The results, which have been published online in European Urology, show that combined treatment with Avodart and tamsulosin significantly reduces the risk of acute urinary retention (AUR) or benign prostatic hyperplasia (BPH)-related surgery by 66% compared with tamsulosin* alone (p<0.001). It was also shown that combination therapy reduces the risk of BPH disease progression by 44% compared with tamsulosin and 31% compared with dutasteride alone [1].
BPH affects nearly 50% of men over 50 years old worldwide [2,3]. It is not a life-threatening condition but associated symptoms, such as incontinence and the urge to urinate more frequently, can impair the quality of life of men suffering from BPH and their families [4]. If left untreated, symptomatic enlarged prostate can increase the risk of serious long-term complications, such as AUR, hospitalization and surgery [5].
Dr Pim Kon, Medical Director of GlaxoSmithKline, commented, ‘There is still a huge unmet need in the treatment of BPH. In the UK there are 3.2 million men over 50 years old with BPH. Of those, only 1.5 million have a diagnosis with just 450,000 men currently receiving medical treatment. The high prevalence of this progressive disease and the detrimental effect it has on the quality of life of patients highlights the need for effective treatment options. Enabling GPs to offer better treatment potentially reduces the development of complications such as acute urinary retention and the need for prostate surgery.’
Men in this study all had moderate-to-severe symptoms of BPH at enrolment. Those treated with combination therapy reported a significant improvement in BPH symptoms at four years, as measured by the International Prostate Symptom Score (IPSS), with a mean change from baseline of -6.3 points, compared with -3.8 for tamsulosin and -5.3 for dutasteride alone.**
CombAT was a multinational randomized study of 4844 men at increased risk of BPH progression, investigating whether combination treatment with the 5-alpha reductase inhibitor (5ARI) dutasteride (0.5mg) and an alpha blocker, tamsulosin (0.4mg), was more effective than either monotherapy in improving symptoms and clinical outcomes in men with moderate-to-severe symptomatic benign prostatic hyperplasia.
The primary endpoint at four years was time to first AUR event or BPH-related surgery versus either monotherapy. Secondary endpoints included clinical progression of BPH, symptom improvement, urinary flow rate improvements, prostate volume and serum prostate-specific antigen (PSA) changes.
BPH is the term used to describe the benign (i.e. non-cancerous) enlargement of the prostate gland, a walnut-shaped gland located beneath the bladder. In BPH, the benign enlargement of the prostate causes a narrowing of the urethra where it passes through the prostate, leading to bladder outlet obstruction (BOO) and lower urinary tract symptoms (LUTS). Common LUTS symptoms include difficulty urinating, incontinence and the urge to urinate more frequently [6].
* Tamsulosin is not indicated to reduce the risk of AUR or BPH-related surgery.
** IPSS is a validated seven-item self-reported questionnaire designed to quantify urinary symptoms.
References
1 Roehrborn, C.G. et al. (2009) The effects of combination therapy with dutasteride and tamsulosin on clinical outcomes in men with symptomatic benign prostatic hyperplasia: 4-year results from the CombAT study. Eur. Urol. doi:10.1016/j.eururo.2009.09.035
2 Napalkov, P. et al. (1995) Worldwide patterns of prevalence and mortality from benign prostatic hyperplasia. Urology 46, 41–46
3 McVary, K.T. (2006) BPH: epidemiology and comorbidities. Am. J. Managed Care 12, 122–128
4 Levy, A. and Samraj, G.P. (2007) Benign prostatic hyperplasia: when to 'watch and wait,' when and how to treat. Cleve. Clin. J. Med. 74 (Suppl 3), S15–20
5 Marberger M, et al. (2004) Optimising the medical management of benign prostatic hyperplasia. Eur. Urol. 45, 411–419
6 National Institute for Health and Clinical Excellence (NICE) Scope. Male lower urinary tract symptoms (LUTS/BPH) draft scope for consultation. 4th September–1st October 2007