Federal Circuit Sides with FDA and PTO in CYDECTIN PTE Decision; Court Rules that Approval Phase Begins when Administrative NADA is Initially Submitted

By Kurt R. Karst –

Earlier today, the U.S. Court of Appeals for the Federal Circuit ruled 3-0 to affirm a March 2009 decision from the U.S. District Court for the District of Columbia granting summary judgment to FDA and the U.S. Patent and Trademark Office (“PTO”) arising from a June 2008 challenge from Wyeth Holdings Corporation (“Wyeth”) with respect to Wyeth’s request for a Patent Term Extension (“PTE”) for U.S. Patent No. 4,916,154 (“the ‘154 patent”) covering Wyeth’s new animal drug CYDECTIN (moxidectin) Pour-On. 

As we previously reported (here and here), FDA first approved CYDECTIN on January 28, 1998 under New Animal Drug Application  (“NADA”) No. 141-099.  The NADA was submitted under FDA’s Phased Data Review Policy and Administrative NADA process.  An Administrative NADA “is a new animal drug application that is submitted after all of the technical sections that fulfill the requirements for the approval of the new animal drug . . . have been reviewed by [the Center for Veterinary Medicine (‘CVM’)] and CVM has issued a technical section complete letter for each of those technical sections.”  (The human drug and medical device counterparts to the Administrative NADA are the statutory “Fast Track” process and the Modular Premarket Approval Application process, respectively.  Both of these processes permit a type of rolling submission and review of marketing application sections.)

In March 1998, Wyeth timely submitted a PTE application to the PTO with respect to the ‘154 patent.  In that application, Wyeth calculated a PTE based on the date the company submitted the first technical section to its Investigational New Animal Drug (“INAD”) (i.e., August 8, 1995).  Using this date, Wyeth calculated a new expiration date of the ‘154 patent of January 28, 2012.  (The original expiration date of the ‘154 patent was April 10, 2007.) 

Under the PTE statute at 35 U.S.C. § 156(g), certain patents covering animal drugs are eligible for a PTE if patent life was lost during a period when the product was undergoing regulatory review.  As with other FDA-regulated products, such as human drugs and medical devices, the “regulatory review period” is composed of a “testing phase” and a “review phase.”  For animal drugs approved under FDC Act § 512, the “testing phase” begins on the earlier of the effective date of an INAD exemption or the date a major health or environmental effects test on the drug was initiated, and ends on the date a NADA is “initially submitted” to FDA under FDC Act § 512(b).  The “review phase” is the period between the initial submission and approval of the NADA.  FDA’s PTE regulations at 21 C.F.R. § 60.22(f) clarify that a marketing application “is initially submitted on the date it contains sufficient information to allow FDA to commence review of the application.” 

In September 2006, FDA issued a Federal Register notice stating the Agency’s determination that the date NADA No. 141-099 was initially submitted to FDA was on January 13, 1998, when the final NADA component was submitted to the Agency.  In the notice, the Agency also stated that “[i]t is FDA’s position that the approval phase begins when the marketing application is complete.”  In November 2006, Wyeth submitted a request for reconsideration and revision of the regulatory review period.  Wyeth argued that August 8, 1995 is the controlling date for PTE purposes.  On May 7, 2008, FDA denied Wyeth’s request, stating that “it is FDA’s position that the approval phase for purposes of [PTE] begins when the marketing application is complete, including all technical sections and the CVM complete letters.”  Wyeth promptly sued FDA alleging that using the August 8, 1995 date for purposes of calculating the PTE regulatory review period is consistent with Congress’ intent in passing the PTE provisions at 35 U.S.C. § 156 and with FDA’s PTE regulations at 21 C.F.R. 60.22(f), and that a mere 16-day approval period “is unreasonable.”  FDA filed a Motion to Dismiss or Alternatively for Summary Judgment and Wyeth filed a Cross-Motion for Summary Judgment.

The District Court reviewed the case under the familiar Chevron framework, and found that while both FDA and Wyeth had advanced plausible readings of the PTE statute – “FDA contends that there was no ‘application’ until Wyeth submitted its Administrative NADA; and Wyeth contends that the application was ‘initially submitted’ upon its submission of the first technical section” – the statute is ambiguous under a Chevron Step 1 analysis, and that under a Chevron Step 2 analysis:

Wyeth has not met its burden here because the court finds the FDA’s arguments to be more persuasive than those made by Wyeth.  Indeed, the FDA’s construction runs true to the text and defines “initially submitted” in a manner “that is reasonable in light of the legislature’s revealed design.” . . . .  Accordingly, the court cannot say that the FDA’s interpretation is based on an impermissible construction of the statute, nor can the court find that the FDA’s interpretation violates the APA.

Wyeth appealed to the Federal Circuit and argued in its briefs (here and here), among other things, that “an application is initially submitted no later than the date the last technical section is filed because at that point the sponsor has submitted all of the elements listed in the statutory definition of an application,” and that “Congress’s use of the term ‘initially’ [in the PTE statute] indicates that the approval phase in fact begins as soon as an applicant submits the first technical section for review, as Wyeth did in August 1995.”  For example, Wyeth notes that “[t]he House Report on the Hatch-Waxman Act explains that Congress chose the term ‘initially submitted’ rather than the term ‘filed’ because ‘an application is often not considered to be filed, even though agency review has begun, until the agency has determined that no other information is needed.’” (quoting H.R. Rep. No. 98-857, pt. 1, at 44 (1984)).  Alternatively, Wyeth argues that even if PTE statute does not unambiguously support one of its interpretations, FDA’s interpretation is not reasonable and should not be given any deference.

FDA countered in its brief that the statutory text compels the Agency’s interpretation that an application is “initially submitted” when the sponsor files an Administrative NADA and that prior to the submission of an Administrative NADA, a  sponsor has not “initially submitted” an application for purposes of the PTE statute at 35 U.S.C. § 156(g).  Alternatively, FDA asserts that even if the Court concludes that the PTE statute is ambiguous,  the Court should defer to FDA’s interpretation because it is reasonable.

Reviewing the district court’s grant of sumary judgment de novo, the Federal Circuit ruled that 35 U.S.C. § 156(g) is ambiguous, but that FDA’s interpretation of the PTE statute is permissible under a Chevron Step 2 analysis:

Section 156(g) created a range of ambiguity by not explicitly defining the term “application,” leaving that term open to interpretation.  FDA’s interpretation tracks the requirements of 21 U.S.C. § 360b(b).  As explained by FDA, the administrative NADA is the first document containing or referencing all of the parts required by 21 U.S.C. § 360b(b).  Thus, it is permissible to characterize the administrative NADA as the first application submitted for purposes of 35 U.S.C. § 156(g).  Because the administrative NADA is the first application submitted, it is reasonable to interpret the date that it is submitted as the “initially submitted” date.  Prior to the submission of an administrative NADA, no application has been submitted, initially or otherwise.  Thus, FDA’s interpretation “reasonably resolves the ambiguity in applying the relevant statutes to a factual situation not fully foreseen or provided for by the Congress when it enacted the statutes or the FDA when it promulgated regulations.”   Mylan, 389 F.3d at 1284.  It is permissible to interpret § 156(g) to mean that “an application” is “initially submitted” when a sponsor submits an administrative NADA in phased review.

It is unclear whether Wyeth will seek en banc review of the unanimous panel decision.  We will update our loyal FDA Law Blog readers if Wyeth seek an appeal of the decision.