Another #Pharma Generic-to-Patented Drug Switcheroo: Swap H2 for H | Pharma Industry Regulation |

It’s just a simple swap. Pop out a hydrogen atom, throw in a “heavy” counterpart, and you’ve got a new drug. But on the shoulders of those bulky hydrogen atoms rest lots of money and potential therapies — as well as some prickly questions.

The chemical tweak appears to improve some drugs, providing safer and easier-to-take treatments. But biopharma companies could also set high prices without competition for their fine-tuned therapies, even though the drugs are based on existing medicines for which cheap generics are often available.

The Food and Drug Administration recently completed its first review of such a drug, deutetrabenazine from Teva Pharmaceuticals. Teva announced on Tuesday that the FDA told the company it needed to see more lab data before it would approve the agent, but analysts say it’s only a matter of time before the first-ever drug containing heavy hydrogen hits the market.

The idea of sprucing up older drugs with heavy hydrogen — a molecule formally called deuterium — has raised some eyebrows in the industry. Some have wondered, for example, if companies would be able to defend their patents on deuterium-modified versions of existing drugs as novel enough to deserve their own patent, though that hasn’t been a problem yet.

Experts say that incorporating deuterium into medicines is another case of companies reworking older drugs to improve them and, in some cases, gain new market exclusivity, without investing heavily in the roots of a new drug. Companies, for example, have long combined two existing drugs and taken the mashup to market.