Continuing benefit of zoledronic acid in preventing skeletal complications in patients with bone metastases.

PURPOSE: We previously reported the efficacy of zoledronic acid 4 mg versus placebo (every 3 weeks for 24 months) for the prevention of skeletal-related events (SREs) in men with advanced prostate cancer and bone metastases. We conducted several retrospective exploratory analyses to determine whether zoledronic acid has continuing efficacy during long-term treatment. PATIENTS AND METHODS: This report included analysis of the occurrence of SREs during the extension phase only (months 16-24), analysis of skeletal complications excluding the first SRE at 15 months (core phase), and stratified analysis of patients by history of SREs before study entry. RESULTS: Patients (N=422) were randomized to receive zoledronic acid 4 mg or placebo. For the 132 patients who entered the extension phase, zoledronic acid significantly delayed the onset of first SRE (P=.009) and decreased the risk of developing an SRE by 53% compared with placebo (P=.022). Among all 422 patients, zoledronic acid significantly reduced the incidence of a second on-study SRE (P=.017) and significantly delayed the median time to second SRE compared with placebo (P=.006) at 15 months. Among 144 patients (34%) with a history of SREs before study entry, zoledronic acid significantly reduced the skeletal morbidity rate by 65% (P=.036) and reduced the overall risk of developing an SRE by 40% (P=.028) compared with placebo at 24 months. CONCLUSION: This analysis confirms our previously reported results and suggests that long-term treatment with zoledronic acid provides continuing clinical benefit in patients with advanced prostate cancer, even after the occurrence of SREs.

The bicalutamide 150 mg early prostate cancer program: findings of the North American trial at 7.7-year median followup.

PURPOSE: We describe the results of North American Trial 23 of the bicalutamide (Casodex) early prostate cancer program in the context of the overall early prostate cancer program findings. MATERIALS AND METHODS: In Trial 23, 3,292 men with T1b-4, N0-Nx (N+ not allowed) M0 prostate cancer who had undergone radical prostatectomy or radiotherapy at 96 specialist referral centers in the United States (2,974) and Canada (318) were randomized 1:1 to 150 mg bicalutamide daily or placebo in addition to standard care for 2 years. RESULTS: In Trial 23 at a 7.7-year median followup there were few clinical events in the bicalutamide or standard care groups and the rates of objective progression were 15.4% and 15.3%, respectively. Mortality rates were 12.9% in the treatment group and 12.3% in the standard care group, including 11.2% and 11.0% for nonprostate cancer deaths in the absence of objective progression and 1.6% and 0.9%, respectively, for mortality due to prostate cancer. No differences in the primary end points (objective progression-free and overall survival) were seen between patients treated with bicalutamide and those treated with standard care alone. Bicalutamide (150 mg) significantly improved time to PSA progression (HR 0.80, 95% CI 0.72 to 0.90, p <0.001). The tolerability profile of bicalutamide was similar to that previously described. CONCLUSIONS: In Trial 23 the current data suggest that early or adjuvant therapy may not benefit patients at low risk for recurrence, such as those with localized disease. The findings of Trial 23 contrast with the results in the overall early prostate cancer program and in other published literature, in which bicalutamide has been shown to provide significant clinical benefit for locally advanced disease.

Long-term efficacy of zoledronic acid for the prevention of skeletal complications in patients with metastatic hormone-refractory prostate cancer.

In a placebo-controlled randomized clinical trial, zoledronic acid (4 mg via a 15-minute infusion every 3 weeks for 15 months) reduced the incidence of skeletal-related events (SREs) in men with hormone-refractory metastatic prostate cancer. Among 122 patients who completed a total of 24 months on study, fewer patients in the 4-mg zoledronic acid group than in the placebo group had at least one SRE (38% versus 49%, difference = -11.0%, 95% confidence interval [CI] = -20.2% to -1.3%; P =.028), and the annual incidence of SREs was 0.77 for the 4-mg zoledronic acid group versus 1.47 for the placebo group (P=.005). The median time to the first SRE was 488 days for the 4-mg zoledronic acid group versus 321 days for the placebo group (P =.009). Compared with placebo, 4 mg of zoledronic acid reduced the ongoing risk of SREs by 36% (risk ratio = 0.64, 95% CI = 0.485 to 0.845; P =.002). Patients in the 4-mg zoledronic acid group had a lower incidence of SREs than did patients in the placebo group, regardless of whether they had an SRE prior to entry in the study. Long-term treatment with 4 mg of zoledronic acid is safe and provides sustained clinical benefits for men with metastatic hormone-refractory prostate cancer.

