reviewed april 2026|next review october 2026|88 physicians psi has verified|40267 published studies
Maridebart Cafraglutide (MariTide)
Maridebart cafraglutide (MariTide, AMG 133) is the first bispecific antibody-peptide conjugate in the obesity pipeline, combining GLP-1 receptor agonism with GIP receptor antagonism and enabling monthly dosing through antibody-mediated half-life extension.
Evidence landscape: 40267 published studies
40,267 published items (inflated by broad GLP-1/GIP query). 47 human studies and 121 animal studies.
- 47 Human
- 121 Animal
- 32 Reviews
- 40067 Other research
Not FDA-approved. Phase II trials are ongoing. No regulatory submission has been filed. The compound is in active clinical development by Amgen.
Available only through clinical trial enrollment. Not available through any pharmacy or specialty pharmacy channel.
First bispecific antibody-peptide conjugate in the obesity pipeline. Combines GLP-1 agonism with GIP antagonism, the opposite GIP approach from tirzepatide. Monthly dosing enabled by the antibody half-life.
PSI Assessment
The first bispecific molecule in the obesity pipeline that combines GLP-1 receptor agonism with GIP (glucose-dependent insulinotropic polypeptide) receptor antagonism, maridebart cafraglutide (MariTide, AMG 133) takes the opposite approach to tirzepatide on one of its two targets. Where tirzepatide activates both GLP-1 and GIP receptors, MariTide activates GLP-1 and blocks GIP. Early-phase data showed substantial weight loss with monthly dosing, a significant convenience advantage over weekly injections. The GIP antagonism versus agonism debate is one of the most actively investigated questions in metabolic pharmacology.
Monthly dosing versus weekly for existing GLP-1 drugs. Activates GLP-1 but blocks GIP, the opposite of tirzepatide on one target. The GIP agonism versus antagonism question is unresolved.
The mechanism is a bispecific antibody-peptide conjugate. An anti-GIP receptor antibody is fused to a GLP-1 agonist peptide. The antibody component blocks GIP receptor signaling and provides the extended half-life that enables monthly dosing. The GLP-1 peptide component activates GLP-1 receptors for appetite suppression. Whether GIP receptor antagonism (MariTide's approach) or agonism (tirzepatide's approach) produces better metabolic outcomes is one of the most significant open questions in the field.
What the evidence supports
Early-phase data demonstrates substantial weight loss with monthly dosing. The bispecific antibody-peptide conjugate design is a validated drug architecture. Monthly dosing provides a significant convenience advantage over weekly GLP-1 injections. The anti-GIP antibody component both blocks GIP signaling and extends drug half-life.
What is not yet established
Whether GIP antagonism produces superior or equivalent outcomes to GIP agonism (tirzepatide). Phase III efficacy and safety data (trials ongoing). Whether monthly dosing compliance translates to better real-world outcomes. Long-term effects of sustained GIP receptor blockade.
Research Evidence
The findings below cover what early-phase data has established and where the key scientific questions remain.
Evidence by condition
Evidence dimensions across MariTide's investigated applications. Obesity has early-phase human data. Monthly dosing feasibility has been demonstrated. GIP antagonism research is ongoing.
| Condition | Mechanism | Animal evidence | Human evidence | Replication |
|---|---|---|---|---|
| Obesity | ||||
| Monthly Dosing | ||||
| GIP Antagonism Research |
Early-phase data demonstrated substantial weight loss with monthly dosing. The rate of weight loss in early weeks was notable compared to weekly GLP-1 agonists.
Phase I/II data only. Larger Phase III trials are needed to confirm efficacy and safety at scale.
The bispecific antibody-peptide conjugate design enables monthly or less frequent dosing through the extended half-life of the antibody component.
Dosing convenience is a potential practical advantage, but whether monthly dosing improves real-world adherence is not established.
MariTide's GIP antagonism approach directly tests the opposite hypothesis from tirzepatide's GIP agonism. Both enhance GLP-1 therapy but through opposite GIP mechanisms.
The GIP agonism versus antagonism debate is one of the most important open questions in metabolic pharmacology. Answering it requires Phase III data from both approaches.
47 Human|121 Animal|32 Reviews
View all 40267 indexed studiesHow Maridebart Cafraglutide (MariTide) Works
MariTide is a bispecific antibody-peptide conjugate: an anti-GIP receptor antibody fused to GLP-1 agonist peptides, developed by Amgen.
AMG 133 is a two-in-one molecule. One arm activates GLP-1 receptors (reducing appetite, like Ozempic). The other arm blocks GIP (glucose-dependent insulinotropic polypeptide) receptors. This is the opposite of tirzepatide, which activates GIP. The theory is that GIP blockade may prevent fat storage and enhance weight loss beyond what GLP-1 alone achieves.
