Pasatru’s approval sets up a market battle in a rare indication where the only available treatment has generated disappointing sales.

A Regeneron drug that treats an ultra-rare disease that causes bone to form where it's not meant to be has won approval.

After more than 10 years in development, Regeneron secured a landmark approval for its monoclonal antibody garetosmab, now commercially known as Pasatru. | Regeneron's Pasatru has…