Is the efficacy of hormonal therapy affected by lymph node status? data from the bicalutamide (Casodex) Early Prostate Cancer program.

OBJECTIVES: To report an exploratory subgroup analysis assessing the extent to which the overall benefit found in the Early Prostate Cancer program is dependent on lymph node status at randomization. The program is ongoing, and the overall survival data are immature. The first combined analysis of the bicalutamide (Casodex) Early Prostate Cancer program at 3 years' median follow-up showed that bicalutamide, 150 mg once daily, plus standard care (radical prostatectomy, radiotherapy, or watchful waiting), significantly reduced the risk of objective progression and prostate-specific antigen (PSA) doubling in patients with localized/locally advanced prostate cancer. METHODS: Men (n = 8113) with localized/locally advanced disease received bicalutamide 150 mg or placebo once daily, plus standard care. The time to event data (objective progression, PSA doubling) was analyzed by lymph node status at randomization. RESULTS: Compared with standard care alone, bicalutamide significantly reduced the risk of objective progression, irrespective of lymph node status, with the most pronounced reduction in patients with N+ (hazard ratio [HR] 0.29; 95% confidence interval [CI] 0.15 to 0.56) compared with those with N0 (HR 0.59; 95% CI 0.48 to 0.73) and Nx (HR 0.60; 95% CI 0.50 to 0.72) disease. The largest decrease in risk of PSA doubling with bicalutamide was observed in N+ disease (HR 0.16; 95% CI 0.09 to 0.29), with significantly reduced risks seen in N0 (HR 0.45; 95% CI 0.40 to 0.51) and Nx (HR 0.38; 95% CI 0.33 to 0.44) disease. CONCLUSIONS: The greatest reduction in the risk of objective progression and PSA doubling with bicalutamide was seen in patients with N+ disease. However, bicalutamide also provided a statistically significant benefit in those with N0 and Nx disease.

Randomized controlled trial of zoledronic acid to prevent bone loss in men receiving androgen deprivation therapy for nonmetastatic prostate cancer.

PURPOSE: A multicenter double-blind, randomized, placebo controlled clinical trial was performed to assess the effect of zoledronic acid, a potent new bisphosphonate, on bone mineral density during androgen deprivation therapy for nonmetastatic prostate cancer. MATERIALS AND METHODS: Men with M0 (no distant metastases) prostate cancer beginning androgen deprivation therapy were randomly assigned to receive 4 mg. zoledronic acid or placebo intravenously every 3 months for 1 year. The primary efficacy variable was the percent change from baseline to 1 year in bone mineral density of the lumbar spine as measured by dual energy x-ray absorptiometry. RESULTS: A total of 106 men were enrolled in the trial. Mean bone mineral density in the lumbar spine increased by 5.6% in men receiving zoledronic acid and decreased by 2.2% in those given placebo (mean difference 7.8%, 95% confidence interval 5.6%-10.0%, p <0.001). Mean bone mineral density of the femoral neck, trochanter and total hip also increased in the zoledronic acid group and decreased in the placebo group. Zoledronic acid was well tolerated. CONCLUSIONS: Zoledronic acid increases bone mineral density in the hip and spine during androgen deprivation therapy for nonmetastatic prostate cancer.

A six-month, open-label study assessing a new formulation of leuprolide 7.5 mg for suppression of testosterone in patients with prostate cancer.

