Broad Biotech Patent Claims-The Saga Continues
There now is increased interest about the written description and enablement requirements for patent applications claiming antibodies. This may stem from the recent U.S. Supreme Court decision in Amgen v. Sanofi, finding lack of enablement for broad antibody claims. Recently, there have been other attempts to capture broad patent coverage for antibodies, as discussed in In re Chamberlain (In re Xencor remand).
Briefly, the Chamberlain case involves an attempt to obtain broad patent coverage for a method of treatment using an antibody by incorporating “means plus function” (MPF) claims and Jepsen claims. Both types of claims were rejected for lack of written description at the USPTO, then went to the Patent Trial and Appeal Board (PTAB), and later were appealed to the U.S. Court of Appeals for the Federal Circuit. The USPTO then asked the Federal Circuit to remand the proceeding, so the USPTO could clarify its position on MPF claims and Jepson claims in the field of biotechnology.
Interestingly, the USPTO convened an Appeals Review Panel (ARP), which found that: (1) the preamble of the Jepsen claim (claim 8) is limiting and therefore requires written descriptive support; and (2) the MPF claim limitation (claim 9) covered the structure disclosed in the specification, along with all of its equivalents. Notably, the ARP concluded that the specification need only describe the antibody structure, not all equivalents thereof, to satisfy the written description requirement.
However, the ARP found that the use of the phrase “treating a patient” in the claims’ preamble lacked written description because the specification didn’t adequately describe such treatment. Thus, the claims ultimately were found to be unpatentable, but not because of the means-plus-function claim limitation, which is broad and covers the antibody and its equivalents.
Claim 8 with Jepsen language is shown below:
- In a method of treating a patient by administering an anit-C5 antibody with an Fc domain, the improvement comprising said Fc domain comprising amino acid substitutions M428L/N434S as compared to a human Fc polypeptide, wherein numbering is according to the EU index of Kabat,
wherein said anti-C5 antibody with said amino acid substitutions has increased in vivo half-life as compared to said antibody without said substitutions.
Claim 9 with MPF language is shown below:
- A method of treating a patient by administering an anti-C5 antibody comprising:
(a) means for binding human C5 protein; and
(b) an Fc domain comprising amino acid substitutions M428L/N434S as compared to a human Fe polypeptide, wherein numbering is according to the EU index of Kabat, wherein said anti-C5 antibody with said amino acid substitutions has increased in vivo half-life as compared to said antibody without said substitutions.
In sum, Jepsen claims and MPF claims provide interesting options to try when contemplating broad claims where there aren’t many examples or data to include in the specification. Though the claims were not allowable here, possibly a few minor adjustments could be made to the claims to overcome those written description rejections.