MBX Biosciences, Inc., a clinical stage biopharmaceutical company developing Precision Endocrine Peptide (PEP) therapeutics to treat an array of endocrine disorders, announced the closing of a $115 million Series B financing. The Series B financing was led by Wellington Management with participation from RA Capital Management and Norwest Venture Partners along with existing investors Frazier Life Sciences, New Enterprise Associates (NEA) and OrbiMed.