Drug Update · Endocrinology

FDA Approves orforglipron for Weight Maintenance: 25.5% MBE

August 09, 2026

ATTAIN-MAINTAIN cohort 1 treatment difference

MBE 25.5% (95% CI 14.5 to 36.5); P < 0.001 [1]

ATTAIN-MAINTAIN cohort 2 treatment difference

MBE 41.7 (95% CI 24.4 to 59.0); P < 0.001 [1]

FDA original approval date

2026-04-01 [12]

Label effective date

2026-04-01 [12]

Clinical Perspective

This affects endocrinologists, obesity medicine specialists, primary care clinicians, and patients: FOUNDAYO is indicated for adults with obesity or adults with overweight plus at least one weight-related comorbidity and is approved as an oral GLP-1 receptor agonist option ^[2]^[3]. The FDA label and randomized data support using FOUNDAYO in combination with a reduced-calorie diet and increased physical activity to reduce excess body weight and maintain weight reduction long term, including evidence of maintained weight reductions after prior injectable therapy in ATTAIN-MAINTAIN ^[1]^[3]. What is the durability of maintenance of clinically meaningful weight reduction beyond the 1-year time frame studied in ATTAIN-MAINTAIN and Trials 1 and 2?

Dr. Amit Desai · Endocrinology

The FDA approved orforglipron (FOUNDAYO) for chronic weight management in adults with obesity or adults with overweight with at least one weight-related comorbid condition on 2026-04-01 based on pivotal randomized data and supporting studies ^[3]. In the double-blind, randomized phase 3b ATTAIN-MAINTAIN trial, orforglipron maintained a model-based estimate (MBE) of body-weight reduction versus placebo with an estimated treatment difference of MBE 25.5% (95% CI 14.5 to 36.5) in the cohort previously treated with tirzepatide and an estimated treatment difference of MBE 41.7 (95% CI 24.4 to 59.0) in the cohort previously treated with semaglutide at week 52 ^[1].

Clinical Context

Orforglipron (FOUNDAYO) is an oral, nonpeptide glucagon-like peptide-1 (GLP-1) receptor agonist developed for treatment of obesity and weight management ^[1]^[3]. The FDA label indicates FOUNDAYO is indicated in combination with a reduced-calorie diet and increased physical activity to reduce excess body weight and maintain weight reduction long term in adults with obesity or adults with overweight with at least one weight-related comorbid condition ^[2]^[3]. The drug is positioned as an oral GLP-1 receptor agonist alternative to injectable GLP-1 receptor agonists; the published ATTAIN-MAINTAIN trial evaluated orforglipron for maintenance of body-weight reduction after prior injectable therapy and reported maintenance outcomes at week 52 ^[1]. The marketing authorization and prescribing information note recommended dosage escalation and precautions for concomitant CYP3A4 interactions ^[2]^[3].

Key Findings

The ATTAIN-MAINTAIN trial showed orforglipron once daily maintained a model-based estimate (MBE) of 74.7% (s.e.m. 4.05) of body weight reduction compared with an MBE of 49.2% (s.e.m. 3.92) with placebo in participants previously treated with tirzepatide (cohort 1), for an estimated treatment difference of MBE 25.5% (95% CI 14.5 to 36.5); P < 0.001 at week 52 ^[1].
Clinicians should consult current prescribing information for full dosing guidance.
In participants previously treated with semaglutide (cohort 2), ATTAIN-MAINTAIN reported an MBE of 79.3% (s.e.m. 4.42) with orforglipron versus an MBE of 37.6% (s.e.m. 7.46) with placebo, for an estimated treatment difference of MBE 41.7 (95% CI 24.4 to 59.0); P < 0.001 at week 52 ^[1].
The FDA labeling describes two randomized, double-blind, placebo-controlled trials (Trials 1 and 2) establishing effectiveness for reducing and maintaining body-weight reduction, with the primary efficacy parameter in those trials defined as mean percent change in body weight after 72 weeks; the label states FOUNDAYO-treated groups had statistically significant reductions in body weight compared with placebo in those trials ^[3].

Safety & Tolerability

The most common adverse events reported in ATTAIN-MAINTAIN were gastrointestinal effects, which were mostly mild to moderate in severity ^[1].
In Trials 1 and 2 reported in the product labeling, trial-drug discontinuation proportions were: Trial 1 — FOUNDAYO groups 22%, 22%, and 24% for the 5.5 mg, 9 mg, and 17.2 mg once daily groups respectively, and 30% for placebo; Trial 2 — 19%, 22%, and 20% for the 5.5 mg, 9 mg, and 17.2 mg once daily groups respectively, and 20% for placebo ^[3].
Clinicians should consult current prescribing information for full dosing guidance.

Study Design

ATTAIN-MAINTAIN was a double-blind, randomized, placebo-controlled phase 3b trial that randomized participants previously treated with tirzepatide (cohort 1: N = 205) or semaglutide (cohort 2: N = 171) during SURMOUNT-5 to orforglipron once daily or placebo and reported MBE-maintenance outcomes at week 52 ^[1]. Clinicians should consult current prescribing information for full dosing guidance. The FDA prescribing information describes two randomized, double-blind, placebo-controlled Trials 1 (NCT05869903; N = 3,127) and 2 (NCT05872620; N = 1,613) that assessed mean percent change in body weight after 72 weeks; Trial 1 excluded patients with type 2 diabetes and Trial 2 enrolled patients with type 2 diabetes ^[3]. Details on randomization ratio, titration schedules, and primary endpoint wording are provided in the labeling ^[3].

FAQ

Q1 What is orforglipron (FOUNDAYO) approved for?

FOUNDAYO is approved in combination with a reduced-calorie diet and increased physical activity to reduce excess body weight and maintain weight reduction long term in adults with obesity or adults with overweight in the presence of at least one weight-related comorbid condition. The indication and limitations of use, including that concomitant use with another GLP-1 receptor agonist is not recommended, are specified in the prescribing information.

Q2 How does orforglipron work?

Orforglipron is an oral, nonpeptide glucagon-like peptide-1 (GLP-1) receptor agonist that binds to and activates the human GLP-1 receptor. GLP-1 is a physiological regulator of appetite and caloric intake, and GLP-1 receptors are present in brain regions that regulate appetite; orforglipron distributed to and activated such neurons in preclinical studies described in the label.

Q3 What is the recommended dose of FOUNDAYO?

The recommended administration is oral once daily. The label specifies a starting dosage of 0.8 mg once daily, increase after at least 30 days to 2.5 mg once daily, then after at least 30 days to 5.5 mg once daily, with further stepwise escalation to 9 mg, 14.5 mg, and up to a maximum of 17.2 mg once daily based on response and tolerability. Do not take more than one tablet per day and follow the recommended titration schedule in labeling. Clinicians should consult current prescribing information for complete dosing guidance.

Q4 What are the most common side effects?

Clinical trial reports and the prescribing information identify gastrointestinal effects as the most common adverse events; in ATTAIN-MAINTAIN these were mostly mild to moderate in severity. Trial discontinuation proportions are provided in the labeling (for example, in Trial 1 FOUNDAYO-treated groups had discontinuation rates of 22%–24% versus 30% for placebo; in Trial 2 discontinuations were 19%–22% in FOUNDAYO-treated groups versus 20% for placebo). "Clinicians should consult current prescribing information for full safety details".

Clinicians should consult current prescribing information for complete dosing guidance.

FDA Approves orforglipron for Weight Maintenance: 25.5% MBE

Direct Clinical Takeaway & Evidence Summary

FDA Approves orforglipron for Weight Maintenance: 25.5% MBE

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

Study Design

FAQ

References

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