Amgen’s third-quarter report on November 3 was mostly about a large, profitable company doing what large, profitable companies do: $10.4 billion in revenue, up 8%, and non-GAAP earnings per share of $6.45.
Buried in the pipeline section was something more interesting for anyone tracking the next generation of obesity drugs.
MariTide, Amgen’s long-acting antibody-peptide conjugate, now has three Phase 3 studies with enrollment completed, including its cardiovascular outcomes trial and two obstructive sleep apnea studies. Two more diabetes studies are planned to begin before the end of the year.
What the November release did not contain was new Phase 3 efficacy data. That distinction matters as much as the enrollment milestones.
MariTide, known generically as maridebart cafraglutide and previously as AMG 133, is one of the most structurally unusual molecules in the obesity race. Its clinical program has become one of the broadest in the field, stretching beyond weight loss into cardiovascular disease, sleep apnea, heart failure and diabetes.
Amgen’s commercial hypothesis is increasingly clear. It wants to compete with Lilly and Novo Nordisk not only on efficacy, but on how often patients need treatment.
What Makes MariTide Different
Amgen describes MariTide as a differentiated antibody-peptide conjugate that activates the glucagon-like peptide-1 receptor while blocking the glucose-dependent insulinotropic polypeptide receptor, or GIPR.
That second feature sets it apart from Lilly’s tirzepatide, which activates both receptors. The approaches involve the same two signaling systems but manipulate one of them in opposite directions.
The antibody component helps extend MariTide’s duration of action. That differs from semaglutide and tirzepatide, whose long-acting designs use fatty-acid modifications that promote albumin binding and support approximately weekly administration.
Amgen is testing monthly starting doses and maintenance schedules that could eventually require as few as four or six injections a year. Those less-frequent schedules remain under investigation rather than established treatment regimens.
There is also a pharmacological puzzle. Researchers have investigated why both activating and blocking GIP signaling can contribute to weight loss when combined with GLP-1 receptor activation.
The biological explanation is complex and remains an active research question. What matters clinically is whether MariTide’s particular combination can produce durable weight reduction with acceptable tolerability.
MariTide is a bet that dosing frequency, not just peak weight loss, could help decide the next phase of the obesity market.
Where the MariTide Phase 3 Program Stands
According to Amgen’s November 3 release, MARITIME-1, in adults with obesity or overweight without type 2 diabetes, and MARITIME-2, in those with type 2 diabetes, remain ongoing.
Extension studies for both trials are enrolling participants who completed the parent studies. They are designed to evaluate longer-term weight maintenance using monthly or less-frequent dosing schedules.
MARITIME-SWITCH is enrolling people moving from weekly tirzepatide or semaglutide to MariTide given every eight weeks or quarterly. That design targets an important commercial question: whether patients already taking established obesity medicines can maintain their results after switching to a less frequently administered treatment.
The November milestone came in three other studies.
MARITIME-CV, evaluating cardiovascular outcomes in adults with established atherosclerotic cardiovascular disease and obesity or overweight, has completed enrollment.
So have MARITIME-OSA-1 and MARITIME-OSA-2, which investigate obstructive sleep apnea in patients using and not using positive airway pressure therapy, respectively.
Not every outcomes study has reached that point. MARITIME-HF, investigating heart-failure events and cardiovascular risk among adults with obesity and preserved or mildly reduced ejection fraction, is still enrolling.
In diabetes, MARITIME-T2D-3 has started enrollment and includes a comparison with semaglutide. Amgen says two additional Phase 3 diabetes studies are planned to begin in the fourth quarter of 2026.
A separate Phase 2b study investigating liver fat reduction and weight loss in people with elevated liver fat has also completed enrollment.
Completing enrollment is a logistical milestone, not a clinical result. It means recruitment is finished for a particular study, not that the study has demonstrated efficacy or safety.
No new MariTide Phase 3 cardiovascular, sleep apnea or weight-loss outcome figures were announced in the November 3 release.
What the Phase 2 Data Actually Showed
The principal published obesity efficacy evidence remains the Phase 2 trial involving 592 participants, reported in the New England Journal of Medicine in June 2025.
Amgen’s original November 2024 announcement highlighted mean weight loss of up to approximately 20% at 52 weeks in adults with obesity or overweight without type 2 diabetes and approximately 17% in those with type 2 diabetes.
Those figures used an efficacy estimand, which estimates weight-loss outcomes under specified assumptions about continued treatment.
The peer-reviewed study also reported a treatment-policy analysis that accounts for participants regardless of whether they remained on treatment. Under that approach, average weight reduction across MariTide dose groups ranged from 12.3% to 16.2% without diabetes and 8.4% to 12.3% with diabetes.
These are different statistical perspectives on the same clinical program, not contradictory studies. Readers comparing obesity treatments need to know which analysis a headline percentage comes from.
Weight loss had not clearly plateaued at 52 weeks in the original company-reported analysis, suggesting further reduction might have been possible with continued treatment.
