Summary Background Ipilimumab is a fully human monoclonal antibody that binds cytotoxic T-lymphocyte antigen 4 to enhance antitumour immunity. Our aim was to assess the use of ipilimumab after ...radiotherapy in patients with metastatic castration-resistant prostate cancer that progressed after docetaxel chemotherapy. Methods We did a multicentre, randomised, double-blind, phase 3 trial in which men with at least one bone metastasis from castration-resistant prostate cancer that had progressed after docetaxel treatment were randomly assigned in a 1:1 ratio to receive bone-directed radiotherapy (8 Gy in one fraction) followed by either ipilimumab 10 mg/kg or placebo every 3 weeks for up to four doses. Non-progressing patients could continue to receive ipilimumab at 10 mg/kg or placebo as maintenance therapy every 3 months until disease progression, unacceptable toxic effect, or death. Patients were randomly assigned to either treatment group via a minimisation algorithm, and stratified by Eastern Cooperative Oncology Group performance status, alkaline phosphatase concentration, haemoglobin concentration, and investigator site. Patients and investigators were masked to treatment allocation. The primary endpoint was overall survival, assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov , number NCT00861614. Findings From May 26, 2009, to Feb 15, 2012, 799 patients were randomly assigned (399 to ipilimumab and 400 to placebo), all of whom were included in the intention-to-treat analysis. Median overall survival was 11·2 months (95% CI 9·5–12·7) with ipilimumab and 10·0 months (8·3–11·0) with placebo (hazard ratio HR 0·85, 0·72–1·00; p=0·053). However, the assessment of the proportional hazards assumption showed that it was violated (p=0·0031). A piecewise hazard model showed that the HR changed over time: the HR for 0–5 months was 1·46 (95% CI 1·10–1·95), for 5–12 months was 0·65 (0·50–0·85), and beyond 12 months was 0·60 (0·43–0·86). The most common grade 3–4 adverse events were immune-related, occurring in 101 (26%) patients in the ipilimumab group and 11 (3%) of patients in the placebo group. The most frequent grade 3–4 adverse events included diarrhoea (64 16% of 393 patients in the ipilimumab group vs seven 2% of 396 in the placebo group), fatigue (40 11% vs 35 9%), anaemia (40 10% vs 43 11%), and colitis (18 5% vs 0). Four (1%) deaths occurred because of toxic effects of the study drug, all in the ipilimumab group. Interpretation Although there was no significant difference between the ipilimumab group and the placebo group in terms of overall survival in the primary analysis, there were signs of activity with the drug that warrant further investigation. Funding Bristol-Myers Squibb.
Summary Background Enzalutamide significantly increased overall survival and radiographic progression-free survival compared with placebo in the PREVAIL trial of asymptomatic and minimally ...symptomatic, chemotherapy-naive patients with metastatic castration-resistant prostate cancer. We report the effect of enzalutamide on health-related quality of life (HRQoL), pain, and skeletal-related events observed during this trial. Methods In this phase 3, double-blind trial, patients were randomly assigned (1:1) to receive enzalutamide 160 mg/day (n=872) or placebo (n=845) orally. HRQoL was assessed at baseline and during treatment using the Functional Assessment of Cancer Therapy–Prostate (FACT-P) and EQ-5D questionnaires. Pain status was assessed at screening, baseline, week 13, and week 25 with the Brief Pain Inventory Short Form (BPI-SF). The primary analysis of HRQoL data used a mixed-effects model to test the difference between least square means change from baseline at week 61. We assessed change from baseline, percentage improvement, and time to deterioration in HRQoL and pain, the proportion of patients with a skeletal-related event, and time to first skeletal-related event. Analysis was done on the intention-to-treat population. This study is registered with ClinicalTrials.gov , number NCT01212991. Findings Median treatment duration was 16·6 months (IQR 10·1–21·1) in the enzalutamide group and 4·6 months (2·8–9·7) in the placebo group. The mixed-effects model analyses showed significant treatment differences