Last updated: September 3, 2026
Relamorelin is an investigational ghrelin receptor agonist for diabetic gastroparesis and other gastric motility disorders. The program reached Phase 3 under Allergan, but the clinical development program did not establish a basis for approval and is not an active commercial product. Relamorelin has no FDA approval, no Orange Book listing, no marketed formulation, and no reported product revenue. Its value now depends on whether a sponsor restarts development with a revised clinical strategy, formulation, or target population.
What is relamorelin and how does it work?
Relamorelin, also known as RM-131, is a synthetic peptide agonist of the growth hormone secretagogue receptor, commonly called the ghrelin receptor. The drug was designed to stimulate gastric contractions, accelerate gastric emptying, and reduce symptoms associated with diabetic gastroparesis.
| Attribute |
Relamorelin |
| Generic name |
Relamorelin |
| Development code |
RM-131 |
| Drug class |
Ghrelin receptor agonist |
| Primary target |
Growth hormone secretagogue receptor |
| Lead indication |
Diabetic gastroparesis |
| Administration studied |
Subcutaneous injection |
| FDA status |
Not approved |
| Orange Book status |
No listed product |
| Commercial status |
No launch |
| Current revenue |
None reported |
Gastroparesis is characterized by delayed gastric emptying without mechanical obstruction. Diabetic gastroparesis is associated with nausea, vomiting, early satiety, bloating and abdominal discomfort. Relamorelin was intended to address both delayed gastric emptying and vomiting, rather than treating only individual symptoms.
Early clinical studies reported improvements in gastric emptying and vomiting frequency, particularly in patients with diabetic gastroparesis. The later Phase 3 program, however, did not produce a sufficiently consistent efficacy profile for regulatory approval.
What is the current development status of relamorelin?
Relamorelin is not an approved drug and does not have an active commercial launch. The program advanced through multiple mid- and late-stage studies before development was discontinued or became inactive.
Development timeline
| Period |
Development event |
| 2010-2013 |
Early clinical development evaluated relamorelin in gastroparesis and related motility disorders. |
| 2014-2017 |
Phase 2 studies reported effects on gastric emptying, vomiting and gastrointestinal symptoms. |
| 2017-2018 |
The program moved toward Phase 3 evaluation in diabetic gastroparesis. |
| 2018-2019 |
Allergan-sponsored Phase 3 studies evaluated efficacy and safety in diabetic gastroparesis. |
| 2019-2020 |
The program failed to generate a clear approval pathway after late-stage development results. |
| 2020 onward |
Relamorelin was not advanced to FDA submission or commercial launch. |
Public clinical-trial records identify Phase 3 studies evaluating relamorelin in adults with diabetic gastroparesis, including trials registered under NCT03420781 and related study identifiers. The studies assessed vomiting, gastric-emptying measures, symptom severity and safety. The clinical program did not result in an FDA-approved New Drug Application.
The principal development issue was efficacy consistency. Earlier studies suggested pharmacologic activity, but late-stage trials did not establish a sufficiently robust and reproducible benefit across the intended treatment population. This is a common failure point for gastroparesis programs, where symptom variability, placebo response, diabetes-related comorbidities and imperfect correlation between gastric emptying and patient-reported outcomes complicate registration trials.
Why did relamorelin fail to reach FDA approval?
Relamorelin did not reach approval because the clinical package did not demonstrate a reliable benefit-risk profile that supported registration. The most important issue was not evidence of biological activity. It was the failure to convert that activity into consistent, clinically meaningful Phase 3 outcomes.
Key regulatory barriers
The relamorelin program faced four material regulatory risks:
- The primary symptom endpoint was difficult to separate from placebo response and background treatment.
- Gastric-emptying improvement did not always translate into a proportional improvement in patient symptoms.
- Diabetic gastroparesis is clinically heterogeneous, limiting the predictive value of small or narrowly selected studies.
- The injectable route created an adherence and convenience disadvantage against generic oral or nasal products.
The FDA has historically required convincing symptom improvement and clinically relevant functional benefit for gastroparesis therapies. A change in gastric-emptying time alone is unlikely to support approval without corresponding improvement in nausea, vomiting, early satiety or other validated outcomes.
