Gathering the record
Relay is organizing the evidence and source boundaries.
GIP-receptor-antagonist antibody / GLP-1-agonist peptide conjugate
MariTide is a long-acting investigational biologic that couples a GIP-receptor-antagonist antibody to two GLP-1 receptor agonist peptides. A 592-participant Phase 2 trial showed substantial weight reduction, and a broad Phase 3 program is underway.
60-Second Overview
Start with what it is, why it matters, what research has shown, and what remains unknown. The science follows after the orientation.
Start here. These four answers explain why the compound matters before the page introduces the deeper science.
MariTide is an investigational, long-acting biologic that joins an antibody to two peptide signals designed to alter appetite and metabolic regulation.
Its unusual format activates one appetite-related gut-hormone pathway while blocking another. Researchers are testing whether that design can support weight and blood-sugar changes with less frequent administration.
A peer-reviewed 592-participant Phase 2 trial reported substantial average weight reduction over 52 weeks in adults with and without type 2 diabetes. The diabetes cohort also showed improved blood-sugar measures, while gastrointestinal tolerability depended partly on how treatment began.
Phase 3 confirmation, long-term immune reactions, cardiovascular outcomes, optimal initiation, weight maintenance, and performance across obesity-related conditions remain unresolved. MariTide is not approved.
The research depth, routes, studies, and primary sources below explain how Relay knows—and where the evidence stops.
Research context
Published research has investigated this compound using the following study designs.
These records explain what researchers did. They are not instructions, recommendations, or a transferable protocol.
A published Phase 2 trial studied MariTide in adults with overweight or obesity, including separate cohorts with and without type 2 diabetes.
Reported study administration—not a recommendation.
Research at a glance
Evidence depth, confidence, and route context explain how Relay knows—not what anyone should do.
A substantial peer-reviewed Phase 2 trial and early pharmacology support active Phase 3 programs.
Research depth describes how large and mature the overall record is. It does not tell you whether the results were positive.
The weight signal is strong; long-term safety, immunogenicity, outcomes, and pivotal replication remain unresolved.
Confidence describes how reliable and consistent the conclusions are. It can be high for one outcome and low for another.
The strongest evidence type shows what the best-supported conclusions are actually based on.
Human findings are more directly relevant than animal or laboratory results, but they still apply only to the populations and outcomes studied.
Route-specific record
These are exposures used in cited research for a specific route and population—not an instruction for an individual.
Half-life describes how long it takes the measured amount in the body to fall by half. It is not a dosing recommendation.
Evidence can change by administration method. Findings from one route should not automatically be applied to another.
Evidence boundary: The study compared several research arms and initiation approaches rather than one transferable schedule. Phase 2 findings do not establish approval, long-term outcomes, or an independent-product handling standard. Amounts shown describe cited research exposure—not a dosage recommendation.
Detailed evidence
Start with the strongest supported conclusion and its main uncertainty. Claim-level records below show how the evidence changes by question, population, route, formulation, and study design.
A peer-reviewed 592-participant randomized Phase 2 obesity trial with and without type 2 diabetes, supported by Phase 1 pharmacokinetic research and active Phase 3 trials.
This is the strongest supported conclusion in the current human evidence—not a summary of every claim made about the compound.
Long-term safety and immunogenicity, optimal initiation strategy, cardiovascular outcomes, weight maintenance, performance across obesity complications, and whether Phase 2 efficacy replicates in Phase 3.
Keeping the main uncertainty visible prevents an early or promising finding from looking more settled than it is.
Questions people bring to the evidence
Research questions—not promises of benefit.
A complex antibody conjugate cannot be evaluated or handled like a generic research peptide.
It is not a standard peptide, not a dual GIP/GLP-1 agonist, and not mechanistically interchangeable with tirzepatide.
The strongest selected regimens approached 20% mean reduction in participants without diabetes.
The diabetes evidence is direct, though the weight response was smaller than in participants without diabetes.
Lower starting doses and escalation were studied to reduce early adverse effects.
The broad MARITIME program is confirmatory; it does not yet prove approval or outcome benefit.
Mechanisms
Maridebart cafraglutide (MariTide; AMG 133) is engineered by conjugating two GLP-1 receptor agonist peptide moieties to a fully human monoclonal antibody that antagonizes GIPR. This creates a mechanistically unusual GLP-1 agonist/GIP antagonist with monthly or less-frequent exposure in clinical development. In a 592-participant Phase 2 trial, participants without diabetes had mean weight reductions approaching 20% in selected regimens at 52 weeks, while the type 2 diabetes cohort had substantial weight and HbA1c reductions. Gastrointestinal events, loading-dose tolerability, antibody-like pharmacokinetics, and limited long-term data remain important. Multiple Phase 3 MARITIME trials are evaluating chronic weight management and obesity-related conditions, but approval and clinical outcome-event benefits are unproven.
A plausible mechanism can explain why a study was attempted. It does not prove that the compound improves a human outcome.
Studies
Study arms are reported for transparency. They describe what researchers did in a defined record and do not transfer across identities, routes, formulations, or populations.
A later trial phase can ask a more mature question, but it does not guarantee a positive result, regulatory approval, or relevance outside the studied population.
Randomized, double-blind, placebo-controlled dose-ranging trial
Adults with overweight or obesity, with or without type 2 diabetes
Selected regimens produced mean weight reductions approaching 20% without diabetes and substantial weight and HbA1c reductions in the diabetes cohort.
Study administration: Monthly or every-eight-week maridebart cafraglutide regimens or placebo
Limitations: Dose groups and estimands differ, loading-dose gastrointestinal effects were important, and Phase 2 cannot establish long-term outcomes or an approved regimen.
Receptor pharmacology, animal models, and early human translation
Laboratory systems, animal models, and early clinical participants
The program established simultaneous GLP-1 agonism and GIPR antagonism with prolonged biologic exposure.
Study administration: GIPR-antagonist antibody conjugated to two GLP-1 analogues
Limitations: Preclinical efficacy and receptor logic cannot predict the long-term human benefit-risk profile.
Randomized placebo-controlled trial
Adults with obesity or overweight and type 2 diabetes
A dedicated Phase 3 trial is evaluating the population that generally showed less weight loss in Phase 2.
Study administration: Maridebart cafraglutide or placebo
Limitations: No completed pivotal results were available.
Randomized, double-blind, placebo-controlled chronic weight-management trial
Adults with obesity or overweight
The MARITIME program is testing whether Phase 2 weight effects replicate in larger pivotal populations.
Study administration: Maridebart cafraglutide or placebo
Limitations: Completed Phase 3 results were not available at the cutoff.
Safety snapshot
Gastrointestinal tolerability and initiation strategy are central to MariTide's benefit-risk profile.
Controlled human evidenceNo approved initiation or maintenance schedule exists.
Open sourceThe current record does not support a reliable common-versus-uncommon frequency split.
Evidence boundaryUnder-detected or under-reported events must not be described as rare.
No source-qualified compound-specific warning or contraindication is encoded in the current record.
Evidence boundaryInvestigational; Phase 3 MARITIME development Long-term safety and immunogenicity, optimal initiation strategy, cardiovascular outcomes, weight maintenance, performance across obesity complications, and whether Phase 2 efficacy replicates in Phase 3.
The current record does not identify a reliable compound-specific pattern of events that caused study discontinuation.
Evidence boundaryThis is an evidence gap, not proof that discontinuations did not occur.
No compound-specific patient-facing urgent-action threshold is established in the current Relay record.
Evidence boundaryRelay does not infer emergency guidance from study discontinuations, mechanism, or incomplete adverse-event reporting.
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