But tolerability was an important qualification. Gastrointestinal adverse events, including nausea, vomiting and constipation, were common. Amgen said gradual dose escalation substantially reduced nausea and vomiting.
In the Phase 2 dose-escalation arms, approximately 11% discontinued treatment because of an adverse event, while fewer than 8% discontinued because of gastrointestinal events.
There is also more recent maintenance evidence than the original 52-week headline suggests.
In early 2026, Amgen reported exploratory results from a second year of Phase 2 treatment among participants who had already lost at least 15% of their body weight during the first year. The company said a large majority maintained their weight reduction for another 52 weeks while receiving lower monthly or quarterly MariTide doses.
Amgen also reported low rates of nausea and vomiting during that additional year and no new safety signals in the selected maintenance population.
Those findings support the rationale for testing less-frequent maintenance dosing. But because the second-year group consisted of participants who had already responded substantially to treatment, it cannot establish that the same strategy will work equally well for everyone starting MariTide.
The comparison with established obesity drugs therefore remains indirect. MariTide has demonstrated substantial Phase 2 weight reduction, but its results cannot be used to declare superiority over tirzepatide or Eli Lilly’s triple agonist retatrutide.
We covered retatrutide’s later-stage evidence in our analysis of the TRIUMPH-1 Phase 3 trial.
MariTide’s potential advantage may prove to be convenience and maintenance rather than a new record for peak weight loss.
The Competitive Clock Is Already Running
Amgen is not alone in chasing less frequent dosing.
AbbVie is investigating ABBV-295, a long-acting amylin analogue with early pharmacokinetic findings that support further investigation of monthly administration. We examined that program in our report on ABBV-295 and the monthly obesity-injection question.
Other developers are researching extended-release formulations and new combinations targeting pathways involved in appetite, metabolism and energy balance.
Lilly and Novo Nordisk are also expanding their oral obesity-drug strategies, creating a different kind of convenience competition: removing injections rather than spacing them further apart.
MariTide’s challenge is to demonstrate that its potentially quarterly or every-eight-week maintenance schedule offers an attractive combination of efficacy, safety, convenience and value.
Less frequent injections could reduce treatment burden, particularly for patients expecting to remain on obesity therapy for years. But fewer doses do not automatically mean better adherence, greater satisfaction or lower overall treatment costs.
The switch trial may be especially important commercially.
Millions of patients are already using semaglutide or tirzepatide. If MariTide can maintain weight reduction after patients switch from those treatments, Amgen could potentially compete for established users without having to provide their initial weight-loss therapy.
That proposition remains unproven in Phase 3. MARITIME-SWITCH is designed to help answer whether less-frequent MariTide administration can sustain outcomes in that setting.
The commercial question is no longer only who can produce the largest percentage change on a weight-loss chart. It is who can deliver durable results that people and healthcare systems can sustain.
What to Watch Next
Several questions will determine whether MariTide’s broad program pays off.
The first is long-term tolerability. Its extended activity may complicate management of adverse effects once a dose has been administered, although comparative evidence is still needed to determine whether this creates a practical disadvantage against shorter-acting therapies.
The second is the GIP-blocking mechanism. The approach has produced substantial Phase 2 weight loss, but definitive evidence on long-term cardiovascular and other clinical outcomes is still unavailable.
The third is maintenance. Preliminary Phase 2 data support the possibility of preserving weight loss with fewer injections, but larger randomized Phase 3 findings will be needed to establish the durability and generalizability of that effect.
Finally, cardiovascular, sleep apnea and heart-failure outcomes could substantially affect MariTide’s future clinical role, regulatory indications and commercial positioning if the studies demonstrate meaningful benefits.
Enrollment completion brings some of those answers closer, but does not guarantee positive results. Amgen’s November 3 announcement did not provide new efficacy results or specific topline dates for the completed-enrollment outcomes studies.
A drug designed to last for months has to be safe and effective over those intervals, too.
For now, the update shows Amgen building a program intended to survive a crowded obesity market by offering a different dosing proposition rather than simply promising a bigger number on the scale.
The Phase 2 weight-loss results earned MariTide a place in the race. The preliminary maintenance findings strengthened the case for its long-acting design.
The completed enrollment milestones move the program closer to crucial outcomes data. Those results, together with findings from the studies still recruiting, will help determine whether MariTide can establish a durable place in obesity treatment.
For now, the trials have enrolled. The decisive Phase 3 evidence has not arrived.
Primary source: Amgen — Third Quarter 2026 Financial Results and Pipeline Update. November 3, 2026.
Phase 2 announcement: Amgen — MariTide 52-Week Phase 2 Weight-Loss Results. November 26, 2024.
Peer-reviewed clinical evidence: Jastreboff AM et al. Once-Monthly Maridebart Cafraglutide for the Treatment of Obesity — A Phase 2 Trial. New England Journal of Medicine. Published online June 23, 2025.
Maintenance findings: Amgen — Fourth Quarter and Full Year 2025 Results, Including Exploratory MariTide Phase 2 Maintenance Findings. February 3, 2026.
