In Wyeth and Elan Pharma International, Ltd. v. Under Sec. of Commerce for Intellectual Property (Federal Circuit 2009-1120, 7 January 2010), the Federal Circuit visited the question of how to restrict the period of adjustment under 35 USC 154(b)(1) when any of the periods of delay overlap.
35 USC 154(b)(1) offers three patent term guarantees.
A. Guarantee of prompt patent and trademark office responses: For each day that the PTO does not meet certain examination deadlines in subdivisions (i) to (iv) of 154(b)(1)(A), the patent term will be extended by one day.
B. Guarantee of no more than 3 years of application pendency: If the issue of an application is delayed due to the failure of the PTO to issue within 3 years after the actual filing date of the application, the term shall be extended by 1 day for each day after the end of that 3-year period until the patent is issued.
C. Guarantee for delays due to interference, secrecy orders, and appeals: If the issue of an application is delayed due to interference proceeding, imposition of a secrecy order, or appellate review by the Board or a Federal court, the term of the patent shall be extended by one day for each of the pendency of the proceeding, order, or review.
Guarantees A and B apply to Wyeth and Elan Pharma International Limited (collectively, "Wyeth")'s U.S. Patent Nos. 7,179,892 (the '892 patent) and 7,189,819 (the '819 patent).
For the '892 patent, the PTO calculated 610 days of A delay and 345 days of B delay. Of the 610 days of A delay, 51 occurred more than three years after the application was filed. During the prosecution of the application that resulted in the '892 patent, the applicant caused 148 days of delay. Under 154(b)(2)(c), any adjustment must be reduced by the applicant-caused delay.
The PTO used the greater-of-A-and-B rubric to resolve any overlaps between the A delay and B delay. According to this rubric, the PTO calculated the total adjustment as 610 (the greater of A delay and B delay) - 148 (applicant delay) = 462 days.
Wyeth argued that an A-plus-B-minus-overlap rubric should have been used. The overlap in the case of the '892 patent is 51 days of the A delay that occurred more than three years after the application that resulted in the '892 patent was filed. Thus, according to the rubric proposed by Wyeth, the patent term adjustment should be 610 (A delay) + 345 (B delay) - 51 (overlap) - 148 (application delay) = 756 days.
For the '819 patent, the PTO calculated 336 days of A delay and 827 days of B delay. Of the 336 days of A delay, 106 occurred after the three-year mark. During the prosecution of the application that resulted in the '819 patent, the applicant caused 335 days of delay. The total adjustment under the PTO's greater-of-A-and-B rubric was 827 (the greater of A delay and B delay) - 335 (applicant delay) = 492 days.
Using Wyeth's A-plus-B-minus overlap rubric, the total adjustment is 336 (A delay) + 827 (B delay) - 106 (overlap) - 335 (applicant delay) = 722 days.
Obviously, Wyeth's formula is more favorable to the patent owner. The Federal Circuit sided with Wyeth.