Core Viewpoint - Tirzepatide, developed by Eli Lilly, is the most effective weight loss drug currently on the market, demonstrating a weight reduction of over 20% in clinical trials, particularly beneficial for patients with severe obesity (BMI > 40 kg/m²) [2][5] Group 1: Drug Efficacy - Tirzepatide has shown significant weight loss effects in obese patients, regardless of the presence of type 2 diabetes, with an approximate reduction of 20% [5] - The drug is particularly advantageous for patients with severe obesity, who face the highest burden of cardiovascular complications and mortality [5] Group 2: Genetic Obesity and MC4R Deficiency - MC4R deficiency is the most common hereditary obesity condition, characterized by hyperphagia and significant weight gain from early childhood, leading to severe obesity in adulthood [5][6] - Current treatments for MC4R deficiency have been ineffective, with no approved therapies available for this genetic condition [5][6] Group 3: Research Findings - A study published in Nature Medicine indicates that Tirzepatide effectively aids weight loss in patients with MC4R deficiency, achieving results comparable to non-genetic obesity patients [2][6] - In a clinical trial involving 2,291 participants, 32 individuals (1.4%) were found to carry pathogenic MC4R mutations, and both groups experienced similar weight loss trajectories over 72 weeks, with MC4R mutation carriers losing 18.3% of their body weight compared to 19.9% for non-carriers [6]

Group 1 - In Q1 2025, sales of semaglutide surpassed Merck's Keytruda by $664 million, marking semaglutide as the temporary global "king of drugs" [1][2] - Novo Nordisk reported Q1 2025 global sales of semaglutide at 55.776 billion Danish kroner (approximately $7.864 billion), a year-on-year increase of 32.17%, accounting for about 71% of the company's total revenue [1][3] - Merck's Keytruda reported Q1 2025 global sales of $7.2 billion, with a year-on-year growth of 4%, indicating a slowdown compared to its 18% growth in 2024 [2][3] Group 2 - Semaglutide's growth is driven by its indications for weight loss, with Ozempic sales at 32.721 billion Danish kroner (approximately $4.613 billion, up 15%), Rybelsus at 5.695 billion Danish kroner (approximately $0.803 billion, up 13%), and Wegovy at 17.36 billion Danish kroner (approximately $2.448 billion, up 83%) [3] - Novo Nordisk highlighted that approximately 1 billion people suffer from obesity, but only a few million receive treatment, indicating a significant market opportunity for Wegovy [3] - Competition is intensifying with Eli Lilly's dual agonist tirzepatide, which has cumulative sales of $6.15 billion, although semaglutide's sales still lead [3][4] Group 3 - Eli Lilly holds a 53.3% market share in the U.S. for GLP-1 receptor agonists, indicating strong competition in the market [4] - Novo Nordisk has revised its full-year 2025 sales growth forecast from 16%-24% to 13%-21%, and its operating profit forecast from 19%-27% to 16%-24%, primarily due to lower-than-expected market penetration of semaglutide in the U.S. [4]