No FDA approval letter, NDA approval, label, REMS program or postmarketing commitment exists for relamorelin. The FDA Orange Book therefore does not list relamorelin as an approved drug product with associated patents or regulatory exclusivity.[1]
What patents protect relamorelin?
No Orange Book-listed patents protect an approved relamorelin product because no relamorelin product has been approved in the United States. Regulatory exclusivity is also absent.
Relamorelin may have been covered historically by composition-of-matter, peptide, formulation, method-of-use or manufacturing patent filings associated with prior developers and licensees. Those rights should not be treated as a current commercial barrier without a claim-by-claim review of:
- Patent family ownership and assignment history.
- National-phase status.
- Patent-term-adjustment calculations.
- Terminal disclaimers.
- Continuation and divisional claims.
- Expired or abandoned applications.
- Written-description and enablement support for the final clinical formulation.
- Claims covering diabetic gastroparesis, nausea, vomiting or gastric-emptying disorders.
- Claims covering subcutaneous dosing and peptide manufacturing.
The absence of an Orange Book listing does not mean that all third-party patent risk is absent. It means that no approved product currently anchors an FDA patent-listing dispute or statutory Hatch-Waxman exclusivity period.
What patent barriers would matter if development restarted?
A restarted program would depend most heavily on patent protection for a commercially differentiated formulation or dosing regimen. Basic claims to the relamorelin molecule may have limited remaining value if the earliest composition-of-matter rights have expired or are approaching expiration.
Potentially valuable claim categories would include:
| Claim category |
Commercial relevance |
| Composition of matter |
Protects the peptide sequence and chemical variants. |
| Stable injectable formulation |
May protect concentration, excipients, pH and storage conditions. |
| Dosing regimen |
May protect once-daily or lower-burden administration. |
| Method of use |
May cover diabetic gastroparesis, vomiting or specific patient subgroups. |
| Combination therapy |
May cover use with insulin, prokinetics or antiemetics. |
| Manufacturing process |
May reduce production cost and improve peptide purity or yield. |
| Device or delivery system |
May protect a pen, autoinjector or alternative delivery route. |
A relaunch based only on an old injectable peptide patent estate would face weak exclusivity economics. A relaunch supported by new formulation, device or biomarker claims could create a more defensible commercial position.
When does relamorelin lose exclusivity?
Relamorelin has no U.S. regulatory exclusivity expiration date because it has never received FDA approval. No five-year New Chemical Entity exclusivity, three-year clinical-investigation exclusivity, orphan-drug exclusivity or pediatric exclusivity has been granted for the product.
Patent expiration dates cannot be treated as a single definitive date without identifying the relevant patent family and confirming terminal disclaimers, patent-term adjustment and jurisdiction. The commercially relevant issue is that any restart would need to establish a new period of enforceable protection around the final product rather than rely solely on historical molecule claims.
In Europe and other jurisdictions, the same distinction applies. Market exclusivity depends on national patent status and regulatory approval. No broad global exclusivity period has been created by an FDA approval.
Which companies developed or controlled relamorelin?
Relamorelin moved through several corporate development structures. Rhythm Pharmaceuticals was associated with the RM-131 program during earlier clinical development. Allergan later advanced relamorelin into Phase 3 studies for diabetic gastroparesis. Following AbbVie's acquisition of Allergan, the asset became part of a broader portfolio rationalization process, but it did not emerge as a marketed AbbVie product.
| Company |
Role in the public development history |
| Rhythm Pharmaceuticals |
Earlier developer associated with RM-131 clinical development. |
| Allergan |
Advanced the program into Phase 3 diabetic-gastroparesis studies. |
| AbbVie |
Acquired Allergan but did not launch relamorelin. |
| Generic manufacturers |
No current generic product because relamorelin is not approved. |
No active licensing transaction has created a commercial relamorelin franchise comparable to a partnered, registration-ready asset. Any new license would likely require a low upfront valuation, milestone-heavy economics and substantial control retained by the licensee over clinical design.
What is the FDA and Orange Book status of relamorelin?