For a more detailed view of the biology, here is what researchers have observed at the molecular level.
AMG 133 is a bispecific antibody with an anti-GIP receptor blocking arm fused to GLP-1 agonist peptides. GLP-1R agonism provides appetite suppression and glycemic control. GIPR antagonism may reduce GIP-mediated lipogenesis and fat storage. The monthly dosing interval reflects the antibody half-life.
What is Maridebart Cafraglutide (MariTide) being studied for?
Researchers are studying Maridebart Cafraglutide (MariTide) across several health conditions. Each condition below is labeled with the strength of evidence that exists for that specific use, not for Maridebart Cafraglutide (MariTide) overall. This means a compound can have human studies for one condition but only animal data for another.
Obesity
·Human TrialsEarly-phase data showed substantial weight loss with monthly dosing. The rate of early weight loss was notable.
Limitations: Phase I/II data only. Phase III trials are needed. Head-to-head comparison with tirzepatide or semaglutide has not been conducted.
Monthly Dosing
·Animal StudiesThe antibody half-life enables monthly or less frequent dosing, a significant convenience advantage over weekly GLP-1 injections.
Limitations: Whether monthly dosing improves real-world adherence and outcomes versus weekly injection is not established.
GIP Antagonism Research
·PreclinicalMariTide directly tests whether blocking GIP produces better metabolic outcomes than activating it (tirzepatide's approach). This is a fundamental question in the field.
Limitations: The GIP agonism versus antagonism question is unresolved. Answering it requires Phase III data from both approaches.
Safety and Regulatory Status
FDA Status: Not FDA-approved. Phase II trials are ongoing. No regulatory submission has been filed.
Availability: Available only through clinical trial enrollment. The compound is a bispecific antibody that cannot be reproduced by specialty pharmacies.
Class context: Early-phase data showed GI side effects consistent with GLP-1 activity (nausea, vomiting). The bispecific antibody format is novel for metabolic disease. Full safety profile awaits larger trials.
Phase I data showed GI side effects consistent with GLP-1 class (nausea, vomiting). Monthly dosing is a practical advantage. The bispecific antibody format is novel for metabolic disease. Full safety profile awaits larger trials. Investigational.
Peptide Structure
Technical molecular data for researchers and clinicians.
Questions and Comparisons
Questions the evidence raises for a Maridebart Cafraglutide (MariTide) discussion.
Comparison and Related Research
MariTide is most often compared with other GLP-1-enhancing obesity drugs, particularly tirzepatide which takes the opposite approach to GIP.
Related compounds
Frequently Asked Questions
References
Each citation links to the original study on PubMed, the U.S. National Library of Medicine database.
- 1.Combined preclinical and Phase 1 report on AMG 133 (maridebart cafraglutide, MariTide), a bispecific molecule that blocks GIP receptor signaling while simultaneously activating GLP-1 receptors. In the first-in-human study, single ascending doses produced substantial weight loss that persisted well beyond the dosing period, a feature attributed to the molecule's long half-life and dual mechanism.Veniant MM et al., 2024 in Nat Metab. View on PubMed
- 2.Phase 2 trial evaluating once-monthly maridebart cafraglutide (MariTide, AMG 133) in adults with obesity. The trial demonstrated dose-dependent weight loss of up to approximately 20% over 52 weeks with a once-monthly injection schedule, a dosing frequency substantially less than existing weekly GLP-1 agonists.Jastreboff AM et al., 2025 in N Engl J Med. View on PubMed
- 3.Preclinical study from Amgen demonstrating that blocking the GIP receptor (GIPR) reduces body weight in obese mouse models and that combining GIPR antagonism with GLP-1 receptor agonism produces additive weight loss effects. These findings provided the mechanistic rationale for the bispecific approach used in AMG 133.Killion EA et al., 2018 in Sci Transl Med. View on PubMed
- 4.Preclinical characterization of bispecific molecules combining anti-GIPR antibodies with GLP-1 peptide agonists. The study demonstrated that this conjugate approach produces greater weight loss than either mechanism alone in both mice and non-human primates, establishing the proof of concept for the molecular design that became AMG 133.Lu SC et al., 2021 in Cell Rep Med. View on PubMed
Medical Disclaimer
This content is for educational and informational purposes only and does not constitute medical advice. The information presented reflects published research as indexed by PSI and should not be used to make treatment decisions. Always consult a qualified healthcare provider before starting, stopping, or modifying any treatment.