Bo-Eric Persson

The efficacy and safety of degarelix: a 12-month, comparative, randomized, open-label, parallel-group phase III study in patients with prostate cancer

To evaluate the efficacy and safety of degarelix, a new gonadotrophin‐releasing hormone (GnRH) antagonist (blocker), vs leuprolide for achieving and maintaining testosterone suppression in a 1‐year phase III trial involving patients with prostate cancer.

Additional Analysis of the Secondary End Point of Biochemical Recurrence Rate in a Phase 3 Trial (CS21) Comparing Degarelix 80 mg Versus Leuprolide in Prostate Cancer Patients Segmented by Baseline Characteristics

BACKGROUND Recent data suggest prostate-specific antigen (PSA) progression may predict overall survival in prostate cancer patients. OBJECTIVE To compare the activity of degarelix and leuprolide regarding PSA recurrence-free survival. DESIGN, SETTING, AND PARTICIPANTS Phase 3, 1-yr, multicentre, randomised, open-label trial comparing the efficacy and safety of degarelix at 240 mg for 1 mo, and then 80 mg monthly (240/80 mg); degarelix at 240 mg for 1 mo, and then 160 mg monthly; and leuprolide at 7.5 mg/mo. Overall, 610 patients with histologically confirmed prostate cancer (all stages), for whom androgen deprivation therapy was indicated, were included. The primary end point of this trial has been reported previously; the protocolled and exploratory subgroup analyses reported in this paper focus on degarelix at 240/80 mg (dose approved by the US Food and Drug Administration and the European Medicine Evaluation Association for the treatment of patients with hormone-naive advanced prostate cancer). MEASUREMENTS PSA progression-free survival (two consecutive increases in PSA of 50% compared with nadir and ≥ 5 ng/ml on two consecutive measurements at least 2 wk apart or death) and change in PSA were reviewed. Effects of baseline disease stage (localised, locally advanced, and metastatic) and PSA level (<10, 10-20, >20-50, and >50 ng/ml) were analysed. RESULTS AND LIMITATIONS Patients receiving degarelix showed a significantly lower risk of PSA progression or death compared with leuprolide (p=0.05). PSA recurrences occurred mainly in patients with advanced disease and exclusively in those with baseline PSA >20 ng/ml. Patients with PSA >20 ng/ml had a significantly longer time to PSA recurrence with degarelix (p=0.04). The relatively low number of patients in each subgroup is a limitation of this study. CONCLUSIONS These results generate the hypothesis that degarelix at 240/80 mg offers improved PSA control compared with leuprolide. PSA recurrences occurred almost exclusively in patients with metastatic prostate cancer or high baseline PSA during this 1-yr study. Further studies are warranted to confirm these findings.

A phase III extension trial with a 1-arm crossover from leuprolide to degarelix : comparison of gonadotropin-releasing hormone agonist and antagonist effect on prostate cancer.

PURPOSE We investigated the efficacy and safety of degarelix treatment and the effects of switching from leuprolide to degarelix in an ongoing extension study with a median 27.5-month followup of a pivotal 1-year prostate cancer trial. MATERIALS AND METHODS Patients who completed a 1-year pivotal phase III trial continued on the same monthly degarelix maintenance dose (160 or 80 mg in 125 each), or were re-randomized from leuprolide 7.5 mg to degarelix 240/80 mg (69) or 240/160 mg (65). Data are shown on the approved degarelix 240/80 mg dose. The primary end point was safety/tolerability and the secondary end points were testosterone, prostate specific antigen, luteinizing hormone and follicle-stimulating hormone responses, and prostate specific antigen failure and progression-free survival. RESULTS During followup testosterone and prostate specific antigen suppression were similar to those in the 1-year trial in patients who continued on degarelix or switched from leuprolide. The prostate specific antigen progression-free survival hazard rate was decreased significantly after the switch in the leuprolide/degarelix group while the rate in those who continued on degarelix was consistent with the rate in treatment year 1. The same hazard rate change pattern occurred in the group with baseline prostate specific antigen greater than 20 ng/ml. Adverse event frequency was similar between the groups and decreased with time. CONCLUSIONS Data support the statistically significant prostate specific antigen progression-free survival benefit for degarelix over leuprolide seen during year 1 and the use of degarelix as first line androgen deprivation therapy as an alternative to a gonadotropin-releasing hormone agonist.

Degarelix: a novel gonadotropin-releasing hormone (GnRH) receptor blocker--results from a 1-yr, multicentre, randomised, phase 2 dosage-finding study in the treatment of prostate cancer.

