Lilly's Foundayo and lower-dose Zepbound helped people maintain weight loss after switching from higher doses of injectable incretin therapy in two late-phase trials

Key Points:

• Eli Lilly announced results from two late-phase trials, SURMOUNT-MAINTAIN and ATTAIN-MAINTAIN, showing that adults with obesity maintained significant weight loss after switching from higher doses of injectable incretin therapies to either Foundayo (oral GLP-1 receptor agonist) or lower-dose Zepbound (injectable tirzepatide).
• In ATTAIN-MAINTAIN, participants switching from Wegovy MTD to Foundayo maintained all but 0.9 kg of weight loss after one year, while those switching from Zepbound MTD to Foundayo maintained all but 5.0 kg; in SURMOUNT-MAINTAIN, participants remaining on Zepbound MTD maintained all prior weight loss, and those reducing to 5 mg maintained all but 5.6 kg.
• Both Foundayo and Zepbound demonstrated safety profiles consistent with previous studies, with common side effects including nausea, constipation, diarrhea, and vomiting; discontinuation rates due to adverse events were low across treatment groups.
• Foundayo is a once-daily oral GLP-1 receptor agonist approved for chronic weight management, while Zepbound is a once-weekly injectable dual GIP and GLP-1 receptor agonist approved for obesity and related conditions; both require use alongside diet and exercise.
• These findings highlight the potential for long-term maintenance of weight loss using oral or lower-dose injectable incretin therapies, addressing the challenge of weight regain in obesity treatment and expanding options for sustained management.