Immediate Versus Criterion-triggered Semaglutide for Suboptimal Clinical Response One Year After Primary Metabolic and Bariatric Surgery

Condition(s) studied

Investigational drug(s) / intervention(s)

Semaglutide weekly injection: semaglutide escalated to 2.4 mg weekly, continued for 12 months.

Placebo: Criterion-triggered strategy: matched placebo with identical lifestyle support; guaranteed open-label semaglutide the moment consensus recurrence criteria are met, and in any case 12 months after randomization if response remains suboptimal.

Study summary

Roughly one patient in five never reaches the expected weight loss after MBS, and long-term regain after SG is well documented. These patients are identifiable at the 12-month visit. Today they are watched, coached, and treated only when failure is established.

Whether the drug works in this group is no longer the question. BARI-STEP, published this year, randomized 70 patients with less than 20% weight loss after gastric bypass (including one-anastomosis) or sleeve gastrectomy, a mean of seven years after surgery, to semaglutide 2.4 mg or placebo: 18.0% loss versus 0.4% gain at 68 weeks, an adjusted difference of 19.1 percentage points. Its population was mixed, 55.7% with recurrent weight gain and 44.3% with suboptimal initial response, and its exploratory comparison found no difference in drug response between the two presentations. BARI-OPTIMISE showed the same direction with liraglutide, as did a randomized trial after gastric banding. Efficacy is settled.

Timing is not. BARI-STEP recruited patients a mean of seven years past surgery, after failure had hardened. No trial has tested treating at first recognition, the 12-month visit, against the current standard of structured waiting. The field's own reviews name timing and duration as the open questions. The 2024 IFSO international consensus reached 100% agreement that medication after MBS should generally be withheld until the weight plateau, and 100% agreement that adding it for a suboptimal response can then improve outcomes. That is exactly our immediate arm: treat at the plateau, at first recognition. The triggered arm is what clinics actually do: wait for established failure. Both positions rest on expert agreement, not on a trial. This is the randomized test of the consensus pathway. A registered open-label pilot starts tirzepatide at 12 or 18 months but is small, unblinded, and not a strategy comparison.

The 2026 consensus draws the line for us, and this protocol respects it. The Delphi panel defined surgical nonresponse as less than 10% TWL at 12 months, defined recurrent weight gain as regain of more than 25% of lost weight from nadir, and treated a 10% swing in %EWL from nadir as normal physiologic fluctuation. It gave no 12-month label at all to the patient with 10 to 19.9% TWL, and the IFSO Delphi consensus expects the weight nadir up to 2 years after surgery (Obes Surg 2023). So a patient at 14% TWL at one year may still be on the way down, and calling that failure would be wrong. The protocol therefore splits eligibility into two tiers. Below 10% TWL at 12 months: consensus-defined nonresponse, randomized at once, waiting adds nothing. 10 to below 20% TWL: randomized only after a documented plateau, defined in Section 4, with a hard cap at month 18 so waiting cannot drift into neglect. Randomization is stratified by tier, and results are reported by tier.

Eligibility

Primary outcome measure(s)

• Percentage total weight loss — at 12 months
  Measured in kilograms from pre-surgery weight at 12 months after randomization, same calibrated scale, morning, light clothing.

Trial sites (1)

More General Committee of Teaching Hospitals and Institutes, Egypt trials in Egypt

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