Urodynamic effects of once daily tadalafil in men with lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia: a randomized, placebo controlled 12-week clinical trial

PURPOSE

We explored the impact of once daily tadalafil on urodynamic measures in men with lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia via invasive and noninvasive urodynamic studies.

MATERIALS AND METHODS

We conducted a multicenter, randomized, double blind, placebo controlled clinical trial comparing once daily tadalafil 20 mg vs placebo during 12 weeks in men with lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia with or without bladder outlet obstruction. Invasive and noninvasive urodynamics, International Prostate Symptom Score and general safety were assessed. The primary study end point was change in detrusor pressure at maximum urinary flow rate.

RESULTS

Urodynamic measures remained largely unchanged during the study with no statistically significant or clinically adverse difference between tadalafil and placebo in change in detrusor pressure at maximum urinary flow rate (mean difference between treatments -2.2 cm H(2)O, p = 0.33) or any other urodynamic parameter assessed including maximum urinary flow rate, maximum detrusor pressure, bladder outlet obstruction index or bladder capacity (all measures p > or = 0.13). Treatment with tadalafil resulted in significant improvements in International Prostate Symptom Score (mean difference between treatments -4.2, p < 0.001). Tadalafil was generally well tolerated with the majority of adverse events being mild to moderate in severity and few patients discontinuing due to adverse events (tadalafil 2.0%, placebo 1.0%).

CONCLUSIONS

Treatment with tadalafil once daily for lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia showed no negative impact on bladder function as measured by detrusor pressure at maximum urinary flow rate or on any other urodynamic parameter assessed. Nonetheless men receiving tadalafil reported significant improvements in International Prostate Symptom Score with an adverse events profile similar to other recent studies of tadalafil for lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia.

Redesigning a large-scale clinical trial in response to negative external trial results: the CAMUS study of phytotherapy for benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH), a common condition among older men, confers its morbidity through potentially bothersome lower urinary tract symptoms. Treatments for BPH include drugs such as alpha-adrenergic receptor blockers and 5-alpha reductase inhibitors, minimally invasive therapies that use heat to damage or destroy prostate tissue, and surgery including transurethral resection of the prostate. Complementary and alternative medicines are gaining popularity in the US. Two phytotherapies commonly used for BPH are extracts of the fruit of Serenoa repens, the Saw palmetto dwarf palm that grows in the Southeastern US, and extracts of the bark of Pygeum africanum, the African plum tree.

PURPOSE

The objective of the Complementary and Alternative Medicines for Urological Symptoms (CAMUS) clinical trial is to determine if phytotherapy is superior to placebo in the treatment of BPH.

METHODS

CAMUS was originally designed as a 3300-participant, four-arm trial of S. repens, P. africanum, an alpha-adrenergic blocking drug, and placebo with time to clinical progression of BPH, a measure of long-term efficacy, as the primary endpoint. Before enrollment started, a randomized, double-blind, placebo-controlled, single institution clinical trial showed that S. repens at the usual dose did not demonstrate any benefit over placebo with respect to symptom relief at 1 year. Consequently, the focus of CAMUS shifted from evaluating long-term efficacy to determining if any short-term (6-18 months) symptom relief could be achieved with increasing doses of S. repens, the phytotherapy most commonly used in the US for BPH.

RESULTS

Results are anticipated in 2011.

CONCLUSIONS

Trial design occurs in an environment of continually evolving information. In this case, emerging results from another trial suggested that a study of long-term efficacy was premature, and that an effective dose and preparation of S. repens had to be established before proceeding to a long-term clinical trial.

