PTO Sidesteps Patent Term Extension “Regulatory Review Period” Issue in Petition Response

March 12, 2008

Under the Hatch-Waxman Act, certain patents related to products regulated by FDA are eligible for extension if patent life was lost during a period when the product was undergoing regulatory review.  The “regulatory review period” is composed of a “testing phase” and a “review phase.”  For a medical device subject to an approved Premarket Approval Application (“PMA”), the Patent Term Extension (“PTE”) statute at 35 U.S.C. § 156(g)(3)(B) states that the “testing phase” begins on “the date a clinical investigation on humans involving the device was begun and [ends] on the date [a PMA] was initially submitted with respect to the device.”  The “review phase” is the period between PMA submission and approval.  A patent term may be extended for a period of time that is the sum of one-half of the time in the “testing phase,” plus all the time in the “review phase.”  The “regulatory review period” must be reduced by any time that the applicant “did not act with due diligence.”  The total (calculated) regulatory review period may not exceed 5 years, and the extended patent term may not exceed 14 years after the date of PMA approval.  FDA’s regulations implementing the PTE statute are located at 21 C.F.R. Part 60.

In March 2004, FDA approved a PMA for Boston Scientific Corp.’s TAXUS™ Express 2™ Paclitaxel-Eluting Coronary Stent System (Monorail and Over-the-Wire).  In May 2004, Angiotech Pharmaceuticals, Inc. (“Angiotech”), which owns U.S. Patent #5,716,981 (“the ‘981 patent”) covering the TAXUS device, submitted a PTE application to the U.S. Patent and Trademark Office (“PTO”) requesting that the Office extend the ‘981 patent.  Angiotech calculated the maximum eligible PTE for the ‘981 patent to be 807 days.  This number is based on a testing period beginning on October 12, 2000, which is the initiation date of the first clinical trial involving the TAXUS device conducted in Germany, and a review period ending on March 4, 2004 when FDA approved the TAXUS PMA. 

In July 2006, FDA issued a Federal Register notice in in which the Agency determined the maximum eligible PTE for the ‘981 patent to be 716 days.  FDA’s PTE calculation was based on a testing period beginning on March 21, 2002 (and not October 12, 2000 as Angiotech claimed), when FDA records showed that the applicable Investigational Device Exemption (“IDE”) was determined to be substantially complete for permitting clinical studies to have begun, and a review period ending on March 4, 2004 with PMA approval.  On April 3, 2007, the PTO issued a notice of final determination to Angiotech stating that the PTE date would be calculated based on the March 21, 2002 IDE date and the March 4, 2004 approval date. Angiotech was given the option of filing a request for reconsideration of PTO’s determination. 

On May 3, 2007, Angiotech filed a request for reconsideration challenging the PTE determination.  Angiotech argued that the testing phase should have begun on October 12, 2000 when the first clinical trial was initiated in Germany, and not on the March 21, 2002 IDE date.  In referring to FDA’s decision that the testing phase began on March 21, 2002 instead of October 12, 2000, Angiotech’s request for reconsideration states that “[t]he apparent basis for this determination is [FDA’s] regulation governing calculation of the regulatory review period.  Although the statue mandates that the regulatory review period be deemed to commence ‘on the date a clinical investigation on humans involving the device was begun,’ 35 U.S.C. 156(g)(3)(B)(i), FDA’s regulation [at 21 C.F.R. § 60.22(c)(1)] imposes additional criteria.” 

Specifically, FDA’s regulatory review period determinations regulation at 21 C.F.R. § 60.22(c)(1) states:

[A] clinical investigation is considered to begin on whichever of the following dates applies:

(i) If an [IDE] is required, the effective date of the exemption. 

(ii) If an IDE is not required, but institutional review board (IRB) approval under [FDC Act § 520(g)(3)] is required, the IRB approval date.

(iii) If neither an IDE nor IRB approval is required, the date on which the device is first used with human subjects as part of a clinical investigation to be filed with FDA to secure premarket approval of the device.

According to Angiotech, FDA’s regulation is contrary to the plain meaning of 35 U.S.C. 156(g)(3)(B)(i).  “The statute directs that the PTE be based on a regulatory review period commencing ‘on the date a clinical investigation on humans involving the device was begun with no additional requirement,” states Angiotech. “The imposition of additional statutory requirements is contrary to the plain meaning of the statute.” 

Angiotech notes that “Congress made clear in the broader context of the PTE provisions that it intended to distinguish the testing phase of the [regulatory] review period based on the commencement of a clinical investigation from a [regulatory] review period based on the effective date of a statutory investigational exemption under the FDCA.”  In support of its argument, the company notes that in contrast to the device PTE provision, the drug PTE provision in 35 U.S.C. 156 specifically states that the testing phase begins on the effective date of an Investigational New Drug Application.  With respect to the PTO’s ability to reconsider FDA’s determination the request for reconsideration states that although “Congress directed that FDA determine the review period for the PTO, it is appropriate for the PTO to consider and to determine – with FDA – whether the terms of the PTE were established on extra-statutory, and unlawful, criteria.”

In late December 2007, the PTO denied Angiotech’s request.  Instead of addressing the difference between the PTE statute and FDA’s PTE regulations, however, the PTO defers to FDA’s authority over regulatory review period determinations.  Under 35 U.S.C. § 156(d)(2)(A), “[n]ot later than 30 days after the receipt of a [PTE] application by the [PTO], [FDA] shall review the dates contained in the application . . . and determine the applicable regulatory review period.”  Citing the statute and judicial precedent, the PTO concludes that “the statute thus plainly mandates the FDA to determine the regulatory review period,” and that the Office “has no authority to change or redetermine the regulatory review period determined by the FDA. . . .”

It is unclear whether Angiotech will fight on with the PTO in court, or perhaps raise the issue with FDA in a citizen petition or in informal communication. 


By Kurt R. Karst