Biotechs are spending billions to cure a rare liver disorder most Americans have never heard of. The contentious race features dueling technologies, patent wars, a broken alliance, and a boiling competition between the U.S. and Chinese drug industries.

The disease, known as alpha-1 antitrypsin deficiency (AATD), is a slow-moving disaster for patients. Thanks to a single misspelled letter of DNA, their livers produce a mutant version of a protein that normally travels through the bloodstream and protects the lung from damage.