In the US, addition of a disclaimer to a pending claim to excise subject matter from an earlier-filed document is generally
impermissible. There is a slim chance of adding a disclaimer, if the application as filed conveys the inventor contemplated
the invention absent the excised subject matter. In practice, this means drafting the application to describe that some of
the invention's embodiments, e.g., certain compounds, can be excluded from the claim scope. This is perhaps most easily achieved
by including a statement in the application that the invention includes any combinations or subcombinations of any of the
compounds disclosed in the application, such as "it is intended that the appended claims be interpreted to include all modifications,
permutations, additions and sub-combinations as are within the true spirit and scope of the embodiments discussed." It can
also be achieved by explicitly reciting various combinations of the compounds, the various combinations composed of all but
one or more of the compounds.
In Europe, the possibility of adding a disclaimer to avoid prior subject matter is more generous. A disclaimer can be added
to a claim to excise subject matter that could not have been known at the time of filing a patent application, either because
the subject matter was in a document filed at a patent office but not yet published, or was in a document so completely irrelevant
to the applicant's field of invention that it constitutes an accidental anticipation.
In summary, disclaimers in the US and in Europe offer a possible, but not a certain approach to restore novelty to a claim
rejected over a document that was not publicly available or was unknown to the inventors or patent attorney at the time of
filing the patent application. The European patent system is more lenient and will permit a disclaimer in defined situations.
The US patent system is less forgiving, and addition of a disclaimer is not likely to be permitted, unless basis for the disclaimer
can be found in the application as originally filed.
1. In re Wakefield, 164 USPQ 636, 638, 641; 422 F.2d 897, 899, 904 (CCPA 1970).
2. In re Barr, 170 USPQ 330; 444 F.2d 588 (CCPA 1971).
3. In re Johnson, 194 USPQ 187, 196; 558 F.2d 1008, 1019 (CCPA 1977).
4. In re Driscoll, 195 USPQ 434, 438; 562 F.2d 1245, 1249 (1977).
5. Ex parte Grasselli, 231 USPQ 395; 738 F.2d 453 (Fed. Cir. 1984).
6. Ex parte Parks, 30 USPQ2d 1234, 1236 (Bd. Pat. App. & Inter. 1993).
7. Ex parte Shalati, 1996 WL 1771413 (Bd. Pat. App. & Inter. 1996).
8. Enlarged Board of Appeal Decision G1/03 (OJ 2004, 413) and G2/03 (OJ 2004, 448); http://
http://legal.european-patent-office.org/dg3/biblio/g030001ex1.htm/ and http://
10. Vertex Pharmaceuticals, Inc. v. Guilford Pharmaceuticals, Inc., (T134/01 2005); http://
Judy M. Mohr, PhD, is a partner with Perkins Coie LLP, Menlo Park, CA, 650.838.4402, firstname.lastname@example.org.
Gina Freschi is an associate at Bozicevic, Field & Francis, LLP, Palo Alto, CA, 650.327.3400, email@example.com.