Metabolic & Endocrine · Clinical trials
Gout 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 gout — and why its trials are hard
Gout is the most common inflammatory arthritis, caused by deposition of monosodium urate crystals in joints and soft tissues when serum urate is chronically elevated (hyperuricemia). It presents with acute, intensely painful flares and, over time, tophi, joint damage, and chronic arthropathy; it is strongly associated with cardiovascular, renal, and metabolic comorbidities. Management has two arms: treating acute flares (NSAIDs, colchicine, corticosteroids, and IL-1 inhibitors in refractory cases) and long-term urate-lowering therapy (ULT) to dissolve crystals by driving serum urate below target, typically <6 mg/dL. Allopurinol, a xanthine oxidase inhibitor, is first-line ULT; febuxostat is an alternative, though the CARES cardiovascular outcomes trial raised a signal of increased cardiovascular and all-cause mortality versus allopurinol, prompting a boxed warning. For severe, refractory tophaceous gout, pegloticase (Krystexxa), a recombinant pegylated uricase, converts urate to soluble allantoin and can dramatically lower urate and resolve tophi, though immunogenicity limits durability, now mitigated by co-administered immunomodulation. Treat-to-target, adherence, and comorbidity management define modern gout care.
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 |
|---|---|---|---|---|---|
| Allopurinol (Zyloprim) | 1966 | First-line xanthine oxidase inhibitor urate-lowering therapy for chronic gout | Long-standing clinical use; comparator in FACT and CONFIRMS trials | Proportion achieving serum urate target (<6 mg/dL) | Reliably lowers serum urate to target with dose titration; large-scale antiflare/tophus benefit established over decades of use |
| Febuxostat (Uloric) | 2009 | Non-purine xanthine oxidase inhibitor ULT, alternative to allopurinol | FACT and CONFIRMS Phase 3; CARES cardiovascular safety trial (NEJM 2018) | Serum urate <6 mg/dL; CARES primary CV MACE composite | More patients reached urate target than fixed-dose allopurinol in FACT; CARES showed noninferior MACE but higher CV and all-cause mortality (boxed warning) |
| Pegloticase (Krystexxa) | 2010 | Recombinant pegylated uricase for chronic refractory gout failing conventional ULT | Replicate Phase 3 randomized trials (Sundy et al., JAMA 2011) | Sustained serum urate <6 mg/dL for >=80% of months 3 and 6 | ~42% of biweekly-dosed patients achieved sustained urate response versus 0% placebo; tophus resolution in responders |
| Lesinurad (Zurampic) | 2015 | URAT1-inhibitor uricosuric used in combination with a xanthine oxidase inhibitor | CLEAR-1/CLEAR-2 and CRYSTAL Phase 3 | Serum urate <6 mg/dL in combination with allopurinol/febuxostat | Increased proportion reaching urate target when added to XO inhibitor (later withdrawn commercially for business reasons) |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in gout development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| Febuxostat (cardiovascular safety) — CARES (NEJM 2018) | Met noninferiority for MACE but showed significantly higher cardiovascular and all-cause mortality versus allopurinol | High trial dropout and the mortality signal prompted an FDA boxed warning and second-line positioning; the later FAST trial did not replicate the signal, leaving controversy |
| Arhalofenate (dual-acting uricosuric/anti-flare) — Phase 2b program | Did not advance to approval; development discontinued | Urate-lowering magnitude was modest and the commercial/clinical profile was judged insufficient to progress to Phase 3 |
| Pegloticase (immunogenicity limitation) — Replicate Phase 3 trials | A majority of patients lost urate response over time due to anti-drug antibodies, with infusion-reaction risk | High immunogenicity limited durability; the problem was later mitigated by co-administering methotrexate to improve sustained response |
Choosing the right endpoint
Primary endpoints that matter in gout trials
- Serum urate <6 mg/dL (treat-to-target) — Primary ULT endpoint; sustained control below saturation dissolves crystal deposits
- Gout flare frequency — Clinical endpoint; flares often rise transiently early in ULT before declining
- Tophus resolution/size — Marker of reversing long-term crystal burden in chronic tophaceous gout
- Cardiovascular MACE (safety) — Central to febuxostat evaluation after the CARES mortality signal
How iNGENū runs gout 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
Gout clinical trials — FAQs
What is the target of urate-lowering therapy?
Is febuxostat safe given the CARES findings?
When is pegloticase used?
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