WAXMAN/HATCH PATENT CHALLENGES: APPELLATE DECISIONS WILL DETERMINE

WAXMAN/HATCH PATENT CHALLENGES: APPELLATE DECISIONS WILL DETERMINE the effective 180-day starting date of generic exclusivity, FDA Office of Drug Standards Director Peter Rheinstein, MD, told a National Association of Pharmaceutical Manufacturers workshop in Puerto Rico Feb. 1. FDA had indicated in a July 1988 letter to NDA/ANDA holders that the 180-day exclusivity period provided under the Waxman-Hatch act for successful patent challenges would begin at the time of the initial court decision. However, Rheinstein said that the agency was persuaded by industry comments that the appellate court decision is the more appropriate trigger.

Accordingly, Rheinstein explained, the exclusivity awardee can choose between marketing his ANDA product "as soon as he gets approval, in which case ]the 180-day exclusivity period[ dates from the date of first marketing. Or he can wait until he gets his appellate decision, in which case, it dates from the date of final decision."

The starting date for exclusivity has been at issue in the challenge of Merck's Flexoril patent, which was won by Danbury in the trial court and is being appealed by Merck in the Court of Appeals for the Federal Circuit. Danbury has maintained that the appellate ruling date should determine the starting date for exclusivity, although the issue was not resolved in the initial court decision.

Noting that the 180-day provision calls for exclusivity to be granted to the sponsor of the first complete application containing a patent challenge (paragraph IV certification), Rheinstein explained how the agency will interpret the word "complete." To be considered complete, he said, the application "must include all the bio-studies which would be necessary to approve the application if the bio-studies show what they purport to show."

If FDA determines that some additional bioequivalence work on the formulation is needed by the first sponsor, this could be conducted by the firm without sacrificing its priority position vis-a-vis any other submitted applications, Rheinstein said. On the other hand, he added, "what you can't do is send something in and say we have to run six more patients."

Rheinstein also noted that, if a reformulation is necessary, the original date of submission would no longer be applicable for exclusivity purposes. "If what is needed is a reformulation, that is probably a new application because we interpret the very guts of an ANDA to be a particular formulation," he maintained.

Rheinstein explained that ANDAs including patent challenges will be initially reviewed for completeness by a committee from the Divisions of Generic Drugs and Bioequivalence. When the committee decides the application is acceptable, the applicant will be notified "that his application has been filed," Rheinstein said. Once the ANDA has been accepted for filing, the ANDA applicant would notify the patent holder.

Kleinfeld, Kaplan and Becker attorney James Rubin asked during workshop discussion whether "for exclusivity purposes, you refer back to the date you received it, not the date the committee made the decision?" Rheinstein responded: "That would seem reasonable providing everything the committee needed to make its decision was there."

Rheinstein noted that the agency has received several industry inquiries about how patent expiration effects the exclusivity period. "Exclusivity won't extend beyond the original expiration of the patent," Rheinstein informed the NAPM workshop. "What that means is that if the litigation goes on until such date as you are less than 180 days from patent expiration, at that point the other applicants will be changing their certification from a paragraph IV to a paragraph III and will thus not be blocked."