The Prostate cancer Intervention Versus Observation Trial:VA/NCI/AHRQ Cooperative Studies Program #407 (PIVOT): design and baseline results of a randomized controlled trial comparing radical prostatectomy to watchful waiting for men with clinically localized prostate cancer

BACKGROUND

Prostate cancer is the most common noncutaneous malignancy and the second leading cause of cancer death in men. Ninety percent of men with prostate cancer are over aged 60 years, diagnosed by early detection with the prostate specific antigen (PSA) blood test and have disease believed confined to the prostate gland (clinically localized). Common treatments for clinically localized prostate cancer include watchful waiting surgery to remove the prostate gland (radical prostatectomy), external beam radiation therapy and interstitial radiation therapy (brachytherapy) and androgen deprivation. Little is known about the relative effectiveness and harms of treatments due to the paucity of randomized controlled trials. The VA/NCI/AHRQ Cooperative Studies Program Study #407: Prostate cancer Intervention Versus Observation Trial (PIVOT), initiated in 1994, is a multicenter randomized controlled trial comparing radical prostatectomy to watchful waiting in men with clinically localized prostate cancer.

METHODS

We describe the study rationale, design, recruitment methods and baseline characteristics of PIVOT enrollees. We provide comparisons with eligible men declining enrollment and men participating in another recently reported randomized trial of radical prostatectomy versus watchful waiting conducted in Scandinavia.

RESULTS

We screened 13,022 men with prostate cancer at 52 United States medical centers for potential enrollment. From these, 5023 met initial age, comorbidity and disease eligibility criteria and a total of 731 men agreed to participate and were randomized. The mean age of enrollees was 67 years. Nearly one-third were African-American. Approximately 85% reported they were fully active. The median prostate specific antigen (PSA) was 7.8 ng/mL (mean 10.2 ng/mL). In three-fourths of men the primary reason for biopsy leading to a diagnosis of prostate cancer was a PSA elevation or rise. Using previously developed tumor risk categorizations incorporating PSA levels, Gleason histologic grade and tumor stage, approximately 43% had low risk, 36% had medium risk and 20% had high-risk prostate cancer. Comparison to our national sample of eligible men declining PIVOT participation as well as to men enrolled in the Scandinavian trial indicated that PIVOT enrollees are representative of men being diagnosed and treated in the U.S. and quite different from men in the Scandinavian trial.

CONCLUSIONS

PIVOT enrolled an ethnically diverse population representative of men diagnosed with prostate cancer in the United States. Results will yield important information regarding the relative effectiveness and harms of surgery compared to watchful waiting for men with predominately PSA detected clinically localized prostate cancer.

The VIOXX in Prostate Cancer Prevention study: cardiovascular events observed in the rofecoxib 25 mg and placebo treatment groups

BACKGROUND

A double-blind, randomized, placebo-controlled study was designed to determine the cumulative incidence of developing prostate cancer over 6 years of treatment with rofecoxib 25 mg/day versus placebo. Before completion, this trial was terminated following the voluntary withdrawal of rofecoxib. (On September 30, 2004, Merck & Co., Inc. announced the voluntary worldwide withdrawal of rofecoxib from the market.) Here we report the cardiovascular (CV) safety data collected from this study.

METHODS

A total of 4741 men (44-81 years old) exhibiting prostate-specific antigen levels (PSA) between 2.5 and 10 ng/mL were enrolled. Patients were stratified by PSA level and use of low-dose aspirin (LDA), then randomized to rofecoxib 25 mg (n = 2369) or placebo (n = 2372). Safety data were analyzed in all patients receiving > or = 1 dose of study medication. All reported thrombotic CV events occurring on-treatment or within 14 days after study drug discontinuation were adjudicated by an independent panel of clinical experts blinded to treatment assignment. Rates per 100 patient-years and relative risk (RR) of thrombotic CV events, rofecoxib vs. placebo, were determined.

RESULTS

Approximately 36% of patients had > or = 2 CV risk factors or LDA indicated. Median treatment duration was 4.14 (range: 0.03-15.90) months. Twenty-nine patients (14 rofecoxib, rate 1.27; 15 placebo, rate 1.36) experienced confirmed thrombotic CV events; RR 0.94 (95% CI: 0.45, 1.94) vs. placebo. Four patients (one rofecoxib; three placebo) died due to a confirmed thrombotic event. Significantly (p = 0.002) more patients receiving rofecoxib (n = 20; 0.8%) experienced hypertension-related adverse events versus placebo (n = 2; 0.1%). There were no cases of congestive heart failure.

