Urology · Clinical trials
Benign Prostatic Hyperplasia Clinical Trials
Approved therapies, the pivotal-trial endpoints they were judged on, the magnitude of benefit — and the drugs that failed their endpoints, and why.
Indication overview
About benign prostatic hyperplasia — and why its trials are hard
Benign prostatic hyperplasia (BPH) is age-related nonmalignant proliferation of prostatic stromal and epithelial cells, producing lower urinary tract symptoms (LUTS) through static (glandular bulk) and dynamic (smooth-muscle tone) obstruction. Pharmacotherapy targets both components. Alpha-1 adrenergic blockers such as tamsulosin relax prostatic and bladder-neck smooth muscle for rapid symptom relief. 5-alpha-reductase inhibitors (5-ARIs) finasteride and dutasteride shrink the gland over months by blocking dihydrotestosterone synthesis, reducing progression, acute retention, and surgery in larger prostates. The PDE5 inhibitor tadalafil is approved for BPH-LUTS. Combination alpha-blocker plus 5-ARI therapy outperforms monotherapy for men with enlarged glands, as shown in the landmark MTOPS and CombAT trials. Efficacy is assessed by the International Prostate Symptom Score (IPSS) and maximum urinary flow rate (Qmax), with 5-ARIs also tracked by prostate volume and prevention of clinical progression. Multiple effective, well-tolerated classes exist; contemporary drug development has stagnated, and unmet needs center on refractory symptoms and avoiding surgery rather than the absence of therapy.
Approved therapies & pivotal evidence
What's been approved — and by how much it moved the endpoint
| Drug (brand) | Approved | Setting | Pivotal trial | Primary endpoint | Magnitude of benefit |
|---|---|---|---|---|---|
| Finasteride (Proscar) | 1992 | Oral 5-alpha-reductase inhibitor to reduce prostate size and progression in BPH | PLESS (Proscar Long-Term Efficacy and Safety Study); later MTOPS | Symptom score, Qmax, and risk of acute urinary retention/BPH-related surgery | Reduced risk of acute urinary retention and need for surgery by roughly half over 4 years in men with enlarged prostates; modest IPSS/Qmax gains |
| Tamsulosin (Flomax) | 1997 | Oral alpha-1 adrenergic blocker for BPH-associated LUTS | Phase 3 registration trials | Change in total symptom score (AUA/IPSS) and Qmax | Significant IPSS reduction and Qmax increase (~1-2 mL/s) vs placebo, with rapid onset within days to weeks |
| Dutasteride (Avodart) | 2001 | Oral dual 5-alpha-reductase inhibitor for symptomatic BPH with enlarged prostate | Phase 3 (ARIA/ARIB/ARID pooled); CombAT for combination | IPSS, Qmax, prostate volume, and acute urinary retention/surgery risk | Reduced prostate volume (~25%) and lowered risk of acute retention and surgery vs placebo over 2 years |
| Dutasteride + tamsulosin (Jalyn) | 2010 | Fixed-dose combination for symptomatic BPH with prostatic enlargement | CombAT (Combination of Avodart and Tamsulosin, 4 years) | Change in IPSS; risk of acute urinary retention and BPH-related surgery | Combination superior to either monotherapy for symptom improvement and progression reduction in men with larger glands |
| Tadalafil (Cialis) | 2011 | Oral PDE5 inhibitor (5 mg daily) approved for BPH-LUTS (and BPH+ED) | Phase 3 BPH-LUTS trials | Change in total IPSS | Significant IPSS improvement vs placebo (~4-5 point reduction; ~2 points over placebo); minimal Qmax change |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in benign prostatic hyperplasia development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| Elocalcitol (vitamin D receptor agonist) — Phase 2b trial in men with BPH | Although a phase 2b study suggested it slowed prostate volume growth, elocalcitol did not advance through pivotal development to FDA approval for BPH. | Effect on symptoms and flow was insufficient to differentiate meaningfully from established alpha-blockers and 5-ARIs; the program was not carried to registration, reflecting broader stagnation in BPH drug development. |
Choosing the right endpoint
Primary endpoints that matter in benign prostatic hyperplasia trials
- International Prostate Symptom Score (IPSS/AUA-SI) — Primary validated patient-reported symptom endpoint; ~3-point change is considered clinically perceptible.
- Maximum urinary flow rate (Qmax) — Objective uroflowmetry co-primary/secondary; alpha-blockers and combination raise it more than PDE5 inhibitors.
- Prostate volume — Key mechanistic endpoint for 5-ARIs, which shrink the gland ~20-25%.
- Acute urinary retention / BPH-related surgery — Progression outcomes; 5-ARIs and combination therapy reduce these long-term (MTOPS, CombAT).
- Post-void residual volume — Secondary measure of bladder emptying and obstruction relief.
How iNGENū runs benign prostatic hyperplasia trials
Physician-led design, built for FDA submission
Endpoint & biomarker strategy
Board-certified specialists design endpoints and patient selection aligned to current FDA guidance for this indication.
FDA-ready data
Built to ICH-GCP and 21 CFR 312.120, with direct FDA submission — data accepted by the FDA, EMA and MHRA.
Faster, lower-cost delivery
~4-week ethics via the TGA CTN scheme, up to 43.5% R&D rebate, and 80–90% below US CRO cost.
Request a fixed-milestone proposal and a tailored endpoint & feasibility summary for this indication.
Frequently asked questions
Benign Prostatic Hyperplasia clinical trials — FAQs
Alpha-blocker or 5-ARI first?
What do MTOPS and CombAT show?
How is treatment success measured?
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