Mexico’s patent linkage system: current state, effects and flaws
The Mexican linkage system for patents related to the drug approval process was enacted on September 19, 2003. The main purpose was to improve the communication between the Federal Commission for Protection against Health Risks (COFEPRIS), which is the regulatory agency in Mexico, and the Mexican Institute of Industrial Property (IMPI), in order to prevent the granting of marketing authorisations (MAs) for generic versions of pharmaceutical drugs which might fall within the scope of valid patents. This system has also served as a tool for public health institutions to verify patent ownership in order to assign direct purchases.
The linkage system is established in article 167bis of the Health Supplies Regulations (HSR) and in article 47bis of the Industrial Property Law Regulation (IPLR). Based on these articles, the system was implemented as a Special Edition of the Official Gazette called “Special Gazette for Medicaments” (SGM), which is issued by the IMPI. The SGM consists of a list of granted patents arranged by active ingredient. Patent applications are not eligible to be listed in the SGM. The SGM is published every six months (in February and August) and each gazette substitutes the former entirely.
SGM listings are not granted or owned by a specific party but published by the IMPI as the patents authority, and the publication of a patent is not linked to a specific registered pharmaceutical product, but to the non-proprietary name of the active ingredient. Accordingly, it is possible to have more than one patent listed for the same active ingredient regardless of how many products are actually registered before COFEPRIS. Additionally, it is possible as well to list a patent more than once in relation to different active ingredients (e.g., in the case of a Markush claim).
According to article 167 bis of the HSR, when seeking marketing authorisation of a pharmaceutical product, along with the dossier filed to COFEPRIS for marketing authorisation, it is mandatory to file a statement under oath signed by the applicant (patents compliance declaration), which states that patents are not infringed by the product, either because the applicant is the assignee of record in Mexico or an authorised licensee of the relevant patents, or because the applicant is not aware of any patents covering the product.
Current practice
Eligible patents for the Mexican linkage system
According to article 47bis of the IPLR, only process or method patents are expressly excluded from the Mexican linkage system. However, because the IPLR refers to a patents list by active ingredient, in the beginning the IMPI established a general criterion that only patents covering active ingredients were eligible for the linkage system. As companies and practitioners disagreed, appeals were submitted for inclusion of patents covering formulations, compositions and second medical uses (Swiss or EPC style claims).
In consequence, a decision by the Supreme Court was issued in February 2010 for formulation patents, establishing a criterion whereby formulation patents became expressly eligible for listing in the SGM. The decision was silent regarding use patents. In spite of this decision, it was not until July 2012 that IMPI started publishing formulation patents in the SGM without litigation. Second medical uses patents are still rejected for publication by IMPI, in spite of the fact that IMPI has lost most of such cases and around 40 new use patents have been successfully included so far, all by judicial order.
Based on the historical publications of the SGM, from the first to the most recent—published on August 17, 2018—more than 1,000 granted patents have been listed. From these, around 23% have expired, so currently there are almost 770 patents in force listed in the SGM. Of these, 43.5% are active ingredient patents, 35.6% are combinations of active ingredients patents, 17.3% are formulation patents and 3.6% are use patents.
Biotechnology drugs patents are eligible for publication in the SGM, but the characterisation of the active molecule must be made clear in order to match the description of the International Non-proprietary Name (INN). To date, 89 biotechnology drug patents have been listed in the SGM (12%).
Procedure for listing a granted patent in the SGM
Regarding the procedure for listing a granted patent in the SGM, article 167bis of the HSR and article 47bis of the IPLR are silent. However, in practice there are two well established possible ways of listing a patent. One is a formal petition before IMPI and the other is a bona fide proceeding available only for companies having a membership to the National Chamber of Pharmaceutical Industry (CANIFARMA) under rules established in an official guideline issued by the IMPI. These proceedings are not mutually exclusive.
The bona-fide proceeding comprises submitting a letter of request for inclusion addressed to the Executive Director of either AMIIF (Mexican Association of Pharmaceutical Research Industries) or ANAFAM (National Association of Drug Manufacturers), both CANIFARMA members, along with a copy of the title and relevant claims of the patent.
This letter is forwarded to CANIFARMA, which shares the full list for comments with both AMIIF and ANAFAM. CANIFARMA submits to the IMPI those patents that have no objection to be published at the chamber level. Typically, only second medical use patents are currently opposed to by this procedure.
The formal petition comprises submitting a letter to request the inclusion of a patent in the SGM addressed to the Director of the IMPI. In such letter, the patent holder must prove that (i) the patent is related to a product considered an “allopathic medicament”; (ii) the correspondence between the INN and the active ingredient of the claimed product; (iii) its nomenclature or identification in the patent; and (iv) the claim covering the product.
