Kailera Therapeutics raised $600 million in a Series B round led by Bain Capital Private Equity to advance KAI‑9531 — a weekly injectable targeting the same receptors as Lilly’s Zepbound — into global Phase 3 testing. The financing also supports development of additional oral and injectable metabolic candidates across Kailera’s pipeline. The round ranks among the largest private biotech financings of the year and signals continued investor appetite for obesity drugs capable of competing with established GLP‑1/Tirzepatide therapies.