Sotatercept, a new drug candidate for pulmonary arterial hypertension (PAH), has been designated an orphan drug in Korea.

The Ministry of Food and Drug Safety recently announced the drug’s designation in the first orphan drug designation announcement it made in the new year.

Sotatercept, which is being developed by Merck, is being regarded to have changed the treatment paradigm for PAH.

The substance, which is a combination of a protein complex, activin, and the transforming growth factor-β (TGF-β), reverses disease progression by blocking abnormal signaling between cells in the pulmonary blood vessels.

Pulmonary arterial hypertension is a condition cha