OBJECTIVE: The safety, efficacy, and pharmacokinetics of monthly subcutaneous injections of a new leuprolide acetate (LA) depot formulation were investigated in patients with advanced prostate cancer. METHODS: The 2-part, 6-month (168-day), open-label, multicenter study enrolled male patients diagnosed with adenocarcinoma of the prostate (Jewett stage C or D). LA-2500 7.5-mg (a new subcutaneous depot formulation containing 7.5 mg of LA) injections were administered at monthly (28-day) intervals. The primary efficacy parameter was total serum testosterone level. A breakthrough response was defined as a single testosterone measurement > 50 ng/dL after achieving castration testosterone levels. Testosterone was isolated from sera by alumina column chromatography and measured by radioimmunoassay (RIA). LA was purified by solid-phase extraction and high-performance liquid chromatography and was then quantitated by RIA. RESULTS: One hundred seventeen of the 120 enrolled patients completed the 6-month study. Three patients withdrew for reasons not related to treatment. LA had a mean (SD) maximal concentration of 26.3 (12.6) ng/mL at 4.66 (1.44) hours and was detected for a mean of 37 days (range, 28-49 days). By day 28, 94.1% (112/119) of the patients achieved medical castration (serum testosterone < or = 50 ng/dL). By day 42, 100.0% (118/118) of the patients remaining in the study had serum testosterone levels < or = 50 ng/dL and 97.5% (115/118) had levels < or = 20 ng/dL. At study completion, the mean (SD) serum testosterone level was 6.12 (4.3) ng/dL (range, 3.0-27.0 ng/dL). No breakthrough or acute-on-chronic responses were reported throughout the study. From baseline to month 6, mean (SD) luteinizing hormone level decreased from 8.0 (7.3) mIU/mL to 0.09(0.1) mIU/mL, and mean (SD) prostate-specific antigen level decreased from 32.9 (86.3) ng/mL to 3.2 (12.0) ng/mL. Treatment-related adverse events were reported by 74.2% (89/120) of patients, the most common being hot flashes (56.7%). CONCLUSION: This 6-month, open-label, noncontrolled study showed LA-2500 7.5-mg depot was well tolerated and maintained testosterone suppression (< or = 50 ng/dL) in the patients completing the study without any testosterone breakthrough responses.

A randomized, placebo-controlled trial of zoledronic acid in patients with hormone-refractory metastatic prostate carcinoma.

BACKGROUND: Bone metastases are a common cause of morbidity in patients with prostate carcinoma. We studied the effect of a new bisphosphonate, zoledronic acid, which blocks bone destruction, on skeletal complications in prostate cancer patients with bone metastases. METHODS: Patients with hormone-refractory prostate cancer and a history of bone metastases were randomly assigned to a double-blind treatment regimen of intravenous zoledronic acid at 4 mg (N = 214), zoledronic acid at 8 mg (subsequently reduced to 4 mg; 8/4) (N = 221), or placebo (N = 208) every 3 weeks for 15 months. Proportions of patients with skeletal-related events, time to the first skeletal-related event, skeletal morbidity rate, pain and analgesic scores, disease progression, and safety were assessed. All statistical tests were two-sided. RESULTS: Approximately 38% of patients who received zoledronic acid at 4 mg, 28% who received zoledronic acid at 8/4 mg, and 31% who received placebo completed the study. A greater proportion of patients who received placebo had skeletal-related events than those who received zoledronic acid at 4 mg (44.2% versus 33.2%; difference = -11.0%, 95% confidence interval [CI] = -20.3% to -1.8%; P =.021) or those who received zoledronic acid at 8/4 mg (38.5%; difference versus placebo = -5.8%, 95% CI = -15.1% to 3.6%; P =.222). Median time to first skeletal-related event was 321 days for patients who received placebo, was not reached for patients who received zoledronic acid at 4 mg (P =.011 versus placebo), and was 363 days for those who received zoledronic acid at 8/4 mg (P =.491 versus placebo). Compared with urinary markers in patients who received placebo, urinary markers of bone resorption were statistically significantly decreased in patients who received zoledronic acid at either dose (P =.001). Pain and analgesic scores increased more in patients who received placebo than in patients who received zoledronic acid, but there were no differences in disease progression, performance status, or quality-of-life scores among the groups. Zoledronic acid at 4 mg given as a 15-minute infusion was well tolerated, but the 8-mg dose was associated with renal function deterioration. CONCLUSION: Zoledronic acid at 4 mg reduced skeletal-related events in prostate cancer patients with bone metastases.

Prediction of pelvic lymph node metastasis by the ratio of cathepsin B to stefin A in patients with prostate carcinoma.

