Orange Book Patent Listing Precipitates DJ Action to Trigger Generic KEPPRA XR 180-Day Exclusivity Forfeiture

March 28, 2011

By Kurt R. Karst –      

Late last week, Par Pharmaceutical, Inc. (“Par”) filed a Complaint in the U.S. District Court for the Eastern District of Pennsylvania seeking a declaration that two recently issued patents – U.S. Patent Nos. 7,858,122 (“the ‘122 patent”) and 7,863,316 (“the ‘316 patent”) (both titled “Extended Release Formulation of Levetiracetam”) – are invalid.  Par’s declaratory judgment action appears to be geared to obtain a final court decision that would trigger a forfeiture of 180-day exclusivity eligibility under the FDC Act’s so-called failure-to-market forfeiture provisions at § 505(j)(5)(D)(i)(I) for the first applicant to have submitted an ANDA for a generic version of KEPPRA XR (levetiracetam) Extended-Release Tablets containing a Paragraph IV certification.

FDA approved KEPPRA XR under NDA No. 22-285 on September 12, 2008 and granted the NDA sponsor a period of 3-year new dosage form exclusivity that expires on September 12, 2011.  At that time, U.S. Patent No. 4,943,639 (“the ‘639 patent”), which had already expired, but was subject to a period of pediatric exclusivity set to expire on January 14, 2009, was listed in the Orange Book.  (The ‘639 patent was also listed in the Orange Book for the immediate-release version of levetiracetam, KEPPRA, under NDA No. 21-872.)  Because no generic sponsor submitted an ANDA to FDA for a generic version of KEPRA XR containing a Paragraph IV certification to the ‘639 patent, 180-day exclusivity remained available with respect to a later-listed patent. 

On December 28, 2010, the U.S. Patent and Trademark Office issued the ‘122 patent; however, the patent was not submitted to FDA for Orange Book listing until January 7, 2011 (but it is still considered timely listed).  (The listing appears to have given rise to a discussion of so-called “anticipatory Paragraph IV certifications” on the popular Linked-In Hatch-Waxman ANDA Litigation Forum managed by Steve Auten.)  Upon Orange Book listing, FDA showed the ‘122 patent with a period of pediatric exclusivity (in the printed annual edition of the Orange Book), but the Agency later determined that to be erroneous (as shown in the current electronic version of the Orange Book).  Curiously, the ‘316 patent, which was issued on January 4, 2011, and which, as noted above, has the same title as the ‘122 patent, was not submitted to FDA for Orange Book listing.  Why?  Your guess is as good as our guess.  Anyhow, the timely Orange Book listing of the ‘122 patent created the possibility of 180-day marketing exclusivity for the first generic applicant(s) to submit a Paragraph IV certification – either in an original ANDA, or, more likely, as an amendment to a pending ANDA.  Clearly, someone decided to do so (and was probably submitting anticipatory Paragraph IV certifications since the ‘122 patent issued), as FDA’s Paragraph IV Certification List was recently updated to show a Paragraph IV submission date of January 7, 2011.  (It is unclear at this time who is a first applicant.  In addition to Par’s pending ANDA, FDA tentatively approved Torrent’s ANDA No. 91-338 on November 17, 2010.)

Par, which almost certainly has a pending ANDA for generic KEPPRA XR (based on statements in the company’s March 23rd Complaint), appears to have missed the patent certification boat.  Instead of amending its ANDA to include a Paragraph IV certification and simultaneously providing notice when the ‘122 patent was listed in the Orange Book on January 7, 2011, Par apparently amended its ANDA and provided notice of its Paragraph IV certification to the ‘122 patent to the NDA holder/patent owner on January 10th and 13th, according to the company’s Complaint.  But there might be another way for Par to skin this cat.  By obtaining a final court decision that the ‘122 patent is invalid (via the company's declaratory judgment action brought after the NDA holder/patent owner failed to sue for patent infringement within the statutory 45-day period), and provided Par has tentative ANDA approval, which the company says in the Complaint it expects to receive within 30 months of ANDA submission, Par could trigger a bookend event under the (bb) failure-to-market forfeiture provisions. 

We recently discussed the bookend events under the FDC Act’s failure-to-market 180-day exclusivity forfeiture provisions and some of the potential interpretations and outcomes based on tentative approval timing.  Par’s KEPPRA XR declaratory judgment Complaint is yet another example of what appears to be a growing number of declaratory judgment actions to trigger the forfeiture of 180-day exclusivity eligibility.