CONCLUSIONS

Rofecoxib 25 mg and placebo demonstrated similar risk of thrombotic CV events in this limited dataset.

Dihydrotestosterone and the prostate: the scientific rationale for 5alpha-reductase inhibitors in the treatment of benign prostatic hyperplasia

PURPOSE

We reviewed the physiological and pathogenic role of dihydrotestosterone (DHT), evidence for the beneficial effects of decreasing DHT through 5alpha-reductase inhibition and the effects of altering the androgen balance with these agents.

MATERIALS AND METHODS

A review of the relevant literature was done using published studies identified from the MEDLINE database.

RESULTS

The androgens DHT and testosterone have complementary roles in male physiology. Each is mediated through the intracellular androgen receptor. It has been hypothesized that DHT may provide an amplification mechanism for testosterone, which could be a beneficial adaptation in men with low circulating testosterone. The recognition of the central role of DHT in benign prostatic hyperplasia (BPH) has changed the way the disease is viewed and has led to the introduction of 5alpha-reductase inhibitors, which can prevent and retard the progression of BPH by suppressing DHT synthesis. The 5alpha-reductase inhibitors decrease prostate volume. In doing so they improve symptoms and urinary flow, and decrease the risks of acute urinary retention and the need for BPH related surgery. The predominant drug related adverse events with 5alpha-reductase inhibitors are reproductive events, that is typically decreased libido, impotence and ejaculatory dysfunction. These events occur in a minority of men and tend to decrease with a longer treatment duration.

CONCLUSIONS

DHT appears to have an obligatory role in the development of BPH. The role of 5alpha-reductase inhibitors in the treatment of BPH has been firmly established with an adverse events profile that is suitable for long-term use.

Efficacy and Safety of Long-Term Treatment with the Dual 5α-Reductase Inhibitor Dutasteride in Men with Symptomatic Benign Prostatic Hyperplasia

OBJECTIVES

Dutasteride, a dual inhibitor of Type 1 and Type 2 5 alpha-reductase, has been shown to improve disease measures in patients with symptomatic benign prostatic hyperplasia (BPH) in three randomised, placebo-controlled, large-scale, 2-year Phase III clinical studies. This paper reports the pooled results of a 2-year open-label extension of the three randomised studies assessing the long-term efficacy and safety of dutasteride.

METHODS

Patients randomised to dutasteride or placebo in the double-blind portion of the Phase III studies were eligible for a 2-year open-label extension, where all patients received dutasteride 0.5mg daily (dutasteride/dutasteride [D/D] group and placebo/dutasteride [P/D group]).

RESULTS

Significant improvements in AUA-SI score and Q(max) were observed from Month 24 to 48 in both study groups. At Month 48, patients in the D/D group had significantly greater improvements in AUA-SI score and Q(max), and significantly greater reductions in prostate volume, than those in the P/D group. Acute urinary retention and BPH-related surgery occurred in a small percentage of patients during the open-label phase. No new safety issues were noted with long-term therapy. Onset of new drug-related adverse events were reported most frequently at the start of therapy and declined over time in patients receiving dutasteride.

CONCLUSIONS

Long-term treatment with dutasteride results in continuing improvements in urinary symptoms and flow rate, and further reductions in TPV, in men with symptomatic BPH. The reduction in risk of AUR and BPH-related surgery, seen in the double-blind phase, was durable over 4-year treatment. Dutasteride was also well tolerated in long-term use.

Effect of dutasteride on the detection of prostate cancer in men with benign prostatic hyperplasia

OBJECTIVES

To examine the rate of prostate cancer detection in three large randomized placebo-controlled benign prostatic hyperplasia trials of dutasteride. Dutasteride, which lowers serum dihydrotestosterone more than 93% by inhibiting type 1 and type 2 5-alpha-reductase, is effective in the treatment of benign prostatic hyperplasia. However, its effect on the development of prostate cancer is unknown.