in change from baseline to week 61 with enzalutamide compared with placebo for most FACT-P endpoints and EQ-5D visual analogue scale. Median time to deterioration in FACT-P total score was 11·3 months (95% CI 11·1–13·9) in the enzalutamide group and 5·6 months (5·5–5·6) in the placebo groups (hazard ratio HR 0·62 95% CI 0·54–0·72; p<0·0001). A significantly greater proportion of patients in the enzalutamide group than in the placebo group reported clinically meaningful improvements in FACT-P total score (327 40% of 826 vs 181 23% of 790), in EQ-5D utility index (224 28% of 812 vs 99 16% of 623), and visual analogue scale (218 27% of 803 vs 106 of 18% 603; all p<0·0001). Median time to progression in BPI-SF pain at its worst was 5·7 months (95% CI 5·6–5·7) in the enzalutamide group and 5·6 months (5·4–5·6) in the placebo group (HR 0·62 95% CI 0·53–0·74; p<0·0001). Progression of pain at its worst was less common in the enzalutamide group than in the placebo group at week 13 (220 29% of 769 vs 257 42% of 610; p<0·0001), but not at week 25 (225 32% of 705 vs 135 38% of 360; p=0·068). 278 (32%) of 872 patients in the enzalutamide group and 309 (37%) of 845 patients in the placebo group had experienced a skeletal-related event by data cutoff. Median time to first skeletal-related events in the enzalutamide group was 31·1 months (95% CI 29·5–not reached) and 31·3 months (95% CI 23·9–not reached) in the placebo group (HR 0·72 95% CI 0·61–0·84; p<0·0001). Interpretation In addition to improving overall survival relative to placebo, enzalutamide significantly improves patient-related outcomes and delays occurrence of first skeletal-related event in chemotherapy-naive men with metastatic castration-resistant prostate cancer. Funding Astellas Pharma and Medivation.
Summary Background MDV3100 is an androgen-receptor antagonist that blocks androgens from binding to the androgen receptor and prevents nuclear translocation and co-activator recruitment of the ...ligand-receptor complex. It also induces tumour cell apoptosis, and has no agonist activity. Because growth of castration-resistant prostate cancer is dependent on continued androgen-receptor signalling, we assessed the antitumour activity and safety of MDV3100 in men with this disease. Methods This phase 1–2 study was undertaken in five US centres in 140 patients. Patients with progressive, metastatic, castration-resistant prostate cancer were enrolled in dose-escalation cohorts of three to six patients and given an oral daily starting dose of MDV3100 30 mg. The final daily doses studied were 30 mg (n=3), 60 mg (27), 150 mg (28), 240 mg (29), 360 mg (28), 480 mg (22), and 600 mg (3). The primary objective was to identify the safety and tolerability profile of MDV3100 and to establish the maximum tolerated dose. The trial is registered with ClinicalTrials.gov , number NCT00510718. Findings We noted antitumour effects at all doses, including decreases in serum prostate-specific antigen of 50% or more in 78 (56%) patients, responses in soft tissue in 13 (22%) of 59 patients, stabilised bone disease in 61 (56%) of 109 patients, and conversion from unfavourable to favourable circulating tumour cell counts in 25 (49%) of the 51 patients. PET imaging of 22 patients to assess androgen-receptor blockade showed decreased18 F-fluoro-5α-dihydrotestosterone binding at doses from 60 mg to 480 mg per day (range 20–100%). The median time to progression was 47 weeks (95% CI 34–not reached) for radiological progression. The maximum tolerated dose for sustained treatment (>28 days) was 240 mg. The most common grade 3–4 adverse event was dose-dependent fatigue (16 11% patients), which generally resolved after dose reduction. Interpretation We recorded encouraging antitumour activity with MDV3100 in patients with castration-resistant prostate cancer. The results of this phase 1–2 trial validate in man preclinical studies implicating sustained androgen-receptor signalling as a driver in this disease. Funding Medivation, the Prostate Cancer Foundation, National Cancer Institute, the Howard Hughes Medical Institute, Doris Duke Charitable Foundation, and Department of Defense Prostate Cancer Clinical Trials Consortium.
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