Determination of enzalutamide long-term safety and efficacy for castration-resistant prostate cancer patients after combined anti-androgen blockade followed by alternative anti-androgen therapy: a multicenter prospective DELC study.

BACKGROUND: Alternative anti-androgen therapy has been widely used as a first-line treatment for castration-resistant prostate cancer, and it may affect treatment outcome of subsequent agents targeting the androgen receptor axis. We conducted the prospective observational DELC (Determination of Enzalutamide Long-term safety and efficacy for Castration-resistant prostate cancer patients after combined anti-androgen blockade followed by alternative anti-androgen therapy) study to evaluate the efficacy of enzalutamide in patients with castration-resistant prostate cancer who underwent prior combined androgen blockade with bicalutamide and then alternative anti-androgen therapy with flutamide. METHODS: The DELC study enrolled 163 Japanese patients with castration-resistant prostate cancer who underwent alternative anti-androgen therapy with flutamide following failure of initial combined androgen blockade with bicalutamide in multiple institutions between January 2016 and March 2019. Primary endpoint was overall survival. Administration of enzalutamide was started at 160 mg orally once daily in all patients. RESULTS: The rate of decline of prostate-specific antigen by 50% or more was 72.2%, and median overall survival was 42.05 months. Multivariate analysis revealed that higher pretreatment serum levels of prostate-specific antigen (≥11.3 ng/mL; P = 0.004), neuron-specific enolase (P = 0.014) and interleukin-6 (≥2.15 pg/mL; P = 0.004) were independent risk factors for overall survival. Fatigue (30.0%), constipation (19.6%) and appetite loss (17.8%) were the most common clinically relevant adverse events. The enzalutamide dose was not reduced in any patient under the age of 70, but adherence was decreased in those over 70. CONCLUSIONS: In the DELC study, the safety of enzalutamide was comparable to that in previous reports. Serum levels of neuron-specific enolase and interleukin-6 were suggested as prognostic factors for castration-resistant prostate cancer with potential clinical utility.

Quality of life in patients with metastatic prostate cancer following treatment with cabazitaxel versus abiraterone or enzalutamide (CARD): an analysis of a randomised, multicentre, open-label, phase 4 study.

BACKGROUND: In the CARD study, cabazitaxel significantly improved radiographic progression-free survival and overall survival versus abiraterone or enzalutamide in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel and the alternative androgen signalling-targeted inhibitor. Here, we report the quality-of-life outcomes from the CARD study. METHODS: CARD was a randomised, multicentre, open-label, phase 4 study involving 62 clinical sites across 13 European countries. Patients (aged ≥18 years, Eastern Cooperative Oncology Group (ECOG) performance status ≤2) with confirmed metastatic castration-resistant prostate cancer were randomly assigned (1:1) by means of an interactive voice-web response system to receive cabazitaxel (25 mg/m2 intravenously every 3 weeks, 10 mg daily prednisone, and granulocyte colony-stimulating factor) versus abiraterone (1000 mg orally once daily plus 5 mg prednisone twice daily) or enzalutamide (160 mg orally daily). Stratification factors were ECOG performance status, time to disease progression on the previous androgen signalling-targeted inhibitor, and timing of the previous androgen signalling-targeted inhibitor. The primary endpoint was radiographic progression-free survival; here, we present more detailed analyses of pain (assessed using item 3 on the Brief Pain Inventory-Short Form [BPI-SF]) and symptomatic skeletal events, alongside preplanned patient-reported outcomes, assessed using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire and the EuroQoL-5 dimensions, 5 level scale (EQ-5D-5L). Efficacy analyses were done in the intention-to-treat population. Pain response was analysed in the intention-to-treat population with baseline and at least one post-baseline assessment of BPI-SF item 3, and patient-reported outcomes (PROs) were analysed in the intention-to-treat population with baseline and at least one post-baseline assessment of either FACT-P or EQ-5D-5L (PRO population). Analyses of skeletal-related events were also done in the intention-to-treat population. The CARD study is registered with ClinicalTrials.gov, NCT02485691, and is no longer enrolling. FINDINGS: Between Nov 17, 2015, and Nov 28, 2018, of 303 patients screened, 255 were randomly assigned to cabazitaxel (n=129) or abiraterone or enzalutamide (n=126). Median follow-up was 9·2 months (IQR 5·6-13·1). Pain response was observed in 51 (46%) of 111 patients with cabazitaxel and 21 (19%) of 109 patients with abiraterone or enzalutamide (p<0·0001). Median time to pain progression was not estimable (NE; 95% CI NE-NE) with cabazitaxel and 8·5 months (4·9-NE) with abiraterone or enzalutamide (hazard ratio [HR] 0·55, 95% CI 0·32-0·97; log-rank p=0·035). Median time to symptomatic skeletal events was NE (95% CI 20·0-NE) with cabazitaxel and 16·7 months (10·8-NE) with abiraterone or enzalutamide (HR 0·59, 95% CI 0·35-1·01; log-rank p=0·050). Median time to FACT-P total score deterioration was 14·8 months (95% CI 6·3-NE) with cabazitaxel and 8·9 months (6·3-NE) with abiraterone or enzalutamide (HR 0·72, 95% CI 0·44-1·20; log-rank p=0·21). There was a significant treatment effect seen in changes from baseline in EQ-5D-5L utility index score in favour of cabazitaxel over abiraterone or enzalutamide (p=0·030) but no difference between treatment groups for change from baseline in EQ-5D-5L visual analogue scale (p=0·060). INTERPRETATION: Since cabazitaxel improved pain response, time to pain progression, time to symptomatic skeletal events, and EQ-5D-5L utility index, clinicians and patients with metastatic castration-resistant prostate cancer can be reassured that cabazitaxel will not reduce quality of life when compared with treatment with a second androgen signalling-targeted inhibitor. FUNDING: Sanofi.