METHODS

A total of 4325 men with benign prostatic hyperplasia but without a history, or evidence, of prostate cancer, and a serum prostate-specific antigen level of 1.5 to 10 ng/mL, were randomized to 0.5 mg/day dutasteride or placebo for 24 months. The prostate cancer detection rates for subjects were determined by non-protocol-mandated biopsies, either during the double-blind phase of the study or during the first 3 months of the open-label extension. A follow-up questionnaire was administered to a subset of consenting subjects to ascertain the number, outcomes, and reasons for the prostate biopsies.

RESULTS

The cumulative incidence of prostate cancer as an adverse event was significantly lower in the dutasteride versus placebo group at 24 months (1.1% versus 1.9%, P = 0.025) and 27 months (1.2% versus 2.5%, P = 0.002). There were no differences in the diagnosis rates of prostate cancer during the first 15 months, after which time the detection rate of prostate cancer increased in the placebo group and remained low in the dutasteride group.

CONCLUSIONS

Prostate cancer detection was significantly lower in subjects randomized to dutasteride compared with the placebo group. These results have prompted the initiation of the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study, which was designed and powered to test the hypothesis that treatment with dutasteride decreases the incidence and progression of prostate cancer.

Transurethral needle ablation versus transurethral resection of the prostate for the treatment of symptomatic benign prostatic hyperplasia: 5-year results of a prospective, randomized, multicenter clinical trial

PURPOSE

We report the 5-year efficacy and safety of transurethral needle ablation of the prostate (TUNA) compared to transurethral resection of the prostate (TURP) for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

A total of 121 men 50 years or older with LUTS secondary to BPH a minimum of 3 months in duration were enrolled in this prospective, randomized clinical trial at 7 medical centers across the United States. Of the participants 65 (54%) were randomly selected to receive TUNA and 56 (46%) were selected to receive TURP. International Prostate Symptom Score, quality of life, peak urinary flow rate, post-void residual urinary volume, and prostate size and configuration were evaluated before the procedure and then annually for 5 years after the procedure. Adverse events were also recorded throughout the study.

RESULTS

Improvement from baseline for TUNA and TURP retained statistical significance at each interval for International Prostate Symptom Score, quality of life and peak flow rate. Post-void residual volume was statistically significant at all time points for TURP and at year 5 for TUNA. The TURP group reported 41% retrograde ejaculation, while the TUNA group reported none. The incident of erectile dysfunction, incontinence and stricture formation was also greater in TURP than in TUNA cases with significantly fewer adverse events for TUNA than for TURP.

CONCLUSIONS

The results of this study demonstrate stable treatment outcomes after 5 years of followup and suggest that TUNA is an attractive treatment option for men with LUTS due to BPH.

Updated meta-analysis of clinical trials of Serenoa repens extract in the treatment of symptomatic benign prostatic hyperplasia

OBJECTIVES

To determine, by analysing all available clinical trial data, the clinical efficacy against placebo of an extract from the fruit of the American dwarf palm tree, Serenoa repens (Permixon, Pierre Fabre Médicament, Castres, France), as there is controversy about the use of phytotherapeutic agents in men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH).

METHODS

All clinical trial data published on Permixon, comprising 14 randomized clinical trials and three open-label trials, involving 4280 patients, were analysed. These trials were of different size (22-1100 patients) and duration (21-720 days). The peak urinary flow rate and nocturia were the two common endpoints. The statistical analysis was based on a random-effects meta-analysis.

RESULTS

Permixon was associated with a mean (sem) reduction in the International Prostate Symptom Score (IPSS) of 4.78 (0.41). The mean placebo effect on peak urinary flow rate was an increase of 1.20 (0.49) mL/s. The estimated effect of Permixon was a further increase of 1.02 (0.50) mL/s (P = 0.042). Placebo was associated with a reduction in the mean number of nocturnal voids of 0.63 (0.14); there was a further reduction attributable to Permixon of 0.38 (0.07) (P < 0.001). There was some heterogeneity among the studies for nocturia; one over 2 years involving 396 patients and showing no difference between placebo and Permixon had a large effect on the results.

