Urology · Clinical trials
Interstitial Cystitis 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 interstitial cystitis — and why its trials are hard
Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic condition of bladder or pelvic pain, pressure, or discomfort perceived to relate to the bladder, accompanied by urinary urgency and frequency, in the absence of infection or other identifiable cause. Its pathophysiology is heterogeneous, implicating urothelial glycosaminoglycan (GAG) layer defects, mast-cell activation, neurogenic inflammation, and central sensitisation, which complicates drug development. Treatment is multimodal and stepwise. The only FDA-approved oral drug is pentosan polysulfate sodium (Elmiron, 1996), thought to restore the GAG layer, though efficacy is modest and it carries a notable risk of pigmentary maculopathy with long-term use, prompting label warnings and ophthalmologic monitoring. Intravesical dimethyl sulfoxide (DMSO, Rimso-50) is approved for bladder instillation. Beyond these, options are limited and off-label (amitriptyline, hydroxyzine, intravesical cocktails, hydrodistension). Several investigational agents have failed pivotal testing, underscoring a substantial unmet need. Trial endpoints center on bladder pain scales, urinary frequency, and validated symptom indices (ICSI/ICPI, GRA).
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 |
|---|---|---|---|---|---|
| Pentosan polysulfate sodium (Elmiron) | 1996 | Oral GAG-layer replenisher; only FDA-approved oral drug for IC/BPS bladder pain | Placebo-controlled registration trials (efficacy modest; specific pivotal magnitudes unverified) | Patient-reported overall improvement and bladder pain/discomfort | Modest benefit over placebo in a minority of patients; long-term use associated with pigmentary maculopathy (safety warning added) |
| Dimethyl sulfoxide (DMSO) (Rimso-50) | 1978 | Intravesical instillation for symptomatic relief of IC | Historical controlled studies (pre-modern endpoint standards; magnitude unverified) | Symptomatic relief of bladder pain and urinary symptoms | Symptomatic improvement reported historically; limited modern trial data |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in interstitial cystitis development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| Rosiptor (AQX-1125, SHIP1 activator) — LEADERSHIP 301 (Phase 3, results June 2018) | Failed its primary endpoint: did not significantly reduce bladder pain versus placebo; placebo response was high. Aquinox halted development. | Large placebo effect in IC/BPS pain endpoints, heterogeneous patient population without validated biomarkers, and an anti-inflammatory mechanism that did not translate to symptomatic relief. |
Choosing the right endpoint
Primary endpoints that matter in interstitial cystitis trials
- Bladder/pelvic pain score (NRS or VAS) — Primary endpoint in modern IC/BPS trials; highly susceptible to placebo response.
- Micturition frequency (24h) — Objective diary-based secondary measure of the urgency/frequency component.
- IC Symptom Index / Problem Index (ICSI/ICPI, O'Leary-Sant) — Validated composite instruments for symptom burden and bother.
- Global Response Assessment (GRA) — Patient-rated overall change; a common responder endpoint in IC/BPS studies.
How iNGENū runs interstitial cystitis 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
Interstitial Cystitis clinical trials — FAQs
What oral drug is approved for interstitial cystitis?
Why are there so few approved treatments?
What other options exist?
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