Relamorelin has no FDA-approved dosage form, prescribing information or commercial application listed in the Orange Book. There is no approved injectable product, oral product, nasal product or device combination.
| FDA and commercial item |
Status |
| FDA approval |
None |
| Approved indication |
None |
| Orange Book listing |
None |
| FDA reference listed drug |
None |
| ANDA pathway |
Not currently available |
| Paragraph IV litigation |
None identified for an approved relamorelin product |
| Regulatory exclusivity |
None |
| U.S. launch |
None |
| Reported product sales |
None |
Because there is no reference listed drug, a conventional Abbreviated New Drug Application pathway is not currently available. A future sponsor would likely need to pursue a full 505(b)(1) NDA or assess whether a 505(b)(2) pathway could be supported by a suitable reference product and bridging data. The latter route would still require substantial clinical and formulation justification.
What is the market opportunity for relamorelin?
The commercial opportunity is real but narrower than the total gastroparesis population. The target market would consist of patients with objectively documented diabetic gastroparesis, persistent nausea or vomiting, inadequate response to existing therapy, and willingness to use an injectable medicine.
Current treatment options include generic metoclopramide, the nasal formulation Gimoti, antiemetics, nutritional interventions and, in selected cases, procedural or device-based treatment. Domperidone is available in the United States only through a restricted FDA expanded-access mechanism. These options leave an unmet need, but they also create pricing and adoption constraints.[2,3]
Relamorelin market scenarios
The following scenarios are analytical estimates rather than company guidance. They assume a successful restart, a new FDA approval and a U.S. launch.
| Scenario |
Treated patients at maturity |
Annual net price |
Estimated peak U.S. sales |
| Conservative |
25,000 |
$6,000 |
$150 million |
| Base case |
75,000 |
$10,000 |
$750 million |
| Upside |
150,000 |
$12,000 |
$1.8 billion |
These estimates assume a chronic-treatment model and exclude international revenue, rebates, patient-assistance programs and manufacturing costs. A twice-daily injectable regimen would push the product toward the conservative case unless it demonstrated a strong reduction in vomiting, hospital utilization or rescue medication use.
A more favorable market profile would require:
- A once-daily or less frequent formulation.
- Clear efficacy in a defined diabetic-gastroparesis subgroup.
- Reduction in vomiting episodes rather than only improved gastric emptying.
- A payer-relevant reduction in emergency visits or hospitalizations.
- Pricing below highly specialized biologic therapies.
- A label supporting chronic use with acceptable injection-site and systemic safety.
How does relamorelin compare with competing gastroparesis therapies?
Relamorelin would enter a market dominated by low-cost symptomatic treatment and fragmented specialty care.
| Therapy |
Status |
Primary advantage |
Main limitation |
| Metoclopramide |
FDA-approved generic |
Low cost and established use |
Neurologic safety restrictions and tolerability |
| Gimoti |
FDA-approved nasal metoclopramide |
Alternative delivery for selected patients |
Same active ingredient and safety limitations |
| Domperidone |
Restricted expanded access in the U.S. |
Prokinetic and antiemetic activity |
Regulatory access and cardiac risk concerns |
| Tradipitant |
Investigational |
Oral neurokinin-1 antagonist approach |
Development and regulatory uncertainty |
| Relamorelin |
Investigational, inactive |
Ghrelin mechanism and potential effect on vomiting and motility |
Phase 3 failure, injectable delivery and no approval |
| Procedural/device treatments |
Selected patients |
Option for refractory disease |
Invasive, variable access and evidence limitations |
Relamorelin’s differentiation would need to come from symptom control, especially vomiting reduction, rather than gastric-emptying data alone. An injectable product with no clear superiority over metoclopramide would face substantial formulary resistance.
What generic entry risks exist for relamorelin?
There is no immediate generic-entry risk because relamorelin has no approved reference product. If a sponsor obtains approval, generic risk would depend on the patent estate and regulatory pathway.
A full 505(b)(1) approval could support market exclusivity and patent protection, but an older peptide sequence with limited remaining patent life would be exposed to follow-on competition. A 505(b)(2) approval could reduce development cost in some circumstances but may create greater exposure to listed patents or competing formulations.
The highest-risk launch scenario would involve:
- A short remaining patent term.
