The Food and Drug Administration (FDA) has granted Orphan Drug designation to MBX 2109 for the treatment of hypoparathyroidism.

MBX 2109 is a long-acting parathyroid hormone (PTH) prodrug. The investigational treatment is designed to release active PTH peptide at a controlled rate. According to MBX Biosciences, the extended half-lives of the prodrug and the active peptide allow for a once-weekly dosing regimen.

The Company is currently investigating the safety, tolerability, pharmacokinetics and pharmacodynamics of MBX 2109, administered as a subcutaneous injection, in healthy adults in a randomized, double-blind, placebo-controlled phase 1 trial ( Identifier: NCT05158335).

“We believe MBX 2109, currently in a phase 1 clinical trial, has the potential to overcome limitations of the current standard of care with fewer administrations necessary due to its long-acting profile,” said Kent Hawryluk, President and CEO of MBX Biosciences. “Our goal is to improve the outcomes and quality of life for patients with this chronic condition.”

The FDA’s Orphan Drug designation is granted to medicines intended to treat or prevent rare diseases or disorders that affect fewer than 200,000 individuals.


  1. MBX Biosciences receives Orphan Drug designation for lead candidate MBX 2109 for the treatment of hypoparathyroidism. News release. MBX Biosciences, Inc. Accessed July 26, 2022.
  2. Pipeline: MBX 2109. MBX Biosciences. Accessed July 26, 2022.