Can a third-party requester comment on a patent owner’s response to a new ground of rejection?

Yes, a third-party requester can comment on a patent owner’s response to a new ground of rejection issued by the Patent Trial and Appeal Board (PTAB) in an inter partes reexamination. According to MPEP 2681:

Where the owner has filed a response requesting reopening of prosecution under paragraph (b)(1) of this section, any requester, within one month of the date of service of the owner’s response, may once file comments on the response.

However, there are limitations:

• The comments must be filed within one month of the date of service of the owner’s response.
• The comments must be limited to issues raised by the Board’s opinion and the owner’s response.
• If the requester had not previously filed an appeal or cross-appeal, they must pay the applicable fees to file comments.

To learn more:

• PTAB
• third-party requester
• inter partes reexamination
• patent appeals