Scott Daniels | January 31, 2011
DexCom’s strategy for dealing with its litigation against Abbott Diabetes Care Inc. through reexamination has taken a major step forward – in separate opinions (here & here) the PTO Board of Appeals affirmed the final rejection of two Abbott patents, U.S. Patent Nos. 6,175,752 and 6,565,509 claiming an assembly for attachment to the skin of a patient and for sensing and reporting levels of specific substances in the patient, such as glucose levels.
In 2005, Abbott sued DexCom for infringing the ‘752 and ‘509 patents and two other patents, U.S. Patent Nos. 6,284,478 and 6,329,161, claiming subcutaneous glucose electrodes. Abbott subsequently sued DexCom for infringing three additional patents, U.S. Patent Nos. 5,899,855, 6,134,461 and 6,990,366 for related microprocessor video and electrochemical analyte monitoring equipment. DexCom replied by filing reexamination requests against each of Abbott’s seven patents, and each request was granted. The trial judge merged the two infringement cases and then stayed the litigation pending completion of all the reexaminations.
Addressing the key issue for claim 1 of the ‘752 patent, the Board determined that the primary prior art reference discloses the claimed housing, plurality of conductive contacts, and an rf transmitter. Further, the Board found that the recitation of “coupling” in claim 1 did not require a particular structure connecting components and that the “coupling” limitation was satisfied by the sensor wires in the reference. Other claims were found to be met by specific passages from the prior art or the examiner’s official notice of what is well known in the art.
Claim construction was the critical issue for the ‘509 patent. Construing the claim phrases “electrochemical sensor” and “substantially fixed” in light of the specification, the Board gave them a broad scope and then found that the claims were either anticipated or made obvious by the prior art.
The reexaminations of the other five Abbott patents are still pending, but none of those patents seems to be close to successfully emerging from the PTO:
(1) Reexamination of the ‘478 patent was ordered November 30, 2009; each of the independent claims was amended in earlier reexaminations, thereby limiting the period for which damages might be collected;
(2) reexamination of the ‘161 patent was ordered January 12, 2010, but Abbott has asked that the reexamination be vacated as abusive;
(3) a non-final rejection issued for the ‘855 patent on October 5, 2010;
(4) reexamination of the ‘461 patent was ordered March 12, 2010; and
(5) a final rejection was issued December 17, 2010 for the ‘366 patent.
With five patents still pending in reexamination and with the possibility that Abbott will appeal the Board’s decisions, DexCom has a long way to go to defeat Abbott. Nevertheless, more than five years into its litigation, Abbott has achieved little.
The ‘752 reexamination included a rejection of claims under 35 U.S.C. § 305 that may interest a few practitioners. Section 305 provides, in pertinent part, that a patentee may not amend a claim to enlarge its scope during reexamination, and thus a reexamination examiner need only determine “that the new and amended claims do not enlarge the scope of the issued claims….” Since the examiner himself had found that the claims he rejected under Section 305 did not go beyond the scope of the original claims, the examiner’s rejection was improper for exceeding the requirements of Section 305, the Board found.