CONCLUSIONS

This meta-analysis of all available published trials of Permixon for treating men with BPH showed a significant improvement in peak flow rate and reduction in nocturia above placebo, and a 5-point reduction in the IPSS.

5-Alpha Reductase Inhibition Provides Superior Benefits to Alpha Blockade by Preventing AUR and BPH-Related Surgery

OBJECTIVES

This analysis examines the relative effectiveness of current medical therapies for BPH in preventing AUR, AUR-related catheterisation and surgery in real-life clinical practice.

METHODS

This is a retrospective analysis of observational data from the General Practice Research Database (UK) (GPRD). The cohort contains 4500 patients experiencing BPH or lower urinary tract symptoms strongly suggestive of BPH, aged over 50 years, who were prescribed a 5ARI (finasteride) or an alpha-blocker (alfuzosin, doxazosin, indoramin, prazosin, tamsulosin, terazosin) as their first BPH treatment between 1996 and 1999 inclusive. Cox regression and competing risks analyses, adjusted for age and year of first treatment, followed patients from the start of their first BPH treatment to AUR, catheterisation or surgery, or censoring.

RESULTS

Patients prescribed an alpha-blocker were significantly more likely to experience AUR (hazard ratio 2.32, 95%CI 1.37, 3.94) or surgery (hazard ratio 1.78, 95%CI 1.30, 2.44) than patients prescribed a 5ARI. These differences were sustained with sensitivity analyses.

CONCLUSION

Real-life clinical practice shows that significantly fewer BPH patients prescribed a 5ARI experienced serious complications associated with the progression of BPH compared with those prescribed an alpha-blocker.

Improvements in benign prostatic hyperplasia-specific quality of life with dutasteride, the novel dual 5alpha-reductase inhibitor

OBJECTIVES

To examine the effect of the dual-action 5alpha-reductase inhibitor dutasteride on benign prostatic hyperplasia (BPH)-specific health status, as measured by the BPH Impact Index (BII), and to identify baseline and treatment risk factors for those most bothered by their BPH symptoms at the end of the protocol.

PATIENTS AND METHODS

Data were derived from three randomized, double-blind, placebo-controlled, 2-year studies conducted in 4325 men with lower urinary tract symptoms caused by benign prostatic enlargement. Each study comprised a 1-month single-blind placebo run-in period, followed by randomization to oral dutasteride 0.5 mg once daily or placebo for 2 years. Patients eligible for inclusion were consenting men aged >/= 50 years with moderate to severe symptoms (American Urological Symptom Index, AUA-SI, score >/= 12), a prostate volume of >/= 30 mL, a serum prostate-specific antigen (PSA) level of >/= 1.5 or < 10 ng/mL, and a maximum urinary flow rate (Qmax) of </= 15 mL/s. BII scores were recorded at baseline and each study visit. Clinically and statistically significant changes in BII scores from baseline were investigated for each study visit. Logistical regression analysis was used to assess the significance of baseline prostate volume, symptoms, BII item 3, baseline Qmax, serum dihydrotestosterone, testosterone, PSA, age and weight in predicting the BII score at 2 years.

RESULTS

Dutasteride, but not placebo, resulted in clinically and statistically significant improvements in mean BII score from 6 months. Of patients with a baseline BII score of >/= 5 (greatest symptomatic burden) treatment with dutasteride improved the scores by 2.41, while the scores in placebo-treated patients only improved by 1.64. Dutasteride-treated patients with a baseline BII score of < 5 (least symptom burden) had a clinically significant improvement in health status, while placebo-treated patients deteriorated. Regression analysis showed that men with a combination of a baseline BII item-3 score of 3 (bothered a lot) and a high symptom score (AUA-SI >/= 20) were more likely to be bothered by their symptoms at the end of the study. Men receiving placebo were also more likely to be bothered at the end of the study than were those receiving dutasteride.

CONCLUSIONS

Dutasteride treatment is associated with clinically significant improvements in BII score, reflecting improvements in the quality of life of men with BPH. Taken together with previously reported improvements in prostate volume, lower urinary tract symptoms and urinary flow, and diminution of the risk of acute urinary retention and the need for BPH-related surgery, dutasteride offers demonstrable efficacy in the management of BPH.

