Eli Lilly (NYSE: LLY) Is Expected to Submit Retatrutide (Once-Weekly Injectable Triple GLP-1/GIP/Glucagon Receptor Agonist Peptide) to the FDA in Late 2026 or 2027 Following the Seven Phase 3 TRIUMPH-Program Readouts Expected Across 2026 (Including TRIUMPH-1 in Obesity Meeting Primary Endpoint With 28.7% Mean Weight Loss at 68 Weeks at the 12 mg Dose, TRIUMPH-4 in Obesity Plus Knee Osteoarthritis Documenting 28.7% Weight Loss and 75.8% Reduction in WOMAC Pain Scores With More Than 1 in 8 Retatrutide-Treated Patients Completely Free From Knee Pain, and Additional Readouts in Type 2 Diabetes, Obstructive Sleep Apnea, and Cardio-Renal-Metabolic Indications); Potential FDA Approval Expected in 2027-2028 Would Position Retatrutide as the Highest-Magnitude Weight Loss Obesity Drug
Eli Lilly (NYSE: LLY) is expected to submit retatrutide (once-weekly injectable triple GLP-1/GIP/glucagon receptor agonist peptide) to the FDA in late 2026 or 2027 following the seven Phase 3 TRIUMPH-program readouts expected across 2026. Program status: TRIUMPH-1 in obesity met primary endpoint with 28.7% mean weight loss at 68 weeks at the 12 mg dose; TRIUMPH-4 in obesity plus knee osteoarthritis documented 28.7% weight loss and 75.8% reduction in WOMAC pain scores with more than 1 in 8 retatrutide-treated patients completely free from knee pain at study end. Additional Phase 3 readouts expected across 2026 in type 2 diabetes, obstructive sleep apnea, chronic lower back pain, and cardio-renal-metabolic indications. If the full TRIUMPH package supports approval, retatrutide would be the highest-magnitude weight loss obesity drug on record (extending the ceiling from tirzepatide's 25.5% at 84 weeks in REDEFINE 4 head-to-head to 28.7% in TRIUMPH-4). The triple-receptor mechanism activates GLP-1 (appetite suppression via hypothalamic pathways), GIP (adipose tissue effects plus central appetite contribution), and glucagon (hepatic effects plus thermogenesis), producing broader tissue coverage than dual-agonist tirzepatide or amylin-plus-GLP-1 CagriSema. Approval is anticipated in 2027-2028 and would reshape the competitive dynamics for the entire obesity drug class, with substantial implications for Novo Nordisk's franchise defense strategy following the August 2026 broker downgrade and Wegovy 7.2 mg higher-dose FDA review submission.