Lilly: Foundayo and reduced-dose Zepbound maintain weight loss after switching from high-dose injectables

SURMOUNT-MAINTAIN results

SURMOUNT-MAINTAIN (NCT06047548), a 112-week Phase 3b randomized, double-blind, placebo-controlled maintenance trial, showed participants who continued Zepbound at maximum tolerated dose (MTD) preserved all prior weight loss at week 112, while reducing Zepbound to 5 mg retained all but 5.6 kg on average; group averages: MTD→MTD — baseline 112.2 kg, after 60 weeks on MTD 89.5 kg, at 52 weeks maintenance 88.7 kg; MTD→5 mg — baseline 113.4 kg, after 60 weeks 89.0 kg, at 52 weeks maintenance 94.6 kg.

ATTAIN-MAINTAIN results

ATTAIN-MAINTAIN (NCT06584916), two 52-week Phase 3b cohorts of SURMOUNT-5 completers, found switching to oral Foundayo maintained most prior loss: Wegovy MTD→Foundayo retained all but 0.9 kg (start of SURMOUNT-5 113.5 kg; at switch 95.0 kg; after 52 weeks oral maintenance 95.9 kg), and Zepbound MTD→Foundayo retained all but 5.0 kg (start of SURMOUNT-5 115.8 kg; at switch 90.9 kg; after 52 weeks oral maintenance 95.9 kg).

Drugs, safety and publication

Agents studied: Zepbound (tirzepatide) once-weekly dual GIP/GLP-1, Foundayo (orforglipron) once-daily oral GLP-1, and Wegovy (semaglutide) injectable; safety profiles were consistent with prior Phase 3 studies; results were presented at the 33rd European Congress on Obesity and published in The Lancet and Nature Medicine.