BACKGROUND Degarelix is a gonadotropin-releasing hormone antagonist (GnRH receptor blocker) with immediate onset of action, suppressing gonadotropins, testosterone, and prostate-specific antigen (PSA) in prostate cancer. OBJECTIVE To determine the efficacy and safety of initial doses of 200 mg or 240 mg of degarelix and thereafter monthly subcutaneous maintenance doses of 80 mg, 120 mg, or 160 mg of degarelix for the treatment of prostate cancer. DESIGN, SETTING, AND PARTICIPANTS The 1-yr study was of open-label, randomised design and involved 187 patients (range: 52-93 yr, median: 72 yr) with histologically confirmed adenocarcinoma of the prostate and a baseline PSA >2 ng/ml. RESULTS AND LIMITATIONS At baseline, median serum testosterone was 4.13 ng/ml (range: P25-P75, 3.37-5.19 ng/ml) and PSA was 27.6 ng/ml (range: P25-P75, 11.9-55.0 ng/ml). On day 3, 88% and 92% of patients in the groups to whom 200-mg and 240-mg initial doses of degarelix were administered, respectively, had testosterone levels < or =0.5 ng/ml. For patients with testosterone levels < or =0.5 ng/ml at 1 mo, the testosterone levels remained < or =0.5 ng/ml until the end of the study in 100% of the patients treated with a monthly maintenance dosage of 160 mg of degarelix. No evidence of testosterone surge was detected. PSA decreased by 97-98% after 1 yr and the median time to 90% reduction in PSA was 8 wk in all but one patient (from the 80-mg dosage treatment group at the initial 200-mg dose of degarelix). Thirteen patients (6%) withdrew from the study due to adverse events, largely related to androgen deprivation. CONCLUSIONS Degarelix treatment for 1 yr resulted in a fast, profound, and sustained suppression of testosterone and PSA, with no evidence of testosterone surge. Degarelix was well tolerated.

A 1-Year, Open Label, Randomized Phase II Dose Finding Study of Degarelix for the Treatment of Prostate Cancer in North America

PURPOSE Degarelix is a gonadotropin-releasing hormone receptor antagonist (blocker) with rapid onset of action suppressing gonadotropins, testosterone and prostate specific antigen in prostate cancer. In the present open label, randomized study in North America we evaluated the efficacy and safety of a starting dose of 200 mg degarelix followed by monthly injections of 60 or 80 mg during 1 year of prostate cancer treatment. MATERIALS AND METHODS A total of 127 patients (median age 76 years, range 47 to 93) with histologically confirmed prostate cancer were enrolled in the study. Efficacy was assessed by measuring serum testosterone and prostate specific antigen. RESULTS Median baseline testosterone and prostate specific antigen levels were 4.13 ng/ml (P25-P75 3.03-5.11) and 13.4 ng/ml (P25-P75 6.80-25.7), respectively. The starting dose induced a rapid suppression of testosterone in that 88% of the patients had testosterone levels of 0.5 ng/ml or less 1 month after the injection. For patients who had testosterone levels of 0.5 ng/ml or less after 1 month, 93% and 98% of those receiving maintenance doses of 60 and 80 mg, respectively, had testosterone levels that were consistently 0.5 ng/ml or less at all monthly measurements from 1 month to 1 year. No evidence of testosterone surge was detected. In both groups prostate specific antigen decreased by 96% after 1 year and median time to 90% reduction in prostate specific antigen was 56 days. Six patients (5%) withdrew from the study due to adverse events. CONCLUSIONS Degarelix treatment for 1 year resulted in a fast, profound and sustained suppression of testosterone and prostate specific antigen with no evidence of testosterone surge. Degarelix was well tolerated.

Disease Control Outcomes from Analysis of Pooled Individual Patient Data from Five Comparative Randomised Clinical Trials of Degarelix Versus Luteinising Hormone-releasing Hormone Agonists☆

BACKGROUND Studies comparing the gonadotropin-releasing hormone antagonist, degarelix, with luteinising hormone-releasing hormone (LHRH) agonists indicate differences in outcomes. OBJECTIVE To assess differences in efficacy and safety outcomes in a pooled analysis of trials comparing degarelix with LHRH agonists. DESIGN, SETTING, AND PARTICIPANTS Data were pooled from five prospective, phase 3 or 3b randomised trials (n=1925) of degarelix and leuprolide or goserelin in men requiring androgen deprivation therapy for the treatment of prostate cancer. Patients received either 3 mo (n=467) or 12 mo (n=1458) of treatment. INTERVENTION Men were randomised to receive degarelix (n=1266), leuprolide (n=201), or goserelin (n=458). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Unadjusted Kaplan-Meier analyses were supported by the Cox proportional hazards model, adjusted for disease-related baseline factors, to estimate hazard ratios (HRs) of efficacy and safety outcomes. The Fisher exact test compared crude incidences of adverse events. RESULTS AND LIMITATIONS Prostate-specific antigen (PSA) progression-free survival (PFS) was improved in the degarelix group (HR: 0.71; p=0.017). For patients with baseline PSA levels >20 ng/ml, the HR for PSA PFS was 0.74 (p=0.052). Overall survival (OS) was higher in the degarelix group (HR: 0.47; p=0.023). OS was particularly improved with degarelix in patients with baseline testosterone levels >2 ng/ml (HR: 0.36; p=0.006). In terms of disease-related adverse events, there were, overall, fewer joint-related signs and symptoms, musculoskeletal events, and urinary tract events in the degarelix group. CONCLUSIONS These data indicate clinical benefits with degarelix, including a significant improvement in PSA PFS and OS, as well as reduced incidence of joint, musculoskeletal, and urinary tract adverse events, compared with LHRH agonists.

