Posted 06 August 2013
By Alexander Gaffney, RF News Editor
The US Food and Drug Administration (FDA) has announced the withdrawal of a new drug application (NDA) for Purdue Pharma's Oxycontin (NDA #20-553), the very same application that had lost patent protection in April 2013 and had been subject to potential generic competition before FDA said it would not approve any non-abuse-resistant formulations of the drug.
Under current regulatory policy, approved drugs products are protected by several types of statutory provisions. For new molecular/chemical entities, FDA grants what is known as marketing exclusivity, meaning it will not approve any generic versions of the product for at least five years. For other types of new drugs, FDA offers three years of market exclusivity. In addition, FDA also recognizes patents granted by the US Patent and Trademark Office, and will not grant approval for any products protected by a relevant patent.
Once these protections end, however, FDA may approve generic competitors to the product under the terms of the 1984 Hatch-Waxman Act. There is, however, one major caveat: If the original drug product is found to be either unsafe or inefficacious, resulting in its withdrawal from the market, FDA may withhold approval from those generic competitors.
This has historically resulted in something of a cat-and-mouse game between branded and generic pharmaceutical companies, with branded companies seeking to take prior iterations of their products off the market before they can be referenced by generic companies, and generic companies petitioning FDA to find that those products were not taken off the market for reasons of safety or efficacy.
Attempts at Generic Competition
April 2013 saw the resolution of one of the most memorable of those confrontations, involving at least eight generic pharmaceutical companies and Purdue Pharma, the manufacturer of Oxycontin (oxycodone hydrochloride), a potent painkiller that had come to be widely abused. In response to that abuse, Purdue had created a new abuse-resistant formulation of the drug (NDA #22-272), and petitioned FDA not to approve any generic applications referencing the original 553 NDA.
In a last-minute decision in April 2013-literally on the day the generic products would have been cleared to reach the market-FDA announced that it agreed with Purdue's arguments, and said it would not approve any generic application that did not include abuse-deterrent qualities, seemingly putting off any approval through the abbreviated new drug application (ANDA) pathway until Purdue's new marketing exclusivity and patent for the abuse-deterrent formulation expired. Companies could, however, access the market through the more expensive 505(b)(2) pathway in some cases.
"Because original Oxycontin provides the same therapeutic benefits as reformulated Oxycontin, but poses an increased potential for certain types of abuse, the FDA has determined that the benefits of original Oxycontin no longer outweigh its risks and that original Oxycontin was withdrawn from sale for reasons of safety or effectiveness," the agency added.
Now FDA has formally granted Purdue's March 2013 petition to formally withdraw the 553 NDA, announcing in the Federal Register on 6 August 2013 that as a result of the original formulation's potential for "abuse and misuse," the drug may not be referenced by any future generic drug applications (i.e. ANDAs).
"Under section 505(e) of the Federal Food, Drug, and Cosmetic Act (the FD&C Act) (21 U.S.C. 355(e)), and under authority delegated by the Commissioner to the Director, Center for Drug Evaluation and Research, approval of NDA 20-553, and all amendments and supplements thereto, is withdrawn," FDA wrote. "Distribution of this product in interstate commerce without an approved application is illegal and subject to regulatory action."