What is the difference between a Paragraph IV certification between the 505j (ANDA, generic) and 505(b)(2)? None.  The difference is the exclusivity outcome – 505(b)(2) never gets any exclusivity based on patent certification.

In a U.S. drug application, in Module 1, Administrative Documents, you must submit a patent certification, regardless of the submission route, generic or NDA. I have previously covered the 4 types of patent certifications.

In a Paragraph IV (Roman numeral makes it seem so much more legal, and it will require lots of legal costs!)  the sponsor certifies that one or more patents exist but that the sponsor’s proposed drug product does not infringe on the patent and/or believes that the patent(s) is invalid, unenforceable.

For both ANDA and 505(b)(2), the submission process is the same – the text in the certification is the same, the notice to the RLD NDA holder, the wait for a legal suit, the potential legal process and the decision.  If successful, a 505(b)(2) drug may be approved for marketing.  Marketing exclusivity for a 505(b)(2) is based on the required studies and the status of the drug.  For an ANDA, if the first filed, 180-day marketing exclusivity may be granted. Since a 505(b)(2) approval is not subject to competition, there is no reason to grant this separate exclusivity period.

A list of ANDA Paragraph IV drug challenges is maintained at FDA’s Office of Generic Drugs.  There is no listing for 505(b)(2).  Because of this, a sponsor of a 505(b)(2) needs to monitor court dockets for their proposed product.

Let’s look at an example 505(b)(2) Paragraph IV filing.  Cipher Pharmaceuticals Limited developed a formulation of fenofibrate capsules that it believed did not infringe on the patents (there were two) held.  Cipher developed a product that would not have the food effect that was characteristic of the RLD (TRICOR(R)).  The RLD is a capsule containing micronized fenofibrate mixed with a surfactant.  Cipher’s product dissolves fenofibrate in polyglyceride, HPMC and sodium starch glycollate.

Cipher filed their NDA in December 2002 and sent a notice on March 5, 2003. Abbott sued in April and October 2003 (messy because Abbott had a license from Laboratoires Fournier SA, so they both got involved).  This suit triggered the 30-month stay until the matter was resolved. Cipher prevailed and was approved by FDA as Lipofen (TM) in January 2006.