Kailera Therapeutics closed a $600 million Series B led by Bain Capital PE to advance KAI‑9531, a weekly injectable targeting the same receptors as market leader GLP‑1/GIP agents, into global Phase 3 testing this year. The financing will also support Kailera’s oral and injectable metabolic portfolio. The round reflects robust private capital appetite for obesity treatments despite heightened clinical and regulatory scrutiny. Investors cited the market opportunity and the program’s Phase 2 data as justification for the large financing.