Claim check

You're in-house at an innovator pharmaceutical company, and one of your drugs is reaching the point where you can expect ANDA filings. Your boss asks "have we done our pre-suit diligence? Is our house is in order?"

Where to start? Begin with a close examination of the claims of your Orange Book-listed patents. Are there any typographical errors? Was that concentration supposed to be .01 and not .1? Does the dependent claim say buffer, but the independent claim says buffer system? Seemingly small mistakes can lead to big problems for infringement and validity, and could sideline or kill what otherwise would have been a strong claim.

If there are mistakes, now is the time to go the PTO to correct them. You're going to have to show that the mistake was of the type that can be corrected, of course. 35 U.S.C. 254 (mistakes by the PTO) and 255 (mistakes by the patentee) are your road map. First, you need to show that the mistake is of a clerical nature, of a typographical nature, or a mistake of minor character. Second, you have to be sure the changes don't constitute new matter or require reexamination. Importantly, while the patent office must limit its review of the error to the intrinsic record, it has the authority to correct errors even where they are not obvious — including corrections that are broadening — provided that it is "clearly evident from the specification, drawings and prosecution history how the error should be appropriately corrected." Novo Indus. L.P. v. Micro Molds. Corp., 350 F.3d 1348, 1356-57 (Fed. Cir. 2003).

What if your litigation has started - can you still ask the PTO to make a correction? You can, but now you have a problem. The correction applies to future litigations, but not the one you are currently in. Sections 254 and 255 state clearly that PTO corrections apply only to "trials of actions for causes thereafter arising." That means that infringement and validity of your claim in the current suit will be assessed as if there were no certificate of correction issued.

Can you ask the District Court to make the correction? Yes, but the Court's ability to correct is more limited. It can only make corrections that are obvious on their face - that is, corrections that are not subject to reasonable date based on consideration of the claim language, and the prosecution history does not suggest a different interpretation of the claims. Novo Indus., 350 F.3d at 1357. That is a more exacting standard, and equally important, it is a standard that will have to be met in the face of determined advocacy by the opposing attorneys.