BACKGROUND: Pathologic grade and/or histologic score, extraprostatic extension indicated by invasion of the prostatic capsule, margin, and/or seminal vesicles by prostate cancer cells, serum total prostate-specific antigen (PSA), free PSA, complexed PSA levels and/or their ratios, regional pelvic lymph node metastases, and clinical staging have been used to diagnose and monitor the treatment of prostate carcinoma (PC) patients. The Gleason grading system is also used to grade/score a patient's stage of disease, with lower to higher scores indicating progression of PC. However, Gleason's system cannot be used to distinguish biologically aggressive PCs within a single Gleason score. Our objective was to identify subpopulations (or clones) of aggressive prostate cancers within an individual Gleason score by utilizing biological molecule(s) that also facilitate cancer cell invasion to prostatic stroma and metastasis to the lymph nodes. MATERIALS AND METHODS: Specimens were collected from 97 patients with PC and from 8 patients with benign prostatic hyperplasia. These patients had not been treated with hormonal and/or chemotherapeutic agents before undergoing a prostatectomy at the Minneapolis Veterans Affairs Medical Center. Formalin-fixed, paraffin or paraplast-embedded prostate tissue sections were stained with hematoxylin and eosin for pathologic diagnosis and adjacent sections were stained for for immunohistochemical study. We also collected data on age, race, extraprostatic extension, margin status, seminal vesicle, and lymph node invasion by cancer cells, clinical stage at prostatectomy, and mortality/survival data, including the available presurgery and postsurgery serum total PSA and prostatic acid phosphatase concentrations in patients. Immunohistochemical localization of mouse or rabbit anti-cathepsin B (CB) antibody IgG and mouse antihuman stefin (cystatin) A IgG was quantified using a computer-based image analysis system equipped with Metamorph software. RESULTS: CB and stefin A identified aggressive and less aggressive clones of PCs within an individual Gleason score. Tumors with a Gleason Score of 6 that are similar histologically and morphologically were heterogeneous with respect to the ratios of CB to stefin A (CB > stefin A, CB = stefin A, and CB < stefin A). We also found a significant positive association (P = 0.0066) between ratios of CB and stefin A (CB > stefin A) and the incidence of pelvic lymph node metastases, but not with ratios of CB less than stefin A and/or ratios of CB equal to stefin A. Patients with Gleason 7 PCs had a higher incidence of positive lymph nodes than those with Gleason Score 6 tumors. Our data indicated that mortality rates increased in patients when the ratios of CB were greater than stefin A. CONCLUSIONS: PC within an individual Gleason score is a heterogeneous tumor that contains clones or subpopulations of aggressive and less aggressive tumors that can be defined by the ratios of CB to stefin A. PC with an aggressive clone can be identified when the ratio of CB is greater than that of stefin A. Less aggressive clones are identified when the ratio of CB is less than that of stefin A or when the ratio of CB is equal to that of stefin A. The ratios of CB to stefin A can be used in the differential diagnosis and treatment of patients with PC. This is the first report to identify phenotypes of aggressive and less aggressive PCs within a Gleason score.

Bicalutamide as immediate therapy either alone or as adjuvant to standard care of patients with localized or locally advanced prostate cancer: first analysis of the early prostate cancer program.

PURPOSE: We determine the efficacy and tolerability of bicalutamide as immediate therapy, either alone or as adjuvant to treatment of curative intent, in patients with clinically localized or locally advanced prostate cancer. MATERIALS AND METHODS: This international program consists of 3 ongoing, randomized, double-blind, placebo controlled clinical trials (trials 23, 24, and 25). Men with localized or locally advanced (T1-T4, Nx/N0, M0) prostate cancer were randomized to receive 150 mg. bicalutamide daily or placebo, in addition to standard care with radical prostatectomy, radiotherapy or watchful waiting. Primary end points are time to objective progression and overall survival. In this first analysis data from the trials were combined in a single overview analysis according to protocol. RESULTS: Data are available for 8,113 patients (4,052 randomized to bicalutamide, 4,061 to standard care alone) at a median followup of 3.0 years. Treatment with bicalutamide provided a highly significant reduction of 42% in the risk of objective progression compared with standard care alone (9.0% versus 13.8%, hazards ratio 0.58; 95% confidence interval 0.51, 0.66; p <<0.0001). The overall result was reflected in 2 of the 3 trials (trials 24 and 25) with trial 3 (trial 23) showing a nonsignificant difference at this time. Reductions in the risk of disease progression were seen across the entire patient population, irrespective of primary treatment or disease stage. Overall survival data are currently immature and longer followup will determine if there is also a survival benefit with bicalutamide. The most frequently reported side effects of bicalutamide were gynecomastia and breast pain. CONCLUSIONS: Immediate treatment with 150 mg. bicalutamide daily, either alone or as adjuvant to treatment of curative intent, significantly reduces the risk of disease progression in patients with localized or locally advanced prostate cancer. This benefit must be balanced with the morbidity associated with long-term hormonal therapy. Followup is ongoing to determine potential survival benefits of this treatment approach.