Many sufferers of Huntington’s disease experience tics, but bad side effects are associated with some of the drugs that could help.
A new technique that’s been in question for at least 40 years—called deuteration—could change that. This once-theoretical approach has finally been presented to the U.S. Food and Drug Administration. If approved, it could open a multi-billion-dollar market for drugs manufactured using the same technology.
Deuteration is the process of introducing deuterium, a heavier form of hydrogen, into a chemical compound. Deuterating drugs can slow their breakdown in the body, allowing them to do their job for longer periods of time. The Israeli drugmaker Teva Pharmaceutical Industries Ltd. has developed a deuterated version of the drug tetrabenazine, called SD-809. Tetrabenazine itself has been available in the U.S. since 2008, but it’s linked with extreme side effects like drowsiness and depression.

Here are Yaacov Benmehleh and Michelle Cortez, reporting for Bloomberg News:
The approach interferes with one of the ways that the body metabolizes or eliminates drugs, involving enzymes that “nibble away” at the hydrogen in the molecule, Timmins said. Deuterium is essentially an armored hydrogen, tougher and more difficult for the enzymes to break down, so it sticks around longer in the body. Other than that, the drug works the same as the original.
Companies like Concert and Auspex Pharmaceuticals Inc., acquired by Teva last year for $3.5 billion, have built their businesses by patenting deuterated versions of marketed drugs, then testing them to make sure they’re safe and effective.
Most companies have steered clear of deuterium due to high costs. But if the F.D.A. approves SD-809, drugmakers might flock to deuteration as an attractive new method for producing high-quality, effective drugs.

