Impact of a Later-Filed Sequence Listing on a PCT’s Filing Date

In PCT applications filed with the United States as the receiving office, the USPTO will issue an Invitation Relating to Missing Parts (“USPTO Invitation”) if the application discloses enumerated sequences that would fall within the length requirements mandating the filing of a compliant sequence listing. The USPTO Invitation, issued pursuant to PCT 20.5(a) and PCT 20.5bis(a), enumerates the “missing parts.” Response to the USPTO Invitation is under PCT rule 20.5(c), which expressly states that the “[o]ffice shall correct the international filing date to the date on which the receiving office received that part.” By responding to the USPTO invitation, the application is viewed as “incomplete” at the time of filing and a new filing date will be assigned to the PCT application based on when the sequence listing is received. The application is considered “incomplete” because the sequence listing is a part of the description and PCT Article 11(1) requires “a part which on the face of it appears to be a description…” As such, adding the sequence listing after the international filing date indicates to USPTO that Article 11(1) was incomplete.

Although the applicant can respond to the USPTO Invitation, the application’s filing date will be shifted to the date of submission of the sequence listing. This is because, as mentioned above, the agency presumes that the original filing was incomplete under PCT Article 11(1) in this case. In that case, a RO126 will be issued which informs the applicant of a change of filing date. In response, the applicant can petition for the original filing date, assuming the substance of the sequence listing is contained entirely within the originally filed specification.  However, it’s important to note that although submission of a sequence listing after the international filing date, in response to a USPTO Invitation, is possible, care should be taken in situations where the disclosure of the sequences is only found in the sequence listing, i.e., the as-filed specification does not disclose the specific residues of the sequences.  In such a case, it might be difficult to obtain grant of such a filing date petition as the USPTO is likely to consider the submitted sequence listing, where the residues are enumerated for the first time in the sequence listing, to lack support in the originally filed specification.

There is an alternative option to furnish a PCT application with a sequence listing without risk of impacting the filing date of the PCT application. Once the internal search authority (“ISA”), e.g., the European Patent Office, receives the application, a notice inviting the applicant to furnish a sequence listing (“the ISA invitation”) for search purposes under PCT Rule 13ter will be issued if the application lacks a sequence listing. A reply to the ISA invitation providing a compliant sequence listing would be sufficient for purposes of the ISA conducting the search. But if the application enters the national stage, the sequence listing submitted for search purposes will not be part of materials transmitted to the USPTO by the international bureau (IB) upon national stage entry. At this stage, the applicant will then need to submit the sequence listing in the national stage under 37 CFR 1.835.

Keeping this practice tip in mind will be helpful to avoid inadvertently causing a PCT application to be accorded a later filing date, thereby resulting in additional steps of needing to petition for the original filing date. The alternative option may be more preferable, as the applicant can simply forgo responding to the USPTO notice, provide the sequence listing in response to the ISA invitation instead, and later submit the sequence listing in accordance with 37 CFR 1.835 in a US national stage application without fearing the potential of losing the original PCT filing date.