- No durable formulation or device claims.
- A high annual price.
- Injectable administration.
- Limited evidence of superiority.
- Multiple peptide manufacturing specialists capable of producing the active ingredient.
Manufacturing could provide a secondary barrier. Peptide synthesis, purification, aggregation control, sterility and cold-chain requirements add complexity. Those barriers can delay entry, but they rarely substitute for strong patent claims and regulatory exclusivity.
What is the investment outlook for relamorelin?
Relamorelin is best viewed as a dormant clinical asset rather than a near-term revenue opportunity. Its scientific rationale remains relevant, but the original commercial thesis was weakened by Phase 3 efficacy results and the lack of an FDA filing.
A rational redevelopment strategy would require a materially different program:
- Select patients using objective gastric-emptying and symptom criteria.
- Use vomiting frequency or a validated composite symptom endpoint as the primary outcome.
- Develop a less burdensome delivery system.
- Establish a commercial manufacturing process before Phase 3.
- Secure new patent claims around formulation, dosing, device or patient selection.
- Demonstrate economic value against generic metoclopramide and existing supportive care.
Without those changes, the probability-adjusted value remains low. The base-case commercial value of a successful relaunch could be meaningful, but the probability of reaching approval after prior late-stage failure would sharply reduce present value.
Key Takeaways
- Relamorelin is an investigational ghrelin receptor agonist formerly developed for diabetic gastroparesis.
- The program reached Phase 3 under Allergan but did not produce an FDA approval.
- No approved relamorelin product, Orange Book listing, FDA exclusivity period or product revenue exists.
- There is no conventional generic-launch pathway because no reference listed drug is available.
- Historical molecule patents may not provide sufficient commercial protection for a future relaunch.
- A viable redevelopment program would need new formulation, dosing, device, patient-selection or method-of-use protection.
- Estimated peak U.S. sales range from approximately $150 million to $1.8 billion in successful relaunch scenarios, with a central analytical case of about $750 million.
- The key commercial risks are late-stage efficacy uncertainty, injectable administration, payer comparison with generic metoclopramide and uncertain patent durability.
FAQs about relamorelin
Is relamorelin available by prescription?
No. Relamorelin is not FDA-approved and is not commercially available by prescription in the United States.
Did relamorelin receive breakthrough therapy or orphan-drug designation?
No FDA approval or publicly established regulatory exclusivity period is associated with relamorelin. A designation, if granted during development, would not itself authorize marketing or guarantee approval.
Can a generic company launch relamorelin?
Not through the standard ANDA route today because no approved reference listed drug exists. A future competitor would need to assess an NDA, 505(b)(2) or other applicable regulatory pathway.
Could relamorelin be repurposed for opioid-induced or postsurgical gastroparesis?
Potentially, but each indication would require supporting clinical data. Prior diabetic-gastroparesis studies would not automatically establish efficacy in other patient populations.
What would make relamorelin commercially attractive to a pharmaceutical licensee?
The strongest licensing case would require a differentiated delivery system, a validated responder population, clear vomiting reduction, improved adherence and new patent protection extending beyond the original peptide claims.
References
- U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
- U.S. Food and Drug Administration. (2020). Gimoti prescribing information.
- U.S. Food and Drug Administration. (2024). Domperidone expanded access program information.
- ClinicalTrials.gov. (2018). Study to evaluate the efficacy and safety of relamorelin in participants with diabetic gastroparesis, NCT03420781.
- Camilleri, M., McKinzie, S., Foxx-Orenstein, A. E., Burton, D., Thomforde, G. M., Baxter, K., et al. (2009). Effect of relamorelin, a ghrelin agonist, on gastrointestinal motor functions in healthy volunteers. Neurogastroenterology & Motility.
- Camilleri, M., McKinzie, S., Foxx-Orenstein, A. E., Burton, D., Thomforde, G. M., Baxter, K., et al. (2013). Clinical trial of relamorelin in diabetic gastroparesis. Gastroenterology.
- Allergan plc. (2019). Annual report and pipeline disclosures.
- AbbVie Inc. (2020). Annual report and pharmaceutical pipeline disclosures.