Efficacy and tolerability of doxazosin and finasteride, alone or in combination, in treatment of symptomatic benign prostatic hyperplasia: the Prospective European Doxazosin and Combination Therapy (PREDICT) trial

OBJECTIVES

To evaluate the efficacy and tolerability of the selective alpha(1)-adrenergic antagonist doxazosin and the 5-alpha-reductase inhibitor finasteride, alone and in combination, for the symptomatic treatment of benign prostatic hyperplasia.

METHODS

In a prospective, double-blind, placebo-controlled trial, 1095 men aged 50 to 80 years were randomized to treatment for 52 weeks with doxazosin, finasteride, the combination of doxazosin and finasteride, or placebo. The dose of finasteride (or its matched placebo) was 5 mg/day. Doxazosin (or its matched placebo) was initiated at 1 mg/day, and titrated up to a maximum of 8 mg/day over approximately 10 weeks according to the response of the maximal urinary flow rate (Qmax) and International Prostate Symptom Score (IPSS). The IPSS and Qmax were assessed at baseline and at weeks 10, 14, 26, 39, and 52 or at the endpoint.

RESULTS

An intent-to-treat analysis of 1007 men showed doxazosin and doxazosin plus finasteride combination therapy produced statistically significant improvements in total IPSS and Qmax compared with placebo and finasteride alone (P <0.05). Finasteride alone was not significantly different statistically from placebo with respect to total IPSS and Qmax. All treatments were generally well tolerated.

CONCLUSIONS

Doxazosin was effective in improving urinary symptoms and urinary flow rate in men with benign prostatic hyperplasia, and was more effective than finasteride alone or placebo. The addition of finasteride did not provide further benefit to that achieved with doxazosin alone.

Meta-analysis of clinical trials of permixon in the treatment of symptomatic benign prostatic hyperplasia

OBJECTIVES

Permixon is a compound extracted from the fruit of the American dwarf palm tree, Serenoa repens. Controversy regarding the use of phytotherapeutic agents in men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia is significant. We analyzed all available clinical trial data of the Permixon preparation to determine its clinical efficacy compared with placebo.

METHODS

All published clinical trial data on Permixon (11 randomized clinical trials and 2 open label trials), involving 2859 patients, were used. These trials were disparate in size (from 22 to 592 patients) and duration (from 21 to 180 days). Peak urinary flow rate and nocturia were the two common end points. The statistical analysis was based on a random effects meta-analysis.

RESULTS

The average +/- SE placebo effect on the peak urinary flow rate was an increase of 0.51 +/- 0.51 mL/s. The estimated effect of Permixon was a further increase of 2.20 +/- 0.51 mL/s (P <0.001). Placebo was associated with a reduction in the mean number +/- SE of nocturnal urinations of 0.69 +/- 0.15. A further reduction of 0.50 +/- 0.01 episodes of urination (P <0.001) occurred that was attributable to Permixon. Some heterogeneity was found among the studies. Treatment duration did not appear to impact either of these effects.

CONCLUSIONS

This meta-analysis of all available published trials of Permixon in the treatment of men with benign prostatic hyperplasia revealed a significant improvement in peak flow rate and reduction in nocturia greater than with placebo.

Management of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a common cause of morbidity among older men. Primary care physicians need to develop expertise in its management. The causes of BPH are unknown; aging and the presence of male androgens are the dominant risk factors. Obtaining a medical history is a key step in assessing whether lower urinary tract symptoms are due to BPH or to some other process. A reliable and valid seven-item questionnaire has been developed to objectively assess symptom severity. A focused physical examination including a digital rectal exam should be performed, as well as a urinalysis and serum creatinine. Optional tests include uroflowmetry, post-void residual urine, and prostate-specific antigen measurements. BPH is treated primarily to improve the quality, rather than increase the quantity, of life. Optimal decisions about treatment are best made by a clinician and an informed patient working together.