It has been over four years since the Second Chamber of the Mexican Supreme Court of Justice analysed the possibility of obtaining patent term extensions through a broad and comprehensive interpretation of the provisions of the repealed North American Free Trade Agreement (NAFTA). The court issued a non-binding precedent that established that all national patents with a validity shorter than 17 years, counted from the date of grant, were eligible for an extension to reach that term.
Diverging interpretations
While the Mexican Institute of Industrial Property (MIIP) argued that such extensions only applied to patents that suffered unjustified delays during prosecution – mainly attributable to the institute itself – national courts upheld another view. They reasoned that the burden of proof did not focus on demonstrating delays but on verifying the effective application of NAFTA in each case and confirming that the patent had a validity shorter than 17 years from its grant date.
This interpretation prevailed among most courts, leading to a clear strategy based on two key conditions:
The application was filed in Mexico (either directly or via its national phase) while NAFTA was still in force; i.e., before July 1 2020; and
The granted patent had a validity shorter than 17 years from the date of grant.
When these conditions were met, the timing of the extension request was immaterial. Even if filed long before NAFTA’s repeal, the rules contained therein remained applicable due to the original filing date, producing consistent and favourable outcomes for patent holders.
Impact on the pharmaceutical sector
This approach has greatly benefited the pharmaceutical industry, providing an effective barrier against the early market entry of generic competitors or applications for marketing authorisations, even when invoking the Bolar clause (experimental use exception). The additional term ensured extended protection for the invention and rewarded the investment required to develop it.
However, this strategy is approaching its conclusion, as the last generation of patents filed under NAFTA reaches the end of its life cycle.
The USMCA and a new legal framework
With the repeal of NAFTA and the entry into force of the United States–Mexico–Canada Agreement (USMCA), the rules changed significantly. The concept of a minimum 17-year term from the grant date was eliminated, replaced by the requirement that each member establish a mechanism to compensate for unjustifiable delays during patent prosecution.
In response, Mexico enacted the Federal Law for the Protection of Industrial Property, which entered into force on November 5 2020. This statute introduced the supplementary protection certificate (SPC) – an additional patent granted to compensate for administrative delays during examination. The SPC takes effect once the original patent expires and remains valid for the period determined by the MIIP.
Key differences between the old and new regimes
The rules for obtaining an SPC differ sharply from those applicable under NAFTA. For instance:
The SPC must be requested during the period granted to pay the corresponding patent grant fees; i.e., after the notice of allowance is issued;
The burden of proof now lies entirely with the applicant, who must demonstrate that prosecution delays occurred and were attributable to the MIIP;
Only applications whose examination exceeded five years (from national filing to the notice of allowance) are eligible; shorter prosecutions will be rejected; and
If such delays are proven, the MIIP will grant one additional day of protection for every two days of delay, up to a maximum of five years.
In contrast to the NAFTA-based mechanism, the new SPC regime focuses exclusively on unjustifiable delays caused by the MIIP rather than the mere existence of a validity shorter than 17 years. Therefore, applicants must manage prosecution efficiently and maintain clear records to support future SPC petitions.
Looking ahead – key takeaways for patent holders
As of today, the SPC mechanism remains untested in practice, since no patent has yet completed a prosecution lasting longer than five years under the new law. This will first occur after November 5 2025. Nevertheless, it is crucial for rights holders to prepare for its proper implementation by adapting their strategies and documentation to the new evidentiary standards.
At the same time, patent holders whose rights still qualify under the NAFTA framework are encouraged to pursue available extensions, as this remains the most straightforward and effective route to obtain additional protection – particularly in the pharmaceutical sector, where such extensions continue to deter early generic entry and secure substantial market advantages.
Becerril, Coca & Becerril is already prepared for this transition and has developed specific argumentation strategies for cases where NAFTA-based extensions are no longer available and an SPC must be sought instead. Nonetheless, all patent holders are encouraged to review their granted rights promptly, as opportunities to claim extensions under NAFTA may still exist for a limited number of patents.
