Israel’s Entera Bio has obtained orphan status from the US FDA for its oral treatment for hypoparathyroidism (decreased function of the parathyroid glands). The condition results in muscle cramping, twitching, or involuntary contraction, and several other symptoms.
http://www.globes.co.il/en/article-dna-biomedical-jumps-on-orphan-drug-status-1000933656