37 CFR § 42.221 - Amendment of the patent.
(2) Scope. A motion to amend may be denied where:
(ii) The amendment seeks to enlarge the scope of the claims of the patent or introduce new subject matter.
(3) A reasonable number of substitute claims. A motion to amend may cancel a challenged claim or propose a reasonable number of substitute claims. The presumption is that only one substitute claim would be needed to replace each challenged claim, and it may be rebutted by a demonstration of need.
(1) The support in the original disclosure of the patent for each claim that is added or amended; and
(2) The support in an earlier-filed disclosure for each claim for which benefit of the filing date of the earlier filed disclosure is sought.
(c) Additional motion to amend. In addition to the requirements set forth in paragraphs (a) and (b) of this section, any additional motion to amend may not be filed without Board authorization. An additional motion to amend may be authorized when there is a good cause showing or a joint request of the petitioner and the patent owner to materially advance a settlement. In determining whether to authorize such an additional motion to amend, the Board will consider whether a petitioner has submitted supplemental information after the time period set for filing a motion to amend in paragraph (a)(1) of this section.