UPDATED: FDA says generic versions of Wellbutrin stack up to branded drug

Mylan ($MYL) and Par Pharmaceutical this week said they have made it through FDA scrutiny of their generics of antidepressant Wellbutrin XL in a regulatory episode that has reignited debate over the quality of generics versus branded drugs.

The generics makers said the FDA approved their supplemental Abbreviated New Drug Applications (sANDA) after they provided bioequivalence study results that had been requested by the FDA for their bupropion hydrochloride tablets. Par's product has been on the market since 2006 and Mylan's since 2010. And it is in no small market. Citing IMS figures, Mylan said sales of generic versions of Wellbutrin amounted to more than $500 million in the 12 months ended June 30.  

The agency last fall asked all Wellbutrin XL generics makers--Anchen (part of Par), Actavis ($ACT), Watson Pharmaceuticals (now part of Actavis) and Mylan--to conduct their own bioequivalence studies. That came after extended testing convinced the agency that Teva Pharmaceutical Industries' ($TEVA) version didn't stack up to the branded version and was pulled from the market. Claims circulated for years that Teva's version of the drug, sold under its own brand name, Budeprion XL, wasn't working like the branded version did. There has been litigation over the question, and a couple of pharmacists even teamed up with Consumer Labs to compare the extended-release brand with Teva's generic. Their tests found that the copy released the active ingredient much faster.

Teva defended its product, and the FDA said its review indicated it was close enough to the original. It did, however, ask Teva to do another study. When Teva was unable to pull that off, the FDA did its own. In October, more than 5 years after the questions first began, the FDA said the Teva med wasn't equivalent after all, and Teva and Impax Laboratories ($IPXL), which made the drug for Teva, stopped shipping it. Since then, the FDA has said it is analyzing its current equivalence testing processes, especially for extended-release formulations.

- here's the Par announcement 
- here's the Mylan announcement

Editor's Note: This story has been updated to point out that Par Pharmaceutical has also had its version approved. 

Suggested Articles

The future may be uncertain for AZ’s Imfinzi in first-line lung cancer, but its targeted med Tagrisso now boasts a green light in that setting.

Ultragenyx is back with another FDA nod, this time for Crysvita to treat X-linked hypophosphatemia in patients one year and older.

Roche got a two pieces of good Hemlibra news early this week—and what's good for Hemlibra must be good for Roche.