Gastroenterology · Clinical trials
Gastroparesis 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 gastroparesis — and why its trials are hard
Gastroparesis is a chronic disorder of delayed gastric emptying in the absence of mechanical obstruction, producing nausea, vomiting, early satiety, postprandial fullness, bloating, and abdominal pain. The most common etiologies are diabetic, idiopathic, and postsurgical, with impaired gastric neuromuscular function involving interstitial cells of Cajal and vagal dysfunction. Diagnosis relies on gastric emptying scintigraphy demonstrating delayed emptying alongside compatible symptoms after excluding obstruction. Management is difficult and largely unsatisfying: dietary modification, glycemic control, and prokinetic and antiemetic agents form the backbone, with gastric electrical stimulation, pyloric interventions, or enteral nutrition reserved for severe cases. Notably, metoclopramide is the only FDA-approved drug for gastroparesis, and it carries a boxed warning for tardive dyskinesia that limits long-term use to short courses. Many candidate prokinetics have failed in development, including the ghrelin agonist relamorelin in phase 3, and agents such as prucalopride are used off-label. This scarcity of approved, durable, and safe therapies underscores a substantial unmet medical need in a symptomatic and often refractory patient population.
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 |
|---|---|---|---|---|---|
| metoclopramide (Reglan) | 1979 | Diabetic gastroparesis (the only FDA-approved drug for gastroparesis; carries boxed warning for tardive dyskinesia) | Early randomized controlled trials in diabetic gastroparesis | Improvement in gastroparesis symptoms and gastric emptying | Significant short-term symptom improvement vs placebo; long-term use limited by neurologic toxicity |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in gastroparesis development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| relamorelin (ghrelin receptor agonist) — Phase 3 program in diabetic gastroparesis (following phase 2b RM-131-009) | Phase 3 trials terminated/discontinued; did not advance to approval | Regulatory and endpoint challenges, including worsened glycemic control signals and difficulty meeting composite symptom endpoints |
| prucalopride (5-HT4 agonist) — Small randomized crossover studies in gastroparesis (used off-label) | Never approved for gastroparesis despite prokinetic activity | Evidence limited to small studies; no pivotal gastroparesis program supporting an indication |
| camicinal (motilin receptor agonist, GSK962040) — Phase 2 diabetic gastroparesis study | Did not deliver durable, clinically meaningful benefit | Tachyphylaxis and modest effect size; development for gastroparesis not advanced |
Choosing the right endpoint
Primary endpoints that matter in gastroparesis trials
- Gastric emptying scintigraphy (T-1/2, % retention at 4h) — Objective measure of emptying rate; the diagnostic standard and a common pharmacodynamic endpoint, though it correlates weakly with symptoms.
- Gastroparesis Cardinal Symptom Index (GCSI) — Validated patient-reported symptom score (nausea/vomiting, fullness/early satiety, bloating) used as a primary efficacy endpoint.
- ANMS GCSI-Daily Diary (GCSI-DD) — Daily-diary version developed for regulatory trials to capture symptom change; a frequent primary endpoint in modern programs.
- Vomiting frequency — Reduction in weekly vomiting episodes, a clinically meaningful component endpoint especially in diabetic gastroparesis.
How iNGENū runs gastroparesis 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
Gastroparesis clinical trials — FAQs
Is metoclopramide really the only approved drug for gastroparesis?
Why has gastroparesis drug development been so difficult?
What options exist when metoclopramide is inadequate?
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