Changes in alkaline phosphatase levels in patients with prostate cancer receiving degarelix or leuprolide: results from a 12-month, comparative, phase III study

Study Type – Therapy (RCT)
Level of Evidence 1b

Cardiovascular Safety of Degarelix: Results From a 12-Month, Comparative, Randomized, Open Label, Parallel Group Phase III Trial in Patients With Prostate Cancer

PURPOSE We assessed the cardiovascular safety profile of degarelix, a new gonadotropin-releasing hormone antagonist. MATERIALS AND METHODS This is the first report to our knowledge on cardiovascular safety data from a completed 1-year randomized controlled trial of leuprolide acetate vs degarelix. Outcomes considered in these analyses included the QT interval by central reading and analysis, and cardiovascular adverse events. On multivariate analyses relationships between selected baseline factors and cardiovascular events were evaluated. RESULTS There were no significant differences between treatment groups for mean change in Fridericias correction of QT during the trial. Markedly abnormal Fridericias correction of QT values (500 milliseconds or greater) were observed in only a small number of subjects by treatment group, that is 2 (less than 1%) in the pooled degarelix group and 2 (1%) in the leuprolide group. Supraventricular arrhythmias were the most common type of arrhythmias, affecting 2% of subjects in the pooled degarelix group and 4% in the leuprolide group. Other arrhythmias occurred in 1% or less of subjects by treatment group. The most frequently reported cardiac disorder was ischemic heart disease, which occurred in 4% of subjects treated with degarelix and 10% of those on leuprolide. Cox proportional hazard ratio estimates for selected baseline covariates showed a significantly increased risk of cardiovascular events by age (p=0.0459) and systolic blood pressure (p=0.0061). CONCLUSIONS In men with prostate cancer degarelix and leuprolide have similar cardiovascular safety profiles. These observations suggest that the cardiovascular events associated with both agents result from hypogonadism rather than a direct drug effect.

Will GnRH antagonists improve prostate cancer treatment

Androgen ablation forms a basis for treating prostate cancer and is achieved either by surgical castration, or pharmacologically using oestrogens, anti-androgens and/or gonadotropin-releasing hormone (GnRH) analogues. GnRH antagonists (or blockers) offer a new means of treatment by directly blocking GnRH receptors. Advantages of GnRH antagonists include lack of the initial stimulation of gonadotropin and testosterone production, lack of gonadotropin microsurges and sustained follicle-stimulating hormone suppression; disadvantages include increased histamine release. This review discusses advantages and disadvantages of the GnRH antagonists currently in development, in light of receptor physiology and pre-clinical and clinical data. Comparative clinical trials will ultimately establish their efficacy in comparison to other pharmacotherapies. Therefore, continuing development and refinement is needed to improve prostate cancer treatment.

An update on the use of gonadotropin-releasing hormone antagonists in prostate cancer

Androgen deprivation therapy (ADT) is the main treatment approach in advanced prostate cancer and in recent years has primarily involved the use of gonadotropin-releasing hormone (GnRH) agonists. However, despite their efficacy, GnRH agonists have several drawbacks associated with their mode of action. These include an initial testosterone surge and testosterone microsurges on repeat administration. GnRH antagonists provide an alternative approach to ADT with a more direct mode of action that involves immediate blockade of GnRH receptors. Antagonists produce a more rapid suppression of testosterone (and prostate-specific antigen [PSA]) without a testosterone surge or microsurges and appear to offer an effective and well tolerated option for the hormonal treatment of prostate cancer. Comparisons with GnRH agonists have shown GnRH antagonists to be at least as effective in achieving and maintaining castrate testosterone levels in patients with prostate cancer. Furthermore, with antagonists, the lack of an initial testosterone surge (which may cause clinical flare) may allow more rapid relief of symptoms related to prostate cancer, avoid the need for concomitant antiandrogens to prevent clinical flare (so avoiding any antiandrogen-associated adverse events) and allow GnRH antagonist use in patients with high tumour burden and/or acute problems such as spinal cord compression. Although several antagonists have been investigated, only degarelix and abarelix are currently available for clinical use in prostate cancer. Currently, degarelix is the most extensively studied and widely available agent in this class. Degarelix is one of a newer generation of antagonists which, in a comprehensive and ongoing clinical development programme, has been shown to provide rapid, profound and sustained testosterone suppression without the systemic allergic reactions associated with earlier antagonists. This review examines the currently available data on GnRH antagonists in prostate cancer.