antigen (PSA) level (PSA50 response) during FGA treatment occurred in 119 (37%) patients and was independently associated with improved OS (hazard ratio 0.233, P < 0.001). Prior FGA treatment did not significantly influence the selection of subsequent life-prolonging treatments for mCRPC or their PSA50 response rates. CONCLUSION: In our present cohort, FGAs were commonly used in lower-risk mCRPC and their use did not significantly influence the choice or duration of subsequent systemic therapy. A PSA50 response to FGA therapy was an independent favourable prognostic marker associated with improved OS.

Real-world incidence of symptomatic skeletal events and bone-modifying agent use in castration-resistant prostate cancer - an Australian multi-centre observational study.

INTRODUCTION: Bone metastases occur frequently in castration-resistant prostate cancer (CRPC) and may lead to skeletal-related events (SREs), including symptomatic skeletal events (SSEs). Bone-modifying agents (BMAs) delay SREs and SSEs. However, the real-world use of BMAs is debated given the absence of demonstrated survival advantage and potential adverse events (AEs). Our retrospective study examined BMA use and SSE rates in Australian patients with CRPC. METHODS: Patients with CRPC and bone metastases were identified from the electronic CRPC Australian Database. Patient characteristics, treatment patterns and AEs were analysed. Descriptive statistics reported baseline characteristics, SSE rates and BMA use. Comparisons between groups used t-tests and Chi-square analyses. Overall survival was calculated by the Kaplan-Meier method. RESULTS: A total of 532 eligible patients were identified with a median age of 73 years (range: 44-97 years). BMAs were prescribed in 232 men (46%), 183 of whom received denosumab. Patients receiving first-line docetaxel for CRPC were more likely to commence BMAs than those receiving abiraterone or enzalutamide (51% vs 31% vs 38%; p = 0.004). SSEs occurred in 148 men (28%), most commonly symptomatic lesions requiring intervention (75%). At the time of initial SSEs, only 28% were receiving BMAs. Patients treated at sites with lower BMA use (

Cancer clinical trial vs real-world outcomes for standard of care first-line treatment in the advanced disease setting.

Clinical trials have strict eligibility criteria, potentially limiting external validity. However, while often discussed this has seldom been explored, particularly across cancer types and at variable time frames posttrial completion. We examined comprehensive registry data (January 2014 to June 2019) for standard first-line treatments for metastatic colorectal cancer (CRC), advanced pancreatic cancer (PC), metastatic HER2-amplified breast cancer (BC) and castrate-resistant prostate cancer (CaP). Registry patient characteristics and outcomes were compared to the practice-changing trial. Registry patients were older than the matched trial cohort by a median of 2-6 years (all P = <.01) for the CRC, BC and PC cohorts. The proportion of Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1 patients was lower for CRC (94.1% vs 99.2%, P = .001) and BC (94.9% vs 99.3%, P = .001). Progression-free survival (PFS) for registry patients was similar to the trial patients or significantly longer (CaP, Hazard Ratio [HR] = 0.65, P = <.001). Overall survival (OS) was also similar or significantly longer (CaP, HR 0.49, P = <.001). In conclusion, despite real-world patients sometimes being older or having inferior PS to trial cohorts, the survival outcomes achieved were consistently equal or superior to those reported for the same treatment in the trial. We suggest that this is potentially due to optimised use of each treatment over time, improved multidisciplinary care and increased postprogression options. We can reassure clinicians and patients that outcomes matching or exceeding those reported in trials are possible. The potential for survival gains over time should routinely be factored into future trial statistical plans.

Treatment outcomes for patients with metastatic castrate-resistant prostate cancer following docetaxel for hormone-sensitive disease.

AIM: Optimal treatment for newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC) has evolved, with many patients deriving benefit from the addition of docetaxel to androgen deprivation therapy (D-ADT). This study sought to define the therapy used and associated activity following D-ADT. METHODS: Retrospective analysis of patients with mHSPC treated with one or more cycles of D-ADT who were identified from a prospectively maintained multisite prostate cancer database of patients treated in a community or academic center setting in Australia. The primary endpoint of this study was first-line time to treatment failure (1L TTF) for subsequent treatment of metastatic Castrate Resistant Prostate Cancer (mCRPC), with secondary endpoints of prostate-specific antigen (PSA) reduction >50% and time from 1L to second-line (2L) treatment initiation. RESULTS: A total of 93 patients received D-ADT for mHSPC, 85 (91%) had subsequent treatment for mCRPC. Median time to mCRPC (biochemical, clinical or radiographic) had been 14.8 months (95% confidence interval [CI], 11.9-16.5). 1L treatment was enzalutamide 47 patients (55%), abiraterone 23 (27%), cabazitaxel 7 (8%), docetaxel 4 (5%) and other therapies 4 (5%). Median 1L TTF was 6.3 months (95% CI, 4.9-7.6), PSA > 50% reduction was achieved in 32 of 89 patients (36%), median time from 1L to second-line treatment was 7.3 months (1.3-27.4), which did not differ significantly between treatment groups. CONCLUSIONS: Abiraterone, enzalutamide, cabazitaxel and docetaxel all demonstrate activity following progression on D-ADT. No difference in efficacy was detected between treatment options for mCRPC. Prospective trials investigating the optimal treatment sequence for prostate cancer following progression on D-ADT needed.