Evaluation of Intense Androgen Deprivation Before Prostatectomy: A Randomized Phase II Trial of Enzalutamide and Leuprolide With or Without Abiraterone.

PURPOSE: Patients with locally advanced prostate cancer have an increased risk of cancer recurrence and mortality. In this phase II trial, we evaluate neoadjuvant enzalutamide and leuprolide (EL) with or without abiraterone and prednisone (ELAP) before radical prostatectomy (RP) in men with locally advanced prostate cancer. PATIENTS AND METHODS: Eligible patients had a biopsy Gleason score of 4 + 3 = 7 or greater, prostate-specific antigen (PSA) greater than 20 ng/mL, or T3 disease (by prostate magnetic resonance imaging). Lymph nodes were required to be smaller than 20 mm. Patients were randomly assigned 2:1 to ELAP or EL for 24 weeks followed by RP. All specimens underwent central pathology review. The primary end point was pathologic complete response or minimal residual disease (residual tumor ≤ 5 mm). Secondary end points were PSA, surgical staging, positive margins, and safety. Biomarkers associated with pathologic outcomes were explored. RESULTS: Seventy-five patients were enrolled at four centers. Most patients had high-risk disease by National Comprehensive Cancer Network criteria (n = 65; 87%). The pathologic complete response or minimal residual disease rate was 30% (n = 15 of 50) in ELAP-treated patients and 16% (n = four of 25) in EL-treated patients (two-sided P = .263). Rates of ypT3 disease, positive margins, and positive lymph nodes were similar between arms. Treatment was well-tolerated. Residual tumors in the two arms showed comparable levels of ERG, PTEN, androgen receptor PSA, and glucocorticoid receptor expression. Tumor ERG positivity and PTEN loss were associated with more extensive residual tumors at RP. CONCLUSION: Neoadjuvant hormone therapy followed by RP in locally advanced prostate cancer resulted in favorable pathologic responses in some patients, with a trend toward improved pathologic outcomes with ELAP. Longer follow-up is necessary to evaluate the impact of therapy on recurrence rates. The potential association of ERG and PTEN alterations with worse outcomes warrants additional investigation.

Impact of enzalutamide administration on primary prostate cancer volume: a metabolic evaluation by choline positron emission tomography in castration-resistant prostate cancer patients.

BACKGROUND: Enzalutamide is active in advanced castration-resistant prostate cancer (CRPC) patients, in whom it has shown to be able to increase survival. We report the enzalutamide effect on primary prostate tumors, assessed by changes of metabolic tumor activity detected by (18)F-fluorocholine-positron emission tomography/computerized tomography ((18)F-FCH PET/CT). PATIENTS AND METHODS: We treated 31 patients with pretreated metastatic CRPC in an enzalutamide named-patient program. All patients were initially evaluated and then followed up by means of repeated (18)F-FCH PET/CT examinations. We identified most radiotracer-avid lesions, which were defined as specific regions of interest (ROIs): for each ROI we defined the maximum radiotracer standardized uptake value (SUVmax) and the threshold-based volume of interest (VOI) with a cutoff SUV value ≥ 2.5. In the 12 patients who did not receive a radical treatment for localized disease, the prostate was also considered an ROI. RESULTS: The baseline prostate median SUVmax of 7.25 showed reductions of 25% (P = .012) and 43% (P = .009) after 3 and 7 months of enzalutamide treatment, respectively. The baseline median prostate VOI of 12.73 cm(3) showed a reduction of 73% (P = .002) at 3 months and a reduction of 90% (P = .005) at 7 months. CONCLUSION: In addition to the metabolic changes of metastatic lesions observed with enzalutamide in CRPC patients, our data have shown significant volume reductions of the primary tumors according to (18)F-FCH PET/CT evaluation. These results could suggest the potential of enzalutamide therapy for localized prostate cancer.